300 Tdi Rebuild
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This is the block side of the gasket. It was stuck to the block in a few places, so there's a few places where bits look missing.
I emailed pictures of the pistons and cylinders to Turner Engineering and they've replied asking me to call them Monday morning.
The exhaust manifold gasket is at the bottom of this pic and you can see it was blowing.
I emailed pictures of the pistons and cylinders to Turner Engineering and they've replied asking me to call them Monday morning.
The exhaust manifold gasket is at the bottom of this pic and you can see it was blowing.
raywin
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Looking at the soft soot on all the piston tops makes me wonder if that's where your oil is going to, question is is it turbo seals, could be piston oil rings, or the engine breathing into the intake.
Did you ever run it with the rocker box vent diverted away from the air intake?
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Yeah, ran it with the breather venting in to a catch can and nothing. The air intake pipe (from air filter to turbo) is not oily.
I think the honing marks look ok. (no expert though) Brand new Kolbenschmidt pistons and rings. So, I think I've got a turbo leaking oil through the bearing rings. Well, it clearly is leaking oil through the rings, but now I'm suspecting that it's leaking enough to cause the full amount of oil consumption and that's creating the carbon build up on the pistons and the top of the cylinders and head.
Struth Al203 ! I feel for you - all that work and expense and now this!
They look as I'd expect them to look - more or less fresh from a recently rebored and honed bore that hasn't done many miles....
I can't see any witness marks on the HG - the exhaust gasket marks are quite easy to see - but even when I zoom in to your HG pics - they pixelate before I can see anything which is
and in equal measure - with a modicum of - which you'd already mentioned.....
The amount of soot is clearly an issue, though, and......, I'm confused, given the new turbo and every other possible cause which has been given consideration.... it's sort of leading me down the road of the bores being too big for the pistons - which I'm genuinely hoping is close to impossible. ( this assumes that the rings themselves are ok, and not from some sort of "bad batch" etc .... will be interesting to see what turners say on Monday )
In terms of the high oil pressure - have you checked the bypass valve spring - both for length and for any miscellaneous carp "keeping it company", stopping it working as intended....?
They look as I'd expect them to look - more or less fresh from a recently rebored and honed bore that hasn't done many miles....
I can't see any witness marks on the HG - the exhaust gasket marks are quite easy to see - but even when I zoom in to your HG pics - they pixelate before I can see anything which is
and in equal measure - with a modicum of - which you'd already mentioned.....The amount of soot is clearly an issue, though, and......, I'm confused, given the new turbo and every other possible cause which has been given consideration.... it's sort of leading me down the road of the bores being too big for the pistons - which I'm genuinely hoping is close to impossible. ( this assumes that the rings themselves are ok, and not from some sort of "bad batch" etc .... will be interesting to see what turners say on Monday )
In terms of the high oil pressure - have you checked the bypass valve spring - both for length and for any miscellaneous carp "keeping it company", stopping it working as intended....?
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Hmmm, hadn't contemplated the bore diameter. Having said that, I did check the gap on the rings and it was spot on, so should be ok.Struth Al203 ! I feel for you - all that work and expense and now this!
They look as I'd expect them to look - more or less fresh from a recently rebored and honed bore that hasn't done many miles....
I can't see any witness marks on the HG - the exhaust gasket marks are quite easy to see - but even when I zoom in to your HG pics - they pixelate before I can see anything which is
The amount of soot is clearly an issue, though, and......, I'm confused, given the new turbo and every other possible cause which has been given consideration.... it's sort of leading me down the road of the bores being too big for the pistons - which I'm genuinely hoping is close to impossible. ( this assumes that the rings themselves are ok, and not from some sort of "bad batch" etc .... will be interesting to see what turners say on Monday )
In terms of the high oil pressure - have you checked the bypass valve spring - both for length and for any miscellaneous carp "keeping it company", stopping it working as intended....?
The honing looks better now than it did then. Must be the light differing in each picture.
No, haven't dropped the sump to check bypass valve spring. I did put a new one in during the rebuild.
It wasn't a new turbo, it was a reconditioned one from a company called Recoturbo. I returned the first they sent me as it wasn't spooling up properly. I could hardly spin the blades with my finger. They replaced it with this one, which certainly spooled up and boosted better, but might be passing too much oil. It's a mystery
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raywin
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Hone marks dont look too bad to me, have you tried running your finger nail accross them? I can only go on the pictures but I honestly dont thing that they are your problem.
I cant see any problem with the head and gasket, if the oil was getting in that way I would only expect one sooty piston, but they all look similar.
So logicaly its going in with the air or up past the rings, if the ring gap was OK then the bores should not be too far out, did you measure the pistons?
If you have had a catch can on the breather then eliminating that leaves turbo oil seal.
By the way I also feel for you it cant be good to have all of your effort rewarded by problems, you deserve better than this, hope you can get it sorted soon.
I cant see any problem with the head and gasket, if the oil was getting in that way I would only expect one sooty piston, but they all look similar.
So logicaly its going in with the air or up past the rings, if the ring gap was OK then the bores should not be too far out, did you measure the pistons?
If you have had a catch can on the breather then eliminating that leaves turbo oil seal.
By the way I also feel for you it cant be good to have all of your effort rewarded by problems, you deserve better than this, hope you can get it sorted soon.
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Cheers, raywin. Yes, it's a shame it's not just running nice and sweet. On the other hand, who doesn't like taking their engine apart
No, I didn't measure the pistons. The cylinders were bored and honed to match the new, over sized, pistons.
Spoke to Richard Turner at Turner Engineering this morning. He thought the honing looked ok too. He thought the turbo was a top suspect for the oil consumption. However, build up of soot and carbon around the top edge of the piston can cause glazing and aid blow by. It can also build up around the top, outer diameter of the piston and the top of the cylinder reducing the pressure that goes down the side of the piston. This pressure is important as it forces the rings out over and helps create the seal of the cylinder. He also thought the injectors might need checking.
He said oil being passed from the turbo often makes number 3 and 4 cylinders the worst in terms of carbon build up as the oil tends to get pushed to the back of the inlet manifold. I suppose this will depend on how hot and atomised it is? Also, the engine has already done 30k miles since the rebuild, so time for all of them to build up a good layer of soot/carbon.He said the cylinder head gasket may have gone, but couldn't tell. Sometimes expansion bottles get old and let go, but usually because the pressure has gone above 14psi (I think he said 14psi) So, I should get the head checked for flatness in case it has been hot and warped. He said he would get the head checked and then bolt it all back together and investigate the turbo.
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Cylinder head gasket looks good, that is the right type also for older engines. Hone looks fine in the pics (as everyone said)
All the injector nozzles apart from no.3 look a bit unhappy to me, not sure if it's just the image though.
The oily wetness on the crowns, but lack of smoke while driving (i.e the intrusive oil is always burnt on compression strokes not constantly leaking in / blowing out) and general "looks good" factor of everything else in the pics does very much point back to the turbo, even though the intercooler should have a few tablespoons of oil pooled at the bottom of it if the oil control rings have failed / were never installed correctly, but I think you checked that already.
Would do as disco1 suggests as well and have a peak at your bypass valve, as nothing answers the high oil pressure question so far either.
More questions no answers! Hope you had a nice spin over to Belfast in the interim if nothing else, mind
All the injector nozzles apart from no.3 look a bit unhappy to me, not sure if it's just the image though.
The oily wetness on the crowns, but lack of smoke while driving (i.e the intrusive oil is always burnt on compression strokes not constantly leaking in / blowing out) and general "looks good" factor of everything else in the pics does very much point back to the turbo, even though the intercooler should have a few tablespoons of oil pooled at the bottom of it if the oil control rings have failed / were never installed correctly, but I think you checked that already.
Would do as disco1 suggests as well and have a peak at your bypass valve, as nothing answers the high oil pressure question so far either.
More questions no answers! Hope you had a nice spin over to Belfast in the interim if nothing else, mind
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Yeah, the injectors look awful.
The oil appearing in the induction pipework does seem to be blowing through without settling in larger quantities. Having said that, the Landy does do 17 miles on it's run to work with the Mrs. Plus, because we live 10 miles from the nearest place with shops, it rarely goes anywhere without getting up to temp and running at that temp for a good while.
I'd like to learn more about this leaking in/blowing out. Is this because of the positive pressure the turbo creates? Is this also why worn valve guides don't leak much, so long as they have decent valve seals on them? There was certainly not clouds of smoke coming out the back, but you could sometimes see some. eg in the dark with headlights behind you
I'm not sure if I'm beginning to doubt myself about the high oil pressure or just trying to convince myself I didn't see it. I can easily take the bypass valve out, but don't know how to check it
It's just a spring. We had a great weekend in Belfast, thank you. Great city with a nice feeling about it. Visited lots of good pubs and met a lot of friendly people. Even quite a few Merkins
To be fair I'm basing the expectation of it pooling on seeing it in much bigger intercoolers, so maybe the 300's is just too tiny and doesn't have enough pressure drop across it to cause the effect, especially as it's sort of upside down compared to some. The insides of the combustion chamber will have a carbon cycle of building up and breaking down, mostly based on whether the EGT's are under or over 200C, Diesels need hard work as well as long runs to stay clean
The oil seals on the turbo always leak a bit, (like any seal) - the control rings are metal, and can leak on either the compressor side or turbine side - yours probably into the compressor housing as you don't actually see the smoke. The boost the compressor creates doesn't cause the leak, but it does help atomize the oil and mix it with the intake charge - the oil just leaks owing to the high oil pressure in the turbo and poor sealing from a bad (or wrongly installed) control seal. I'm pretty sure you can still buy brand new Garrett cartridges for around £250-300, might be a safer bet than another recon if you go down the turbo route?
Worn guides will always leak, new stem seals of course slow the leak of worn guides - but remember worn guides leak fairly evenly across the whole cycle, blowing oil straight out the exhaust without it burning, whereas a turbo leaking on the compressor side will only pass oil into the intake tract - causing it to only enter the engine on the intake stroke. So you'd see bluey / whitey smoke all the time with bad guides, especially on start up after sitting overnight.
I can easily take the bypass valve out, but don't know how to check it
Keep your peepers peeled for foreigners in the assembly, beyond that nothing to check for besides damage.
Glad to hear it, nothing quite like a holiday to see family ending stress free! Pity about the merkins though eh?
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When I was rebuilding the engine I discussed on my thread changing the valve guides as they had a bit of wear. James Martin said he wouldn't bother because they wouldn't cause much bother. I think because it was a diesel and I was raising a problem associated more with petrol engines. Early on after the rebuild, when I realised it was burning oil, I raised the worn valve guides as a potential culprit with Turner Engineering. Richard Turner also said they wouldn't be an issue and he said something about the aspiration of the engine and I think the turbo. Going back a few years now though. I didn't understand the theory and still don't
Ahh, ok.
Ha ha, we met the Merkins in the Crown Liquor Saloon. It's very popular with American and Chinese tourists (All tourists really, including us). Bus loads walk in the front door, walk through and go out the side door. Some stop for a drink. There was only three of us, so we kept inviting people in to share our drinking booth. They all turned out to be Americans. They were good companyGlad to hear it, nothing quite like a holiday to see family ending stress free! Pity about the merkins though eh?
+1 - it's about the only thing that can cause high pressure...
I can easily take the bypass valve out, but don't know how to check it
Yep, ....but there is a correct length and rate for said spring, which you can check - or just bin it and fit a new one.... Sadly, my experience of new ones has been a bit variable
- so I'd be checking a new one too - also worth checking the surfaces of the the valve - both plunger and seat - they can go a bit raggy over time and, whilst highly unlikely, it might be just enough for them to stick together occasionally - the whole valve can't be too much money - might just be simpler to replace the thing and be done with it.....Did you check the guides at all during rebuild? If you weren't using / seeing much oil / smoke before it would stand to reason they were all good, mind.
RE It mattering more on petrol engines, it's to do with the fact petrol intakes are under vacuum 99% of the time, which can draw oil past worn guides into the intake - on a diesel there is no vacuum, and this effect is much reduced, even more so on a turbo engine as the intake is often charged with positive pressure. The effect on the exhaust valves is the same for both engines if neither are turbo'd, as the exhaust gasses cause a modest venturi effect which can draw oil past worn guides, but this effect is somewhat reduced on turbo engines because of the back-pressure that sits in the exhaust manifold owing to having a turbo in the way. Finally of course, oil burns great in a diesel, but seriously lowers the octanicity of the mixture for a petrol engine.
Any attraction that has something to both see and drink at the same time is doing fine by me
. Really must make my way over to the emerald isle one of these days!
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Glorious day here today, so decided to do more work on the engine. Thought I'd take the pistons out to clean them up.
Piston number one out. Notice the carbon build up around the top of this side of the piston.
This is side is clean.
After a clean up. Carboned side.
Non carboned side.
The crown, which you could see in images in previous posts, was thick black carbon.
Another worry are these bits I found in the bottom of the sump. The top bit is metal. All the rest is rubber. It looks a bit like the main journal L shaped seals, but don't really know. No idea where the piece of metal is fro. It's about 3mm across. I've got all 8 valve stem caps and no bits are missing.
Haven't taken pressure valve out yet.
Piston number one out. Notice the carbon build up around the top of this side of the piston.
This is side is clean.
After a clean up. Carboned side.
Non carboned side.
The crown, which you could see in images in previous posts, was thick black carbon.
Another worry are these bits I found in the bottom of the sump. The top bit is metal. All the rest is rubber. It looks a bit like the main journal L shaped seals, but don't really know. No idea where the piece of metal is fro. It's about 3mm across. I've got all 8 valve stem caps and no bits are missing.
Haven't taken pressure valve out yet.
Was there a pic?
Would've expected some carbon on the piston sides (above the top compression ring) owing to the buildup on the top, none on the skirts though which is good.
What does the turbo look like both sides?
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Yes, there is a pic of the bits in the sump. Thought I'd put it in
Taking the other pistons out might reveal where the small piece of metal came from. If not, the only thing I can think of is that I snapped one of the small bolts that hold the cylinder oil squirts in. It might be a bit off that because they are hollow up the inside.
Haven't investigated the turbo yet, pulled it and the manifold to one side in order to lift the head off.
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I wasn't very clear there. The oil squirt didn't fall off. When I was rebuilding the engine and putting the oil squirts back in, one of the bolts snapped. I bought a new one and fitted the remaining oil squirt. The oil squirt bolts are hollow, to allow the flow of oil up them. When the original bolt snapped it's possible that a small piece of the bolt wall came away. It could have stuck in the engine somewhere as there was a lot of engine assembly lube about. When I take the remaining pistons out I might be able to see where it came from. If not, the broken oil squirt bolt is my best guess.
Forgot to reply earlier, but were the bits metallic / magnetic in the end? or seal material as suspected?
Had another thought earlier in the week as well, did you ever check in the top of FIP boost compensator for oil? Can't remember if it was mentioned before. That'll deffo be full of oil if the turbo is leaking
Had another thought earlier in the week as well, did you ever check in the top of FIP boost compensator for oil? Can't remember if it was mentioned before. That'll deffo be full of oil if the turbo is leaking
