What would be considered "Normal" oil consumption

[jgillott]

Vehicle in question is my 2010 1/2 ton 4.7L V8 with approximately 83K on it. For the first 75,000 miles or so, the oil level wouldn't budge over an oil change cycle (approx every 5000-6000 miles based on the change indicator light). I've used Mobil 1 5w20 and Mopar or Napa Gold filters since new.

Over the last few thousand miles, I've noticed it starting to use maybe 1/4-1/3 quart every 1000 miles. Not a drastic amount by any means, but just more than it ever did before. Truck doesn't leak anywhere, runs great, no noticeable smoke etc. I'm not in a panic by any means and I certainly understand a little oil usage as the truck gets more miles on it. However, I was wondering what would be considered normal oil consumption in a small gas V8 with that mileage? I apologize for asking. It's just been a long time since I've had a gas powered vehicle with that many miles on it.

 

[TFucili]

Good question. I haven't had an engine that used oil since we had two 6.9 Fords that used oil like mad(about a quart per 400 miles), one from new and the other soon after. My very general rule of thumb would be if it gets much beyond a quart beyond change intervals. Even then, I'd consider it a bad sign, but not be in a rush to tear into it. Any indication of crankcase ventilation issues?

 

[RustyJC]

I don't think 1 quart every 3000 to 4000 miles is alarming on a higher-mileage engine, but I'd be more concerned if it went from zilch to using oil at these levels all at once - in other words, a step change in oil consumption. A step change like this normally isn't associated with progressive wear but rather with failure of a component such as an oil ring, a valve stem seal, etc. If the engine has a PCV valve, it might be worth changing it out.

Years ago I had a 1993 2.5L 5 cylinder Volvo 850GLT that used 1 quart every 2500 miles from the day it was new. I kept waiting for it to dry up, but it never did - it still used the same 1 quart every 2500 miles when I traded it at 85K miles. Unless usage was greater than 1 quart per 1000 miles, Volvo wouldn't do anything about it.

Rusty

 

[jgillott]

No indication any ventilation issues or signs of oil anywhere. Engine is clean and dry front to back. I'll look again today to see if I missed anything.

 

[jgillott]

I don't think 1 quart every 3000 to 4000 miles is alarming on a higher-mileage engine, but I'd be more concerned if it went from zilch to using oil at these levels all at once - in other words, a step change in oil consumption. A step change like this normally isn't associated with progressive wear but rather with failure of a component such as an oil ring, a valve stem seal, etc. If the engine has a PCV valve, it might be worth changing it out.



Rusty

This is sort of what I am concerned about. I have no symptoms of a bad ring or valve seat, no noises, etc. The fact that it just seems to have started suddenly makes me wonder what's going on in there.

 

[WalterRyan]

That sounds excessive to me. I have a 2004 Grand Cherokee with the 4.7 that just turned 192,000 Saturday and it has never used more than 1/2 quart between changes, every 5,000-6,000 miles. I have only owned it less than 3 years but it does not appear that the engine has ever been removed. Your usage seems way above what I would expect from any newer vehicle but not really terrible as others have mentioned the fact that this started in less than 10,000 miles would bother me more than how much it is using.

 

[RustyJC]

No indication any ventilation issues or signs of oil anywhere. Engine is clean and dry front to back. I'll look again today to see if I missed anything.

My reference to the PCV valve was as a source of your oil consumption, not necessarily leakage. From a PCV valve diagnostic:

Fresh oil in the PCV hose suggests a problem
Another definitive pcv valve test is to remove the vacuum hose and look for fresh oil. A PCV vacuum hose, with oil dripping or a wet valve, usually suggest too much flow, which causes oil consumption. Checking the PCV vacuum hose is a wise precaution, on any engine that consumes oil. Also, if you see blue smoke coming from tail pipe can mean many reasons, but the first step is to check the pcv valve. Basics First!

Rusty

 

[GrantP]

I have a similar issue with my wife's Jeep with the 4.7. It has 140k on it now and is burning a quart or more between changes. It has always used some oil (I bought it with only 9k on it back in 2004 so I have a long history with it) but it has steadily become worse. It runs great, no leaks. I have heard the valve stem seals on these engines don't hold up and that's where the oil consumption begins.

 

[jgillott]

My reference to the PCV valve was as a source of your oil consumption, not necessarily leakage. From a PCV valve diagnostic:



Rusty

Oh...OK. I understand now. I'll go out and take a look. Thanks.

 

[jgillott]

I have a similar issue with my wife's Jeep with the 4.7. It has 140k on it now and is burning a quart or more between changes. It has always used some oil (I bought it with only 9k on it back in 2004 so I have a long history with it) but it has steadily become worse. It runs great, no leaks. I have heard the valve stem seals on these engines don't hold up and that's where the oil consumption begins.

You are the second person to mention that to me today. I was talking to a buddy of mine that mentioned that there were potential valve seat issues with both the 4.7L and some of the 5.7L Hemi engines. He did say though that there was often a slight tick or tapping sound (almost like a stuck lifter) present when the wear became pronounced. I've never heard it myself.

 

[RustyJC]

You are the second person to mention that to me today. I was talking to a buddy of mine that mentioned that there were potential valve seat issues with both the 4.7L and some of the 5.7L Hemi engines. He did say though that there was often a slight tick or tapping sound (almost like a stuck lifter) present when the wear became pronounced. I've never heard it myself.

GrantP and I mentioned valve stem (oil) seals, not valve seats. Unless there's a lot of wear in the valve guides, you won't have any noise associated with failed valve stem seals.

Rusty

 

[jgillott]

I'm typing faster than I'm reading today. Sorry guys.

I'm leaving with it tomorrow for approx 950 mile round trip. It's right on the full mark now. I'll be interested to see where it ends up by the time I get back.

 

[Tuesdak]

Less than 1 qt every 1000 miles isn't anything to worry about. It's cheaper to put oil in it and over time oil deal with fouled cats and O2 sensors. And even that takes some high oil consumption.

You should do a UOA on your engine as this will tell you if there is anything going on to worry about.

The big question is steeping up from the water thin EPA MPG oil to say 10W-30. Some engines will trigger the computer via a sensor if you put the wrong grade in. To hold all that thin oil in 5000 miles without using any is impressive.

The PCV system was mentioned as a source - how about driving style? Warming the engine up on longer drives where water condensate gets boiled off rather than making up (masking) for small amounts of oil usage?

 

[jgillott]

The truck does see a lot of highway miles. Some short distance stuff mixed in, but mostly highway.

I did just pull the pcv valve on the drivers side valve cover and didn't notice any noticeable fresh oil hanging on it or in the vacuum hose. It is original. I'll grab a new one in a couple of days just for the heck of it. I think they are only $25 or so.

 

[JR]

Putting a heavier grade oil in certain engines can be more detrimental in some cases. Yes the EPA drives the thinner weight oils but the manufacturers consequently design the engines around the use of thinner oils. You might get away with putting a 30w oil in an engine spec'd for 20w in hot climates but in climates that get zero degree weather cam phasers in particular don't like the thicker oil. Nor do the bearings designed for said oil. I've got first hand experience with this in our 3 valve Ford 4.6 engines.

5k miles is actually a short OCI for 20w oil, I typically do annual changes using Schaeffers 9000 5w20 which averages out to 13-15k miles and have never had any viscosity or shear related issues, nor any other for that matter. Unlike the beliefs of old, thin is in. Modern engines (gas and diesel) are being designed to run it. Nothing to worry about.

 

[crispyboy]

We have the 4.7 high output engine with 114k in a 2002 GC. I usually have to add a quart about half way to the 6k oil change interval. I use Valvoline full synthetic. I love the motor - it really moves out!

Oil usage in general: My mother has a 2005 Cadillac with what I believe a V-8 Northstar engine. The service manager says the oil pan is oversized on purpose by GM (8 quarts). The service manager told my dad that this is so that people could get the car back to the dealer in time for the next oil change and GM would not have to be replacing engines under warranty. It uses at least a quart or so every 1K miles.

A co-worker had a GM 3500 truck with the 8.1 gas engine. One quart per 800 miles was considered "normal" consumption for that motor.

 

[jgillott]

My 950 mile trip over the weekend used almost exactly 1 quart. I'm in Florida now with the Sprinter, so I'll have to look in to it when I get back home.

 

[jgillott]

Quick update. Approx 750 miles since PCV valve replacement and no oil use. Crossing fingers that was the issue.

 

[GrantP]

Thanks for the update, keep them coming.

 

[TFucili]

Hopefully that's got it. Just love simple fixes.