Cucv m1008 blow by

[crownjewel4]

Have a 1986 M1008 with what looks like a new 6.2L engine.
Once it warms up has blow by, (smoke), coming from oil cap. Can anyone tell me what causes this? and if there is any simple fix.
The truck runs great, lots of power, starts right up etc...

Any help is appreciated.
Thanks,

 

[2002ford]

Does it smoke out the exhaust while you drive it? They all have a little smoke that come from the oil cap if it is removed. If you follow the rubber tube off the oil fill pipe to the side of the intake you will see a big round object called the CDR Valve. The cdr is then routed back into the intake to re burn the smoke. Check your intake for excessive amount of oil in it. If it is not smoking while you drive it you will be fine. If it smokes like a freight train while driving it you have an issue with the valves or piston rings. Hope this helps.

 

[timarr]

Also the system is like a sealed unit if you have the air cleaner top off the blowby is greater. Just make sure everything is fitting right and as 2002ford stated if nothing out of the tailpipes drive and enjoy!

 

[crownjewel4]

Thanks @ TIMARR and 2002FORD.
I did change the CDR valve over the weekend, it got a little better. Some smoke out tail pipes on cold start, otherwise no when warmed up. When warm it does push some smoke through oil fill tube. Runs great, no power issues. Thanks again..

 

[crownjewel4]

Any other quick tips or additives that would help?

Thanks,

 

[Warthog]

One of the best things for any diesel engine is to take it out run it fairly hard. Let it warm up fully.

 

[2002ford]

I wouldn't worry about it. Drive it and enjoy it. Use quality oil when changing oil and dong over rev it and you will get years of service out of it.

 

[cucvrus]

I have a CUCV M1009 that seems to have a lot of blow by at idle. The engine runs fine and the blow by is visible at the dip stick at idle and the oil cap. It disappears after you accelerate it a bit above idle. I will change the CDR valve but I think this has a lot of blow by. I can smell the clean oil when I take the cap off and it has a light shadow around the cap when it is on and idling. Same goes above idle it is gone. I ran this CUCV hard a few days back and it runs fine. It has a tick in the valve train somewhere and that is what lead me to open the hood and look at the engine. I changed the oil and it has great power. Starts right up so I am thinking maybe a bit tired or has some other issue. Any ideas?