overheating, ? Options

[jayi12-15psi]

Lately my engine has been running warm, it's not getting too hot, just almost to the top of the little temp. emblem(as opposed to being on the little wavy line). I replaced the radiator in august, and it started doing this a few months later, so I took it to a mechanic. The mechanic found a small leak when he pressure tested the system(it was a hose he tightened it, and filled the radiator back up with coolent). Then about a weak later it started doing it again. I seem to be losing a small amount of coolent, is it possible for coolent to somehow disapeer in a pressure tight system? Because I can't seem to find a leak.

Thanks for listening.

[sugarfree]

maybe its leakin from the thermostat. Like the seal.

This post has been edited by sugarfree: Jan 17, 2006 - 12:45 PM

[CheesyLobster]

bring it back to the mec. its probably either the thermostat or there is an air bubble in your coolant. try running the car with the radiator cap off and rev the engine a little and squeeze the top hose. be careful because it may geyser a little but thats kind of what you want for getting out a bubble if there is one.

[gnetik]

Yeah, maybe you need to replace the thermostat.

[Coomer]

A stuck thermostat shouldn't cause a loss of coolant. How does your oil look when you drain it?

This post has been edited by Coomer: Jan 17, 2006 - 7:14 PM

[jgreening]

I seem to be losing a small amount of coolent, is it possible for coolent to somehow disapeer in a pressure tight system? Because I can't seem to find a leak.

Thanks for listening.

The answer is no. If you are loosing coolant, you have a leak somewhere. By the way, I have the same problem, but my temps have been ok. Make sure you keep the coolant full. If you have been keeping it full and are still getting high temps, I would definately check the thermostat too.

[jayi12-15psi]

well, how much loss in coolent would make a difference? For instance I add coolent everytime it starts heating up, which is about once a week of daily driving. Maybe every couple hundred miles. Each time I only add a little coolent, as in maybe a couple cups worth. So if the coolent is just a little low, will the temp register low? I've never replaced my thermostat, and my car has about 187k miles, I'm just trying to avoid a costly diagnostic.

thanks again guys.

[Coomer]

If a couple cups worth of coolant is disappearing per week and you can't find a leak, I'd guess that it may be your head gasket. I'd see how your oil looks.

[jayi12-15psi]

Do I need to drain the oil? or whould looking at my dipstick work. How expensive is replacing the head gasket. Is it easy enough to do myself? Is it expensive?

[jgreening]

So if the coolent is just a little low, will the temp register low?

If its a "little low", there should be no effect on temperatures. If its really low, your temps will skyrocket and you could damage your engine.

I hate to say it but Coomer may be right with the head gasket. Its not a cheap fix. Typically, it requires removing the head and refinishing the block and head surfaces (I think both) and installing a new headgasket. Its actually my fear right now about my car but I guess I might be able to upgrade to a MLS headgasket and ARP studs and bolts. Then I could try some race gas and 25psi!

Actually, I really hope thats not it for both of us.

[jAzn95GT]

Well, from previous experience, i once own a 1988 celica and i kept having this same problem of overheating. I change the thermostat and still, same o' problem. so i talk to a couple of my friends about this and they said the way they "solve" this problem was by putting a "manual switch" connecting to the wire from the thermostat. with this, whenever the temp guage is above normal, i would turn the switch on that will then turn on the cooling fan to cool the radiator down. It work. But i'm not really sure if it's the case with your celica. I'm thinking that there may be a bad circuit between the thermostat and the fan that should cool down the radiator or engine when it begins to overheat.