What causes blowby?
What causes blowby? The past year I have had breathers only on the car, no pcv valve, and the last few months, oil would be pushing out of the breathers bad. Burnt oil smell above 4k rpms, blowing oil, and even blew the dipstick out on the dyno. When I had the compression check done at a shop, they put a PCV valve back in, but it’s not hooked up exactly like factory spec (or so how I remember it was). Car holds idle a lot better now (more vacuum I guess), but oil can still be smelled when getting on it, just not quite as bad.
I am assuming its rings that are leading to excessive crank case pressure, but I am not sure. I did a compression check, and that turned out fine, 150 psi in all cylinders, except for #7, which had 145. Leak down test next? Thoughts, inputs?
I am assuming its rings that are leading to excessive crank case pressure, but I am not sure. I did a compression check, and that turned out fine, 150 psi in all cylinders, except for #7, which had 145. Leak down test next? Thoughts, inputs?
TECH Enthusiast
Joined: Apr 2002
Posts: 537
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From: Lehighton Pa
The past year I have had breathers only on the car, no pcv valve, and the last few months, oil would be pushing out of the breathers bad. Burnt oil smell above 4k rpms, blowing oil, and even blew the dipstick out on the dyno. When I had the compression check done at a shop, they put a PCV valve back in, but it’s not hooked up exactly like factory spec (or so how I remember it was). Car holds idle a lot better now (more vacuum I guess), but oil can still be smelled when getting on it, just not quite as bad.
I am assuming its rings that are leading to excessive crank case pressure, but I am not sure. I did a compression check, and that turned out fine, 150 psi in all cylinders, except for #7, which had 145. Leak down test next? Thoughts, inputs?
I am assuming its rings that are leading to excessive crank case pressure, but I am not sure. I did a compression check, and that turned out fine, 150 psi in all cylinders, except for #7, which had 145. Leak down test next? Thoughts, inputs?
What year car? Miles? How exactly is the pcv system setup?
I think you should address your Pcv issues first, but blowing the dipstick out isnt a good sign, kinda surprised that you didnt blow oil out of the rear seal.
You are correct, usually blowby is an indication of worn rings. Pretty typical with a LS1. Your compression is still decent. Slap an oil catch can on that bad boy and keep on truckin'.
That is one thing I am worried about, and need to check next time the car is jacked up. Oil out of rear seal would be bad. 99, 103k miles. H/C set up for about 20-30k miles. PCV set up is driver side valvecover breather, PCV is there, hooked up to the TB. I'll try to find a camera and snap picstures today after work and get them posted on here so you can see. From what I remember the stock PCV looking like, the valve was on the passenger side. My passenger side breather is still there, just the driver side is now replaced with a PCV.
The past year I have had breathers only on the car, no pcv valve, and the last few months, oil would be pushing out of the breathers bad. Burnt oil smell above 4k rpms, blowing oil, and even blew the dipstick out on the dyno. When I had the compression check done at a shop, they put a PCV valve back in, but it’s not hooked up exactly like factory spec (or so how I remember it was). Car holds idle a lot better now (more vacuum I guess), but oil can still be smelled when getting on it, just not quite as bad.
I am assuming its rings that are leading to excessive crank case pressure, but I am not sure. I did a compression check, and that turned out fine, 150 psi in all cylinders, except for #7, which had 145. Leak down test next? Thoughts, inputs?
I am assuming its rings that are leading to excessive crank case pressure, but I am not sure. I did a compression check, and that turned out fine, 150 psi in all cylinders, except for #7, which had 145. Leak down test next? Thoughts, inputs?
