1995 Toyota Corolla oil missing

Hi there,

You can still have good compression and still use oil because of a defective oil control ring, also oil consumption may be via valve guides or stem seals, if you are using a syn th oil from new you may have run in problems, what oil are you using.

Mark (mhpautos)

Hi there,

Oil control rings are very easily damaged as are compression rings if fitted incorrectly, with out getting to technical, ring end gaps are critical and on Toyota oil control rings there is a small tab that that the ring seals against (end to end) that is critical, also engine preparation on assembly is very important, es must be washed spotlessly clean so there is no hone material in the bore hatch marks, these are tiny criss cross lines that hold oil for ring lubrication, if not prepared correctly oil usage can result, as for mineral V synth oil. Synth oil is not used for run in of a new engine as it will not allow the rings to bed in correctly, basically it is just to slippery, mineral oil should be used for the first 1=2,000 Kms then a synth can be used if desired.

Mark (mhpautos)

Hi there,

you can check fore worn valve guides by doing a normal start cold engine, and watch for a puff of blue smoke, when the oil is hot and thin it will by pass seals and worn guides and sit on the valve head, when it starts this oil will burn off with a puff of blue smoke, you don't get enough oil running down with the engine hot to see much smoke, it has to collect a little before you see it, as for rings and particular oil control rings, there is no real test as compression is independent of the function of the OK control ring, you may see some deposits building up on the spark plug, that may help identify a suspect cylinder, so if the head is sound valve guides and stem seals are OK, check the oil filler for any back pressure when running and any sign of oil in the air filter (via the PCV) if that is all OK, I would be suspecting the oil control rings or faulty bed in procedure with synth oil as the possible cause.

Mark (mhpautos)

Hi there,

A compression test will not show up a cracked head, cracks in a head are normally very small and terminate in a water or oil gallery, heads are crack tested when removed as precaution, some cracks are not a problem, but normally that are the secondary result of a over heating problem, As the oil ages and you start to clock up the miles the oil will start to break down ad in its changed chemical start thin and is more susceptible to burning this is quite normal with engines that have worn rings and compression problems, is there any excessive blow by when you take off the oil filler and is the PCV working correctly and is the engine temp in the normal range and not running colder than normal and do you do a lot of short trips?

Mark

Hi there,

Change the PCV as by now it will be rather clagged up with carbon deposits. As for oil consumption and cold engines, pistons are actually slightly oval when cold and expand to correct size when they are at correct operating temp, with the engine operating cold over a long time you will get uneven bore wear and poor piston ring seals, (was the ovality of the bores checked before new rings were installed?) This is not normally a problem in the short term, but if the bores are well worn, this could well be your problem, there is no way of checking this with out dismantling the engine, this check should have been done before the re build, but if it was over looked this could well be the problem.

Mark

You will be better off with a full suspension make over, coils & struts or it will handle like a steel filing cabinet.

Mark (mhpautos)