Banks4004

This is unusual overheating from what I've seen in the past. First off, my air dam is fine and clear, fan is operational, radiator is clean, cap is new, new coolant, full coolant, new thermostat, timing is set correct. The car overheats at higher speeds, like on the highway or just cruising (reads up to 240 on the gauge and stopped running once sputtering and not restarting) and cools down when its idling or at a light (but never all the way just to about 220 on the gauge). A/c obviously doesn't help. The car normally reads just over the line between 100 and 220 (160?). It is strange that it actually gets hotter at higher speeds. All I can think of is back flushing the engine and getting a new water pump just to throw parts at it. But I'm not sure if a water pump could cause this type of problem. Anyone have any tips or suggestions?

Thanks

mcrandrz

Blockage inside the radiator causes this. Check for hot spots. Also. Take a thermometer to your thermostat housing. I just replaced my entire system to find out my gauge was reading 40 high. But overheating on highway and big load is almost always blockage in the radiator.

Have you or the p.o. Put stop leak in it?


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Banks4004

I have not put any in, and I have been maintaining the radiator without issue for 5 years, but I cannot speak for the p.o. But thanks there could still be a blockage somewhere, do you literally feel these hot spots to troubleshoot?

mcrandrz

No. you would need an infrared thermometer. if you think you need a water pump do a simple test. Open the radiator cap and start the car. Look inside. There should be a goood amount of fluid moving around. Its also possible your pulley is slipping at high rpms.

One more check.
Pull your top radiator hose off and look inside. ( engine off ) any signs of anything but coolant?
Also squeeze the top and bottom radiator hoses. If theres any cracking or they are easily flexible then its also a possibility that they are collapsing under high pressure.


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mcrandrz

But mostly I would move away from your water pump. If its bad then you would overheat all the time


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mcrandrz

And when you say full coolant. I'm sure you dont mean 100% coolant do you?


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sofakingdom

iTrader: (1)

Lack of high-speed timing advance, such as from running a stock (computer-controlled) dist, but no computer, will do this.

Banks4004

The coolant is 50/50 haha. I had the radiator out in December and ran a hose through it in reverse. The water was coming out clean in a matter of seconds. The hoses are all clean there is no debris that I can see in the coolant, but I wont disregard a possible radiator clog. The collapsing hose might be it, after you mention it I remember that I changed the lower hose in December and that was the only change to the cooling system since the issue as started occurring. I also noticed the new hose did not have a spring inside it to keep it from collapse. I will replace/ investigate that first. Sometime this week I will also get a timing light and check it again and check to make sure the advance is coming in correctly.

mcrandrz

Alright. Good luck! I hope thats it keep me posted on progress. Ill subscribe


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Banks4004

Ok I have finally had time to attack some things on this issue. I got a new aluminum radiator and changed the lower hose to a good shape. Checked the timing again, and it still overheats at speed. Its not as bad, but it still overheats. All I can think of is changing the water pump. but only because it is related to engine revs

Snoopywasaga

This is gonna sound dumb but I had a similar problem many years ago with my 84 Z28. Ran hot under load on the highway or around town but cooled down at idle. Some times the car would get hot and sputter and buck like a bronco. Other times it would conk out and leave me in the middle of the road until it cooled down. Spent a lot of time with an old family mechanic friend (god rest) and spent a lot of money on the cooling system. Nothing seemed to work. Smelled fuel one day driving to work and saw the fuel pump was pissing gas out of some hole. Replaced the pump and mysteriously the car ran fine afterwards. Go figure.

Banks4004

thanks for the input, Im going to change the water pump tomorrow. If no luck then I will check out the whole fuel system.

TTOP350

iTrader: (8)

Make sure you get the correct rotation water pump.
sounds like a timing issue, lean issue or the incorrect WP.
Of course it could be other things also.

Banks4004

How can I be sure I get the correct rotation/ what is the correct rotation?

Thanks

Dakota W.

counterclockwise for serpentine, clockwise for v-belts.

Banks4004

It overheated really bad on the highway yesterday, maybe 20 minutes with the gauge pegged over 260. luckily it was ok. changed the water pump today with the correct rotation and it is still terribly overheating. its only been 80 degrees max here lately and its overheating at night. I have no garage and limited tools so its time to take it to the shop and drop the bucks...

TTOP350

iTrader: (8)

I just quickly scanned thru all the posts and didn't see any mention of the air dam.
Is yours on the car? Big flat plastic piece under the radiator core support..

Banks4004

hmm I'm not sure about that piece. Nothing has fallen off since it has started overheating, but I'll check. I at least have the grill vents and big curved piece and top piece. Other at kind of hard to see

Banks4004

Here is what my stuff looks like




from the top

bitchin_buick

The air dam is located Below the radiator.... Our cars sit so low, many get lost.... Had to throw one on my bird after I bought her.

<Mike>

bitchin_buick

In your first pic the cross-member piece of red framing where your radiator is sitting on. Directly below that should be your air dam. At least that is how it is on my 91' Bird and assuming it should be the same on your Camaro....

Banks4004

oh ok i see. I dont remember ever having one but I'll get one soon and throw it on. Thanks for the input

TTOP350

iTrader: (8)

Yup, yours is gone. The air dam is a must have.

Banks4004

Just ordered my air dam today. I am also missing the plastic plate that goes on the drivers side front corner and covers that black vacuum ball thing. Is that just a skid plate or does it channel airflow as well?

GOTCHEVY

iTrader: (1)

I have the same problem bro. I don't think it's the air dam. I've been running the car without it for years in the SoCal summer heat and never had it overheat. It started doing this to me last weekend no changes were done to the car. If I figure it out I'll make sure to post.

Snoopywasaga

Given you replaced almost your entire cooling sytem I'm going to suggest chnging out your fuel filter. Your car is 23 years old and you should do the easy, cheap stuff first.

Another problem may be a head gasket. Check your engine oil, If it looks like chocolate milkshake antifreeze is mixing in with your oil and you have a blown head gasket. If not take out your spark plugs and look at their color. They should all look about the same. Do a compression test with a hand guage on your cylinders. Start with the odd color plug cylinders first. There are a lot of youtube videos on how to do this. Low compression means bad head gasket.

TTOP350

iTrader: (8)

If everything is ok, not overheating driving in town and then it overheats at highway speeds, its the air dam missing, which his clearly is gone. There is a reason GM put them on. It has to be there to move air thru the rad.

GOTCHEVY

iTrader: (1)

Banks mentioned that temps never go over 80 where he lives. And it's overheating. My car on the freeway at 80* will never go past 180 but since I'm driving in 100+ weather I'm much more likely to run into these kind of problems.
Don't attack me I'm just saying. Its never happen to me in years why the change now. Try the air dam and get back to us banks maybe I'll have to order me one too.

Banks4004

I actually live in central oklahoma where it is usually much hotter but lately the weather has been mild. I will certainly put on the air dam, I may also see if a shop can flush the system. I have changed the coolant but maybe if they can force some water through backwards in the block a blockage could be dislodged.

TTOP350

iTrader: (8)

I'm not attacking you at all, if It came off that way, sorry. When I get tired I get short and to the point. Plus I can't type to save my azz

Keoman

iTrader: (3)

Its your air dam, or lack thereof. Plain and simple.
Fuel? haha...
Lean and rich are a pebble in the lake to a stock engines temperature.

I have the same story, car ran fine for YEARS and all the sudden, with ZERO change in parts it starts overheating. Couldn't figure it out. Put a 4th gen air dam on my car (a little more efficient design) and voila, problem disappeared.
With an efficient air dam, AC off and alum radiator, your fans shouldn't come on at all on the highway. Just took a road trip in 90*+ temps and stayed right at thermostat temp (170*) the whole time.

Banks4004

I will still be a little worried if the air dam makes it run fine just because there may be another problem that made it overheat out of nowhere. But im getting the cooling system flushed so there is nothing else to try essentially. Will keep it updated after the air dam

Banks4004

I got the air dam on (also known as reducing my ground clearance to 2 inches). But it is cooling fine on the highway now. The pressure flush of the radiator got it to regulate to 220 and now with the dam it stays at 180. Thanks for all the help I would have no idea there was even supposed to be an air dam.

t-top havoc

iTrader: (3)

Good to see you got it!!

TTOP350

iTrader: (8)

I'm wondering if you had a air dam and it got ripped off one day, then next day your over heating..

Banks4004

I don't think so because I have owned the car for 6 years and never noticed it. A possible blockage probably just put the system over what it could handle with no air dam

Update: Just made a 900 mile trip from okc to chicago with no problem. I think its safe to say that the problem was fixed!