Sometimes LT5 will drive you nuts! - ZR-1 Net Registry Forums

secondchance · 07-06-2015

I have been chasing mysterious coolant loss since early March. Eventually I ruled out (at least for now) head gasket failure because I don’t see any exhaust contamination in the coolant and coolant is disappearing as opposed to being pushed into the over-flow bottle.
Then two weeks ago my battery died on me suddenly and wouldn’t hold the charge. I took it back to the Sears and replaced it with a new Sears Die-hard but still wouldn’t hold the charge – dreaded parasitic loss! While checking the coolant level in the expansion tank I heard a faint whirr of electric fan coming from AC evaporator housing. Turns out my HVAC fan controller has failed and failure was such that, even with the ignition turned off, HVAC fan was running at low speed constantly – fixed!
One day I am driving back home from work and I noticed bluish smoke coming from my exhaust. At first I thought it was coolant steam but I could smell the burning oil. After some thought I remembered when I drained my oil catch can about a year ago, after dropping in my mini-stroker, catch can had this gooey, almost caramel like, mix of engine oil and coolant resulting from coolant getting into the cylinder. Theorizing that he same goo must have entered the PCV valves on its way to the catch can I removed both PCV valves. Sure enough driver side PCV valve was clogged shut. Cleaning out both PCV valves seems to have cured oil smoke from the exhaust.
Finally, after much thought and failure to track down where the coolant was getting into the intake despite multiple plenum pulls and inspections, I ran a bottle of coolant dye as I drove to WAZOO HQ last Saturday. Coolant was drained and plenum removed carefully to minimize coolant spill over the injector housing. Once the plenum was removed black light revealed thin line of coolant glowing along the bottom edge of #1 cylinder secondary intake/IH gasket and not as pronounced but the same the same in the #2 cylinder – both facing the coolant port on injector housings.
Permatex, Form-a-gasket #1 (fast drying/hard curing sealant) was used to reassemble the injector housings to the heads after quick check with aluminum straight edge. I had a bit of fiasco mistaking kinked throttle cable for a vacuum breach (2,000 rpm idle) resulting in unnecessary removal of plenum followed by starting the motor before torqueing the plenum bolts (fatigue induced stupidity). During this process (and reuse of plenum gaskets) I may have damaged plenum gaskets because I am still getting some coolant seeping into to driver side bank (most likely #1 or #3 cylinder).
I have a new set of plenum gaskets coming from Jerry’s and hopefully replacement of plenum gaskets will cure this issue once and for all.

Thank you Jim for your never ending support & help!

07-06-2015	#1
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,723	Sometimes LT5 will drive you nuts! I have been chasing mysterious coolant loss since early March. Eventually I ruled out (at least for now) head gasket failure because I don’t see any exhaust contamination in the coolant and coolant is disappearing as opposed to being pushed into the over-flow bottle. Then two weeks ago my battery died on me suddenly and wouldn’t hold the charge. I took it back to the Sears and replaced it with a new Sears Die-hard but still wouldn’t hold the charge – dreaded parasitic loss! While checking the coolant level in the expansion tank I heard a faint whirr of electric fan coming from AC evaporator housing. Turns out my HVAC fan controller has failed and failure was such that, even with the ignition turned off, HVAC fan was running at low speed constantly – fixed! One day I am driving back home from work and I noticed bluish smoke coming from my exhaust. At first I thought it was coolant steam but I could smell the burning oil. After some thought I remembered when I drained my oil catch can about a year ago, after dropping in my mini-stroker, catch can had this gooey, almost caramel like, mix of engine oil and coolant resulting from coolant getting into the cylinder. Theorizing that he same goo must have entered the PCV valves on its way to the catch can I removed both PCV valves. Sure enough driver side PCV valve was clogged shut. Cleaning out both PCV valves seems to have cured oil smoke from the exhaust. Finally, after much thought and failure to track down where the coolant was getting into the intake despite multiple plenum pulls and inspections, I ran a bottle of coolant dye as I drove to WAZOO HQ last Saturday. Coolant was drained and plenum removed carefully to minimize coolant spill over the injector housing. Once the plenum was removed black light revealed thin line of coolant glowing along the bottom edge of #1 cylinder secondary intake/IH gasket and not as pronounced but the same the same in the #2 cylinder – both facing the coolant port on injector housings. Permatex, Form-a-gasket #1 (fast drying/hard curing sealant) was used to reassemble the injector housings to the heads after quick check with aluminum straight edge. I had a bit of fiasco mistaking kinked throttle cable for a vacuum breach (2,000 rpm idle) resulting in unnecessary removal of plenum followed by starting the motor before torqueing the plenum bolts (fatigue induced stupidity). During this process (and reuse of plenum gaskets) I may have damaged plenum gaskets because I am still getting some coolant seeping into to driver side bank (most likely #1 or #3 cylinder). I have a new set of plenum gaskets coming from Jerry’s and hopefully replacement of plenum gaskets will cure this issue once and for all. Thank you Jim for your never ending support & help! Last edited by secondchance; 07-06-2015 at 11:38 AM.