Engine/Transmission (1994 - 1998) So how much blowby is normal?

[Johnstra]

Ok, so I've been reading blowby threads and now I'm beginning to worry. How much blowby is normal? My truck when idling emits a fairly steady flow from the breather hose. It doesn't pulse noticeably, but it's a pretty decent fog of vapor coming out. I don't ever notice any oil on the underside of my truck so I don't think there's much if any spray. Overnight I always get a few drips out of the hose. My engine has 150k miles on it, it's been well maintained, and it was totally stock up until I bought it this summer. The only thing I've done to it is install an AFC spring kit and slide the stock plate about halfway forward and slide the AFC housing all the way forward. What do ya'll say. Am I being paranoid or should I get a crankcase pressure test?



Thanks,

-john

 

[tp0d]

Probably paranoid...



My breather hoses down everything under and behind it, and my truck runs fine. . A thin fog at idle and 1200 rpm is all thats there, pretty normal i think. I have 157k now, and almost the same fuel mods as you, cept I ground my plate to a approx #10.



I wouldnt worry about it, its a good rust protector heh



-j

 

[Shell 96]

mine does the same thing with 225k i consider it normal, however my cousins truck will move the dipstick off its seat when you get on it but still runs strong with 260k.

 

[Vaughn MacKenzie]

Does it use much oil John?

 

[Johnstra]

Vaughn,

No appreciable oil consumption, but... I've only put 5000 miles on the truck since I bought it in July and I immediately ran 2 Auto-RX cleaning cycles. Those were both 2000 mile intervals with an oil drain at the end, so I haven't run any interval longer than 2000 miles yet. I'll be watching closely as my next oil change will be at 5000 miles. I'll have a better idea then if it's using oil.

-john

 

[Vaughn MacKenzie]

John mine goes through some strange stages. Sometimes it uses oil, sometimes it doesn't.



Ever since I bought my truck last year it's used 2-3 quarts every 5k, but last winter consumption went WAY up and it blew through a quart every 300 miles. It sprayed oil specks all over the back and quite a bit of oil underneath. Then strangely it went away and didn't hardly use a drop of oil in 3000 miles. Lately again it's started using oil, about a quart every 1200-1500 miles.



I don't have a lot of vapor out the tube, and every night I get a spot between the size of a dime and a half-dollar on the driveway.



Last year I did do a blowby test at 352k and the numbers matched that of a newer engine. Checked compression at 356k, had 500+ psi per cylinder.



Vaughn

 

[vssman]

Mine put out a decent constant fog out of the tube too. It also will leave a drip mark overnight. I have 74k on the clock so I'm taking it as normal.