A sad start to my first 911 ownership...Bought the car in PA(after PPI and recent service when the engine was removed to fix oil leaks), was driving back to Maine. Engine temp was at bottom of the red mark 30 miles into the trip. Checked the oil level, (on level ground with motor running, with engine warm...perhaps hot). It took 3 quarts of 20-50W to bring it to the midpoint on the dipstick. Drove 10 more miles, checked again, level just right, no leaks seen under the car. Still running hot at bottom of red mark on temp gage. At mile 69 other drivers were waving me off the turnpike, smoke and oil is coming from the back of my new (used) Porsche! 15in puddle under back of car, oil sprayed all inside the compartment and a path of sprayed oil on the road behind the car. The car is towed back to shop that did the work and the PPI. No source of the leak can be found by the mechanic. Did I overfill? Blow a gasket? Why so hot? Help.
Bob (a very newbie Porsche owner)

 

Sorry to hear that Bob...and welcome! I'm sure the more knowledgable will chime in with ideas and things to look for. Was the PPI mechanic an air cooled 911 guy and was the oil level correct when you started out? I find it hard to believe that he can't find the leak source...we're talking about an Exxon Valdez leak here (3 qts in 30 miles)! Good luck...

Keith
'88 CE coupe

 

Hi Bob:

There are many reasons for too-high oil temperatures:

1) Insufficient oil level

2) Overfilled oil level

3) Faulty oil thermostats (engine mounted and fender mounted)

4) Slipping fan belt

5) Foreign material on top of engine under fan shroud blocking oil cooler. One must pull the fan housing assembly to see that.

6) Air/Fuel mixture far too lean

7) Ignition timing overadvanced or retarded

8) Plugged up catalytic converter


I should mention that the bottom of the red zone on the oil temp guage is around 250 deg F and thats FAR too hot to continue driving. If you see that, its time to pull off and diagnose whats wrong.

I'm with Keith, oil leaks that large are NOT hard to spot once the engine is cleaned off and observed while the engine is running on a lift. Some sources are: oil return tubes, "S" hose, slipped valve cover gaskets, rocker shafts, improperly tightened oil line fittings when the engine was replaced.

Hope this helps,

 

Quite frankly I think something was misse on your PPI. I think you may have just found the reason the car was sold. I sure hope not. The first step is obviosly finding out where the oil is comming from. Did you have a leak down or compresion test done on the PPI ? I wonder if they even drove it ?
Well regardles of that they have to be able to tell you where the oil is coming out. You are in mAine so it is not blazing hot there so the temp should barekly have cracked the first 3rd for this time of year. I hope it is something like the thermostat not opening , but it does sound very ominous.

 

Many thanks for the info and help offered so quickly! I will do my nubie best to answer the questions. The PPI did include compression and leak down. It was done by a mechanic with special interest in the 911SC's. If oil is removed (?) for the leak down testing - not sure if it was replaced, I did not check at the start of my trip (I plead complete ignorance for not checking this). The car recently got a new finned oil line and thermostat to help with the running hot issue according to the mechanic.
Recall that I did add the 3 quarts of oil during the trip - is it possible that this was the only source of the leaking oil? The mechanic has since run the car on a lift for 20min and has not seen any oil leaking. Any help much appreciated.
Bob

 

No oil is removed . i was just wondering about a catastrphic failure , but it looks good. if it has had work for a running hot condition this was a known issue before sale which is what I was suspicious of.

 

Anyway, will they take it back if it has a "problem"?

 

The car was private sale, "as is". So the previous owner is not helpful. The mechanic is being helpful. He did the engine drop to fix the oil leaks less than a month before I bought the car. I assume he will stand behind his work and work out the problem. He has the car back in his shop now. I just want to know that he is looking in the right places...he still can't find the source of this LARGE loss of oil. :-(
Bob

 

There is no way if the car recently received a correct PPI that it would take 3 quarts to fill it to the mid level this soon afterwards. If this was the case you started off the trip about 3 quarts low. It only takes me one quart to return mine from the bottom mark to the top mark.

My first guess, and I hope this is the case, is that you added oil to a car that was already full; although it sounds like you took the reading correctly. Remove the air filter cover and see if you have oil pooled in the air box. Did you have the oil changed as part of the PPI? Also, did the oil level gauge indicate low at the same time as the dip stick or did it indicate level in the tank?

 

That's interesting as I thought it was 2 litres from bottom to top . Anyway on a good working car with the oil full what should the guage on the dash read ?

anyay regardless of the oil sprayng out ( whether it was driver error or or not.. whic is some place we have all been ) there is still the issue of being at the bottom of the RED , there is no way that car should have been running there.. not even close,that just has to be fixed. I i was out all day and barely made it past the first 3rd of the dial, and i am about the same temp as maine..

 

I think you are correct. Mine has been slightly above the bottom mark when I added the quart. I don't think my car has ever been more than a quart low thus my erroneous comment. On the other hand, I tend to prefer to stay a little below the top line to prevent overfill.

 

I have heard that comment from many also , try to be at the middle , not at the top.. on my first oil change I filled it to the top , no ill effects but in future i will do as you did . so where does your guage sit when you are at the mid point of the dipstick ?

 

I ignore my oil level guage...it's about as useful as the 'shift light' . I'm not saying that it is inaccurate on all cars, but the dip stick is the ONLY way to know for sure...keep it at the midpoint mark.

Keith
'88 CE coupe

 

I was thinking about this a little more last night and I was just wondering something. Something that Maybe Steve Tony or Pete could chime in on. what if what he read was correct. Is there any condition on the car that would indicate no oil while idling . ( just as if the car were cold turned off being checked ) some kind of scavenge pump maybe ? . Also contribute to a running very hot condition. It is almost loke the oil is not being pumped back into the tank, maybe the engine is trying to cool on a lot less oil. Maybe sansor has noticed a key item. when the guys in the shop run it it does not overheat and i imagine the oil level checks fine ?
I am not sure but just trying to come at it from a different angle

 

Many thanks for your interest and thoughts. I just hope to one day return the favor and be of help to a fellow list member in need.

More details in response to your questions: The oil gage was reading low at the start of the trip, just barely off the bottom mark. When driving it seemed to just sit at the bottom. After I added the 3 quarts of oil, the gage appeared to rise to the mid point. Just before I pulled over with the oil spraying the gage dropped down to the bottom. I really did not get a good feel for this oil gage ,in the short time I was able to drive my car :-( It seemed to be up and down a lot and changed with driving vs. standing still. Is this common with this gage? Was this part of the problem?

The other observation that may be helpful was that the oil did actually spray out of the engine...it was not a stream. When I stopped the only additional oil that came out was dripping from the oil soaked engine compartment. (thank goodness it did not catch on fire, ...no extinguisher - (saw the recent thread on this topic---GOOD INVESTMENT!)

Being a novice at this...how does an oil overfill get oil into the airbox
Thanks for the ongoing support.
Bob