Oil consumption
Thread Starter
TECH Junkie
Joined: Aug 2006
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From: Western North Carolina
Oil consumption I did a search but the results were messed up today. I'm sure it has been discussed to death but would like to hear about experiences with oil consumption. I have a very low mileage 'stock LS1 that burns about 1 quart every 1,000 miles. No leaks, clean exhaust, etc.. How does this compare to your similar 'stock' LS1??
I've been running 0w30 and 5w30 castrols for the last 30k miles in my car (currently 120k miles) and never had to add more than a quart or two for every 5k miles between changes. then recently I noticed my PCV system was basically completely clogged with oil condensation crap so I replaced the entire system and now I lose probably twice as much oil.
Thread Starter
TECH Junkie
Joined: Aug 2006
Posts: 3,919
Likes: 676
From: Western North Carolina
Just the opposite. The car is a weekend cruiser and car show attendee. Only 23,000 miles. I really just noticed it when I went to the Charlotte Auto Fair and back last weekend. About 450 miles total and it used 1/2 quart. The owner's manual says 5w-30 or 10w-30 and I don't think I want to go heavier if it doesn't call for it.
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As above, the root of most oil consumption is the way the PCV is setup on these motors. Valve seals are possible, but I think you might notice a little puff of smoke on startup if that were the case.
So was it really 1/2qt in just 450 mi, or do you mean you noticed it after you checked it on that trip?
At any rate, some people do have luck switching oils whether it be slight viscosity change or even brand change. I understand what you are saying about the recommended viscosity, and I somewhat agree with you. The German Castrol 0W-30 has a good viscosity index and a little more robust HTHS than most 5W-30's. It will not be too thin at any temperature. In fact, with a good synthetic from a good base stock there is almost no reason not to go with a 0W if available. Not that it is an exact science, but there have been a large number of use oil analyses done by members running GC 0W-30 and they seem to be for the most part good. Now as to whether or not it will cure your oil consumption I cannot say.
I personally have been running Pennzoil Platinum 5W30 and lose maybe 1/2 to 1 qt per oil change interval. Mine aren't fixed, I just go by the oil life monitor (or 6k mi if it hasn't gone off). I still have the stock PCV type system, but I do have LS6 heads and cam... doubt that would really make much of a difference though.
So back to switching from 5W30 to a 10W30, it might not guarantee any difference in consumption. It depends on what base stock they are using and how much and what type of viscosity index improvers are in the oil... so just going to 10W30 may or may not give you an oil that will be consumed less. But ultimately the main driving force is probably just sucking the oil out through the PCV and marginally different oil specs may or may not make much of a difference.
Just the opposite. The car is a weekend cruiser and car show attendee. Only 23,000 miles. I really just noticed it when I went to the Charlotte Auto Fair and back last weekend. About 450 miles total and it used 1/2 quart. The owner's manual says 5w-30 or 10w-30 and I don't think I want to go heavier if it doesn't call for it.
At any rate, some people do have luck switching oils whether it be slight viscosity change or even brand change. I understand what you are saying about the recommended viscosity, and I somewhat agree with you. The German Castrol 0W-30 has a good viscosity index and a little more robust HTHS than most 5W-30's. It will not be too thin at any temperature. In fact, with a good synthetic from a good base stock there is almost no reason not to go with a 0W if available. Not that it is an exact science, but there have been a large number of use oil analyses done by members running GC 0W-30 and they seem to be for the most part good. Now as to whether or not it will cure your oil consumption I cannot say.
I personally have been running Pennzoil Platinum 5W30 and lose maybe 1/2 to 1 qt per oil change interval. Mine aren't fixed, I just go by the oil life monitor (or 6k mi if it hasn't gone off). I still have the stock PCV type system, but I do have LS6 heads and cam... doubt that would really make much of a difference though.
So back to switching from 5W30 to a 10W30, it might not guarantee any difference in consumption. It depends on what base stock they are using and how much and what type of viscosity index improvers are in the oil... so just going to 10W30 may or may not give you an oil that will be consumed less. But ultimately the main driving force is probably just sucking the oil out through the PCV and marginally different oil specs may or may not make much of a difference.
Thread Starter
TECH Junkie
Joined: Aug 2006
Posts: 3,919
Likes: 676
From: Western North Carolina
Thanks for all the replies. I am going to start simple and replace the pcv valve. Now I have to figure out where it is. I just looked and too many hoses, etc... Anyone have a diagram with an arrow pointing to it?
If you don't know where your PCV valve is, I'd bet its very old and not working for you correctly. (Lube places won't change it typically.) GM has a TSB out for oil consumption on our cars if your PCV doesn't change things. (attached)
Thread Starter
TECH Junkie
Joined: Aug 2006
Posts: 3,919
Likes: 676
From: Western North Carolina
Again, thanks for the replies and the diagram and assistance. My local GM dealer did not have one in stock so I ordered one at a total cost of $7.94. If I knew they were that inexpensive I would have just changed it for grins a few years ago. I'll keep you posted. It should be in tomorrow. Once I see what it looks like I shouild be able to figure out where it goes.
Again, thanks for the replies and the diagram and assistance. My local GM dealer did not have one in stock so I ordered one at a total cost of $7.94. If I knew they were that inexpensive I would have just changed it for grins a few years ago. I'll keep you posted. It should be in tomorrow. Once I see what it looks like I shouild be able to figure out where it goes.
I think the last time I bought one it was less than $1 on sale. Any auto parts store should have them. 
Thread Starter
TECH Junkie
Joined: Aug 2006
Posts: 3,919
Likes: 676
From: Western North Carolina
Well, I did it. A big thanks to all 
. This place is great for assistance and it is appreciated.
When I removed the old PCV valve it really stunk of oil and was much 'heavier' than the new AC Delco. I could hear it rattling but Lord knows what the inside looked like. It felt as though it was saturated but I have no idea. I cleaned the inside of the hoses before connecting the new one. Not too bad overall. We'll see what this does. Hopefully it will improve the oil consumption a bit.
. This place is great for assistance and it is appreciated. When I removed the old PCV valve it really stunk of oil and was much 'heavier' than the new AC Delco. I could hear it rattling but Lord knows what the inside looked like. It felt as though it was saturated but I have no idea. I cleaned the inside of the hoses before connecting the new one. Not too bad overall. We'll see what this does. Hopefully it will improve the oil consumption a bit.
