losing coolant....

[Spinnetti]

Racing my 91, and have overheated the engine twice. Doesn't seem to be steaming out, but losing it somewhere.... any likely sources?

Thx

 

[cribbj]

Get yourself a block test kit and "sniff" the coolant for combustion gases. That'll tell you if you've blown a HG. Amazon sells them for ~$60 or you can probably pick them up at a NAPA store.

 

[Spinnetti]

Thanks for the tip! - that was new to me (not much is!). I was going to get a Harmless Freight coolant pressure tester too and see if its blowing out a cracked fitting or something too....

So I've cooked this thing hard twice now... any easy way to tell if I hurt something? bore scope inspection? Oil analysis? I hate to yank and refresh the motor if I don't have to especially since a freshen up isn't particularly cheap (gaskets, timing belt, water pump, idlers, rings, bearings, hone, head job etc....).... would prefer to keep limping along if I can....

 

[cribbj]

The block test kit will tell you if the HG is blown.

A leakdown test will tell you where it's blown, and if it's not a HG problem, it will tell you if you have other sealing problems, although it can be difficult to tell exactly where they are. People say/write that when you hear air coming out the exhaust pipe, you have exhaust valve leakage, coming out the intake manifold is intake valve leakage, and coming out the crankcase is ring leakage. In reality, however, it's difficult to pinpoint the leakage.

I'd run the block test, a compression test, and a leakdown test and try to correlate the data from all three tests, much like a doctor would correlate lab tests and try to draw a conclusion.

 

[Bushwhacker]

Also, try a new pressure cap.

 

[Spinnetti]

Thanks for tips guys....