Defender 90 2.5 TD drinking oil

hi all, new to this forum and not amazingly mechanically minded. But I understand terminology. My 2.5 TD defender (1988) is drinking oil. Will go through 5 litres every 2-3 months or every 300 miles. I’ve read about the piston rings being a possible culprit. Could anyone else advise on what could be the cause? Thanks.

Leaks!!!...

I guess if it's not leaking, could be valve guides but with a 19j engine, more often than not it's pistons/rings. Can also be Turbo. Is there much smoke under load?

No oil leaks from the engine, and yeah it does seem to. Is it a big job for pistons and rings? I’ve not had to face this with any vehicle I’ve owned. So I have no idea how bad/big a job it would be

NorthantsDefender90 said:

hi all, new to this forum and not amazingly mechanically minded. But I understand terminology. My 2.5 TD defender (1988) is drinking oil. Will go through 5 litres every 2-3 months or every 300 miles. I’ve read about the piston rings being a possible culprit. Could anyone else advise on what could be the cause? Thanks.

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Have you checked the breather pipes to see how much oil is blowing down there?
And does the breather pipe route into the air intake tract?

Also, your vehicle is not a Defender, it is a Ninety, or a One Ten. Defenders have 200Tdi or later engines.

Fair size job, yes but can be done without removing engine, as long as bores arenta badly worn. Just need to remove sump and head, although after doing that, you may as well remove the entire lump. If the bores are badly worn, will need block reboring. Check out Turners website for piston prices.

You may wish to consider replacing with a 200 or 300 TDI from a Disco. I like the 19j but tdi's are better motors.

Britcyclerider said:

Fair size job, yes but can be done without removing engine, as long as bores arenta badly worn. Just need to remove sump and head, although after doing that, you may as well remove the entire lump. If the bores are badly worn, will need block reboring. Check out Turners website for piston prices.

You may wish to consider replacing with a 200 or 300 TDI from a Disco. I like the 19j but tdi's are better motors.

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It is quite likely that his problem is simply that a blown head gasket is blowing the oil down the breathers, and into the air intake, or onto the road, depending on how the breathers are routed.

And it would be a very good idea to check this, before spending a lot of money on pistons and rebores.

Pop your air filter out and see if it is wet with oil. A few oily marks are probably ok but heavy oil contamination suggests excessive blowby.

Dude, really, before you go spending a fortune get a compression test done, check also for blown head gasket. When its running at idle pop the oil filler cap off and see if its chuffing out the hole, as said check all the breather pipes, a photo of your engine would help but my guess is you have the late type engine in there. Is it smoking from the exhaust? Pop the pipe (blue one) from the turbo to the inlet manifold off and see if there is any oil pooling in there. Is it down on power? How long has it been like this?

Britcyclerider said:

Pop your air filter out and see if it is wet with oil. A few oily marks are probably ok but heavy oil contamination suggests excessive blowby.

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You wont find a 19j with a clean oil free filter, it really doesnt mean a thing if there is a lot of oil in there, except that the filter needs changing.

Oh, and how many miles has it done?

nobber said:

You wont find a 19j with a clean oil free filter, it really doesnt mean a thing if there is a lot of oil in there, except that the filter needs changing.

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You will if the breather pipes aren't routed into the air intake.

If there is no problem, a little oil on the filter may not be an issue. But if the air filter can has an inch of oil in the bottom, and the paper element is a black sodden lump, it is a sure sign of trouble, and probably well on it's way to a terminal diesel runaway.

Ive had three now, all had oily filters and none ever ran away, if you vent the crank cast straight into the filter you will get oil in there.

nobber said:

Ive had three now, all had oily filters and none ever ran away, if you vent the crank cast straight into the filter you will get oil in there.

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Vent the crankcase, via the rocker box cover into the chassis. Or use a long pipe with a catch can, and go into the air intake.

I have seen several TD, and NA, run away, and it destroys the engines completely.

I must have worked on scores of these, not to mention hundreds of similar old tech engines.

Britcyclerider said:

I guess if it's not leaking, could be valve guides but with a 19j engine, more often than not it's pistons/rings. Can also be Turbo. Is there much smoke under load?

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piston crowns split, or rings and bores wear