Greetings All -

I recently purchased a 2001 WS6 manual car with about 72,000 miles. Essentially bone stock. Physical condition and documented history indicates it was well taken care of. So before I start putting $$$ into it to freshen up the motor and do some basic performance add-ons I'd like to ascertain if the car has any underlying, serious issues.

While I've learned from this thread that oil consumption is a chronic issue with the Gen 3 LS1 - oil changes and maintaining a seemingly healthy oil level over the life cycle of Mobil 1 5w-30 ( which I figure should be good for AT LEAST 4,000 miles before breaking down ) has me concerned about the health of my engine. I checked my level the other day after letting the car sit overnight - I'm about 2800 miles into my most recent Mobil 1 oil change (5.5 qts) - and the dipstick read out came in just below the hash/cross section ...

First question, please - is the hash/cross section on these dipsticks representative of approx 1 quart of oil ( so if the reading were at the bottom of this section, you could safely say your level is at least a quart low ? )

Burning a whole quart in less than 3k miles on a car that isnt driven hard or has high mileage seems very suspect to me. I added 1/2 a quart and it brought the level back within the hash/cross section for now, but I'll be damned if this thing doesn't produce inconsistent readings under the same testing conditions i.e. level ground, sitting overnight to allow for everything to drain back down and settle in the pan.

Some additional info:
1) there are no major leaks to speak of
2) no smoke
2) I replaced the PCV valve as I know this system inherently allows blow by, but the lines and throttle body are pretty clean. From what I can see inside the intake, there is a light oily film but I'm told that is normal ...
3) despite the low level reading, my oil pressure pressure gauge is always pretty high from what i can tell from other's accounts - between 50 & 70 at idle and heavy load
3a) I know these gauges are often inaccurate and the sending units also go bad - but still a concern I would think

I've never had this much difficulty trying to maintain an accurate oil level / or measure excessive oil consumption on any car I've owned, including several 3rd gens and one LT1 car.

I really appreciate any advice/feedback. Sorry to inquire about something so rudimentary, but I am genuinely concerned. Took me a long time to get this car and naturally I want to ensure I'm doing everything to keep her in good health!

Thank you in advance!

 

Put a catch can on it.

 

@RB04Av - appreciate the response, however a catch would merely mitigate the amount of oil blow by from the PCV system to the TB and Intake manifold, correct? and even in severe cases this wouldn't amount to a full quart over the course of 3k miles, would it?

I'm searching for / would greatly appreciate a comprehensive assessment of whether or not the oil consumption timeline and approximate amounts I described above is considered "normal" or "acceptable" for a healthy LS1.

And if what I described is, in fact, cause for concern - suggestions on where or how to begin a deep dive diagnoses to determine root cause.

Obviously, I'm very unfamiliar with the power plant, and like I said, I'd like to ensure I'm doing all the right things as far as preventative maintenance OR catching serious issues before they cause permanent damage.

I'd sincerely appreciate further thoughts / opinions / analysis.

 

I had a 2000 M6 Trans Am I never babied it or called it her and I was still usually a quart low after 3,000 miles. Your car should have come with the Ls6 intake, but I am unsure if it came with the Ls6 valley cover. Either install a Ls6 valley cover with the pcv on it and a catch can or just do the catch can. No matter what route you take stop calling IT her.

 

Thanks for the recommendations @91LS1T56 - so in your experience, 1 qt consumption over 3k is fairly commonplace and not imminent cause for concern? Make the adjustments to valley cover, PCV, catch can where applicable and let it ride?

 

That was about right, I was running mobile1. I would change my oil every 3,000 to 3,500 miles. I also drove the car a good amount, I put 75,000 miles on in 2 1/2 years. When I did eventually take my intake off it had a large amount of oil in it, probably a quart or close to it. My block required some grinding for the valley cover with the pcv to fit.

 

Catch can is a common need even for newer motors of this type. Not sure why, it just seems that it is. And I agree, 3k miles per quart is well within the "normal" range. My truck with 230k on it - it has a 5.3, which is the same basic motor, just a smaller bore - goes through about that much.

Obviously if the can catches lots of oil, then where it's been going, is through the PCV. If it's not too terribly funky with water and fuel vapor (depends on how you drive the car... lots of short trips in the cold will do that) you can just pour it back into the motor.

They've improved the PCV system over the years; better baffles in the valve covers, the LS6 valley cover with a MUCH better baffle http://rpmspeed.com/product_info.php...ts_id=23454668, etc. But, once you get a handle on where the oil is going, you can make decisions about upgrades to things like that, if you want.

 

The pcv ports on the rear of the valve covers is in my opinion the contributing factor. Under acceleration the oil gets forced to the back of the heads. I am sure it comes out of the pushrods with enough force to get behind the baffling as well. Also being in a state of heavy mist and or vapor it will collect in the mile long pcv tube and return to a more liquid state before being sucked into the intake. When that oil and vapor go down through the drain holes in the head and then back up into the valley area where the ls6 pcv is located, it is a lot like the trap of a catch can. I personally have the ls6 setup on my engine with plans to install a catch can in the future. I believe either method is a step in the right direction and both would be best.

 

Back in the day, GM considered 1 quart in 1000 miles normal for the LS1

 

The rest of us have NEVER considered that much consumption "normal". Not for ANY motor. Not even back in the 60s when the warranty was only 12k miles.

In GM's case, what that REALLY meant was, "we're not going to do a damn thing about it unless it exceeds 1 qt / k, so get your ancient sludge-covered filthy road grime covered hooptie with 10k miles on it already out of our NEW CAR dealership". Which is a VERY DIFFERENT THING from anything WE'RE talking about here.

 

file:///C:/Users/CLASSI~1/AppData/Local/Temp/01-06-01-023A.pdf

After my car was modded I would check the oil every time before I drove to make sure it was topped off. As the gm bulletin states, 1qt in 400-600miles, with my modded car and how i drove it, those numbers seem about right. I had the catch can, at least you can stop most of it from going into your intake with one. Not sure if the oil rings and engine valley cover was truly the fix. Pretty sure there was reports of the issue even after the new parts. But we do know 98 and 02 Camaro-Firebird didnt seem to have the issue as bad as the 99-01 cars. We also were told or found out somehow, (I dont remember it was so long ago) that the 98 and 02 cars were built with different oil rings from factory which is probably why they were not included in the bulletins.

 

If you conclude you have pcv issues, you might look at the adjustable pcv by M/E Wagner.

 

Regarding big oil loss, recently, the car developed a P0153 Bank 2 Side 1 O2 slow response, with bad gas mileage. After doing some swapping of O2s, O2 extensions, and inspection of headers, etc, I noticed that the intake man bolts were very loose (<35-40 in lbs), in some cases, especially the pass side (Bank 2). I recall someone, long ago, commenting about the intake gaskets compressing over time. After re-torqueing to specs, the same problems persist. At about the same time, after hardly ever losing a drop of oil, I'm suddenly losing 1/2 quart, quickly. The engine has a catch can, and it hardly ever had more than a few drops in it, and virtually no oil in the intake. The LS1 has been driven 25k miles over 8 years. After removing the intake, it is obvious that the gaskets need replacing, as they are completely flat, and no amount of re-torqueing will help. There is evidence of oil leaking around the gaskets to the outside. Looking into the intake runners shows a small puddle of oil sitting on the downward side of each valve. I'll let you what develops after the intake gaskets are replaced.

 

Appreciate the follow up posts and insights from every one on their respective experiences / setups / applications. Sounds like I'm in store for a lot of trial & error / process of elimination - but I certainly have a better idea of where to begin. Thanks again all.

 

I'll tell you where its going and that's through the tailpipe. Its being introduced by way of the intake manifold and being filtered through the catalyst and by the time it makes to the end of the pipe you don't see it. Now a catch can will help some but I'm sure is getting past the rings and you may see some signs of this on the spark plugs. It's probably not noticeably enough to indicate that you have a ring issue yet but as time goes on you may run into a catalyst issue a/k/a clogged cats and those will need to be replaced.

 

Have you ever done a compression and leak down test on the motor?