'81 SC oil consumption/oil loss problem

[911SCRVA]

A while back, I noticed that my 911 was either losing or consuming too much oil.

The details:

I've had to add a couple quarts of oil after only a few hundred miles.

I don't know what kind of oil all the previous owners used, but I know the mechanic preferred Liqui Moly. When I noticed the oil level had changed pretty dramatically, I was forced to use Mobile 1 15W50 because I was on the road and that was my only choice.

I occasionally get a puff of white smoke when I'm on the highway, but rarely.

The exhaust has started to smell a little rich.

There are oil spots beneath the car, but nothing dramatic.

The oil gauge, which used to perpetually rest at empty (regardless of it not being empty, but not uncommon from what I hear), but it has begun acting erratically, flicking all the way to full and then bouncing back and forth.

I reached out to the mechanic who has serviced the car for all of its previous owners. This is what he said:

"As you know, the car has compromised oil plumbing on the passenger rocker area. This plumbing leads from the engine to the oil cooler in the passenger front fender area. It is and has been a small seep of oil loss. If this has turned into a “drip” (where it is leaving oil accumulation on the ground OR dripping oil while car is running) then this can also attribute to changing oil levels on your dipstick. A change of a seep to a drip can happen at anytime."

This was all news to me, but that's irrelevant at this point. My problem now.

How would you recommend I proceed trying to solve the loss/consumption issue?

I found an article "How to Replace the Hard Oil Cooler Lines on an Air Cooled Porsche 911". Is this my next step? Or are there a number of smaller, simpler things to try first?

I could bring the car to the mechanic to do forensics and repair, but I'd like to attempt to do this myself.

Thank you for your help.

[proporsche]

hi, from all of this info i do not see how do you check your oil level? And how many Q per 1000 miles?

Ivan

[911SCRVA]

Originally Posted by proporsche

hi, from all of this info i do not see how do you check your oil level? And how many Q per 1000 miles?

Ivan

Since buying the car, I've driven it 2,178 miles and have added four quarts.

[darrin]

Unless you see a LOT of oil pooling under the car (or, with the engine running and at full operating temperature, you observe oil dripping out of the oil lines under the passenger rocker panel leading from the engine to the oil cooler just in front of the passenger side front wheel) , don't think "losing oil" is your issue. A VERY small amount of oil (say a teaspoon) creates a surprising large oil spot. I echo Ivan's comment above -- how are you checking your oil level (you should only use the dipstick and only check while engine's fully warmed up, running and sitting on level ground).

You should also ignore the oil gauge's gyrations -- this is a sign that the sending unit's going bad (or there's a continuity issue in the wiring between the sending unit and the gauge), only trust the dipstick to show you the actual oil level.

Ultimately (and assuming you're using the above methodology to check oil level and add oil), unless you discover a gusher (or a significant amount of oil coating the underside of your car), sounds like your issue is oil consumption (the engine's burning the oil while running), with the common culprits being either through worn valve guides or piston rings.

How many miles are on the car/engine?

[911SCRVA]

Originally Posted by proporsche

hi, from all of this info i do not see how do you check your oil level? And how many Q per 1000 miles?

Ivan

Sorry, I missed the first question. I check it parked on a level surface while it's running, preferably when the engine is hot (but sometimes when it's only warm). But there are so many atmospheric variables (I've been told) in getting the engine hot, I don't even know I've ever truly gotten the engine hot, even on hot summer days driving it 100 miles.

[911SCRVA]

Originally Posted by darrin

Unless you see a LOT of oil pooling under the car (or, with the engine running and at full operating temperature, you observe oil dripping out of the oil lines under the passenger rocker panel leading from the engine to the oil cooler just in front of the passenger side front wheel) , don't think "losing oil" is your issue. A VERY small amount of oil (say a teaspoon) creates a surprising large oil spot. I echo Ivan's comment above -- how are you checking your oil level (you should only use the dipstick and only check while engine's fully warmed up, running and sitting on level ground).

You should also ignore the oil gauge's gyrations -- this is a sign that the sending unit's going bad (or there's a continuity issue in the wiring between the sending unit and the gauge), only trust the dipstick to show you the actual oil level.

Ultimately (and assuming you're using the above methodology to check oil level and add oil), unless you discover a gusher (or a significant amount of oil coating the underside of your car), sounds like your issue is oil consumption (the engine's burning the oil while running), with the common culprits being either through worn valve guides or piston rings.

How many miles are on the car/engine?

Thanks, Darrin. The car/engine has 122,442 miles. (The mechanic says it's time for a rebuild, and although I'm definitely a novice, I've seen scant evidence the engine needs a rebuild.)

I do check the oil with the dipstick and only after the car has been running for at least 30 minutes, preferably highway driving. But I've been told it's nearly impossible to know what the true oil level is unless the engine is optimally hot. Would you say that the car, when idling at warm temp (not hot) that the oil level should sit between the low and high markings on the dipstick?

I'll check the car later today for dripping oil lines after I get it on the highway.

--Kurt

[creaturecat]

that's an acceptable amount of oil usage.
add when necessary. monitor usage carefully.
or buck up. your choice.

have you viewed the oil line that is suspected to be contributing to the loss? fitting weeping? etc? there are aftermarket solutions available - to minimize the pain of installing a new oil line.

[911SCRVA]

Originally Posted by creaturecat

that's an acceptable amount of oil usage.
add when necessary. monitor usage carefully.
or buck up. your choice.

have you viewed the oil line that is suspected to be contributing to the loss? fitting weeping? etc? there are aftermarket solutions available - to minimize the pain of installing a new oil line.

Thanks for your response. What would you say the acceptable range is? And when you say "or buck up, your choice", do you mean live with it as it is or spend the money to replace the lines?

I haven't inspected the lines. I'm new to this, so I'm not sure what I'd be looking for. Any tips?

[proporsche]

Originally Posted by 911SCRVA

Since buying the car, I've driven it 2,178 miles and have added four quarts.

That is basic oil usage...1-2 Q per 1000 miles is normal in your case plus some drips makes it ok...of course the less the better.If you have a white smoke in the morning-or cold that is your valve guides,if you see puff of white smoke while driving piston rings....

clean the engine and see where it drips-or take a picture before cleaning so i can see....

Ivan

[kltarga72]

I think if there was a hole or break in the oil cooling lines running to the front fender you would see a significant amount of oil splatter around the oil lines. Also if there is a hole forward of the external oil thermostat you maybe loosing oil when driving the car as the thermostat will open when oil temperature is hot. Either way you should see visible signs of the oil leak

Before you jump into an engine rebuild consider fixing the oil level gauge or sender first. Make sure you have the proper amount of oil. Drive the 911 and keep tabs on the mileage driven and oil usage.
When driving, the engine temperature gauge after ten miles or so should be reading normal, when your engine is idling and your on a level surface the oil level indicator should be near the 3 o-clock position

[MichaelSJackson]

I agree with darrin. Treat the oil level gauge as nothing more than a fancy idiot light, at best. Still nice to have it working.

I quit trying to top off the oil, long ago. I check mine fanatically and try to keep the level dead in the middle. Minimizes leaking pass the valve guides while parked. Parking on the tilt also aggravates valve guide seepage.

I'm not saying you shouldn't chase this down. It's best to know what's going on.

[911SCRVA]

Originally Posted by proporsche

That is basic oil usage...1-2 Q per 1000 miles is normal in your case plus some drips makes it ok...of course the less the better.If you have a white smoke in the morning-or cold that is your valve guides,if you see puff of white smoke while driving piston rings....

clean the engine and see where it drips-or take a picture before cleaning so i can see....

Ivan

Thank you, Ivan. I have a stupid question (as a novice, I reserve the right to ask stupid questions): Do you mean just a regular old picture of the engine, or is there something in particular you'd like me to focus on?

[pmax]

You can also pull the plugs using that nifty tool and see how they look.

[911SCRVA]

Originally Posted by pmax

You can also pull the plugs and see how they look.

Again, reserving the right to ask stupid questions: How do I diagnose what I see?

[proporsche]

take a picture of your oil leak-drip and the bottom of the engine.....
For the plugs if you take it out take a picture again and show to PMAX and us

Ivan

[pampadori]

911SCRVA - are you in Richmond? i'd be glad to take a look at your car and see what can be seen and help with diagnosis.

Feel free to text me if you want a local set of eyes to take a look.
540-537-1545

[911SCRVA]

Originally Posted by proporsche

take a picture of your oil leak-drip and the bottom of the engine.....
For the plugs if you take it out take a picture again and show to PMAX and us

Ivan

I just took the car for a 30 min spin and looked under it to see if there was a drip. I knelt there for a while and saw nothing.

I'll take a pic of engine's underside as well as the plugs. But I'm going to have to do it tomorrow a.m.

Thank you all for your help on this!

[911SCRVA]

Originally Posted by pampadori

911SCRVA - are you in Richmond? i'd be glad to take a look at your car and see what can be seen and help with diagnosis.

Feel free to text me if you want a local set of eyes to take a look.
540-537-1545

I am in Richmond. I'll text you. Be good to meet a local owner anyway.

[Reiver]

IMO that is a lot of oil for that many miles.... I have about 121k on the bottom end and 55k on the top and burn about 8-10 ounces every 3k miles. I do drive it hard. '83 930-10.
I had an '83 930-16 (as you have) with 230k miles and it burned about what you have now at half the miles.
Have you checked all of your head studs.... the play in your valves. I'd suspect some serious valve guide wear here.
Now, if you were tracking it and always driving at wot perhaps but normal driving at that mileage indicates serious wear of the top end.

[proporsche]

in the other hand yes 4 is a little too much but again we do not know where did you started with the measurements....

Ivan