Head Gasket vs Block issue

[tahoesteve666]

I have another thread where Im debugging a rough idle and am now suspecting that I have an internal coolant leak making its way down the tail pipe. Basically, my chemical radiator test showed no gas, but I suspect I have a slow pressure drop from the radiator pressure test and am losing fluid out the tailpipe. I dont really have any 'white' smoke, but maybe some steam and significant fluid drips (Im waiting for a pressure tester to arrive and will run a dye test on the tailpipe tomorrow). I do have to top off the coolant so I know Im losing it.

I am contemplating a mechanic in the bottle approach for a fix and have been reading up on all the different brands, their chemistries etc. A few brands have a variety of different products, in some cases, they have product recommended for head gaskets, and a separate product for the block and even a separate product targeting intake manifold gaskets.

My basic question is, what is the easiest and/or best way to distinguish between a block issue and a head gasket issue? And in the case of not knowing, which type of product should I target?



Any comments appreciated...

 

[sntrym95]

The only way I can think of coolant getting into the exhaust through the block would be a cracked cylinder/block, but I'm pretty sure you'd know if that was the case. This would be very rare.

Most of the time, the head gasket is the culprit, although an intake gasket leak could get coolant into the intake manifold or the oil. A cracked head is also a possibility if the engine ever overheated.

The mechanic in a bottle solutions are very bad, I would advise against using them. They will likely clog up something else, like the radiator or heater core where the passages are very small.

My suggestion would be to pull the intake and look for a bad gasket. If you don't see it there, pull the heads or just leave it alone until it gets worse. If you do pull the intake and/or the heads, have them magnafluxed by a shop to find any cracks.

After reading your other thread, I should add that the intakes on these are notorious for leaking, as well as the heads cracking due to the thinness of the casting.