Ok I have a 94 idi turbo 7.3 that has a miss in cylinder 6. Started doing a compression test and found oil on #6 cylinder. This truck has 100,400 miles on it. Took the engine apart to find no broke rings and no play in the valve guides. The intake valve on cylinder 6 has a build up of carbon on it but not enough to keep it from seating properly. Compared to the other intake valves only having soot on them. Valve stem seal was good also. This engine when running is smoking blue at idle cold and operating temp. Compression on cylinders was 425. Wasnt able to check #6 because of the oil in the cylinder. Help me out why do I have a miss.
7.3 idi turbo cylinder miss
- Thread starter Diesel85
- Start date
crash-harris
Breaker! Breaker!
First thought, bad injector. As for the oil on #6, maybe a small breach in the head gasket 
Could also be a chip in the cylinder wall deeper in the bore. Sounds odd to me, but maybe someone else will get you closer to that answer.
Welcome btw! What part of Kentucky are you in? I'm about 80 miles +/- north of Huntington, WV.
Could also be a chip in the cylinder wall deeper in the bore. Sounds odd to me, but maybe someone else will get you closer to that answer.
Welcome btw! What part of Kentucky are you in? I'm about 80 miles +/- north of Huntington, WV.
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I'm about 5 hours from you. I'm in Webster county. The only thing I can think is the intake valve on #6 is not seating correctly. I forgot to add the injectors are new. Thought we had bad injectors to start with changed all and the miss still stayed in 6.
IDIoit
MachinistFabricator
did you pull valve springs before assessing valve guides?
crash-harris
Breaker! Breaker!
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IDIoit
MachinistFabricator
i would have done a leak down test before the head removal.
by the sounds of it, the oil has to be coming from the intake valve, somewhere.....
if it was rings, the entire chamber would be oily, no?
have you mag'd the heads yet?
stupid question time. is the injector line clogged? cracked?
by the sounds of it, the oil has to be coming from the intake valve, somewhere.....
if it was rings, the entire chamber would be oily, no?
have you mag'd the heads yet?
stupid question time. is the injector line clogged? cracked?
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