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Oil Use

drj_191970

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drj_191970 New Member

drj_191970

Posted
Posted

I have an oil use problem with my truck. It is a 4.8L V-8 2006. It uses a lot of oil between changes (about two qts). It smokes when i crank it occasionally. I checked inside the tailpipe and there is no smut. Could this be the valve stem seals or pcv? Or a bigger issue.

Rat4go Enthusiast

Rat4go

Posted
Posted

I'd expect PCV before valve stem seals (the stem seals are much better than they used to be) unless you have a zillion miles on the truck.

 

Is your smoke on start a blue-ish color or something else? How often does it do this? Blue-ish smoke is usually oil. Valve stem seals usually cause the smoke only after the motor has sat for a while (overnight),but it will do this on every start after sitting. If it smokes after a short time of not running or smokes on some starts (after sitting overnight) but not on all of them, I'd suspect something else.

jrrod2004 Senior Enthusiast

jrrod2004

Posted
Posted

crap, that sucks since I have a 2006 with the 4.8. I would suspect a seal may have gone out, but I am not a certified mechanic

MikeInCtown Enthusiast

MikeInCtown

Posted
Posted

Pull the plugs one by one and find out which cylinder is burning the oil. If it's an intake/pcv issue you should have a coating on most all the plugs as the oil would be sucked into most every cylinder. If it's a stem/seal issue then only a few cylinders will be black and have an oiled up plug. You can also get a compression guage pretty cheap at HF and test the cylinders. This may confirm anything you find wrong with the plugs.

Norseman Senior Enthusiast

Norseman

Posted
Posted
Pull the plugs one by one and find out which cylinder is burning the oil. If it's an intake/pcv issue you should have a coating on most all the plugs as the oil would be sucked into most every cylinder. If it's a stem/seal issue then only a few cylinders will be black and have an oiled up plug. You can also get a compression guage pretty cheap at HF and test the cylinders. This may confirm anything you find wrong with the plugs.

 

If it were the PCV wouldn't the Oil mostly be in the area around the PCV??

 

Again, are you using the fixed orifice type of PCV?

Rat4go Enthusiast

Rat4go

Posted
Posted
If it were the PCV wouldn't the Oil mostly be in the area around the PCV??

 

My experience is that PCV problems usually allow oil past rings due to not enough crank case vacuum, so in that case, burned oil is evenly located in all cyls.

 

I think this is why MikeyZ suggested evenly coked up plugs with a PCV issue.

MikeInCtown Enthusiast

MikeInCtown

Posted
Posted
If it were the PCV wouldn't the Oil mostly be in the area around the PCV??

 

My experience is that PCV problems usually allow oil past rings due to not enough crank case vacuum, so in that case, burned oil is evenly located in all cyls.

 

I think this is why MikeyZ suggested evenly coked up plugs with a PCV issue.

 

 

 

 

 

 

 

yea, same thing. I was thinking if there was too much manifold vacuum and a problem with the pcv then you would be sucking oil into the manifold where it would migrate toward more than just one cylinder. It is natural to get a slight buildup of oil on any PCV valve but not normal to have a completely gunked up valve and a hose full of oil. If the pcv was blocked then I guess the oil could push past the rings, but the rings should be wiping the cylinder anyway. IIRC the PCV assembly goes into the top of the intake but is not normally a replaceable part. It looked like you have to pull a bracket or two in order to even get the hose off there and I don't think they list one on the auto store catalog pages.

 

Mike

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