300E oil usage
 

'90 300E 4matic:

I've noticed an increase in oil consumption recently, as well as a noticeable puff of white exhaust when engine is pressed hard on highway. Don't see any unless really pressing accelerator.

The oil is something i check regularly, at most gas fillups, and was normal only a few weeks ago. Now it's at the low dipstick mark and even the dash warning light flickered on / off.

Any thoughts?

This will make a good opportunity for you to become familiar with the 'search' function available. Spend a little time there and narrow it down. Then come back and we'll fix you right up!;)

A white puff usually indicates water. If its cold when you see this then it might just be condesation from the catalytic but if its warm there could be something from the cooling system getting in. You checked the oil, it didnt have a white milky look to it right? I only ask because when water mixes in the oil usually it could cause higher useage of the oil because of the lower burn off point but it sounds like you would have caught this already. Try looking at the coolant level too to make sure this isnt going down. I would try looking around the engine as well (front head gasket especially) and see if you notice any spots that look like they may be leaking. Just a few ideas, hopefully its something simple...

How is your water level?
 

Check for oil in your water reservoir. I hope is not the head gasket.:(

90 300e, 103 engine.

If it has over 90,000 miles on it and is using too much oil odds are the valve guides are worn, dending on the amount of guide wear you might be able to get away with a set of stem seals but, with the 103's history of oil leaks from headgasts, mixing oil in the coolant and so on, I'd do a valve job on it if it has over 100k on it.

I know, time to flame me for recomending a valve job over seals for oil consumption but, we all know 103;s are hard on guides.



Joe

I know what your saying dude
 

mine does the same thing. It just burns the oil. I started using hotter spark plugs and changing the oil more often. I add about a quart of oil every three weeks or less, depending on how often I drive it. It's caused by warn valve guides, just as stated above. I was quoted $1800 to fix the problem, but considering I payed $2000 for the car.... I'll just buy the oil.

Above advice sounds good.

Are you sure you are seeing white smoke? At freeway speeds it can be difficult to distinguish colors of smoke from your rearview mirror. Any other symptoms? Is the mixture setting correct? Any pinging?

Don't condemn your valve guides until re-sealing them no longer works. I'm at 263,000 miles on my '86 300E and a fresh set of seals last year took my oil consumption from about a quart every 700 miles up to 1 every 2,500. New guides eventually, but not today.

Of course if the head needs to come off for a new head gasket, send it off for new guides and whatever else. Even if the head gasket seeps a little oil and coolant, does it need to be replaced if no cross contamination of fluids is present?

-Blake
'86 300E (It loves the highway. Loves it!)