1995 Lumina Overheating

[JBMark33]

I have replaced the water pump, all hoses, heater core, readiator, thermostat, and this car still overheats. It is very odd though, it will be fine for about 5 or 6 days, then when i turn it on and it gets near operating temperature, it will keep going toward the red line. It used to not over heat, but get close, but now every couple days, it will go past it, and then a couple miles down the road, it feels like something breaks loose and lets the coolant through. Maybe something is blocking the system somewhere, because if i shut the car off while it is above operating temperature, and i check the hoses, the hoses have almost no coolant in them at all. This has been frusterating me for several months and i have no idea what is left to check on it. Joe <[email protected]>

[northwichita]

-hoses have no coolant- sounds like pressure is not being built up- could need a new radiator cap.

[bobss396]

My money is on it being air-bound. You have a pocket of air somewhere in the system and it needs to be bled off. I'm not sure how to do it on a Lumina, but I'm sure the info can be found in a manual or someone here can answer it.

Bob

[RahX]

is it losing coolant? lower intake gaskets are quite common on the 3.1/3.4 engines. if its not that there is a trick to get air out of the engine, some of those engines are a pain and the trick works pretty good but takes a bit of time to do.

[DJorgie76]

I dont mean to hijack your thread, but I am having the same exact problem. I initially thought it was a head gasket but now I dont think that. When I fill the coolant up it will blow smoke from the exhaust then stop. It's weird, I had a car before that blew a head gasket and it would blow white smoke until all the coolant was gone. Not this Lumina. My car also overheats then it seems like something breaks loose and the coolant starts to flow because the temp will go down.
Also, what is the trick that was mentioned to get the air out of these engines? I dont really care how long it takes. I need to get my car running again. Any help is extremely appreciated!!

Thanks!!
Doug

[bobss396]

Coolant smoke out of the tail pipe is never a good sign. To rule out a head gasket you need to take it to a shop where they can analyze the coolant for combustion gases.

Also the same goes for bleeding the cooling system to rid it of air. You can try it yourself or any decent shop can do it for a small fee. It may require vacuum equipment.

If you feel brave, there are 2 air bleeders, easy to find if you can get a decent manual that tells you how to bleed it. Your local library should have a set of car manuals in the reference section, look for a Mitchell manual. The latest Chiltons might have it, not sure if the Haynes manual would have it.

Bob

[bobss396]

I was just thinking, since the radiator is lower than the engine (cylinder heads), have you tried filling the coolant with the front of the car jacked up, or on ramps? The old Fords with this problem had "surge" tanks which solved the problem.

One air bleed is above the water pump on the intake manifold. First make sure that the bleeder works, at least it can be loosened and tightened without breaking as some of these are known to do. Try cracking the bleeder with the engine fully warmed up and running, just watch out for the coolant it's goning to be hot, maybe you can run a piece of vacuum hose off it. I think you would have best luck with the car on ramps.

Bob

[VBall17]

On my 92 Lumina there is a bleed off valve above the Thermostat housing.
Same thing there, just open slowly while the engine is warm and running.
Be careful, coolant will be hot!

[JBMark33]

I took it to a shop and the mechanic said i had a faulty radiator cap, and the type of coolant i was running was the wrong type. He also installed a new temperature gauge, so i could keep a better eye on the temperature. If you want to try to bleed the air yourself, the one bleeder valve is on the thermostat housing, and the other is on the top of the black metal coming out of the top of the water pump.

[bobss396]

Isn't it amazing how the car manufacturers' can elevate coolant selection to a point where it becomes a black art?

I'm glad that you have a relatively painless solution to your problem, not everyone is hip to the bleeders either, which should be done by cracking the lowest one first (air bubbles rise to the top of the system).

Bob

[wafrederick]

I know a trick to get the air out and it works.Remove one side of the bypass hose,have someone pour coolant into the radatior with the engine OFF.When coolant starts to come out,the air is gone and put that one side of the bypass hose back on.

[tblake]

that works, but only if where you remove te hose is the highest part of the cooling system. some heater cores are quite high up, sometimes even higher than the radiator. If you did that with the front end jacked up, it would be a good idea.

[jdb1941]

I have the same issue with the same year car. Still banging my head against the wall. I believe I have got all of the air out of the system, but it still over heats. The car use to loose heat in side the cab when overheating, but now I got it not to loose heat when it overheats. My point is that all of the air should be out of the system. The needle seems to goto the right (hotter side) when slowing down (foot off accelerator). If I downshift the car when the needle starts going right, it will stop and go back to middle. It sounds to me if I keep the engine RPM's higher than idle, It's creating a needed force to keep the water flow going to keep the engine cool. Does this sound like Theromstat is sticking? Also when its at the point of the hot light coming on, I'll shutdown the engine, open the bleaders, and I'll get steam out of the driver side bleader for a good 5 minutes.

(FYI -- theromstat, water pump, have been changed already, raditator has been flushed)

any other suggestions other than listed above?

[bobss396]

I'm considering buying a Lumina but after hearing all of the overheating and head gasket woes, I dunno.

If your problem with air in the system continues, I would check every hose to make sure its tight, change the radiator cap and if the thermostat is easy enough to do, change it. You're getting air into the system some how. Most cars will run hotter when moving slow or in traffic, but the fluctuation on the gage should be minimal.

As a last piece of advice, have you had a shop pressure check the cooling system and radiator cap? A good shop should be able to do this and make a decision on what to do next. I would also have them check the coolant for combustion gases, just to rule out a head gasket.

Bob

[jdb1941]

Don't ever rule out a headgasket problem. I'm helping out a friend with her car. Same issue. It would overheat then cool back down. Everything was replaced like the thermostat, water pump, raditor flushed, ect. with no resolution. I decided to tear apart the engine. This is what the headgasket on cylinders 2,4,6 looked like:









When the car was running, cylinder 2 was acting like an aircompressor to the cooling system. With the engine off and not started for like a day, coolent would leak into cylinder 2 causing it to miss for about 2 minutes during warm-up. I'm quite amazed that the car actually ran like this!

I would suggest to see if your loosing any compression in any of the cylinders. If you are, then you may want to look into getting the headgaskets replaced.