excess oil consumption, 1 qt/200mi.

[russ coyote]

my 1999 996 coupe, 6 spd has 94,000 mi and runs great w/e of intermittant "check engine" light and excessive oil consumption.

The left tail pipe and fender becomes covered with soot. There are no visible leaks,

I just changed oil and filter, using Moble 1 syn. Oil lite came on momentarily after 150 miles and engine was 2 qts low.

Has nyone experienced this, and do you know trhe cause?

Thanks,

[Silver_TT]

sounds like your AOS needs to be replaced. are you seeing any smoke from the tail pipes (on start-up, etc).. ??

Edited December 17, 2012 by ferrugia

[RFM]

It is essential to note the error codes, which undoubtedly exist because the "check engine" light comes on, without faultcodes it stil a guess and can be expensive.

[JFP in PA]

With the car at idle, try and remove the oil filler cap; if it is extremely difficult, your AOS is dead.

[mdgcentral99]

Funny, that happened to me a few years ago. Ate oil for a month, then oozed a milky slime from the dipstick, then engine broke. The classic oil/water intermix. Had to replace engine. Hope your's isn't that, but it started with oil consumption. Check the oil color, hopefully, they can seal it before it becomes bad.

New reman engine works great, no leaks. It's just the cost of ownership.

[Hedges]

Another question along the same lines as above.

2001 996 C2 Cab Carrera 911

I had a rebuilt engine supplied by a NC supplier and installed by a local Indy which failed in the first 500 miles. Since the orignal supplier didn't supply a rebuilt engine for over 9 months, the local Indy at their expense sent the engine out had Cylinders 1 and 5 rebored and they reassembled and replace all the damaged parts destroyed in the engine supplied by the NC supplier. My question is that since I have gotten it back last July I have put about 3,000 miles on the car and have seen an average use of oil of about 1 liter per 300 miles. We have replaced the oil separator which didn't help the problem. I have had the oil tested and the results have shown no abnormalities.

Occasionally on startup there is blue smoke coming out of the passenger side tail pipe. During the initial warm-up of 3-5 minutes upon acceleration blue smoke can be seen occasionally coming from the passenger side tail pipe. After warming up I do not see any smoke even on hard acceleration or deceleration. However the oil has to be going somewhere. No warning lights, car runs good, no unusual noises.

Could this be worn valve guides or a problem with the rings? Any ideas?

[Loren]

Another question along the same lines as above.

2001 996 C2 Cab Carrera 911

I had a rebuilt engine supplied by a NC supplier and installed by a local Indy which failed in the first 500 miles. Since the orignal supplier didn't supply a rebuilt engine for over 9 months, the local Indy at their expense sent the engine out had Cylinders 1 and 5 rebored and they reassembled and replace all the damaged parts destroyed in the engine supplied by the NC supplier. My question is that since I have gotten it back last July I have put about 3,000 miles on the car and have seen an average use of oil of about 1 liter per 300 miles. We have replaced the oil separator which didn't help the problem. I have had the oil tested and the results have shown no abnormalities.

Occasionally on startup there is blue smoke coming out of the passenger side tail pipe. During the initial warm-up of 3-5 minutes upon acceleration blue smoke can be seen occasionally coming from the passenger side tail pipe. After warming up I do not see any smoke even on hard acceleration or deceleration. However the oil has to be going somewhere. No warning lights, car runs good, no unusual noises.

Could this be worn valve guides or a problem with the rings? Any ideas?

Improperly seated rings on the new/rebuilt engine as well as worn valve guides would be on my checklist.

Did they do the heads in the first or second rebuild?

[JFP in PA]

Another question along the same lines as above.

2001 996 C2 Cab Carrera 911

I had a rebuilt engine supplied by a NC supplier and installed by a local Indy which failed in the first 500 miles. Since the orignal supplier didn't supply a rebuilt engine for over 9 months, the local Indy at their expense sent the engine out had Cylinders 1 and 5 rebored and they reassembled and replace all the damaged parts destroyed in the engine supplied by the NC supplier. My question is that since I have gotten it back last July I have put about 3,000 miles on the car and have seen an average use of oil of about 1 liter per 300 miles. We have replaced the oil separator which didn't help the problem. I have had the oil tested and the results have shown no abnormalities.

Occasionally on startup there is blue smoke coming out of the passenger side tail pipe. During the initial warm-up of 3-5 minutes upon acceleration blue smoke can be seen occasionally coming from the passenger side tail pipe. After warming up I do not see any smoke even on hard acceleration or deceleration. However the oil has to be going somewhere. No warning lights, car runs good, no unusual noises.

Could this be worn valve guides or a problem with the rings? Any ideas?

Could be a couple issues; loose valve guides will cause the engine to suck in oil, as will rings that have not seated properly. I would start by pulling all the plugs, noting there cylinder locations, and check hem for evidence of oil. If you spot one or more questionable plugs, have a leak down test run on those cylinders for ring or bore issues. If you get some questionable leak down values, time to drop a bore scope in the cylinder to look for the problems.

[Hedges]

I checked with my local guys and there is no indication that the NC supplier did any work to the heads and the local folks say they didn't. What's involved with the heads and what's a best guess cost to work on them?

[JFP in PA]

I checked with my local guys and there is no indication that the NC supplier did any work to the heads and the local folks say they didn't. What's involved with the heads and what's a best guess cost to work on them?

Before you go to pull the heads, which means pulling the engine, check the plugs, leak down the engine, and bore scope it; you need to know what you are dealing with before you try and start fixing things.

[Hedges]

Will do, thanks!