Smokey td42

[scallywag]

Hey, I know there's a few posts on smokey td42 engines but just thought i'd ask again incase anyone has some new suggestions.

The td42 in question gets a fair amount of blue/white smoke out it's arse end after idling for a short period of time and then giving a bit of a rev, it reaks of oil. I've also notices a small amount of oil at the no 1 exhaust port(seeping through the gasket). It does this regardless of wheather its hot or cold. I have changed the engine oil to castrol gtx diesel, 15/40, possibly too thin or just plain crap? This did occur a couple of months ago but seemed to fix itself. I'm leaning towards valve stem seals but not 100% sure. I'm a mechanic by trade but have minimal diesel experience.
Any suggestions would be much appreciated.

cheers

[not not]

stating the obvoius but you have done all filters including the little gauze one in the fuel pump inlet pipe under the banjo bolt. But this would not explain the sepige.

[scallywag]

Yep, checked all the filters. One thing i forgot to mention earlier, both times this has happened, it's been while out playing. Maybe having the thing on some steep angles is allowing oil into the breather system? I don't know. Just took it out and gave it a bit of a hard time and the smoke seems to have stopped Been thinkin' about giving the whole show a freshen up and then sticking a turbo on the old girl.

[not not]

The smoke might be from the fuel pump geing wound up a bit??? Does it blow heaps when up it??

[Woop]

could be valve guide seals? If so, they are easy to replace--just drive them out with a drift--the only difficult bit is that the replacements need to be reamed once in position. Other than that, the only other thing i can think of would be bore glazing--ive never used GTX diesel before. Castrol JMAX works well for me. The Crankcase breather breathes via a long slot in the roof of the Rocker cover--you would have to be going on extreme angles to get oil up there. How many KM's on Engine? Done a compression test?

Nick

[scallywag]

It's just about to hit 300k, haven't done a comp test yet (gotta get hold of a gauge from somewhere) I'm not overly concerned about it as it appears to be behaving itself today. Still like to find out what it is though.

[fnqcairns]

I will put this reply in point form to make it easy for me, done it many times to diagnosed as terminal petrol engines with long lasting results, of coarse with the obvious changes, never to a diesel so change as you see fit if you give it a go.


*buy a can of outboard engine tune (decarboniser), mercury/Johnson etc
*mix a full dose of engine flush (strong stuff) into a bit of engine oil for
pouring
*add to sump
*get it to a true operating temp preferably with a drive
*disconnect and pull glowplugs
*divide the entire can down plug holes
*plug holes
*after 1 hour pull plugs turn engine over until sure all excess decarboniser has been blown away.
*reassemble
*Start engine and run at a fast idle 1200/1400rpm for next 15/20 minutes.
*Dump oil and drain for half an hour
*run a average oil (like your GTX -sorry) with a dose of kinder engine flush.
*drain after just a few hundred kms
*change oil filters
*fill and run forever with a ci-4 oil, preferably a known heavy duty one.

*see what happens.

Carbon on ring lands from crook oils causes heaps of problems in petrol engines, doing the above cannot fix a mechanical problem but it will help greatly to clear stuck rings/lands etc. The tip is to then use an oil that can clean what it creates as well as create slowly.

I never talk to mechanics face to face about this sort of procedure because it's just too hard but you sound reasonable because you asked the question, so I have taken the chance
Mostly they believe if the car is smokey/blowby etc then a re-ring/rebuild is the only fix when very often an in-situ cleanup of the stuck rings/coked lands is all that is needed - if not already too late, it can take more than one application also.

my 02

cheers fnq

[scallywag]

Cheers fnqcairns sounds like a good idea, i'll probably have a go, nuthin to lose, if it needs a rebuild then it needs a rebuild. The smoke came back today but seems to be more white than anything. One question though,if you're getting white smoke from diesel fuel,will it smell like burning oil? th reason i ask this is that i've been told deisel is a form of oil. Being that it's done 300k it's more than likely due for a set of injectors. The smoke is only there after after it's been idling and stops shortly after take off.

[fnqcairns]

I am still new to diesels and absorb everything I read on the net about their tuning and diagnosis still have a long way to go to feel as confident with them as I do petrols in this regard.
So others will probably know far better than me, would not be hard to in any case.

I can remember more than one post that advocated (as one reason) when white smoke was a problem that a simple timing change might make all the difference, from memory in the end one needed a smidge more advance on the pump. This came too late for the owner who on advice had injectors etc serviced when all that was needed was a simple timing advance. Might have been a post on this site, nissan forum probably.

Sorry I have no olfactory experience with the white smoke .touch wood.

cheers fnq

[GUte]

If the smoke is diesel, it will smell like diesel.

[Woop]

White smoke can be unburnt fuel. Overfueling is usually dark blue--burning oil slightly lighter in color. AT 300,000 should still have plenty of KM's left. Still sounds like bore glazing--oil your using may not be suitable. Rebuild about 6-7K using genuine bits doing it yourself--easy engine to rebuild, but i cant imagine it needing it at those kms

Nick

[scallywag]

Hey fellas, decapitated the patrol tonight, easiest head i've ever removed(nowhere near as much crap boleted to it as a honda). Bores are glazed and the thing's pretty heavily sludged (in my opion it is) Got a price today on havin' the head reco'd, 300-800 bucks, depending on what is required.
I'm also gonna do rings and bearings and give it a hone while i'm at it, injectors too. Who's the best to see in brissy for injectors?

Can't wait to bolt a whistle to the side of it!

[fnqcairns]

You don't muck around!!!!Your problem scares me some. Is it glazed like in poor bore hygiene on assembly or is it polished? Polished bores and and sludge will go hand in hand.

cheers fnq

[scallywag]

No point muckin' around! I had to do something before those bloody vigalanty greeny 4wd hating people report me. Uhm, not exactly sure what's caused it, it's not all of the bores, just 3 4 and 6. The injectors that came out of those cylinders are in a pretty sorry state of afairs so maybe they've been dribbling and washed the bores, i really don't know. The sludge and apparently crap brand of oil possibly played a part too.

You say it scares you? are you experiencing similar dramas?

[Woop]

$300-800 for Cyl overhaul I need to move to QLD. When shop do your cyl head, check for cracks around the pre-comp chambers. Pretty common here, and will significantly push the price up if they need replacing. Make sure you use the correct thickness of head gasket--normally a grade 3. Engine uses dry liners which are very thin--dont overhone....

Nick

[scallywag]

300-800 for the cylinder head,not the cylinders. The shop that's doing the head is very good and we use them for doing all our heads at honda. Yeah i've already been warned about the precombustion chambers, the reckon about 25 bucks a peice plus fitting and machining. Got a mate who's a diesel fitter to come over and have a look at the bores, he reckons he's seen alot worse and reckon's a real light hone would be cool.