loosing oil after rebuitd

[awinn]

I have my 911 rebuilt by a guy who is a well a know builder in my area. At first he said he could "make" me an engine looking at and re-using my old parts, rings, bearings ect. No guarantee just a good running engine for about 3500.00; I said I wanted new parts and a good job. He said it would be 8 k to do heads, flux crank and do it right with a 2 year guarantee. Well I said do the full job. 9 months later I have my car, for the most part it runs great, stutters a little up hill but he said the fuel reg which was replaced might need tuned. What bothers me is I have driven about 300 miles and it has used 7 qts of oil. It does not leak any, smokes a little at warm up, and looks like it blows a 2’ light oil spray of oil on the drive until warm up. It does not smoke going down the road and the tailpipe seams dry and some time really runs great. Should I be concerned with that kind of oil usage? It does not seem to be fowling the plugs.....My demons say he used the old rings maybe I’m paranoid; he just seamed so adamant of how the old part were not too bad. I had him rebuild the motor because it had several broken head bolts and leaked oil like a BP oil well, I just don't know, guy refused to give me back my old parts after rebuilding, then said he didn’t keep them, He came highly recommended but I'm worried. Well I have a garentee in writing so will wait and see. I just wish I had a way to tell.

Thanks Guys,,,any ideas…

[lindy 911]

If you went through seven quarts in 300 miles your plugs would be badly fouled, tail pipe covered in soot and it would smoke like the Iceland volcano. If you are checking the level with the dip stick, I would confirm that the level is indeed low and then drain the oil. Check to see how much oil comes from the crank case. It sounds like you might have a scavenge issue and there is build up in the case. There should be no more than a quart and a half or so coming from the crank case after the engine has been warmed.

Lindy

[euro911sc]

WELCOME TO THE BOARD!

Sorry to hear of your troubles, but this is the place to get answers! What was the procedure you used to break in the engine? It may be possible that your rings did not seat. That would not explain the 7 qts. though... that's over 50%. There has to be a huge puddle or smoke plume to go through that much oil in 300 miles...

Since you are new here and I don't know your car I'll ask some stupid questions to start with:

• Where are you located?
• What year is the car?
• Stock engine or modified?
• How long have you had the car?
• Do you do the work yourself, primarily, or hire it out?
• When you checked the oil the car was warmed up, running, and on level ground, right?
• Are you certain you have the correct dip stick for your car?
• Are you sure you started with a full complement of oil?
• Who changed the oil the last time? If it was some place like Jiffy Lube they only put in 5 qts and that would explain the missing 7...

Lets start here and see what diagnosis we can come up with.

Best regards,

Michael

[Two Rivers]

Sounds to me you might have a ring problem.It is true if you used that much oil in 300 miles your plugs would be wet with oil but the smoking untill warm is what I would worry about.I have never seen a air cooled engine or eny engine for that matter smoke after a proper rebuild. After a hot air cooled engine sits and is restarted hot you might get a little puff once and a blue moon.More then likley from the hot oil seeping past the rings under the right conditions.Also if the cylinders have a coating on them and they were honed to agresivly the coating would be damaged.Not being able to get your old parts back would set off red flags to me.

[4sd911]

Originally Posted by awinn

and looks like it blows a 2’ light oil spray of oil on the drive until warm up.

This needs better explaining, where is this oil spraying? If oil is spraying it must come from the pump either the pressure side lines or the return lines. 7 qts. of oil leaking should leave a good oil slick, is bottom of engine wet with oil? As stated above that much oil going through the rings would leave very oily plugs and a lot of smoke out the tail pipe.

[kenikh]

Hmmm...what kind of motor? While I have heard several mechanics say it is impossible to install the oil sump screen backwards I have seen firsthand that it can be installed 180 degrees (backward). This results in terrible scavenge, which pools oil in the case, making it seem as if you are using excessive oil. The only other telltale sign of this is that when the motor gets warm...are you having higher than norm oil temps? 7 qts is a lot, but between break-in usage and pooling, especially if the motor was initially filled at the low side of the dipstick, it is possible. The 2.7 in question had the same symptoms as you: precipitous drop of oil level right after rebuild.

Check that screen, if appropriate.

[awinn]

First, let me clear the air. Its a 1980 911 SC Targa 3.0,and this freaks me out. It was just showing about 1/2 inch on the dip stick at idle on Wednesday night. I thought well, I'd get 3 qt. after work on Thursday after work. Drove to Harrisburg, PA from home approx. 38 miles, NO smoke after warm up, then after work to Advance Auto, Checked oil and it was just at tip of stick. NO SMOKE all day. Minor when I first start up. Added 3 qts to MAX at advance. Drove home and at house exit, car smoked so damn much car behind me backed up thought I was on fire, hell I thought I was on fire!, smoked and couched for about two minutes and cleared up. Ran ten miles more to home. Maybe I saw light smoke in rear but not much, in drive at idle it smoked a little and cleared up. Seams to spit a light spry of oil out of the tailpipe. NOW I checked oil @ idle and it literally splashed out of the oil cap like it was way over filled......I'm so damn confused....ran for a couple minutes and re checked it and its was at MAX.......its ??????? with my head....

PS Tachometer quit working all of a sudden also, dead not jumping. Is there a fuse, my book does not address it much, Also what is the best repair book for these cars. I am handy with my tools, mostly an old Mopar guy but always wanted one of these,

[kenikh]

It's backed up in your case. DO NOT ADD MORE OIL. The smoke is from too much oil.

DRAIN THE CAR NOW. I'll bet when you measure it up on the way it, it is all accounted for.

[pete3799]

Keep it 1/2 way between add and full when warmed up, level and engine running.

[lindy 911]

There is definitely a scavenge circuit problem. The motor is not getting the oil back to the tank effectively. Drain the oil and measure how much comes out. If it's close to what you've put in you're not burning or loosing any. If it's close to what you put in, pull the sump cover and check the screen and the orientation of the cover plate. The drain bolt should by 90 degrees from the crank, off to one side. If the screen or cover plate are not installed properly the scavenge side of the oil pump won't work right and the case will fill with oil from the tank.

This needs to be corrected right away as you risk running the tank dry and starving the pressure side of the pump. If this happens there will be no oil supply to the engine components and your motor will be destroyed. Don't drive the car any more until you've sorted this out.

The most common source for repair information is a Bentleys manual. They are pretty good but not as complete as a factory Porsche manual set.

Lindy

[euro911sc]

Don't forget to get at least a 15 quart drain tub!! If you have all that oil in there its going to come out!

I believe, if you rotate the sump plate the drain plug will block the scavenge tube of the pump... Its hard to believe a recommended builder would screw up the screen orientation.

I have found my factory manual to be useless. Get a Bently and the 101 Projects book. After that... Almost every possible repair question can be answered on these forums.

enjoy!

-Michael

[kenikh]

Originally Posted by euro911sc

I believe, if you rotate the sump plate the drain plug will block the scavenge tube of the pump... Its hard to believe a recommended builder would screw up the screen orientation.

Correct and easier to do than you might imagine. I had a Porsche mechanic with 38 years of experience tell my buddy it was impossible to install the screen wrong...I am sure he just never tried it and in his mind, as a result, it was...that was until my buddy installed it backwards!

A shop lead may have had his assistant button up the motor by adding the fluids and the junior guy may have made the mistake...who knows.

If this is what happened, no harm was was likely done. Flip the screen, tell the shop lead what happened and keep on trucking. Any good shop will make good if there are future issues related.

[Eagledriver]

Most of this could be explained by the possibility of an new 911 owner overfilling the oil. The oil level in the tank varies by about 5 quarts depending on tempurature and RPM. If he filled it when it wasn't warmed up it will overflow into the intake when it warms up (when I got home it smoked like crazy....he said).

-Andy

[Flat6pac]

Well, it is possible that the seal on the pump was knocked off when the 2 halves were put together.
Drop the oil and the screen and look for a pump seal loose or off loation on the pump side.

Bruce

[kenikh]

Any news? Curious to know what the cause was.