Insane oil consumption on my 4x4

[rcx132]

I've had my Isuzu Trooper 3.5 V6 petrol auto for six months and I've just had to put over 3 litres of oil into the engine to get the level back to max. The car has now consumed 6 litres of oil in approx 2000 to 3000 miles. This is way higher than any car I've owned before. There's no oily deposit at the tailpipe, just dry soot, and no visible oil leak. The car has 110'000 on the clock and otherwise drives very well.

Correct me if I'm wrong, but don't all the common oil loss routes result in the oil being burnt up and showing up at the tail pipe?

I've got a spare Trooper that I use for spares. The previous owner of the donor Trooper kept a log book which shows he was putting in ½ litre of engine oil every couple of thousand miles, which seems way more normal for me. Same engine, and same mileage car. I'm thinking of swapping the engine over.

 

[scottmk1]

It’s not leaking into the coolant? Does it smoke when running?

 

[Rrobson]

You could look at the bright side, certain grades of oil is cheaper than petrol now so if it’s burning it the car is doing you a favour!

Both of those seem excessive, you might expect a small top up once or twice a year, not every couple of thousand miles and certainly not a litre every 500 miles. I don’t know those engines but it may be a common thing? Could be hundreds of reasons why it’s going through oil but at that amount you’d expect blue smoke if it’s burning. If it’s leaving the engine else where then your either leaving a trail where ever you go or it’s collecting else where…

 

[rcx132]

There's no excessive visible smoke, and it passed emissions. I'll check the coolant but didn't see any oil in there last time.

 

[Robotstar5]

Rear engine crank seal and it's filling the bell housing up with oil?

 

[8ob]

There's no excessive visible smoke, and it passed emissions. I'll check the coolant but didn't see any oil in there last time.

I would get someone to follow you down the road and observe what comes out of the exhaust, long overruns/deacceleration cause hivac and could be bringing oil up past worn rings that wouldn't under normal driving conditions.

Bob

 

[Nomad]

I bought a sporty Nissan 2L turbo, oil was ok most of the time but on a long motorway run the level would drop from full to minimum - the oil went down quicker than the petrol but only when the turbo was working hard. Very odd !
It got rebuilt under warranty and they found one of the bores was badly pitted, we guess due to standing with water in it after a headgasket failure at some point in it's history.

 

[m_c]

Catalysts are very effective at burning off oil once up to temperature, so you may rarely see any visible smoke from the exhaust.

 

[Brad93]

All the oil will be in your cat or you've got a leak

 

[mike 109444]

See if you can get/borrow a GoPro and set it up looking out/down at the rear of the vehicle to see what is happening on a run. As suggested could be on overrun so no cloud of smoke when driving.

 

[dobbslc]

Turbo oil seals? Keep an old wooly jumper ready to stuff in the air intake if it runs on...

 

[123hotchef]

Worn turbo seals or piston rings let it burn the oil as said its cheaper than desiel

 

[slim_boy_fat]

Get a compression test done?

 

[Blobber]

It cant be the turbo as it hasnt got one, is it the wrong spec oil? I think the book states 10/30 and I wouldnt be going for anything too funky on that engine it doesnt need it

 

[rcx132]

@Blobber that is a possibility as it's got fully synthetic in there.

Yup, no turbo.

Some good ideas here. Please keep them coming. I'll get the car into my garage as soon as I find a way to move my wheel-less buggy project out of there to make space. I'll let you know what I find, but please do keep the ideas coming.

 

[dobbslc]

It cant be the turbo as it hasnt got one, is it the wrong spec oil? I think the book states 10/30 and I wouldnt be going for anything too funky on that engine it doesnt need it

Ah that'll teach me not to read the post properly!
PETROL.!

 

[CompoSimmonite]

There is only two ways oil can be used - leaking or burnt. It there is no leaks then it's going out the exhaust. First thing I'd do is a compression test to determine if rings or valves are source

 

[The_Yellow_Ardvark]

If it is not leaking and not filling up other parts it must be bieing brunt.

One of my works van was the same. past all the tests, no blue smoke visable to me when I was driving.

But when I was followed there was a fine blue smoke all the time on the motor way, worse going down hill.

Get a leak down test done and you will see.

Oh check the crank case breathers and filters.

 

[8ob]

I would go for a leak down test, wet bores can give duff readings when doing compression tests.

Bob

 

[Kram]

My first car was as bad, about a litre every 250 mile tank of fuel. The oil ring in one pot was bad. I kept it topped up with cheap oil and lasted a while. On motorway consumption was much higher - suggesting the leak was only significant at high engine rpm.

To diagnose, pull the spark plugs. Firstly look at the plugs and stick a cheap £5 bore camera inside. If theres any oil being burnt the deposits will be quite obvious, a thick layer of ash covered the 3rd pot of my cylinder head.

Compression/leak tests did not tell me much, the bore can have perfect compression but still allow oil in.
This is the reason I thought it was valve seals and pulled the head off to replace them.