ive seen new GM engines do this and they werent under boost

 

do what?

 

Yessir.

 

The bulletin I have just said to replace the PCV valve? Didn't know there were more steps. It didn't whistle until I installed the catch can, it was the combo of the two that caused the whistle (the fixed orifice PCV by itself was quiet). FWIW, I got the same amount of oil in the catch can with either PCV valve.

If you could elaborate on the other steps of the TSB I'd greatly appreciate it

(sorry about hijacking your thread Zick)

 

Eh, no problem. I'd like to hear more about this as well.

 

consume oil thru the pcv

 

TECHNICAL
Subject:
Higher than Expected Engine Oil Consumption
(Replace PCV Valve)

Models:
2002 Chevrolet Avalanche
1999-2002 Chevrolet Silverado, Suburban, Tahoe Models
2002 Cadillac Escalade, Escalade EXT
1999-2002 GMC Denali, Sierra, Suburban, Yukon Models
with 4.8L, 5.3L or 6.0L Engine (VINS V, T, N, U - RPOs LR4, LM7, LQ9, L04)

This bulletin is being revised to clarify the parts information. Please discard Corporate Bulletin Number 01-06-01-029A (Section 06 - Engine/Propulsion System).

Condition

Some customers may comment on higher than expected engine oil consumption. They may further comment on consumption in the range of 3,200 km (2,000 mi) or less per quart (0.946 liter) of oil under normal driving conditions.

Cause

The condition may be due to the positive crankcase ventilation (PCV) valve flow rate under certain engine operating conditions.

Correction
1. Verify that the oil consumption is not the result of an oil leak or other engine concern.

2. The dealer should perform an oil consumption test. The vehicle should have accumulated over 6,450 km (4,000 mi) before establishing the oil consumption rate. Reference Corporate Bulletin Number 01-06-01-011, Information on Engine Oil Consumption Guideline, for details.

3. Remove the PCV valve and inspect the hose going to the intake manifold for signs of excessive oil being present.


4. If excessive oil is present in the PCV hose, replace the PCV valve (Type 948C) (2) with a new-style fixed orifice PCV valve, GM P/N 12572717 (1). See the illustration shown.

Important: The new style fixed orifice PCV valve contains no moving parts, and does not rattle when shaken.

If the vehicle has an orifice style PCV valve, investigate other causes for high oil consumption.

 

gm put out four bulletins on this that i can find, but for some reason my link to tis isn't working 01-06-o1-029 29a 29b and 29c. The first two exclude the 4.8l because it will make it have poor idle quality and whistle. It also did the same thing to some of the 5.3L but not all. What I did was a service procedure under bullitin 02-06-04-054b whenever I installed the new pcv on 4.8s or 5.3l. It is actually for a sticking tb plate you replace the pcv with fixed oriface style, plug the hole in the throttle plate and open up the minimum air rate a specific amount using the scan tool and tps voltage. When I went to the hands on school in Dallas we talked about this procedure and I was under the impression gm was going to revise the bulletin again. When I said you didn't follow all the steps I was thinking of the wrong bulletin. Sorry for the misinformation I really think you should switch back to regular 10w30 untill you get about 10k on it.

 

Here is a question for you guys. Do you guys have a lot of vacuum at your oil filler cap? I took mine off and it feels like a damn vacuum cleaner. If I disconnect the rear driver side pcv line it will be normal and that line has a ton of vacuum on it.
I'm wondering if I'm getting too much vacuum and it is still sucking oil up into the intake.
I took off the filter on my catch can and there is barely any oil sitting in the bottom.