I pulled my inspection cover...

[dsa87gn]

...to clean it out since I have a minor rear main leak. Stange thing is it had a small puddle of coolant in there.

It wasnt a milkshake type thing, the coolant and oil were distinctly seperate. My oil and coolant are both fine.
After I noticed this, I took it out and did some good 20+psi blasts. the car ran great and I rechecked the oil and it was fine.

How did the coolant make it down there and what can i look for to see if I have a potentially serious problem?

 

[Chuck Leeper]

Rear freeze plug leaking?
Intake leak? [Could be all the way to the ft, and running down the pan rail.]
Put a cooling system pressure tester on it, and let it sit.
Pressure hold?
A shot of dye in the cooling system, and a black lite could help find it..[What I use.]
One of your "20psi" blasts could have a head gasket leaking..

 

[dsa87gn]

I took a look today and there is quite a bit of coolant pooled underneath the coil pack on top of the intake.

I cant really see where it is coming from.

Any recommendations on a decent but not too expensive coolant pressure tester ?

 

[turbofrank]

take coil/module off and use a small mirror and light back there.

 

[Nick Micale]

Check your heater control valve and the hoses for a water leak.

 

[dsa87gn]

take coil/module off and use a small mirror and light back there.

Sorry if it sounds like a lame question, but what am i looking for down the back of the block ? How would coolant get up on top of the intake from the back ?

Check your heater control valve and the hoses for a water leak.

The was some coolant/moisture around the hard line connection to the heater valve and along the 2 tubes.
Tightned up the clamps and replaced the coolant bypass rubber caps.
Do the heater control valves ever leak internally where the vacuum line connects ?


I'm really hoping its not a headgasket, but Im concerned about the amount of coolant pooled under the coilpack and wet around PCV grommet. I figured with the amount I saw it would be obvious.

There is no coolant in the oil or oil in coolant, vacuum is rock steady 19" in park, no sweet exhaust smell, but I am definately loosing coolant.

 

[Nick Micale]

.......Do the heater control valves ever leak internally where the vacuum line connects ?

Yes, they can leak internally,

 

[turbofabricator]

Another possible leak point is the rear intake bolts, too. Give them a snug. Your steel heater lines may be rusted bad enough that they're leaking. But as Nick has suggested its probably the control valve. Also make sure the heater core tubes aren't kinked at the clamp point causing a leak there.

 

[aminga]

I've also seen the coolant line leak where the -10an fitting screws into the intake. It will run back the manifold and leak off the back of the block

 

[Tom Tom Turbo]

just had this exact same scenario and it was a loose hose clamp on the heater control valve