She still smokes like crazy!

[Redlineshftr]

I checked my exhaust and no oil so i know that not where the burnoff is comming from. It smokes slightly at idle and looks like a big rig when I take off from a stop light. The motor was rebuilt by the Po and never driven. I've driven prob around 100 miles. Could it be siezed rings?

[Dixie]

Sorry, not enough data to give you a good answer. Here are some questions to get you started...

• Who did the rebuild?
• Do you have any leaks?
• How many miles are you getting per quart?
• Does it smoke only at idle, and coming off idle, or does it smoke at constant cruise speed?
• Have any numbers from doing compression or leak-down tests?

PS: Remember oil burns. To find oil in the exhaust, you need a REAL big problem.

[Redlineshftr]

I was told that the previous PO rebuilt the motor. Im not sure how many miles I get per quart. I drove around town for about 30 min today and the oil level went from being fine to not reading on the dipstick. It smokes slightly at idle and a lot coming off idle. I had a local mechanic do a compression check and he didnt give me numbers but said they were good. Im sure I have leaks but haven't pinpointed any of them.

[pwd72s]

Damn, this is sad. Redline, do you know of an independent P-car shop in your area. One that could perform compression and leakdown test, then perhaps have a heart to heart talk with? I mentioned leakdown, because it can tell quite a bit too. I'm just hoping this experience doesn't sour you on the early 911.

[copper]

Sounds like rings or valves.

Have you checked your plugs for oil?

Check em, clean em, drive and check again. You'll see if you're getting oil through the valves in a particular cylinder.

Jim

[Halm]

Redline, just to be sure, you know to check the oil level with the motor idling and fully warmed up?

[Redlineshftr]

yep I always drive for about 30 min then check it. Im gonan check my plugs tom. Keep you guys posted. Thanks for the info.

[copper]

Are you noticing any increase on a hard downshift? As in when you are approaching a light and shifting down into 2nd or 2st and the RPMs kick up?

How about when you've driven a while at a steady speed, like on the highway, and then decelled on the ramp?

Both are good indicators of oil getting past rings or pistons under pressure. As I said, the plugs will be a good way of assessing which cylinder(s).

Leak down and compression will give you some answers as well.

Jim

[MobileWrks]

Who did the rebuild???? sometimes i strip engines, clean them myself and have a local shop rebuild them...

Update.

Thanks

[Joeaksa]

Wonder if the engine was really broken in after the overhaul?

When we have an aircraft engine like this (another aircooled engine) that is burning oil due to rings not seated we take it up and run it at full throttle for an hour or so then land, taxi in and after the prop is stopped do not touch the prop until the next day. It tempers the rings and they usually have seated by this time. Might try driving it on the highway for a while in 2nd or 3rd at a high rpm.

Sure needs some more detail on the condition and such.

Joe A

[Early_S_Man]

red,

Good compression numbers don't sound like an engine with ring break-in problems!

It doesn't sound like you have determined whether the oil smoke is being burned in the engine or in the muffler. Cars that have been stored for long periods without being driven can have oil leak into the heat exchangers and muffler.

Just for clarification ... oil smoke isn't necessarily being burnt in the combustion chamber! Lots of people speculate about oil seepage past the rings, etc. ... causing the oil smoke, but I have examined spark plugs on several 'smokey' engines and found no trace of oil on the spark plugs!

Many 911 engines smoke after being left to sit a long time! The average 'new' owner always gets concerned without trying to find out what is happeneing. I have seen engines that smoke occasionally, and others that do it every time, yet never show a sign of oil on the plugs! After much reading on the subject and examination of engine details ... have come to the conclusion that as the oil level in the sump rises above the level of the exhaust valve guides ... oil is actually seeping 'up' the exhaust valve guides and running down the exhaust port into the heat exchangers! The reason this can happen is that the white Teflon valve stem seals that allow a 'controlled' amount of oil seapage in operation to keep the valve stems lubricated ... are not good at resisting static pressure from a rising oil level in the sump! It seems to be worse when the car is parked on an incline, and I suspect that the higher oil level at cylinders #1 & #4, or #3 & #6 when inclined raised the static oil pressure at the valve stem seal ... and leakage is worse than if parked on a level surface!

Naturally, if an engine sits for weeks, months or years ... a considerable amount of oil can be in the heat exchangers and muffler! It could take an hour or more of running at highway speeds to burn the oil off!

A past Pelican thread by a frantic owner with a badly smoking engine ... turned out to be a used muffler that had been purchased and recently installed! The troubleshooting took multiple days, but no oil on the spark plugs, and no oil in the heat exchanger outlets ruled out the engine as the source of the smoke! So, the used muffler became the culprit!!!

So, pull the plugs, and if clean ... pull the muffler. Rinse out muffler with Varsol or similar solvent and let air dry. Chances are that oil remaining in muffler was the source of the smoking, and that a good one - two hour drive on the highway after reinstalling muffler will end the smoking problem!

[MobileWrks]

[Redlineshftr]

yea it is.. thanks early s

[Redlineshftr]

Hey Jimmy do you guys make calls to the valley?

[Joeaksa]

Originally posted by MobileWrks

One of thousands of excellent posts from Warren. One of our real assets on this board.

Joe A