rscamaro90

So i just replaced the thermostat, radiator, fan switch and had the cap tested it is good. My wife drove it to work yesterday and it did fine. I drove it today, it stayed below 220 until about an hour and started to overheat again.
The radiator was replaced last friday, so now I am thinking it is the water pump, any ideas?

zero13

didja do a pressure test?..or ,just in case, did your airdam fall off,or get removed?...

camaronewbie

1) Is the guage reading hot, or is it literally boiling over? If it's not boiling over, it's not overheating. I say that because 99 times out of 100, these guages are far from accurate.

2) As asked above, air dam in place? It's directly under the radiator - if it's heating up on highway, that's usually a damaged or missing air dam

3) Are the fan(s) working? If it's heating up in town/traffic, that's usually a fan issue. You need to run it and when it gets hot, verify the operation of the fan. If it's not coming on, or coming on way late - then forget about the factory fan switch setup and get an aftermarket fan controller - the factory fan switches are junk IMO and I never got them to work, whether expensive (like Thermaster) or el cheapo (like AZ).

4) If not boiling over, I wouldn't be concerned necessarily. I'd get a laser temp reading (any local shop can shoot it for you) to get a REAL idea of the temps. Remember, these cars were designed to run in the 210 - 240 range as "normal" op temps - this was to reduce emissions.

rscamaro90

Thanks for the replies. It is boiling so it is overheating. The air dam hasnt been there for 5-6yrs. As for the fan, I drove it earlier it stayed around 220 till about 20min then it started to get hot. I got out to see if the fan was on, it was. I then turned the air on and it cooled it down. I let it run with ac until it cooled back down, then turned the ac off. About 5min from the house it started overheating again. When I got home I turned it off, then let it cool for a few minutes started it back up, ran it up to about 1500 -2000rpm, while watching the fan. Kept it at that rpm for 2min, fan running the whole time. After a few minutes of idling, fan still on it started to overheat again. And on a different note, I noticed that I have a little oil in my air breather but I know that is blow-by.

pvr007

iTrader: (1)

mmm well the fan is on, like you said, the water pump could be an issue, or, the thermostat, thats my guess

rscamaro90

Like I said before I just replaced the thermostat. I was thinking water pump also but it is pumping and circulating in radiator. Water pump is not leaking and it is not loose.

pvr007

iTrader: (1)

Oil pump? not enouph lubrication could couse Overheating, idk XD

rscamaro90

it could be I think Im just gonna take it to a guy and let him look at it. It will be cheaper than me guessing with no diagnostic tools (ie, scan tool, etc.) I will let you know.

camaronewbie

There's nothing to scan with a scan tool regarding cooling anyway.

dunkirk

If yours is like mine, 89 305 California car the thermostat is a 195 and factory specs set the fan to come on at 223 degrees. I went Carb and ditched all the comp crap and now run 160. Keep in mind I live Southern Arizona

rscamaro90

I realize there is nothing to scan w/a scan tool, just need someone that has more diagnostic tools than i do, cause I can only go so far with no tools except a meter. Im afraid I have a cracked block or a warped cylinder head or a blown head gasket, I hope not. I just need someone to diag. with the right equip.

camaronewbie

Not sure what you put in for a stat, I'd use a 180 on a computer controlled car (160 is too low). What temp does the fan come on at?

I've never heard of "testing a radiator cap" - why would you, they're like $8 - I'd replace that - too easy and too cheap not to.

Tried a radiator flush?

Check between the radiator and the A/C condensor - that's a debris collecting station inbetween the two on these cars - remove top rad mount, tilt radiator forward towards motor, get the shop vac in there.

rscamaro90

I used a 195 thermostat not to sure about using a lower temp will it turn on the ses light. There is no debris between radiator and condenser already checked that. I havent flushed the system but that reminds me of something I forgot to mention earlier, before it started overheating I was constantly having to top off the radiator. Since its been overheating it seems like its loosing fluid even faster now. I havent seen anything leaking underneath.

jkrustchinsky

seriously? are you a youtube mechanic?



ok, Buy an air dam, test the radiator, test the fan(look at it, if it works it works) replace the waterpump. Waterpumps are 14.99 BRAND NEW, if it still overheats please let us know. Joshua

pvr007

iTrader: (1)

sorry, it was just a wild guess, dam you guys have no compassion for noobs

rscamaro90

Thanks, I've already priced the water pump, and not to worried about the air dam right now since it hasn't been on there (will replace thought as soon as possible). It may be the end of next week but I will keep you posted and again thanks for the help.

jkrustchinsky

these cars breathe through the bottom, without the air dam your fans are doing all the work and will fail leaving you stranded

rscamaro90

That 's what has me puzzled, I know it needs to be there but I haven't had it on for 5-6 years and its never done this. Also if the water pump was bad wouldn't it not be flowing and circulating in the radiator. And also I need to figure out where I'm losing antifreeze.

camaronewbie

DING DING DING DING DING We have a winner!

Find that leak. How long since oil changed - no coolant in oil is there?

And no, a 180 stat will not create any codes, even no stat will not make any codes. It's just that the ECM might make car run a tad richer if using a stat below 180, since the car never warms up enough {maybe}.

rscamaro90

I changed the oil less than 1000miles ago and there is no coolant in the oil. I will be looking for that leak number 1 priority before I do anything. I know it should have been mentioned in my o.p.

rscamaro90

I changed the oil less then 1000miles ago and there is no coolant in the oil. I should have mentioned the leak in my o.p. but finding that leak is my #1 priority right now. And I have ran it w/o the thermostat before so I should have known it wouldn't throw a code. Thanks for all the help and keep the suggestions coming, the more the better. I know I do not post that much, but ya'll have helped me before and have been dead on every time. This is the most feedback I've ever got. I will reply to a post if I feel like I have something to offer, but most of the time I'm just looking around. Any I will keep ya'll posted on the leak.

luvmy64

Any white smoke or antifreeze smell coming out the tailpipe? Im leaning toward blown head gasket......

rscamaro90

No there is no white smoke or antifreeze out of tailpipe. I had it cranked up earlier didn't see anything leaking anywhere.

VelocitySc0pez

hey. i have the same car. i did the same things.

replaced radiator. thermostat. cap. AND I OVERHEAT AT IDLE. I have no muffler but i do smell a weird smell from my exhaust. I need help. please go look at my posts under cooling

ASE doc

Head gaskets will generally fail between a coolant passage and combustion chamber resulting in combustion pressure, and gases in the coolant. We test for this using a 4 gas analyser to test for HC in the gases from the coolant. Coolant in the exhaust either means a more severe head gasket failure or, more likely, a cracked head. The combustion pressure from a failed head gasket can overcome even a good radiator cap and cause coolant loss, usually in the form of the reservior overflowing. Make sure that the relay tube between the radiator and reservior is tight and doesn't leak.

water pumps almost never fail to pump coolant. Unless the impeller comes loose from the shaft, they just don't not pump coolant. The bearings may fail or they may leak, but they don't not pump.

dunkirk

I really do not think it would run richer at that temp? When mine was stock it ran on the Freeway at approx 160 degrees, the only time it would hit the 220 mark was in traffic on a Hot day

rscamaro90

Still haven't had anyone look at it yet, but I was looking at it a few days ago, I was holding the rpms about 2000 like I was doing earlier, adding water as I went after doing that a few times when i released the throttle the last time antifreeze spewed out of the radiator.

ASE doc

A head gasket failure, the type that allows combustion gases into the coolant, will cause severe overheating. Look for steady bubbling in the coolant reservior.

Hannah Racing

Im not sure if they make them for chevy motors but if i were you i would look at flow kooler water pumps. I just put one on my 86 firebird and it is supposed to flow 35% more water at idle. Flowkooler.com

ASE doc

The 86 Firebird has a Chevy motor. All GM V8s after 81 were Chevys.

rscamaro90

Due to it overheating severely last week there is a crack in the coolant reservoir but there is bubbles in the radiator itself.

ASE doc

Yeah, blown head gasket. No matter how well you cool the coolant, you can't prevent the displacement of coolant from the upper engine due to high combustion pressure entering the cooling passages. The engine will overheat after several minutes of operation.

If you want to avoid doing both heads(if the head gaskets are OE, you will want to do both anyway), you can check plugs to find the one that is seeing coolant. It will be the really clean one. I have seen head gasket failures bad enough that with the plugs out, using a pressure tester, I could fill the cylinder with coolant so that it ran out the spark plug hole. Do not crank the engine when doing this because you will break rings from the piston(s) trying to compress liquid.

rscamaro90

Alright, thanks I have been leaning toward the head gasket, cause everything else is checking out ok, and I see no fluid leaking anywhere. It pisses me off cause I take great care of this car she is my baby, but I guess when the fan switch went out it just snowballed from there.

rscamaro90

I don't know whether I'm gonna do the head gaskets with the oil coming up thru my breather. I might just go ahead and put a 350 in which is what I've wanted to do since I've had it. My money situation hasn't allowed for that yet, but God willing maybe my situation will change and I can do it finally.

ASE doc

Sounds like a plan!

rscamaro90

Update; I got it over to that mechanic yesterday. Wouldn't u know it the first time I ever take it to anyone else it does fine for him. He said it didn't overheat or anything. I didn't ask him how long he drove it but I will tomorrow when I pick it up. He did say that he smelt gas in the radiator, I also smelt it last week sometime.

Camaro305SB

So coolant temp has nothing to do with the cooling system? Interesting....


OP are you sure the gauge is reading correctly? Did you verify the temp with a scan tool or temp gun? Still though, if your losing coolant, its going somewhere. Gotta find that leak either way... Shouldn't overheat though unless you run the reservoir dry and the radiator low.

rscamaro90

I'm almost positive the gauge is accurate, but I will check that tomorrow when I get it back home. It was overheating before I put the rad. in, when I filled it with coolant I turned on the heater and let it fill up the whole system. Is it a possibility that I just didn't fill it completely? I've never used the reservior tank I just added it to the rad. and now there is a crack in the bottom of it. Also what is the gasoline smell in the radiator, head gasket?

Camaro305SB

Are you sure thats not where the coolant is going? The cracked reservoir?

I usually just fill a cooling system until the temp is in the middle, the heat blows, and the radiator won't take anymore. SBCs aren't known for making bad air pockets.

rscamaro90

Now that there is a crack in it I know that's where it's going now, but what about before? I am still inclined to say it's a head gasket. But the only time it comes out of the reservoir is when it overheats and boils. When the tank cracked I had it off for about a day and had the hose plugged from the tank to the rad., but didn't know what it would do if it overheated again so I put it back on. Any clues on the gas smell in the rad.

Camaro305SB

If your losing coolant, running hot, and smell fuel in the rad, my vote is head gaskets. Does the car have some miles on it?

rscamaro90

car has 265,000 the engine was rebuilt has maybe 75,000 miles

rscamaro90

With everything I know plus what everyone here has told me I'm sure now that is is a head gasket.

Toqwik

IF you have bubbles in the radiator, you have head gasket problems.....

rodsatheart

iTrader: (1)

Need to replace the reservoir. As the engine heats up coolant expands and excess is transferred into the reservoir. As it cools the excess is pulled back into the engine to fill it back up. If the reservoir is cracked and will not hold any coolant, when the engine cools it will just pull air back into the engine. It will continue the coolant to air swap until there is so much air that no coolant will transfer and over heating occurs.
While you have the heads off take them down and have them check for cracks and warping, also put a straight edge on the block after cleaning and check for warping there. A little is normal, but if it excessive all your work will be in vain and still have the leaking. Everything is prob. fine and will be fixed with new gaskets, but it never hurts to play it safe.

rscamaro90

Right now I'm leaning toward the 350 swap but I'll just have to wait for now. If I do just replace the gaskets I will def. check for cracks and warpage.

ikeepitreelz

Fuel smell: thats the charcoal canister located on the passenger side (on firebirds) , prolly has a bad purge valve or bad filter very common with these cars.

rscamaro90

Didn't think about that, but still doesn't explain the overheating and losing coolant.

ikeepitreelz

check the overflow coolant bottle, mines had a small hole and would loose anti freeze, remember that anti freeze expands as it heats up and overflows to the bottle and when it kools down it sucks it back up, if there is a leak it will suck in air..happened on my other gta..i just changed my thermostat too to a 180 degree and drilled a few small holes to always have coolant coming into the engine and the car runs so much colder and better.!

rscamaro90

I know I've been thinking it's the head gasket, but I have also thinking that I have missed something small are you saying that if I replaced the reservoir that would possibly fix it? It didn't have a crack in it until it overheated a few times after the fan switch went out. After I replaced the switch it was still overheating and then the reservoir cracked.