Smoking 300 TDI. * CAUSE FOUND *

[markgenesis]

I have a 95 Disco 300 TDI, 135.000 miles, this year it's had an absolute fortune spent (in parts, did the work myself), brand new Garret Turbo, brand new injectors, new glow plugs, new pistons, big end shells, headgasket, during this work bores were checked for wear and de-glazed (they still had the factory cross hatch anyway), head was stripped, checked, no wear in guides, valves cleaned up and lapped in, new stem seals fitted, head refitted and torqued down properly.

Motor has the usual EGR blanking mod, a straight through exhaust (real straight through, no silencer or cat), an AllySport intercooler, Silicone Turbo hoses, pulls very well and sounds great.

Has the usual bit of black soot when i boot it over 3K but that's normal.

Problem is it's started smoking badly, started as clouds of grey smoke on start up (hot or cold), and a bit of smoke pulling away from lights, but has been gradually getting worse and yesterday it was smoking all the time when idling, smoking clears/lessens if i hold the motor at 2K, strangely went out in the evening to move it into the naughty corner of the garden and it seemed fine.

Reamoved the Turbo hose to the inlet last night, clean, no oil being blown by the Turbo so it's not the Turbo seals.

I know the colour thing for smoke, white = water, blue = oil etc but it always looks grey to me, motor doesn't apear to be using water (or oil for that matter) but then i have'nt done a big journey in it yet.

Motor also idles quite rough when started (oil in bores ?), but as mentioned pulls very well so suspect compression is fine.

It's all pointing to valve stem seals/worn valve guides but as mentioned the guides seemed fine and new seals were fitted, read on a LR forum the seals have been known to lift but i cant see inside the spring to see if this is the case, for it to be as bad as it's been it'd need to have no seals at all.

Disapointingly motor has a fair bit of back pressure too but read somewhere thats pretty normal for a 300TDI ?

In this too deep to give up on it (besides i love the beast) so whatever it is i'll need to fix it even if the head needs to come back off.

Would just like to be %100 sure whats causing it and if the stem seals have lifted what to do to prevent that again.

[Dez]

symptoms are exactly the same as my iveco motor just before it filled the sump up with diesel(9L in a 5.5L capacity sump), pressured the crankcase and blew it all out the breathers
mine was just the same- a bit lumpy at startup but cleared pretty quick, grey-ish smoke, particulalry on part-throttle overrun. no discernable loss of power at all.
so it sounds highly likely its the rings if its creating crankcase pressure. keep a very close eye on the oil level- if it goes up at all (or tbh on a older turbodiesel, stays the same i.e. doesnt burn a little bit) you'll know what it is.

it *could* be guides, but is less likely. id do a leak-donw compression test and see what the results are.

[markgenesis]

But if it was rings wouldn't it be smoking all the time ?, doesn't smoke on overrun and is clear if held at 2K

Only 135,000 miles on the engine, be surprised if the bores and valve guides have worn.

Compression test would be a good idea, not got the kit for that so may give it to a garage.

[Dez]

thats what i thought, but mine didnt smoke all the time either.

basically, its can only really be 3 things (possibly 4) none of which are good- turbo (but youve more or less rules that out if the inlet manifold is clean), valve guides, rings, or outside chance of headgasket.

[chairchild]

when you honed the bores, did you refit the original rings? They kinda wear to the shape of the bore, so once you hone them, they don't seal well (kinda like brakepads and discs)

Also - grey smoke is usually unburnt fuel, so could be leaky injectors. Have you got another set you could swap in, just to rule them out?

[colnerov]

Hi, White/grey smoke is incorrect fuel timing, injectors faulty or low compression. So check pump timing. Just because the injectors are new doesn't mean they can't be faulty, they may be "hosing" instead of spraying due to going out of adjustment and so injecting early. It may not be low but do a compression check anyway.

Colin

[froggy]

Valve clearances ok ? Had this issue on one a while back with rough idle and smoke but drove ok

[markgenesis]

New piston rings fitted with the new pistons, turned all the ring gaps round so the didn't line up, pistons installed carefully with the proper tool.

Regarding the injectors only other set i have is the old ones that came out, motor smokes exactly the same with both sets.

What would knock the pump timing out ?, timing belt was done in 2012 by a previous owner, hasn't been touched by me yet, could the belt have worn or slipped and knocked the timing out ?.

Valve clearences are fine.

Cheers for the help guys but i think i'll be taking it to an engine specialist tomorrow, will let you know the outcome.

[chairchild]

I've had a belt go slightly loose before - gradually got worse and worse to start (with lots of white smoke once it started!) as it retarded the timing.

Worth a check to see if the belt's still taut?

[vtecpowergt]

How does it drive on the road it might help to advance the pump timing slightly see if that helps to clear the smoke might be worth having a look in the pump return bolt on the pump and check the filter for metal particles the diesel pumps can sometimes start breaking up and swarf ends up in the return bolt this in turn means the internal pump pressure is low

[glenanderson]

White/grey smoke from a diesel is unburnt fuel. Does it really make your eyes sting? That's another sign of unburnt fuel.

What's the oil level like? If it's rising it could be the lift pump diaphragm holed, filling the sump with diesel. If not, I'd check your cambelt pronto.

[bortaf]

I've had this once on a transit, the filter head was loose and sucking air, made the old Di smoke like a steam train and loose power, bolted the head up tight and fixed the air leak and it went away ?
Differant engine i know but same symptoms ?

[markgenesis]

Cheers for the help guys, would you believe i drove it to the engine specialist on Monday intending to leave it with them, it didn't smoke all the way there, so decided to bring it home again (garage said let it develop), stopped at the shops on the way home, came out, started it, and, massive clouds of smoke , a mate commented last night when i had it running that the smoke smells sweet, like anti-freeze, sticking a hand in the fumes it is damp, also noticed it has used a bit of water so now pretty sure the smoke is actually steam, the smoking when the engine is started when hot is water being blown in under pressure.

Read recently that these heads have been known to crack in an exhaust port meaning the engine will perform fine and not overheat but will use water and smoke like Thomas The Tank Engine, think the head will need to come back off and get crack tested.

[dodgerover]

Does it just smoke (sometimes) on start up then clear after running for a time - motor sounds flat whilst smoking? When the advance all went wrong on my pump I had these symptoms

[markgenesis]

Oct 1, 2014 19:08:31 GMT dodgerover said:

Does it just smoke (sometimes) on start up then clear after running for a time - motor sounds flat whilst smoking? When the advance all went wrong on my pump I had these symptoms

My engine smokes from cold start every time, eventually clears a bit at idle, then clears when driving, then smokes worse if started when hot, then smokes a lot at idle after hot start (embarrassing at traffic lights) motor runs a bit rough at cold start but pulls and drives fine.

No excessive black smoke.

[glenanderson]

My 200 Tdi smoked (well steamed actually) like mad when the head gasket went. If your smoke smells sweet and doesn't sting your eyes, then it's coolant.

[markgenesis]

Oct 1, 2014 21:00:39 GMT glenanderson said:

My 200 Tdi smoked (well steamed actually) like mad when the head gasket went. If your smoke smells sweet and doesn't sting your eyes, then it's coolant.

This was the case Glen, motor had new head gasket though.

Removed the inlet manifold last week and found number four inlet port had traces of coolant in it, also also when i removed the Turbo found number four exhaust port was damp, so looks like there has been a crack in the inlet port, removed the head and found a crack between number four injector and the inlet valve so head is scrap.

My fault for being a pleb and not checking the head properly when motor was first stripped, dug deep and bought a new head, came as a kit with all gaskets, new head bolts etc (£410), arrived on Monday but just need to find the time to build it all back up.

Cheers for the help guys

[frag]

Just out of interest,does this engine have an egr cooler ?

I know you've found fault now,seen same symptoms with egr coolers leaking also......

Steam/smoke from exhaust,sometimes 'hydraulicing' on start up or head gasket symptoms and pressurising.....

People overlook egr cooler as it pretty much whichever way they fail barring external leaks,it smacks of head gasket or head failure.....

Seems you've got proof of failure tho if head is cracked.
Good luck with the rebuild :-)

[markgenesis]

Oct 17, 2014 22:38:12 GMT frag said:

Just out of interest,does this engine have an egr cooler ?

I know you've found fault now,seen same symptoms with egr coolers leaking also......

Steam/smoke from exhaust,sometimes 'hydraulicing' on start up or head gasket symptoms and pressurising.....

People overlook egr cooler as it pretty much whichever way they fail barring external leaks,it smacks of head gasket or head failure.....

Seems you've got proof of failure tho if head is cracked.
Good luck with the rebuild :-)

No EGR cooler on the 300TDI engines, EGR system is pretty basic but has all been removed and blanked off on this one anyway

[gurnersimps1963]

Glad you found the problem bud.