V8 oil consumption

[coonerboy]

My '98 has just clicked over 100kmi. I have had to add about 2 1/2 qts of oil since I changed the oil in July. Has been driven about 3800 mile since then. I have no oil leaks anywhere and there is no visible oil smoke(blue) from the exhaust. I am running Mobil 1 5w-20 synthetic.

Has anyone had any similar oil consumption problems with the 5.0? The only other issue I think it may be is a problem with the PCV system. I always notice oil in the rubber intake tube. Time for a new PCV valve and maybe install an oil seperator? At $7 a qt, this it getting a little expensive dumping oil into it constantly.

 

[coonerboy]

Well I looked into this yesterday after buying a new PCV valve wich I just changed. I have to say, changing the PCV valve on the V8 is truly a "blind" job. Have to do it by feel only. Anyway that went OK, but while looking around for oil leaks, I took the driver side inner fender flap down. Looked in near the exhaust manifold and found a couple of small holes in the dipstick tube! Rusted right trough. UGH! The holes were quite small and there was no sign of oil leaking from them but I wonder if could have been loosing vapor from them. Time to start looking for a new dipstick tube. Damn rust!

 

[duke16]

Switch over to a high mileage oil, see if that helps. Valve guides or piston rings could just be worn.

 

[CobraSix]

5w-20 is a bit thin for the 5.0. At a minimum I'd be running 10w30. a 5.0 with 100k miles will burn that up.

I'm not a big fan of "High Mileage" oils. Additives and stuff that don't do much for the engine except make the price of oil changes go up. My 91 has 322k miles and I still don't use high mileage oils. Sometimes you don't want things cleaned up, as it can result in gaskets starting to leak.

 

[coonerboy]

Thanks for the input cobra. I agree that the 5w-20 is a bit thin, but it is the recommended viscosity by Ford. I also don't agree with the high mileage crap. Its all marketing to me.

I think a change in viscosity is due for my next oil change. Just don't wanna go to heavy for the upcoming winter.

 

[JohnnyO]

Burning about a quart every 1500 is not excessive...at least that's what GM said about my mother's car. I would switch to 5w-30 and see if it is any better. There is no difference in the engine from earlier ones that called for 5w-30. My mother's car definitely uses less oil after I switched to Max Life, even though it does not have a lot of miles on it ('99 Cadillac with 55,000 miles).

 

[fallenauthority]

Yea I would use at least a 5w30. If it still does it try 10w30, you wont notice any negative effects with a heavier oil as long as you dont go crazy and throw 20-50 in it or anything lol.
Oh and JohnnyO, its a Cadillac their secondary job is to burn oil, the northstar motors are notorious for burning oil something terrible doesnt matter how little miles, they always burn oil.

 

[CobraSix]

I have to run 20w50 in mine now. I've had to do it since 250k miles. Only burns about a qt every 3k miles now and been doing that for 80k miles. I was hesitant running that during the winter at first, but I haven't had any issues.

I honestly think ford recommends a bit on the thin side to eek out gas mileage for fleet standards.

If you are worried about cold starts and burning oil, you can always try 0w-40. I use it in my volvo since it has a turbo. Acts as a 0w oil when cold so it flows real nice up to 40* below 0. Protects the turbo bearing and other parts better. Once it warms up, acts as a 40w and keeps the turbo from burning the oil up.

 

[CobraSix]

Yea I would use at least a 5w30. If it still does it try 10w30, you wont notice any negative effects with a heavier oil as long as you dont go crazy and throw 20-50 in it or anything lol.
Oh and JohnnyO, its a Cadillac their secondary job is to burn oil, the northstar motors are notorious for burning oil something terrible doesnt matter how little miles, they always burn oil.

That reminds me of the quote from the movie "Captain Ron"

"Well boss, a diesel needs its oil like a sailor needs his rum."

"Why is that Captain Ron"

"Nobody knows, just one of those things"