Okay, any cooling system experts in the group?

I just installed a Stewart Components Stage II water pump over the 4th of July weekend and my car now runs HOTTER at times than it ever did with the stock pump.

Here's the deal. My daily commute consists of driving Topanga Canyon to PCH. In the morning, the canyon run is mostly down hill. The temps stay nice and cool at this stage.

This morning I watched the temp closely. It stayed pretty much at the 1/4 mark all the way thru the canyon. Once on PCH, and mild stop-and-go traffic, the temp slowly climbed to just below the 220° mark.

During my drive home on Tuesday evening, with canyon run now being mostly uphill, the guage had climbed to the 3/4 mark. Once out of the canyon and back on surface streets, the temp only dropped to 220°.

This is hotter than it ever got with the stock pump. Typically, it would only reach 220° on the drive home, then cool down some as I exited the canyon.

I've posted my concerns over at the Stewart Components web site, so hopefully they can offer some insight. Anyone else got any suggestions?

I've noticed that when under load, the trans temp jumps to close to 210°. I'm wondering if the added heat is also affecting the cooling ability of the radiator. I have a trans cooler installed, but am considering strapping an electric fan to it to see if I can keep the trans temp down.

It's not fun to watch the gauges climb during canyon runs. It also has me really concerened about taking the car out on the track. At this rate, I'll cook the crap out of everything.

I'm really starting to dislike this dang car.

 

Obviously no expert, however when I installed the Stewart Pump on my IROC a couple years back (also a stage II) I did go through about two thermostats before I finally broke down and purchased on of Stewart's 'balanced' thermostats - just has three holes drilled it. Anyways that seemed to help me keep thermostats from freezing open. Though now I just have a cheapy Auto Zone one installed I would first suggest checking yours, and then making sure that your fans are both working. I have had some pretty crappy cooling issues with my IROC ever since it's rebuild, but with higher compression that is bound to happen. I have a temp gauge for the tranny pan, and I have never, and I do mean never seen it climb above 150! I don't know if your tranny cooler is too small, but I have no fan on mine and it works just great it takes at least an hour of freeway traffic to get the tranny temp up to over 125 for me. To battle my cooling issue I just installed a Be Cool Radiator. Upon removing the old radiator I noticed two things - a crack - duh yeah I know, so another suggestion would be to test your radiator for pressure and make sure it doesn't leak. Also I noticed that the water in Fontana is even worse then I thought, I had been using a 50/50 solution of coolant and water - no shocker there however I had unfortunately been using the hose as the water source rather than potable or disstilled water, which left me with a large amout of deposits in the radiator. After the installation of the Be Cool, I won't say that the car never gets hot anymore (BTW hot for me, as in when I shut it down is 225 - no way I want to go higher than that) but I think I still need to upgrade the fans to a single large CFM fan like a Perma Cool kit. I hope some of this helps

 

Both fans are working fine and I do have the modified Stewart Components thermostat installed. In fact, the thermo has been in for a little while as I was running it with the stock pump.

I always use distilled water in the cooling system and everything looked nice and clean when I installed the Stewart pump. The radiator is clean, the stock water pump is clean (I even opened it up to inspect the impeller), the block passages look clean.

I just don't get it.

In cold weather, my trans temp stays around 150°. This leads me to belive the trans cooler isn't getting enough air flow in warmer weather. Add that to a higher stall converter and you get extra heat in the trans.

Also, I usually run around with trans in 3rd gear unless I'm the freeway. So, typically, I turn around 2k RPM. You'd think this would help cool the engine. Insead, the less load/RPM the engine sees, the cooler it runs.

 

My trans temps are based on initial use of a 2200 stall converter and now a 3200 Vigalante Have you tried removing the cap and letting the car to see the thermostat open up and watch the water circulate? I know the cooling issue can be quite a pain I have battled it with every chevy so far

 

Yep, the thermostat appears to be wroking correctly.

After installing the new pump, I ran the engine with the cap off to
1) ensure the thermo was working properly and 2) to purge any air from the system.

 

The store did'nt get the standard flow/reverse flow thing mixed up did they?

 

Also, make sure to run the heater full blast for a while to get the air out of the heater tube lines.

 

Did that too when the pump was installed.

 

When it runs hot like that, like on your daily drive home. When you get home is the overflow full or empty, unchanged? Also a bottle of water wetter might help.

 

Water Wetter has been in for few years and a fresh bottle went in on Sunday. Overflow is where it should be, to the "FULL HOT" line.

What I did yesterday was to let the car idle and hosed down the radiator to bring the temp down. I also flipped the lever on the radiator cap to relieve the system pressure.

Once the engine cooled down, I shut it off. Immediatley the overflow bottle filled up to the top. To the point coolant was coming out the vent holes in the cap. I could also hear bubbling in the cooling system. I then turned on the auxilary fan I have installed to get air moving thru the radiator. A short while later the bubbling stopped and the coolant level dropped in the overflow and returned into the rad. The overflow leveled out at the Full Hot line.

A Be Cool radiator is sounding better and better, except for the $600 price tag. Has anyone tried the Griffin custom fit radiator? It's only $439 in comparison.

First, I'll probably relocate the auxiliary fan from the front of the a/c condenser/radiator to the trans cooler and see if it makes any difference. The auxil. fan never seems to do much when the car is hot anyway and is more helpful in cooling things off when the engine is stopped.

I'd rather open up the space back up in front of the rad. and see if the trans will run cooler with the fan located on the trans cooler.

 

Brett, look here:

https://www.thirdgen.org/techbb2/sho...hreadid=247826

 

Thanks for the post Dan. I'm half tempted to pull my A/C condenser out along with the rest of the A/C system. I don't use it much anyway.

 

Before you take a torch to it.

If this is a high flow pump you could be collapsing your lower heater hose.

This happened to my truck one time, I had replaced the lower hose (it was a alternate use number hose).. and when I ran over 65 the truck would start to overheat. Found the original number hose no problem.

Or it could be a bad water pump. Chris has a brand new edlebrock that is junk.

 

As I'm researching this, I just thought about the lower radiator hose as well. I have a Goodyear High Miler hose on there, but it is a few years old and it has no spring inside of it.

The pump I installed is a high flow pump. I'll be hitting Pep Boys on the way home. Hopefully they will have some type of performance hose that's better than just a stock replacement hose.

 

Yeah the hoses collapsing, always causes havoc

 

I know many of the hoses come without springs, but find one that has a spring or that at least has VERY stiff rubber. Most of them are too weak to handle any serious amounts of flow without the spring or something to prevent the hose from collapsing. You can usually just rev the engine in park in the comfort of your own driveway to about 3000+RPM and watch it close if its going to do that at all.

I assume the airdam is ok? Fans working, and up to finger cutting speed?

I've been through hell and back with the TA, probably tried every fix under the sun. Not going to tell you what it was, but you dont want that problem. Try the lower hose first, make sure the radiator cap is in good shape or just replace it (really hard to tell a bad one from a good one), and slow down

One way I know of to tell the diff (has been perfect so far) between the serp and non serp pumps besides taking them apart is the serp pumps dont have the raised area and fitting location for the heater hose to attach at the top back of the water pump.

Oh yea, and I wanted to say dont even bother with any high dollar radiator because if you have a problem it will not fix it. That and there are better options out there than that.

 

Air dam is fine. Fans working and ready to remove any finger that dares get close.

I hit Pep Boys, but the only hose behind the parts counter was a flimsy stock replacement with no spring. I've had drinking straws that were stronger. They do have a stout steel braided hose w/spring in the bling-bling aisle, but I doubt it will bend enough to snake around like the factory does. I'm going to explore Summit and see what they have.

The pump I have is correct for the application. The Stewart pumps do also include the heater hose location. http://www.stewartcomponents.com/htm...rtNumber=23123

As for slowing down, that actually seems to help. I drove home tonight with the auxil. fan on and kept the RPM's between 1500 and 2000. The temp hit 220° climbing the hill, but didn't go much past it. As I ran errands tonight, I left the fan running while the car was parked. It helped cool it off and it ran at a respectable temp the rest of the evening.

It's goofy, the lower the RPM, the cooler it runs. Almost makes me want to re-install the underdrive crank pulley except that I like having alternator voltage.

 

That's probably the problem.. That pump is flowing so good and the curve in that hose is nearly open.. I have seen the flow in the radiator watching the water pump flow and it was pretty good flow with a stock pump..

 

Well, I just ordered some trick hose from JEG's - Mr. Gasket GFLEX. Similar to Cool Flex, but a little more affordable. http://go.mrgasket.com/PressReleaseD...ndID=10&ID=736

I'm also going to try Auto Zone and see if they carry this:
http://www.goodyearbeltsandhose.com/cars/flex.html

 

Well, you can overdrive the pump. I had a stock mid 70's pulley setup on my stang, and I was repeatedly blowing up heater cores. Literally. I finally threw a late model underdrive setup (and boy is it ever an underdrive), along with a bypass and restrictor, and I have no more overpressure problems. I'd say 90% of it was the overdriven pulley setup that was on there, it cools just fine right now.

See if you can find a supplier that carries Gates. Last one I got from them came with the spring.

 

Bret,

From the description, it seems like you're using an aftermarket radiator cap. Maybe the cap is getting weak and not pressurizing the coolant system properly.

Oh yeah, try using a 17psi radiator cap instead of the stock 15psi cap. It worked wonders on my uncles '91 Z28. His car rarely gets above the 1/4 mark on the temp gauge now and this is in city traffic with the A/C on in 90*+ weather too.

 

I have heard of instances were you can actually pump the water to fast thru the radiator and not giving the radiator a chance to do its job by cooling the coolant mixture. Maybe worth checking.

 

RWB is dead on here.
Think about it....what does the radiator do?
It cools the water in it as it passes thru....but if you circulate it too fast...it never stays in the radiator long enough to take the heat out. Hence the lower temp at slow speeds.

 

I used to follow that same theory, but Stewart Components doesn't agree with it. I even asked them that exact question – Is possible to move the water too fast thru the system?

Their exact response was – "No, you can't move the water too fast." Also, keep in mind, that's why we have thermostats, to keep the water moving at a controlled rate.

------------------------------
Quoting Stewart Components web site:
A common misconception is that if coolant flows too quickly through the system, that it will not have time to cool properly. However the cooling system is a closed loop, so if you are keeping the coolant in the radiator longer to allow it to cool, you are also allowing it to stay in the engine longer, which increases coolant temperatures. Coolant in the engine will actually boil away from critical heat areas within the cooling system if not forced through the cooling system at a sufficiently high velocity. This situation is a common cause of so-called "hot spots", which can lead to failures.

Years ago, cars used low pressure radiator caps with upright-style radiators. At high RPM, the water pump pressure would overcome the radiator cap's rating and force coolant out, resulting in an overheated engine. Many enthusiasts mistakenly believed that these situations were caused because the coolant was flowing through the radiator so quickly, that it did not have time to cool. Using restrictors or slowing water pump speed prevented the coolant from being forced out, and allowed the engine to run cooler. However, cars built in the past thirty years have used cross flow radiators that position the radiator cap on the low pressure (suction) side of the system. This type of system does not subject the radiator cap to pressure from the water pump, so it benefits from maximizing coolant flow, not restricting it.
------------------------------

I have also been unsuccessful in finding a new lower radiator hose. Auto Zone or Kragen can order me a quality Goodyear hose, but I figured by then I'd have my Mr. Gasket hoses. Well, of course today I then get an e-mail from JEG's stating the parts are on back order.

 

Guess you better get up earlier on Sunday mornings and visit the ATM before services.

 

Is the ATM now dispensing auto parts?

 

https://www.thirdgen.org/techbb2/sho...hreadid=247900

Brett, you do not have to lose your ac for this radiator to fit.

 

Only one problem with that....they have no clue what you are doing with your system or what thermostat you are using.
I've been doing radiators since the '80's and I can assure you it is possible to send the water too fast thru the system.
I've heard these manufacturers spew out this kind of stuff before but think about it.....they just sold you something...do you think they are going to admit it is causing your problem...even tho you have said it is the only thing you changed before the problem started? Just like high volume oil pumps...if you will buy it they will sell it to you, even if if does cause problems (and they do).

BTW...that is old school theory today systems are a horse of a different color. (little skinny cores, high temp thermostats) etc.

 

Well, actually they do know what I'm doing with the system and what thermostat I'm using. I have been in contact with Stewart Components directly thru their message board and explained in detail what is happening.

As far as the, "We're selling bogus parts, but we won't admit it so we can keep selling bogus parts" - I don't really buy into that. When a company specializes in one particular area, it doesn't do them much good to blatanly promote bad parts. You won't be in business very long.

If a car was running with NO thermostat, I could see the "water moving too fast" as potentially being an issue. Even then, speed wouldn't mean much. What would basically happen is that the water would constantly circulate within a closed system and would get as hot as the heat source permitted.

(Ever own a swimming pool or Jacuzzi? Same principal – You have a closed system with a heat source (gas heater) and pump that constantly circulates the water thru that closed system. I spent 7 years working in the pool industry and have owned a pool and jacuzzi since the late 70's. You can have a low-hp/slow pump or high-hp fast pump. The only effect it may have is the amount of time it takes to get the water hot. Either way, the water heats up to the desired temp.)

Back to the car, when the thermostat is closed, the water is only circulating thru the block while some water is basically stopped in the radiator to cool off. When the thermostat opens, the cooler water enters the block and the hot water gets to take a time-out in the radiator. That's the whole point of a thermostat — to maintain an average temperature.

Now, I am using a Stewart modifed thermostat that has holes drilled in it to allow some water to constantly flow thru the system. This is supposed to eliminate hot spots. It is also necessary with the Stewart Stage 2 pump since it has no internal bypass like a factory pump or the the Stewart Stage 1 pump.

Lon is running the exact same water pump and thermostat that I am and he has no trouble with the RS. This is why I think there is something particular to my car that is the cause.

 

If water is flowing faster through the radiator the metal doesn't absorb the heat and dissipate it as well... The opposite is true though... if the water is flows fast through the block it doesn't get as hot. Here is the real question, is the water not taking enough heat away from the engine and to the radiator? or does faster radiator/block flow just work itself out. The only real way to tell is to ask someone running 600+ horsepower (street legal or not) and see what kind of water pump they're running? Probably one with really good flow... maybe? I remember reading about this a few years ago on thirdgen.org - in the end I got a high flow pump and I've never looked back or had cooling problems. Of course, my engine is a lopo pos.

 

The idea is that if the water moves faster through the block, the less likely that hot spots will develop. Too fast thru the radiator and yes, the water probably won't cool too well. Again, that's why we run thermostats, to make the water pause in the radiator to cool down.

Don, I have a theory I want to run by you. I was thinking about this all the way home tonight as I watched my temp gauge.

What if it's not a question of the water moving too fast, but instead, a question of the pump trying to pull more water than the system can deliver?

Similar to our TPI engines. They are nothing but big air pumps. At low RPM, they make great power, but at high RPM the engine trys to pull more air than the intake will allow. The result, loss of power at high RPM.

What if there is some type of restriction in my cooling system? I'm doubting now that it's the lower radiator hose since I do have a quality hose on the car. However, it could be some build-up that at higher RPM chokes the system. I say this because I am running the Prestone version of Dex-Cool and while the system appears clean, I did have about a tablespoon of the "orange mud" in the overflow bottle before I cleaned it out last weekend.

Also, as I've mentioned, I also have a '96 Cadillac that uses Dex-Cool. The overflow bottle is coated with the orange crud AND the heater core had to be relplaced last year becuase the heater stopped working. Well, guess what, this year the heater stopped working again. Hmmmm.

I plan to thouroughly flush the cooling system on my car tomorrow and refill with the good ole green Prestone. If that helps my car, I'll do the Caddy next.

Stay tuned.

 

Okay so I've been on the road for the last couple days.

First, you can get the hose with the spring inside from NAPA. That's where I got mine.

Second, my 91 has always run 220+. Even cleaned the a/c, drilled 3 holes in thermostat etc. It will stay under 200 with a/c on.

And yes if the water runs too fast, it won't cool down unless you put on a high velocity fan.

 

Glenn,
NAPA was next on my list, although I am using a Goodyear Super Hi-Miler hose and these are fairly stout compared to the average hose. I'm now doubting that the hose is collapsing. Still it could be cheap insurance and eliminate another variable.

Next, I've been doing quite a bit of reading on Dex-Cool coolant and trying sort urban legend from fact. Many people, including several here at TGO, claim that Dex-Cool cannot ever be mixed with traditional coolant. From what I'm learning this is BS.

Both Dex-Cool and traditional "green" coolant are Ethylene Glycol based. The difference apparently lies in the anti-corrsion additives. Adding "green" coolant to Dex-Cool simply reduces Dex-Cool's effectiveness.

It also appears that Dex-Cool's claim of lasting 5 years or 150,000 miles isn't necessarily true. Some literature I've read online recommends changing it every 2 years or 30,000 miles, just like the "geen" stuff. This ensures proper protection. Also, there is some evidence suggesting that air in the system due to a leak can lead to the sludging problem.

If not properly maintained, "green" coolant will attack aluminum and can leave scale in the cooling system. My original intake manifold fell victim to "green" coolant and electrolysis.

On the coolant speed, I still feel that this is not an issue. The coolant in our cars is not constantly moving thru the radiator. It pauses in the radiator when the thermostat closes. If slowing the coolant down was a serious issue, then why is everyone switching to 160° or 180° thermostats when the factory T-stat is 195°? The factory secondary fan switch is set for 235°.

The L98 TPI engines were designed to run around 220° to balance power with emissions requirements, but I think we all agree that's a tad too high and that engines last longer at a lower temp. They also make better power since heat robs power.

It seems to me then, that using a lower temp T-stat would cause overheating since it will be open more often, letting the coolant move too quickly thru the system. In practice this isn't true. A 180° T-stat does let the car run cooler. IMHO, a 160° T-stat should only be used with a properly reprogrammed ECM to get any benefit.

Now on my car, since switching to the high-volume pump, the car runs cooler at low RPM and about 20° hotter under load or higher RPM. If there's no other problem in the cooling system, then underdrving the pump may be one solution. A 195° T-stat may be another.

This whole thing is starting to give me a headache.

 

Time to bust out some thermodynamics. I found this online:

------------------------
There is an elementary equation from basic thermodynamics that states that the rate of heat transfer (Q) equals the mass flow rate (M) times a Constant (the specific heat of water) times the Delta T (fluid temp out minus fluid temp in):

Q = M x C x Delta T

In other words, the rate of heat transfer is directly proportional to mass flow rate. If you increase the flow rate, you will then increase the rate of heat transfer. Since you cannot mess with mother nature, it is very naive to think it works any other way.
------------------------

and this from Stewart Components:

------------------------
Higher coolant flow will ALWAYS result in higher heat transfer.
http://www.stewartcomponents.com/htm...tem_basics.asp

 

Bret:


I guess you are not tuned in to the public way of things:

[As far as the, "We're selling bogus parts, but we won't admit it so we can keep selling bogus parts" - I don't really buy into that. When a company specializes in one particular area, it doesn't do them much good to blatanly promote bad parts. You won't be in business very long.]


What comes to mind is "McDonalds"
I rest my case.

 

What Bret said is correct.

Heat transfer from the coolant to the radiator tubes, fins, and then air isnt affected by coolant speed, its only affected by coolant temperature... assuming there are no problems in the system like corrosion or low coolant level.

 

Don hit that right on the Spot...

A stock pump flows pretty well.. If me Id take that pump back off.. Unless you try another thermostat first while you clean that orange stuff also.. Then see how it works for you.. If you notice any changes try your thermostat you like running back in the car.. But most likely more flow does not mean cooler temps in our cars, Well atleast not always..

 

Don,
We're having a discussion about cooling systems and you bring up McDonald's?

Well, since you brought it up let's look at your example. Ever hear of "You get what you pay for?" If ANYONE goes to McDonald's and thinks a $0.99 hamburger is going to be the quality of prime rib, then you really need help.

I don't see McD's promoting their food as being "Super healthy". In addition, I don't know about you, but I tend to be a bit of a health nut. I also used to work for a Health & Fitness company, so I pay attention to ingredients in food. All you have to do is read the ingredients from McDonald's and you'll know exactly what you're getting.

With that said, there's nothing wrong with eating McD's once in a while. Eat it everyday and you'll have problems.

Now, IIRC Don, don't you like to eat at McD's quite a bit? What does that say?

No doubt there ARE companies trying to make a buck by selling junk. Ever see those infomercials for tight abs in just 2 minutes a day? Totally bogus. See any of those companies in business for very long? Nope.

I want to end by saying I'm not trying argue or give anyone a hard time. Just trying to conduct an informative discussion. Let's try to stay on topic.

 

Branden,
The temp was acting similar with the stock pump. When climbing the hill on my way home, the temp would hit 220°, then cool down some on the downhill side. It had also gone higher than 220° while driving stop-and-go on a hot day.

This tells me that there could be something that needs attention in the cooling system. All the higher volume pump did was make the problem (provided there is one) a little more pronounced.

 

Now I see I missed that part.. I thought this only happend with the new pump.. And of course when you change a pump your most likely going to get a new thermostat.. So that's where I thought we were at..

You can most likely be right about the cooling system needs completly looked over.. A few of those things you mentioned and also your cfm and condtion of your fans.. This pump I think we all know is not your problem.. If it was it would be getting your cooling system to work properly with it.. more cfm more rows I don't know..

Good Luck With It Bret

 

Bret says it runs hotter at times now with the new pump than it ever did with the old pump. Sounds like a starting point to me.

My question to Bret would be have you changed out the radiator from the stock unit? If so does the new one have as many cores or as thick as the stock unit?

On the cooling aspect of the radiator. It does take time for the heat transfer from the water to the radiator or heat exchanger if you will. It stands to reason that the shorter the time the water is in the radiator the less it will cool down before reentering the engine. I know there is a happy trade off. Maybe you have a fast pump and a smaller radiator than stock?

One trick I use in an emergency is to turn on the heater to help cool the engine. However it makes the car hot as h*ll and I have all windows down when doing so.

 

My reference was to your statement "they won't stay in business very long" they have, and the public has been told they sell trash but they keep on eating it.



I don't and never will !!!

I was refuting (sp?) your statement about businesses that stay around selling junk.
Didn't mean to rile anyone



[edit by kevin to fix quoting]

 

Bret,

Have you ever replaced the radiator yet? I mean, is it still the original one? If so, might be a good idea to get a new one.

IMO, running that Dex-Cool is worst thing you can do. LOL! Yeah, they may be both Ethylene Glycol based. However, if you had a tablespoon of CRUD in your overflow tank, just think what you have in the radiator tubes and the possibly the engine block.

My uncle tried running the orange Dex-Cool thinking it'd be better for the cooling system. Wrongo! After awhile, he had that same crude on the bottom of his coolant tank and his car ran hotter under load too.

Ok, lets see. You bought new radiator hoses, a new water pump and a new stat. The only thing left really is the radiator itself, the cap, and the cooling fans.

Don't make this more complicated than it has to be. No need to whip out any complex "heat transfer" math formulas to figure out this problem. Jeez, my brain is starting to hurt now.

 

If the residence time is less in the radiator, and the block as well, what else is happening? The volume of coolant changes. You cant just say, oh, its spending less time there so it cools less. Doesnt work that way. If you were to say that you could achieve a 1 degree drop in temp with 1 second residence time, then say that you have a 10 degree drop if you let it stay 10 seconds, in a 10 second period of time the same amount of temperature drop has occured in both cases.

 

I've read through this thread & it doesn't appear that throwing parts at the problem will serve any purpose except to spend money. I think 100% of your problem is probably the red junk from the Dexcool insulating everything so that the coolant is not transfering heat. It doesn't matter how big your radiator is, or how fast or slow your water pump circulates coolant, if your cooling passages in the block are coated with insulating material that keeps the coolant from pulling out the heat, you are done.

 

Looky here:

http://www.dexcoolcase.com/

 

As Fonzie used to say: "Exactomundo!"

That orange crude coats everything in the system. The coolant tank, the bottom of the radiator cap everything. Not good!

 

Dexcool is the devil. It will eat your gaskets (chevy truck vortec intake manifold anyone???), mame small children, and when exposed to air it will sludge. Replace that crap ASAP. I used Dexcool because I thought because it was newer it must be better...WRONG.

 

http://frrax.com/rrforum/index.php?act=ST&f=8&t=1692&

 

Bret,

Try a fan motor with more power. When I went with a heavy duty fan clutch for my 79, it cooled the car right down.

On my 85 and 91, they'll run hotter going up hill than down hill as the engine dosen't have to work harder. The 85 temp stays pretty down as it as a Stage 2 chip in her and the fan turns on at 185.

I'm going to try and find a more powerful motor. I *think* the single fan motor has more RPMs but haven't found any info let since the single fan motor has a different number but if you find one first, let me know