91 Celica GT slow coolant leak

[hakachukai]

Hi, I have a 91 Toyota Celica GT with a very slow coolant leak. Sometimes it will be good for over a month before it gets low and starts to over heat.

I can't see any leaks anywhere, but that car is very tight on space, so I could be missing something. If it is leaking into the engine, how can I tell? And how hard is it to replace a head gasket on that car?

Thanks for your help.

[pat052003]

If you've never done it before it can be slighty difficult, I just did mine on my 90' ST a few months back and it was a bi#@h but I think that was mostly because once I got in there I realized how many other things were wrong with the car. Not to mention that I didn't start using my Chilton until about half way throught the process. So my advice...use a Chilton and follow it's every direction.

[KimMG]

Get a pressure tester for the cooling system. Some auto parts stores rent tools. Pressurize the system. Look for the leak.
There are additives available at auto parts stores that will make the leak glow under a black light.

[pat052003]

yeah the pressure test is good, i don't know if ya'll have autozones there in NC but here in TX i know they'll rent you one for about $20.00

[hakachukai]

Someone told me that there was a chemical that I could add to the collant that would make it change color if combustion gasses were presant.

Is this a sure test, to see if it is leaking into the cylinder? Or could it be misleading somehow?

I'd rather not have to buy a black light if I don't have to, so i'm trying to figure out the easiest/cheapest test to do first.

If it is leaking into the cyclinder, I'd like to know right off the bat. If it's leaking somewhere else... I'll find it.

BTW... I have done one head gasket before, on my 89 Honda Accord LX. It was a B!@#$ Mainly because of the intake manifold nuts, and the EGR tube that WOULD NOT COME OUT!

[pat052003]

the chemical will work but chances are if you're getting coolant or water in your head you should just be able to pull the oil dipstick and look at it, if the oil looks all milky or anything like that then chances are you're going to have to replace your head gasket...that's how I knew about mine. I was driving to work one night and it started smoking and shaking and spitting the coolant out of the tail pipe. when I pulled the head one of my cylinders was blasted clean like it was brand new.