During a tear-down of a 1998 Honda Accord engine I found a hole in the exhaust valve of the number two cylinder, but I also noticed that the bolts for the crankcase has a bad odor… they smell like sulfur. Any idea what would cause this? Burnt oil maybe?

Thanks,

SnoopyMan

 

yep, or extreme leaning/detonation. but most likely lack of oil or never changed it. is everything black & brown?

 

What bolts are you referring to when you say crankcase bolts?

I always find that the cam cap bolts and head bolts all have a very strong and weird odor to them when you fist remove them..... I'm pretty sure that is the assembly lube that is used, ether that or it is old dirt and grime trapped down there for years. I smell it on most engines that I break down. Not just Honda's. It is usually accompanied by a greyish/green grease/sludge looking substance.

 

Yes, crankcase bolts. The main bearing baffle is varnished and smelled really foul. I was able to clean it up for the most part using car cleaner.

Most of the smell if not all is gone now.

One of the exhaust valves had a hole blown through it, and that cylinder (#3) had a lot of carbon in the bowl and piston, but everything else in the engine looks good. Most of the measurements are still within serviceable specs, no gauling or or scoring in bearnings, crank, cam shaft, bearing shafts.... The pistons are just under specs, so they will need to be replaced. Not sure about deck surfaces on block and head... still need to check them before sending to machine shop.