Head Gasket repair failure, what did I do wrong?
#11
Ok, compression test was OK. 120-130 psi on all cylinders. I also did a spark test on #7 (which was good) after which I put it back together and fired it up. It seemed to idle a little rough, but not quite a misfire. After lap two around the block I noticed drips from a coolant leak and temps spiked again. I found that the upper radiator hose had a bad seal (reused the spring clamp) on the larger pipe running straight forward out of the intake manifold. When I pushed sideways on the hose it would get worse. I installed a fresh clamp and fired it back up, but my #5 misfire returned. I parked it back under it's shade tree to try again another day. My brother is coming down for some mountain biking, so I don't know if I'll get to it this weekend or not.
#13
The miss has been a bit of a moving target. It was 5 and 7 first, cleared it then 7 only. Today it was 5 only. I’m getting some O2 sensor errors too which may, or may not be related. I’ll add a screen shot from a generic OBDII reader in case it is informative. I REALLY wish I could use my GAP Diagnostics tool from my 3!
#14
This may sound obvious, but with all the fussing around, you may have loose connections at the ignition coils. I know that when I replaced my coils a few years back two of the boots were not fully seated. Car ran rough on start up, but smoothed out for a while then popped spark plug codes. Went bac and made sure the plugs were all properly seated at the coil and the spark plug. I had two not fully seated at the coil.
#15
This may sound obvious, but with all the fussing around, you may have loose connections at the ignition coils. I know that when I replaced my coils a few years back two of the boots were not fully seated. Car ran rough on start up, but smoothed out for a while then popped spark plug codes. Went bac and made sure the plugs were all properly seated at the coil and the spark plug. I had two not fully seated at the coil.
#16
whenever there is a 'misfire' on these engines, my first though is coolant in the cylinder....
but many other things do it:
leaky/sticky injector
intake air leak
crossed/bad spark plug wires
bad coil
fouled plugs
crank/cam sensors
bad wiring harness connection
sticky valve/valve seat issue
but many other things do it:
leaky/sticky injector
intake air leak
crossed/bad spark plug wires
bad coil
fouled plugs
crank/cam sensors
bad wiring harness connection
sticky valve/valve seat issue
#17
Well, I seemed to have tracked down all the leaks and installed a new coolant reservoir cap after carefully bleeding the air out of the system. I still get a miss on #5, which has good spark. Today temps slowly rose to about 170 about half way around the block and then spiked like mad and was accompanied by coolant blowing out the top of the reservoir. To me it seems I'm getting combustion gas in the coolant which is causing me to heat up and blow out after whatever flaw I've got is heating up and expanding open.
#18
whenever there is a 'misfire' on these engines, my first though is coolant in the cylinder....
but many other things do it:
leaky/sticky injector
intake air leak
crossed/bad spark plug wires
bad coil
fouled plugs
crank/cam sensors
bad wiring harness connection
sticky valve/valve seat issue
but many other things do it:
leaky/sticky injector
intake air leak
crossed/bad spark plug wires
bad coil
fouled plugs
crank/cam sensors
bad wiring harness connection
sticky valve/valve seat issue
#19
#20
So I got back to this project finally. I found a youtube video of a guy who had pinhole leaks in the aluminum in the cylinder walls, which then creeped up into the cylinder. I was convinced this was my issue, he had the same symptoms. I bought a junkyard engine for $300. My plan was to use the short block off the junkyard engine and put on everything else off my old engine. As I'm tearing things apart I found water under the valve covers and a rather significant build up of a waxy substance on the intake of #5, the one with the miss, and now I'm second guessing myself. Do I attempt a new intake gasket, or keep with my plan to swap out the short block? What would cause that build up? The vehicle ran very little, so it built up quick.