First off I just find it weird that I can't find any pictures of failed headgaskets. I usually take pics of my R&R but maybe that's just me. I was hoping that some pictures of the failed headgaskets would help me narrow down my problem a bit more.
Coolant leaks: Found the upper heater hose on my '97 Deville leaking through the factory rivet hole. Fixed that and then a leak sprung at the radiator endtank. Fixed that and flushed the coolant which was murky brown (DOH!). Also added bars leaks tablets. I had only owned the car for about 2 months at that time. A third leak developed at one of the short hoses near the backside of the throttle body. I tightened up that hoseclamp and wish I wouldn't have
Looks like now that my cooling system is all sealed up, I uncovered a bigger problem.
I filled the purge tank up to just below the filler neck and went for a drive...I have my AC accumulator out and routed the overflow tube into a 2-liter bottle. I had about 32 oz of dexcool in it on a 25 minute trip...no overheating but it started misfiring on a cylinder or 2. I later read in the owners manual to fill 2.5" below the fillerneck so I did and still had the misfire. Pulled the plugs and all the groundstraps were white--none looked steamcleaned.
Drove to the autopart store and got a block test kit where the fluid is supposed to turn from a blue to a yellow color if ehaust gas is in the
coolant. It was dark out. I ran the car for a minute to test it and then went in my glovebox to get my flashlight to check the color of the test fluid. In those 15 seconds, I went back underhood and I had boiled out about 2 quarts of coolant.
So...I've never overheated but it looks like it might be headgasket time. Just some things I was thinking of. I had replaced my positive battery cable and the intake manifold bolts were
all loose. Since it appears to be a 'dry' manifold, I am assuming that all the plugs being white were not from an intake leak. All of those bolts being loose though makes me wonder about the headbolts actually loosening up which
might be more common than a headgasket failure in my mind because I haven't seen pictures of bad headgaskets. I was going to use an air-hold in the sparkplug hole but the autopart store open late didn't have one tonight. I figure that I could narrow it down a bit more by using an airhold since I no longer have my leakdown tester.
I was also wondering about the timeserts. I read that the later N*s used a coarser thread for the headbolt. If this is true, do they make the threadsert kit in that size and would I be better off buying that kit and later headbolts or is the OD/threads on the timesert the same (if they have one available) for both models?
I'm going to pull the injector clips off a bank of cylinders at a time and run the block test again during the daytime...hopefully that will be able to enlighten me some more and narrow down the problem.
Thoughts?
