Overheat??? Where could coolant going?

[fuji_man]

Ok, first I have done a recent oil change and it have no report of any fluid being low, but after 1 week my car almost overheated (like the meter when to the orange zone), and upon opening the coolant tank there were no coolant left in the system.

I suspected a leak, so I monitor the level for almost 1 week and then took it to get a pressure tested, and the pressure test shows that no leaks are found, and from monitoring the level for another week, there are still no drop.

However when talking to the oil change place as to why they didn't inform me of a low coolant level, they said they will look into the paper work, but they said that a PSI test could only check for external leak but not internal leak (I am guessing he is talking about the head gasket or something) or even a slow leak.

So I wanted to ask the experienced people, could this even be true? Or will the Pressure test about to see any leak internal or external, fast or slow?

[thelefteyeguy]

what kind of car?

For civic 97-01 ...(head gasket crack) leaking coolant into the engine.
I've had that problem before

$500-600 to fix for me...cant remember

[nsr250]

When the oil was changed did they check the oil itself to see if coolant is in it? If the head gasket is leaking you'll get coolant in oil.

[ells]

My wild guess ...

The rad cap may not have been tight (after oil change) and you lost fluid when it boiled over. When you added more fluid you most likely unknowingly corrected the loose cap. Does that make sense? I have also had a bad rad cap leak fluid.

[fuji_man]

Thanks for all of your reply.

1. My Car is a 99 Sunfire
2. I don't know if they checked if there are coolant in the oil
3. When I refilled the fluid back, I didn't touch the rad cap.

I think I will go to do a UV trace test, but I was just wondering were the PSI test suppose to able to pickup rad cap loose, head gasket problem, or other leak, or even after such a test, those problem could still be there?

[Hybrid88]

This is a known problem with the sunfires and cavaliers. There is actually some sort of manufacturer bulletin on this. I don't have the exact details since I got rid of the $hitbox many years back ('96 cav).\

Thanks for all of your reply.

1. My Car is a 99 Sunfire
2. I don't know if they checked if there are coolant in the oil
3. When I refilled the fluid back, I didn't touch the rad cap.

I think I will go to do a UV trace test, but I was just wondering were the PSI test suppose to able to pickup rad cap loose, head gasket problem, or other leak, or even after such a test, those problem could still be there?