air bowing out oil fill

[deepseeman]

So this morning while my truck was idling I noticed a bit of milky oil on the top rim of my oil fill. I took the cap off and was surprised to find air blowing out of it. Is this normal? If not, what could it be?

 

[kenz5380]

Sounds like you've either got a lot of blow by in a worn out lower end of your engine, or a stuck cdr valve, or both. I'd change out the cdr and see what happens. They're about $20 or $30 on ebay.
Not a pro, but that is my 2 cents.

 

[Matt65]

When you shake the oil fill cap it should rattle. If not, soak and clean. Is your CDR valve in good condition? I soaked both the filler cap and CDR valve in Carb Cleaner and have had no problem. There was a lot of Contamination in the CDR Valve.

 

[combatmech]

Are you getting any valve train noise during accleration?

 

[doghead]

Isn't the purpose of the CDR to pressures the base?

 

[deepseeman]

Cdr was replCed a year ago and yes I believe I have valve train noise. Could it be a head gasket as well?

 

[epartsman]

Cdr was replCed a year ago and yes I believe I have valve train noise. Could it be a head gasket as well?

If the oil is milky ie water in the oil I think you have a blown head gasket or a cracked head.. Get a pressure tester and test the cooling system at the radiator. Sounds like time for a rebuild if it doesnt hold pressure or if there is water in the oil (oil looks like foamy chocolate milk). Good luck.

 

[combatmech]

Dont want you to worry needlessly, most if not all 6.2's are noisy in one way or another. I'd ckeck the oil as well....

 

[deepseeman]

a little history...the head gaskets have been done twice over the past year. never these symptoms though. I am losing coolant. i was told that it might be the timing chain cover seal. is this true?

 

[ryan77]

If your head gasket was done twice your head is probably warped and causing it not to seal proper and blow, Headgaskets should last 150,000 miles!!!! Were the heads machined and the block checked when u did the gaskets???

 

[deepseeman]

the first time the mechanic used a cheap aftermarket seal kit. heads were machined and block was checked out. used felpro kit second time around.

 

[southdave]

is it parafine, sorry , is wax like substance?

 

[deepseeman]

is it parafine, sorry , is wax like substance?

parafine?

 

[deepseeman]

ok. so its the head gasket AGAIN! here are a couple of newbie questions;

what head gaskets do you guys recommend?

do I need to replace the head bolts each time?

is there anything out of the ordinary that I should look at?

 

[ken]

I have good service from fel-pro. I strongly recomend you replace the head bolts. They will and do strech. But before you pull the heads grab a tourque wrench and retourque them. See how much they have streched. You might get lucky and get them to seal. If so. Replace the bolts with out pulling the heads.

 

[DriverSideImpact1008]

Check and test everything before you jump to conclusions. None of us here can tell for sure what it is.

Is all the oil milky or was there just a little gunk on the rim of the oil fill?
Sometimes if the temperatures change a lot, just humidity in general, or from lots of short trips condensation can form and cause a little waxy/milky gunk that builds up on the oil fill. It happens to my mom's Beetle, and my buddy's Xterra.

Also, check the coolant. Is there oily film/black spots in there?

I would definitely run an engine compression test and pressure test the coolant system. Before just hauling off and doing head gaskets.

To answer your questions, Fel-pro are good quality gaskets and yes always replace head bolts with a head gasket.

 

[ryan77]

Always use new bolts! Use arp head bolts and felpro gaskets! Have heads rechecked and block! U might have a cracked block! I would junk the motor and get a surplus 6.2 hummer motor and be done with it!

 

[deepseeman]

Always use new bolts! Use arp head bolts and felpro gaskets! Have heads rechecked and block! U might have a cracked block! I would junk the motor and get a surplus 6.2 hummer motor and be done with it!

thats what I am considering. weighing the costs now. any hot tips on where to find a good used motor? Im in San Diego and there arent many cucv's here.

 

[southdave]

Paraffine.. Cheap oil is what based on that. along the lines of what DSI1009 was saying it cooks off and separtates it is white... blown head gasket always seam more like coffee with cream not white.
as for cucv 6.2 I would stay away from them.. the 6.2 was vastly impoved in 1989 and 1990.
as where the pumps ect.. 1993 clean air act was the first reformulated diesel and the begianing of pump issue.. Parts for the CUCV furnish 5 years all cucv where moreless 1983 ect.. More or less the part per contract ran out about 199? There is TM around about the 6.2 6.5 that may help you form an opinion. I would get 6.2 in a can buy a re ring kit send the heads out and go from there.. look for block made around 92-93 they have more metal in them and are less likely to crack..