Coolant Loss

This one was actually hesitating on each startup during normal driving. After adding the repair concoction, the hesitation is gone but coolant is now escaping from the reservoir cap. I may have created a mess internally but also need to make sure the cooling fan is working properly.

 

The EGR problem caused P0300 and also broke the input damper plate. I assumed the misfire condition was due to the EGR clog. There wasn't coolant loss or coolant/oil mixing. It may have caused other damage, although everything was fine for 20K miles after the EGR cleaning. If something was marginally damaged but not enough to cause symptoms, maybe that has subsequently failed more completely. Still, there are no current codes relating to any of these issues.

 

I'm planning to verify cooling fan operation, verify coolant flow in radiator, and then leak down test. After that, let the Head Games begin!

 

If you're asking about the Head Games comment, that means cylinder head removal and head gasket replacement. I had so much fun with the last such episode, after all.

 

After your deck chair comment, I have renamed the Gen 3 Pri-Tanic.

Anyway, I drained the coolant and only got about a gallon. I'm thinking that's a bit low and would cause high cylinder head temps? I added new coolant and went for a 7 mile test drive. It was 35F outside and ECT was between 185 and 200 and peaked at about 3 or 4 miles. Coolant level looked the same at the end. I don't think the cooling fans ever came on either while driving or while adding coolant.

The K-Seal instructions say you can leave it in long term or replace the coolant after a short time. The ICE is still running well with no hesitation or bobbling on startup. Also, the coolant reservoir excess pressure is gone. My recent engine block test did not detect combustion gas in the coolant but the result may have been different when the excess pressures were there. I think crankcase pressures are still too high so there's either piston ring bypass or broken head gasket. I'm leaning toward piston rings since there are no misfire codes. We will see whether there's a long term result in terms of the startup miss.

I'm thinking one or several factors caused the coolant loss. 1. Broken head gasket either causing coolant loss directly or thru exhaust gas pressure. 2. Oil starvation after striking a chunk of freeway ice which perhaps caused overheating?

 

Continued coolant loss at the reservoir cap was resolved with installation of a new cap. (Maybe some K-Seal got into the relief valve on the old one?)

Anyway, I put several hundred miles on it and it ran great! In fact, it previously never did better than 42 mpg and today it was at 48 mpg with predicted range going from 440 to 560 miles.

The hesitation/miss had disappeared several days ago. Then, it appeared again tonight with some coolant being lost past the new reservoir cap. I'm thinking the K-Seal repair was dislodged and then combustion gas pressure into a coolant passage expelled some coolant.

I'm inching closer to head gasket replacement, although my lazy side would love to find a solution in a bottle.

 

Too late.

 

Figured head gasket was compromised at Cylinder 1 because the EGR Cooler was completely clogged about 25K miles ago and trouble codes were P0300, P0301, and P0302. There were no codes recently, however, even though the ICE regularly stumbled on startup. Removing the spark plugs, I noticed the 1 and 2 pistons were wet but 3 and 4 were bone dry. I'm thinking there is a head gasket break between 1 and 2 which was temporarily fixed with K-Seal. Now, I'm ordering a new head gasket kit with bolts.

 

Also, supplying Cylinder 1 with compressed air at TDC on compression caused expulsion of coolant from top reservoir hose. That confirms gasket break at least at Cylinder 1 but I'm still curious that there are no pending or stored codes.