Do big block Chevy motors not like synthetic oil?

[Dogmeat]

I bought a 2005 8.1L last November ... I've put about 10,000 miles on it so far.

I'm on my third oil change with synthetic Mobil 1 5W30 ... the last two oil changes I've done, my "Check Oil Level" light has come on about 3,000 miles in even though my oil life indicator still read like %60 or so ...

My question is, do the BBC motors just not like synthetic? I ran Mobil 1 5W30 for nearly 250,000 miles on my last two vehicles combined and neither one of them ever burned a drop of oil ...

Any thoughts?

 

[dangerfield]

Check Oil Level, has nothing to do with Oil Life Remaining. If Check oil is showing up, it's low, either leaking or burning. Couldn't tell you if they like synthetic or not.

 

[AZ800]

Can't say about a BB Chevy, but I had an 01 Dodge 5.9 gasser. Ran synthetic, mostly Mobil 1, just so I didn't have to change the oil as often. Tried Amsoil in it and it went from using a qt every 5000mi or so to about a qt every 2500mi. Thought it was a fluke, ran Amsoil again, same results, back to mobil 1 = less oil usage.
Try a different brand or weight of oil and see what that does. Most other vehicles I've had, brand of oil made no difference in consumption, but my DMax seems to drink Delo faster than Rotella, now I stick to Rotella.

 

[Dogmeat]

Sorry, should have clarified ... I just said the engine oil life meter was still at %60 to show that I hadn't really been stressing the truck that badly and it was still using oil ... That oil life meter takes into account cumulative engine load (I think) ...

Either way, I have been towing with this truck quite a bit, but not more than about 4,500 lbs ...

But yes it actually IS losing oil ... I check the dipstick and it's a quart low when the "Check Oil Level" light comes on.

 

[ruffryder]

Sorry, should have clarified ... I just said the engine oil life meter was still at %60 to show that I hadn't really been stressing the truck that badly and it was still using oil ... That oil life meter takes into account cumulative engine load (I think) ...

Either way, I have been towing with this truck quite a bit, but not more than about 4,500 lbs ...

But yes it actually IS losing oil ... I check the dipstick and it's a quart low when the "Check Oil Level" light comes on.

I would take a look at your coolant, maybe have it tested along with your oil to see if it is head gasket problem or something else. If you are not burning it, it has to go somewhere. Any large oil slicks after you have parked for a while?

 

[Dogmeat]

I would take a look at your coolant, maybe have it tested along with your oil to see if it is head gasket problem or something else. If you are not burning it, it has to go somewhere. Any large oil slicks after you have parked for a while?

Haven't noticed any but then again I haven't been paying attention ... doesn't seem like it's dripping any though.

If it's a problem I'd like to get it figured out while this truck is still under warranty

 

[markgyver]

Ive had several 8.1s they seem to use about a quart in 3000 miles.

 

[dangerfield]

I would take a look at your coolant, maybe have it tested along with your oil to see if it is head gasket problem or something else. If you are not burning it, it has to go somewhere. Any large oil slicks after you have parked for a while?

I'm not going to say it's impossible, but I have never seen oil going into the coolant, seen coolant going into oil numerous times, but never the other way around.

 

[Vern]

from what i have heard its a common thing for chevy big blocks to use a bit of oil. ive also heard its caused by the intake gaskets leaking a bit but not sure. i know my brothers 03 8.1 usually uses about a quart between oil changes and he uses non-synthetic 10w40.

 

[ruffryder]

I'm not going to say it's impossible, but I have never seen oil going into the coolant, seen coolant going into oil numerous times, but never the other way around.

They both get mixed up a little if you have a head gasket failure in between the engine cylinder and a water jacket.

 

[milehighassassin]

I don't think it has anything to do with the oil itself. Get the oil analyzed and see what is happening with the internals (it will cost you <$20).

I have a BB 472 that I run synthetic in with no problems. The synthetic should be a better oil assuming you are using a quality brand.


How far apart are you oil changes? A quart an oil change is not too bad. You will burn more oil on a fresh engine.

 

[hilinerider]

your synthetic might be doing bad things to your intake valve seals or you have an intake gasket leak, problably valve seals, if you pull the plugs and they are black and have deposits that be my guess,

 

[milehighassassin]

your synthetic might be doing bad things to your intake valve seals or you have an intake gasket leak, problably valve seals, if you pull the plugs and they are black and have deposits that be my guess,

Sythetic oil will not be ANY different on seals or gaskets than a regular dino oil.

 

[Blu Du]

those 8.1 are oil burners for sure! me and a buddy both had em, Gm says 1 qt. low at 2000 miles is normal

 

[switchback]

The 8.1 will use oil, no big deal. Some prefer an engine that uses a little. The oil life monitor does not sense or test anything. It simply a timer type setup.

 

[Wildcat]

The oil life monitor does not sense or test anything. It simply a timer type setup.

This is where you are wrong. The GM Oil Life System tells you when it's time to change your oil, based not only on your driving patterns and mileage, but also things like the climate of your area. This means that changing your oil every 3,000 miles may no longer be necessary.

 

[Wyoming T/A]

ran ams oil in my 2001 8.1 chev, no problems

 

[Blk88GT]

What happens when you run a thicker oil? Worth a test. If you're towing frequently, the 5w40 is likely not the best choice. I run 0w40 in the winter in my diesel, and it uses a bit but nothing like that, even in twice the mileage.

Why have you changed synthetic oil 3 times in 10k? Get your oil analyzed by someone like Blackstone Labs. I push 8k miles on a synthetic change, towing included and they suggest trying for 8500 next time.

 

[catssuk]

ive had a 2001,02, 03 ,8.1liter hd 4x4 gm trucks. they all used about a quart of oil every 2200-2700 miles. sold the 01 with 260k trouble free miles on it. only used whatever was on sale 10w-30 oil, those engines use a little oil ,with no smoke at all, and are bullet proof. ive never had an engine problem with a gm 8.1, and have over 400k miles on the ones i have owned.

 

[carguy]

The The oil life monitor does not sense or test anything. It simply a timer type setup.

Agreed! Oil life monitors are for those who just know to turn the key to get the vehicle to go. They are a waste of time imo.