Oil Consumption

[msgm1]

My 1987 Turbo goes through about half a quart of oil with every one to two fill ups of gas, does that sound normal? The engine was fully rebuilt about 10k miles ago - fwiw

[msgm1]

Hello is there anybody out there...?

[908/930]

1/2 quart to two tanks of fuel sounds like a lot, have seen worse but that was a friends 1974 Vega.
Is there lots of oil in your intercooler? Engine leaks? Is that street use only?

[gsxrken]

Trying running your oil towards the lower mark on the dipstick. You’ll probably notice less consumption like that.
With a rebuild only 10k ago, your valve guides should be fine. Of course, if you’ve been detonating due to lean AFRs on boost, you could have broken some rings. A leak down test would tell you if that’s the case.
Turbos use oil, no doubt about it. I think the Porsche manual says as much as a quart per 1,000 is expected. Never rebuild an engine simply because it burns oil… oil is much cheaper. If your plugs loook good and your power isn’t down, I’d drive it.

[Bucketlist]

Originally Posted by msgm1

My 1987 Turbo goes through about half a quart of oil with every one to two fill ups of gas, does that sound normal? The engine was fully rebuilt about 10k miles ago - fwiw

One to two fill ups could be between 20 and 40 gal of gas per 1/2 quart. Let's say about 30 gal gas @ 20 mpg is 600 miles on a 1/2 quart (1200 per Qt) which isn't that bad with an old Turbo motor. If you only get 10 mpg or worse who knows. If your running rich your oil could be contaminated with gas making it thinner and you will probably use more. Then it depends on how you drive the car. If you have a heavy foot you'll burn a lot more oil at 1 bar of boost than you will puttering around town.

[timc]

Originally Posted by gsxrken

Trying running your oil towards the lower mark on the dipstick....

FWIW, Back when I first bought the car, I was trying to run it at the upper mark, kept adding oil to keep it at upper mark, then I began keeping it at the middle, or even 1/4 from lower mark, and it's been fine (with only maybe a qt or two every 5k miles) for the last 100K or so miles. I stopped trying to keep it full pretty quick.

[msgm1]

Ah very interesting about not running it will the oil fill indictor towards the top. I guess I was getting c20mpg at 20 gallons per fill. The car is making really good power. the Turbo Kraft kit we put on it is rated at I think 420hp from memory plus we changed out the cams as well. I do notice some engine hesitation at wot, but i think that is due to one of the fuel pumps needing to be replaced as the fuse that feeds the pump is running very hot c180 degrees very the other fuses at 100 degrees

[spuggy]

Like the guys said, although it's possible you didn't bed the rings in, broke the rings or have some problem with oil escaping that you haven't noticed - seems more likely that you're just trying to keep the oil level too high. Or doing comparatively short runs where the motor is spending more time cold, and the clearances are bigger. My oil consumption is way higher on short runs - like daily driving 15 miles on city streets in traffic - versus longer runs. Just because of the proportion of time the motor is warming up and getting to operating clearances.

Get it good and hot - like drive somewhere 600 miles away - and see what oil consumption is like then. Chances are it will use a lot less once hot; the factory developed these motors through endurance racing, and they love getting up to temp and staying there - my experience is that they run better for weeks afterwards...

I'm pretty sure (although I can't find it with a quick look in the FSM, or locate my spec booklet just now) that the factory stated maximum oil consumption is 1.0-2.0 L/1000Km.

While a liter (or litre) is "meh, close enough" to a quart, 1000 kilometers is 621 miles. So, a quart per 300 miles would be the upper limit of "acceptable" oil consumption per the factory (mine's never used anything close to that).

I too tried to keep the oil level in the upper half of stick at one time. And was always checking/adding oil to keep it there (I also think it just blows excess out the breather or something when driven hard - y'know the owner's handbook says you've got to get the wastegate open and hold it through a gear to max RPM every time you drive the car, right? LOL). My experience was exactly the same as Ken and Tim;

Now I aim to keep the oil level around the lower 1/3, 1/4 mark of the stick and it uses very little oil by comparison - and I think most of that is lost during warmup. I make a note to check/add oil when idling on the flat at a stop light, hot, shows a low level on the gauge. Because mine matches the stick perfectly, always has.

I also wouldn't sweat oil level very much; short of a blown hose or a massive leak, only reason to be concerned about low oil level on a dry sump motor is if volume of available oil is significantly reduced and what is left has to work too hard (higher temps, additives getting used up etc).

With an extended/baffled oil tank and an FMOC that holds an extra couple of quarts over stock, I see no reason to be disturbed so long as I can see oil on the bottom of the stick, as the pickup is quite a long way down from that..

[spuggy]

Originally Posted by msgm1

think that is due to one of the fuel pumps needing to be replaced as the fuse that feeds the pump is running very hot c180 degrees very the other fuses at 100 degrees

I've only ever run a single fuel pump, but I believe current for both pumps on a 930 goes through a single fuse - might take a look at 930 Fuel Pump Fuse Overload - The Solution

The design of the original fuses really doesn't provide a lot of contact area to transfer current - ATO fuses are a much better design in that regard. The Classic Retrofit fuse board is a nice upgrade - and the headlight relays provide markedly brighter and whiter illumination at night with no other changes. And the headlight stalk switch won't burn out...

Oh, while you're thinking about improving what the factory did, check for a fuse on the dash/instrument illumination, and add one if this hasn't been done already... Dash lighting fuse installation

[msgm1]

Originally Posted by spuggy

I've only ever run a single fuel pump, but I believe current for both pumps on a 930 goes through a single fuse - might take a look at 930 Fuel Pump Fuse Overload - The Solution

The design of the original fuses really doesn't provide a lot of contact area to transfer current - ATO fuses are a much better design in that regard. The Classic Retrofit fuse board is a nice upgrade - and the headlight relays provide markedly brighter and whiter illumination at night with no other changes. And the headlight stalk switch won't burn out...

Oh, while you're thinking about improving what the factory did, check for a fuse on the dash/instrument illumination, and add one if this hasn't been done already... Dash lighting fuse installation

Thx U!!!!