how fast should my engine use up its oil?

[sd88supra]

i have an 87 5pd NA, 110k original miles on it. my engine consumes about 3/4 of a liter of oil after about 300 miles. Is this normal? No leaks. Also, is it very important to always keep it full (not overfilled, of course)?

on a different note, my power steering fluid is leaking through the rack and pinion. i have replaced the boot, but it still leaks. where would the problem lie?

[Burn N' Up]

3/4 of a liter after 300 miles is excessive. does it stop after that 3/4s or does it keep going down? Any smoke out the tail pipe? Any oil or white milky residue in the radiator or on its cap?

[sd88supra]

i did the math again and it uses up about 3/4 of liter per 420 miles or so. it still seems like a lot, but ill see later if it keeps going down. also, is it very important to keep it full?

there is no milky reside nor smoke, just the normal vapor from the exhaust. and no oil leaks, just the power steering leak from the rack and pinion.

[supra_91]

Originally Posted by sd88supra

i did the math again and it uses up about 3/4 of liter per 420 miles or so. it still seems like a lot, but ill see later if it keeps going down. also, is it very important to keep it full?

there is no milky reside nor smoke, just the normal vapor from the exhaust. and no oil leaks, just the power steering leak from the rack and pinion.

very very important to keep your oil full. it it gets too low you will lock up your engine and then your screwed

[rnoswal]

If it is not leaking it, it is burning it. Bypassing the valve stem seals or the rings. Not necessarily a time for a rebuild, but it is getting close. If the oil is getting burned then it is leaving deposits on the valves and if it is going past the rings then you are losing performance. Save up and go for a rebuild.


Russ

[Isphius]

You motor should use any oil at all normally lol. And i also have that same power steering leak. i started putting corn oil in instead of ATF cause its starting to get expensive haha. it actually feels better with the oil too. Im looking for a rack and pinion rebuild kit. cant seem to find one thou.

[sd88supra]

how "long" till a rebuild? i still get good performance but i imagine it can get even better. i am saving up, and looking to put in another $2000 or so into my car. i think its worth it since it has 110k original miles.

also, what are the pros and cons of a rebuild compared to swapping it with a JDM engine? im not looking for a 1jz, not even a 7mgte. i was thinking about first going for a rebuild and in the future (years from now) going for a JDM. im also thinking i should upgrade my head gasket while i do the rebuld.

[sd88supra]

anyone? help appreciated.

[Black'88]

Originally Posted by rnoswal

If it is not leaking it, it is burning it. Bypassing the valve stem seals or the rings. Not necessarily a time for a rebuild, but it is getting close. If the oil is getting burned then it is leaving deposits on the valves and if it is going past the rings then you are losing performance. Save up and go for a rebuild.


Russ

Around how much would a good rebuild cost for a mk3?

[TONY!]

I had this as a write up already, this would be a good thread to place it in.



Well, if I just bought a car like that and wanted to assess it and its oil seals, I would do some of the following procedures and think of the following questions:


As far as burning it:

Valve stem seals: Does it smoke on start up? If so it is your valve stem seals.

Rings: If you do a compression test and or a leak down test, you can get an idea of what shape your rings are in. From that, you can sort of gauge the sealing of that area.

Turbo seals: I once hear this mechanic tell me that if your turbo is damp on the outside, then that means that one of oil seals is bad. Possibly if your turbo’s seals are bad, you will get quite a bit of carbon build up on your pistons. I think that is the reason why my pistons had an excessive amount of carbon on them, from oil entering the cylinders.



As far as leaking it:

There are two types of oil leaks: the ones that drip, and the ones that don’t. You can have an oil leak that runs down the engine and sort of evaporates. If you have multiple leaks like this, collectively running down a large surface area, you will loose a bit of oil and won’t even see it on the ground.

Valve covers: Having a leak like that in the valve covers would be that way. The leak would have to run the height of the engine before it reaches the ground.

Cam position sensor: On my car it was very black and gunky in that area. The CPS has an O-ring that shrinks after so many years and heat cycles. A leak in an area like that (high and around other parts) would get everything damp and evaporate rather than leak—if it is a small leak and not gushing out.

The front cam seals: They are also very high and would run in the timing case and get many things wet and evaporate before reaching the ground.

There are also other places/seals that can also contribute to oil loss, but I just named the ones that I suspect the most for "invisible" leaking.


On an old car with drying out rubber gaskets—and so many of them—it can all add up to quite a bit of oil loss without even dripping on the ground.


Those are my thoughts and theory on the matter so far and what I have come up with.



losing oil leak consumption