Helped a friend of mine tear his lb7 down and do head gaskets on it, after the repair was completed, the truck ran fine until we got back from the test drive, it had a slight missfire hardly noticable but it was getting more than usual blowby out the crankcase breather, compression tested it, found the cyl, tore it back down to the injector to find the injector hold down bolt broken. at this point we were lost as to why it would do this?
but at any rate, we picked up a new bolt installed it torqued to spec and put it all back together, truck ran fine again until about 10 miles were on it. Tested again, same thing same cyl, tore it back down to find the bolt was in tact fine just loose.
hoping the 3rd time would be the charm, i cleaned out the bolt hole with q tips rags and brake parts cleaner to ensure no contamination, used blue loc-tite and torqued to spec, reassembled tested drove it about 5 miles it ran like a champ, brought it back to the shop and again, ticking slight missfire and blowby!
WTF is causing this and how can we get it to stop?
but at any rate, we picked up a new bolt installed it torqued to spec and put it all back together, truck ran fine again until about 10 miles were on it. Tested again, same thing same cyl, tore it back down to find the bolt was in tact fine just loose.
hoping the 3rd time would be the charm, i cleaned out the bolt hole with q tips rags and brake parts cleaner to ensure no contamination, used blue loc-tite and torqued to spec, reassembled tested drove it about 5 miles it ran like a champ, brought it back to the shop and again, ticking slight missfire and blowby!
WTF is causing this and how can we get it to stop?
