Carbon buildup on one head bolt & threads?
10-03-2018, 08:12 AM
#1
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Thread Starter
Carbon buildup on one head bolt & threads?
92 22RE 120K
One head bolt (2nd one from firewall on the exhaust side) did not come out as easy as the rest and noticed a lot of carbon buildup on the threads and in the rocker arm assembly hole for this bolt. The rest of the holes on the rocker arm assembly all look fine and the other 9 bolts all came out of the block just fine. What would cause this? The reason I removed the head was to replace the valve seals (#1 cylinder valve seal was bad). Thanks!
One head bolt (2nd one from firewall on the exhaust side) did not come out as easy as the rest and noticed a lot of carbon buildup on the threads and in the rocker arm assembly hole for this bolt. The rest of the holes on the rocker arm assembly all look fine and the other 9 bolts all came out of the block just fine. What would cause this? The reason I removed the head was to replace the valve seals (#1 cylinder valve seal was bad). Thanks!
Last edited by Paul22RE; 10-03-2018 at 09:47 AM.
10-03-2018, 11:22 AM
#2
What you found is "coking", in short this is baked on oil (Google it). It's pretty common and indicates a hot exhaust on the adjacent cylinders.
The forward right hole is a major oil passage, not sure the others have any at all. You have it off poke around and let us know if there are secondary passages there or if it's gasket leakage due to dissimilar metals that leads to wet head bolts.
The forward right hole is a major oil passage, not sure the others have any at all. You have it off poke around and let us know if there are secondary passages there or if it's gasket leakage due to dissimilar metals that leads to wet head bolts.
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Paul22RE (10-03-2018)
10-03-2018, 12:05 PM
#3
Registered User
Thread Starter
What you found is "coking", in short this is baked on oil (Google it). It's pretty common and indicates a hot exhaust on the adjacent cylinders.
The forward right hole is a major oil passage, not sure the others have any at all. You have it off poke around and let us know if there are secondary passages there or if it's gasket leakage due to dissimilar metals that leads to wet head bolts.
The forward right hole is a major oil passage, not sure the others have any at all. You have it off poke around and let us know if there are secondary passages there or if it's gasket leakage due to dissimilar metals that leads to wet head bolts.
10-04-2018, 02:26 AM
#4
I was referring to the foremost right head bolt hole in the block where you will find a machined trianglish or egg shape oil passage..
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