problems after valve adjust

[Driver Ed]

I did a valve adjustment, oil change, plug change, distributor cap and rotor change, etc. last weekend on my 1982 911SC and other than my fingers being really cold, it went OK. Monday morning I drove about 45 miles and things seemed fine. When I got to my destination, I checked the oil level and it was full.

Monday evening when I drove home, I heard what I think was valve noises, so I figured I must just have forgotten to sufficiently lock down the valve last adjustment nut or something dumb like that. However, as I got closer to home, the temperature started to climb and the engine ran more and more poorly. It never got into the red, but it was higher than usual and sounded just awful. In addition, I was getting a lot of engine vibration from the pedals.

I limped on home and let it sit overnight. In the morning, I drained the oil again, and re-adjusted the valves. All seemed OK, but #6 and #5 exhaust valves seemed a little tight (I figured that it was probably because my cold fingers had problems feeling the feeler gauge) so I readjusted them. I put it all back together, refilled with oil and didn't drive it until the following morning.

After about 20 miles at mostly highway speed, the engine temp started climbing again and the oil pressure seemed to be too low, so I immediately pulled over and checked the oil. It was low, so I added a quart and also let it cool off for ten minutes. After that, I drove it straight back home, and it was running badly again by the time I got it in the garage.

I didn't retime the engine after I replaced everything -- could that be it? I don't know what the problem could be -- I've adjusted my valves many times before without any problems. What could have changed? What can I check/do/replace?


Thanks for any help!

[ChrisBennet]

Welcome to the board. You don't mention what year your car is but if you were adjusting the valves that narrows it down to a only 30 year window ('63-'94). ;D
Any chance you have a motor with a sump plate ('63-'83) and put the sump plate on backwards?
-Chris

[DW SD]

Chris,
Driver's posting says 1982 SC. Interesting problem. Good thought on the sump plate. oil pressure would be non-existant, though, wouldn't it?

Doug

[Jeff Alton]

I'd look into what Chris suggested. Also, are you checking the oil level correctly, with the engine running and at operating temp?

Jeff

[Driver Ed]

It's a 1982 911 SC with a 3.0 engine with tensioner upgrade, turbo valve covers and a couple of other things. Hmm. Backwards sump plate is a possibility, since I replaced the sump seal.

Well, I don't think I made an error -- my recollection was that the drain plug was to the rear of the car, but I can't find a photo of the bottom of this engine to verify and I'd rather not dump out all of the oil (again!) to check. Anybody know for sure?

The thought of running the engine without a working sump kind of makes me sick...

[Driver Ed]

Oh, two other things I should mention -- the engine was rebuilt less than a year ago (by a competent mechanic -- not by me!) and the car had been running relatively well before the adjustment. It was just time to do it according to my calendar.

[Driver Ed]

OK, I've just verified that my sump plate is installed correctly. Correct me if I'm wrong but it looks from this diagram that the drain plug is indeed facing the back of the car.

Still, it was a very good guess -- matches the symptoms uncomfottably closely.

[walt]

Interesting. I always thought facing left was correct.

[450knotOffice]

I've got an '84 so I can't help you by looking at mine, but I just looked at a picture in Wayne's"101 Projects..." book on page 19 and it clearly shows the drain plug on the left side of the engine.

Is yours facing aft?

-Scott

[jthwan22]

Was the engine stone cold before the valve adjustment?

[Cold Deck]

Welcome to the board. I just climbed under my 83SC and the drain plug is on the left (drivers) side.

[Por_sha911]

Check the cap, rotor, and wires (at both ends) to make sure they are on correctly. Pull the plugs and check for fouling or overheating.
Make sure you are checking the oil with the car running, on level ground, and up to temp. Did you adjust the valves STONE COLD? If not, you may have issues there.

[Doug Steinel]

My '82SC has drain plug on driver's side.

[AFJuvat]

Drain plug is definately on the drivers side of the engine.

If you are slightly off, that could explain the erratic but not a total loss of oil pressure.

AFJuvat

[Driver Ed]

First off, I want to thank you all for your thought provoking questions and observations. It's nice to have some help with this.

Some answers:
1. Yes, the valves were very cold when I adjusted them. My typical habit is to park the car, jack it up, drain the oil and then do the valve adjustment the following morning. The day I did the valve adjustment it was probably around 0C in the garage.

2. Yes, until earlier this week I have always checked the oil with the car running, warm and level. However it's been a bad week for me, automotively speaking, and while trying to check the oil level in dim light the other morning, I accidentally dropped it into the tank. I tried fishing with a magnet and grabbing with a flexible grabber tool, but no luck with either method. I have a replacement dipstick on order from our sponsor.

3. I have seen photos of engines in this era which have the drain plug to the left of the car (driver's side in most countries) but I am quite certain mine has never been that way since I've owned it. Even if it had been installed incorrectly all these years, there was no change that would have accounted for the difference, so maybe it's another thing that might be wrong, but not the thing.

My Porsche manuals are on microfiche so I can't really post them very easily, but they also don't have any clear picture showing the drain plug in the context of the rest of the engine. These manuals show that there was a change for the the 1980 through 1983 models (these manuals were updated in 1984) in the sump plate. Maybe this was one of those changes?

Alternatively, mine really was installed incorrectly all along, but if there was no change, what accounts for the difference in engine performance? As Alice once said in Wonderland, "Curiouser and curiouser...."

Ed

[Britwrench]

Timing chain will not jump when engine is turned backwards unless there is something radically wrong. Even then I doubt whether it would happen..never seen it on any 911 engine (or any others).

Any chance you left a rag in the engine compartment and the noise and temp increase was due to it being sucked through the cooling fan?

Altered the ignition timing or left something loose?

[geof33]

you said the oil was "full"... Define that and at what temp it was measured at "full"... Where was the dial in relation to the marks...

[David Goodman]

I would double check the ignition timing (it might have moved when you replaced the rotor and cap) then make sure you put the right spark plugs in it.
Dave

[Wayne 962]

Weird symptoms. It's important not to have the drain plug under the pickup tube for the oil pump. As long as it's not there, it can be basically anywhere.

So, the engine is running fine for the first part and then starts running hotter? Oil pressure should decrease as the engine temps go up...

-Wayne

[Driver Ed]

Britwrench: interesting thought about a wayward shop rag. I checked with a trouble light but saw nothing out of the ordinary. Also, I am very sure I never turned the engine the wrong way.

geof33: I'm going to take a risk and answer without consulting my lawyer. I checked the oil after a 45 minute drive, so the engine was certainly warm. The temp gauge was a bit above the halfway mark, which is the norm for this car, and my definition of "full" is "somewhere between MIN and MAX on the dipstick" when checked with the engine running and the car parked on level ground.

Dave: plugs are Bosch, Pelican part number W5DC, freshly purchased from our sponsor (as were all other parts except the oil).

Wayne: It's nice to see it's not just me who thinks these are weird symptoms!

It's good to check the dumb stuff -- this will probably turn out to be some simple stupid thing; it's just a matter of figuring out what.

Unfortunately, I won't have any time to work on it for a few days, but here's my plan for when I get back to it:

1. drain the oil (for the third time!) and double check the sump plate placement
2. verify the timing
3. put it all back together and test drive

If, as I suspect, the timing is unaltered and OK, and the sump plate's drain plug is not under the pickup tube, anybody have a clue as to what step 4 should be? Any suggestions for alternative plan? In any case, thanks for the brainpower already expended. I'll let y'all know what I find when I figure this out -- or further detailed symptoms if I don't!