Blowin' smoke from the wrong end?

[nccatfan]

Ok, so my thread title may be a little misleading. Actually, I was finally inspired to pull my oil cap while the truck was running. There's a decent puff of smoke/blow-by coming out of the oil filler neck. Would this warrent me doing a compression test? How would I do that on a '99 7.3L? Truck has 234,xxx miles. Runs good and has good power, not hard to start... just wanna catch any bugs before something gets bad.

[fatboy95]

pull valve covers and glow plugs special fitting required and disconnect the idm so it wont start on crank.

[nccatfan]

Hmm, Anything I can do that would be less involved? Would a cylinder contribution test tell me anything? This is my daily driver at the moment... I'd REALLY hate to disable it while I find the tools to do this.

compression test will be the best thing to do if you want, my 02 blows quite abit of smoke out of the filler. the tech at the local dealership (he is a good guy and has done alot of work for me, one of the better techs i have worked with) said it was an excessive amount, i did a compression test and it was in the "new" specs of 375+ PSI

[nccatfan]

So I may actually be ok? If your compression comes back ok what else would it be? I'm just seeing worst case scenarios where I end up pulling pistons! That would SUCK!!

[nccatfan]

Has the blowby tube in the driver side valve cover ever been known to clog? Surely some seal would have blown by now if that were the case?

all diesels have blow by, some are worse then others. on my big rigs the blow by is so bad that if you dont thread the dipstick in, it will blow it out and blow oil out by the quart

[nccatfan]

222,xxx miles on this truck when I bought it, and I KNOW there was a fair amount of pulling done with it. That's where I'm imagining some higher heat could cause cracked pistons or bad rings. Maybe I'm just panicing... like I said, she runs good. Anyways, I looked at the same thing on a '00 F250 from work (90,xxx miles) and NO smoke from filler neck.

[nccatfan]

Originally Posted by wriott

all diesels have blow by, some are worse then others. on my big rigs the blow by is so bad that if you dont thread the dipstick in, it will blow it out and blow oil out by the quart

Yeah, I've actually seen that too... never thought much of it before. Wonder how much Scott (host of SSS) would charge me for a compression test? Does yours still smoke? How long has it been doing that?

yup mine smokes and it has been doing if for as long as i have had it (3 years)