high oil consumption with leaks

[tmblackflag]

Howdy,

My 86 Carrera has approximately 87k miles. I took it to a reputable shop for an oil change and valve adjustment about a month ago.

They gave the car back to me with a full tank of oil. I've now driven 1,000 miles and had to add about 2.5 quarts to get it back to near full.

Now my car leaks oil onto the left heat exchanger, as well as onto the right rear hard oil line that comes from the back of the block to the oil thermostat on the passenger side. I changed the flexible line but it doesn't appear to have fixed the leak so now I think it's coming from somewhere higher up.

Now the kicker, since i got the car i haven't had a single drop of oil on my driveway, never. Is it possible that I am leaking that much oil while driving, or is the more likely scenario I am burning tons of oil and looking at a top end job soon?

When the PPI was done, the compression and leakdown numbers all came back solid. Additionally, the mechanic wiggled the valve guides and said there was minimal play. In other words, he thought they were in good shape.

The only potentially related issue to needing a top end i have noticed is the car blows white smoke on startup. About 20-30 seconds after startup, and for a good minute or two after that it puffs a decent amount of white, stinky exhaust smoke. It usually isn't too bad but somedays is worse than others. I'd been letting the car idle for 1-2 minutes once reaching my destination as I've read this helps (and it seems to be helping).

[plumb4u2]

they did not use a quality oil most likely synthetic

this happened to me when I bought my car and decided to change the oil I used Castrol GTX and leaks started immediately cause it is very thin

so I had to replace a bunch of seals and now only use Brad Penn

[DaddyGlenn]

Oil pressure sender and/or thermostat is leaking. That is common. They will leak when the engine is running only. Be sure you are not overfilling it.

[tmblackflag]

Originally Posted by plumb4u2

they did not use a quality oil most likely synthetic

this happened to me when I bought my car and decided to change the oil I used Castrol GTX and leaks started immediately cause it is very thin

so I had to replace a bunch of seals and now only use Brad Penn

This was TRE Motorsports in SoCal, these guys are studs and used Brad Penn.

[tmblackflag]

Originally Posted by DaddyGlenn

Oil pressure sender and/or thermostat is leaking. That is common. They will leak when the engine is running only. Be sure you are not overfilling it.

Motor is definitely not overfilled. I'm read countless threads about people putting in too much oil and getting white smoke on startup.

I'm getting the white smoke now even while the oil level was a bit low and I filled it back up.

Is it possible to diagnose triangle of death leaks from the top of the engine? Say with the air filter housing removed and maybe a mirror and flashlight?

[plumb4u2]

Originally Posted by tmblackflag

This was TRE Motorsports in SoCal, these guys are studs and used Brad Penn.

ok so you say that your car did not drip a drop of oil until the day after they touched your car?
They may be Studs but shouldn't you have it back in their shop right now?

[tmblackflag]

Originally Posted by plumb4u2

ok so you say that your car did not drip a drop of oil until the day after they touched your car?
They may be Studs but shouldn't you have it back in their shop right now?

To clarify, since I purchased the car a year ago it has always leaked. But never badly enough to drop onto the driveway.

I'm concerned about burning a ton of oil and wondering just how much could be lost to leaks while driving the car. You would think if it leaked that badly it would end up on the driveway in at least some quantity.

[Rot 911]

Could be bad valve guides. Your 3.2 mileage is right in the middle of where it tends to occur (60-100K miles). If it is just bad exhaust valve guides the oil gets sucked into the exhaust and is not burned so you don't see the typical smoke on decelleration like you would if the intake guides were bad.

Do a compression and leak down test and report back.

[tmblackflag]

Originally Posted by Rot 911

Could be bad valve guides. Your 3.2 mileage is right in the middle of where it tends to occur (60-100K miles). If it is just bad exhaust valve guides the oil gets sucked into the exhaust and is not burned so you don't see the typical smoke on decelleration like you would if the intake guides were bad.

Do a compression and leak down test and report back.

These were both done during the PPI about 5k miles ago. leakdown were all around 5% and compression was consistent across all cylinders with little variation.

[Rot 911]

Originally Posted by tmblackflag

These were both done during the PPI about 5k miles ago. leakdown were all around 5% and compression was consistent across all cylinders with little variation.

Well I don't think your valve guides went from good to worn in 5K miles. I went back and reread your post. As you probably know, check your oil with the car on flat ground, up to operating temperature and with the car idling. Now, if you are doing all of that and adding oil up to the top mark on the dip stick, you are adding too much oil. Full is half way between the marks. Fill to the top mark and you will be sucking oil into the airbox, particularly on hard turns. Sucking oil into the intake would be consistent with the car smoking for any period longer than 4-5 seconds on startup.

[tmblackflag]

Originally Posted by Rot 911

Well I don't think your valve guides went from good to worn in 5K miles. I went back and reread your post. As you probably know, check your oil with the car on flat ground, up to operating temperature and with the car idling. Now, if you are doing all of that and adding oil up to the top mark on the dip stick, you are adding too much oil. Full is half way between the marks. Fill to the top mark and you will be sucking oil into the airbox, particularly on hard turns. Sucking oil into the intake would be consistent with the car smoking for any period longer than 4-5 seconds on startup.

When I add oil it's always after a drive with the car at full operating temp and o a flat surface. I don't add all the way to the line, it's more like 1/4" to 1/2" from the top mark. And the car still smokes even when I'm at the lower mark on the dipstick and slightly below it.

[spuggy]

Originally Posted by tmblackflag

I'm getting the white smoke now even while the oil level was a bit low and I filled it back up.

Oil smoke is not white.

[tmblackflag]

Originally Posted by spuggy

Oil smoke is not white.

It's white, and stinky. Smells like exhaust.

I guess the point of my thread was to question whether or not oil could leak enough while driving to justify me being down 2.5 quarts over 1000 miles. And that much leaking without seeing any of it in my driveway.

I'll attack the triangle of death asap, or at least inspect it and go from there.

[timmy2]

2 things:

1.Oil level should be 1/2 way between the marks on the dipstick. That's 1.5 inches from the top on my dipstick.

2. What valve cover gaskets did they use when they replaced them after the valve adjustment? Did they use all new hardware (locknuts and washers) as they are supposed to?
Did they torque them correctly or possibly over tighten them?

White smoke in lower temperatures takes a while to clear up. May take a good 20 minute drive to burn off the condensation.

And to answer the oil use question, yes, it can burn off that quickly from leaks, Mine hasn't used anything on the dipstick in 500 miles since repairing the leaks, where it would have been down almost a quart before.
I had P-car drivers behind me seeing the puffs of smoke as the oil hit the HE's before I fixed the leaks! Not much on the ground. If it hits the HE right, it burns off and doesn't drip!

[theiceman]

Okay the above post is finally getiing close

Recheck your valve covers as they were ALL off for the valve adjustment. I am sure you are leaking there.
Also look at the back of your car .. if you are leaking a decent amount underneath the tail and the back of the car will have oil drops or oily residue as the oil gets caught in the slipstream , this is another clue.

Your start up white smoke is probably humidity and moisture burning off . Just because it is stinky doesnt mean it isnt normal combustion gasses from a cold engine. If you think you have valve guide issues have someone follow you and have them watch as you downshift and report back , you might not see it driving it but they will. Also After a hard drive , the next time you start it is smokey then that cold be an indication also , The oil is very thin and when you stop the engine will seep by the valve guides. Dont panic though as this is not totally unusual for a flat engine as you probably know ..

Also the dip stick half way up is a pile of crap that has been around the internet for years. Certainly if you overfill and start taking wicked right handers some will seep over . But under normal conditions you will be fine. In fact Porsche addressed this years ago with a recalibrated dip stick for early cars. people just love to propegate the myth though. but if you have had your 911 for any legnth of time you know this already.

Oh just for other people looking on who are going to argue " the myth" i will attach a pic of the old and recalibrated dipstick. The low mark is the same obviously but the full mark is moved down to address the issue.

My rule of thumb with these is fix what you can see before you fix what you cant see. In other words work on your physical leaks first, then reassess.



All the best and good luck.

[javadog]

Why not just get the oil leaks fixed? TRE would be happy to do that and I'm sure your oil consumption would drop. It will never be zero, though. You'll always consume some oil, depending on the type of oil you run and how you drive the car.

JR

[E Sully]

Leak down and compression tests will not show worn valve guides. Pull a spark plug out and see if it is coated with carbon from oil. I am curious about the check for valve guide wear the mechanic did, seems tough to check by wiggling the valves in the guides unless he removed the valve springs. Leaks on the left exhaust is most likely valve covers, unless one of the rocker shafts is loose.

[MrBonus]

Originally Posted by javadog

Why not just get the oil leaks fixed? TRE would be happy to do that and I'm sure your oil consumption would drop. It will never be zero, though. You'll always consume some oil, depending on the type of oil you run and how you drive the car.

JR

I agree with JR.

When I bought my car, I was going through a quart every 400 miles despite a clean compression check. I spent the first two months of ownership lamenting the fact that I was going to need a top end rebuild.

One day, I spotted a few drops of oil underneath the oil tank and traced it back to the oil level unit and its cork gasket which was leaking all down the tank and into the fender wells. I replaced the gasket, tightened down the bolts, and my consumption went to a comfortable quart per 850 miles.

[kidrock]

How often do you drive the car, and for how many miles? Does the inside of your oil filler cap have hints of thick yellow cheese? Maybe it's just a condensation issue that can be solved by a couple of nice long hot drives?

[spuggy]

Originally Posted by tmblackflag

It's white, and stinky. Smells like exhaust.

Oil smoke smells like burnt oil.

White, thin, wispy smoke is steam. That's the water you see running out of tail pipes when they're cold. Why exhaust systems rot from the inside if they're used for short journeys.

Black is gas (rich). Probably should never see that on a 3.2.

Oil smoke is grey/blue - if it's being burnt. Not a problem for it to puff oil on starting after sitting overnight, so long as it clears in a few seconds (2-3) of running; that's oil that drained into the combustion chamber getting burnt.

Once hot, blue/grey smoke on acceleration is rings, or guides on deceleration. Probably only folks directly behind you can see this, unless it's bad enough to see it in the mirror.

I guess the point of my thread was to question whether or not oil could leak enough while driving to justify me being down 2.5 quarts over 1000 miles. And that much leaking without seeing any of it in my driveway.

Where did the oil level get set? Most good shops set the level, @180, mid-way between the two marks, to allow the oil to get hotter without puking out the overflow. That's more than a "quart low" from the top mark right there. If you fill right to the top mark, that's too much oil in traffic where my motor reaches @ 210 or 220 without airflow through the FMOC.

How did you use the car? My motor uses lots more oil on short (15 mile) journeys because the clearances are larger for longer and more oil "escapes". Uses almost nothing on long journeys.

Factory quotes 1 quart per 1000 miles for a 3.2, no? Seems to me you could be only 8 ozs or so adrift. And if it were overfilled, it could have rejected some of that when it got hot...

I'll attack the triangle of death asap, or at least inspect it and go from there.

Looking at it is always a good start.