luv2per4m

So as I was doing my fall tuneup this past October and I noticed that my coolant was SUPER low in the reservoir - only about 2-3 inches in the bottom. I opened up the radiator cap and found the dreaded "milky turd" sludge. I did a coolant system flush and there was probably a solid 2 cups of "sludge" mixed in with the coolant. There is NO coolant in the oil, no white smoke coming from the exhaust. I noticed my thermostat sticking slightly on the way home from work so I pulled that out and it was pretty sludgy despite the system flush. Heater core seems to be functioning properly. There are absolutely no visible signs of a leak. I suspected that my head gaskets were blown/leaking so I checked the compression and got readings that were 140-155psi, which seems good. The car is still losing coolant - where do I go next? She's partially disemboweled in the unheated garage and it's February in Cleveland so I'm really trying to avoid putting her back together only to have to take her apart again or taking her apart only to realize that it wasn't my head gaskets. Any advice? Similar scenarios? Something I've overlooked? Thanks for any insight.

Bert

A head gasket can be leaking slowly and not show exhaust smoke yet. There's a tester that can check for exhaust in the coolant called a comustion leak check. Head Gasket or Combustion Leak Test Procedure (Gasoline Engines Only)
Are there milky deposits in the oil fill cap? Does the engine overheat? Has the coolant been flushed regularly? Maybe the cap is causing the coolant loss.

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Bert

R.S.LOGAN

If you are losing coolant , a pressure test on cooling system should show any external leaks and as suggested by Bert , a block test ( sniff test ) show show any problems with head / gasket . You also tend to get emulsified oil symptoms , when car is used on short journeys , especially in cold weather and the engine is not getting run at normal working temp for any length of time to clear the condensation that engines create .

luv2per4m

Thanks for the responses. There is NO sign of coolant (milky turds or froth) in the oil/oil fill cap/dipstick etc. BUT there has been traces of oil in the coolant and cooling system. The engine has not overheated. The coolant was not flushed for 90k miles (I know - shame on me for neglecting it - had other cars with worse problems that made doing my flushes take a back seat). I did it this past fall when I noticed that burnt maple syrup smell running my heater for the first time and that the coolant was low and sludgy. I ran a compression check on the coolant system as well as the heads and there is no sign of a leak. I did replace the radiator cap "just in case" and I'm still losing the coolant. So, basically, there is no obvious "LOOK AT ME" symptom that's telling me where I'm losing the coolant. I'll go ahead and try that combustion leak test but I already have the cooling system drained and dismantled to change the thermostat. Major bummer to have to go backwards to look for the leak. It's cold out in that garage and I was hoping to limit my "labor" hours =) Again, thank you for the advice, suggestions, and just letting me grumble about my woes.

Bert

Since the coolant wasn't flushed for so long, the acid build-up in the coolant could have ate through the heater core causing a leak there. Normally it wouldn't be a lot though. If the windows fog up easily, that would be a symptom. The 3.8 can blow the headgaskets pretty easily, do to the small clearance between the combustion chamber and the water jacket. That combustion leak check will test that.

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Bert