TD massive over revving / runaway... blown turbo and engine

[themildbunch]

Partner got in the TD this morning - little smokey as usual on startup as one of the glow plugs needs replacing I think... Started but huge revving - very scary apparently - I wasn't there... Carried on when ignition was off for a short while....

Went and had a look and disconnected the rubber hose from the turbo to intercooler - a load of oily diesel came out - started up ok after that with hose disconnected - still smokey though and starts to over rev with the pipe reconnected and a little throttle...

Not sure what's happened here but worried that the short run away has damaged the engine

It was parked pointing down a fairly steep hill last night and had just been filled up with diesel too...

[electrokid]

Wow - that does sound scary !

The only thought I have - related to my recent work on the pump and the need to get emissions down - those who recommended Fortes Advanced Diesel treatment were spot-on - it really cuts out the smoke. And though this doesn't address your problem directly - if you put some Fortes treatment in the tank then any other smoke that happens is likely to be the result of a problem - so at least you could identify whether there's a problem or not.

Hopefully a full tank and pointing downhill was the only cause.

[mat_fenwick]

What's the engine oil level like? I've heard about engines with overfilled sumps ingesting and running on oil mist (from increased splash) via the breather system. Someone did say it's possible for a leaking injector to dribble past the rings and increase the oil level, but personally I would expect the engine to hydraulically lock if that was the issue.

[themildbunch]

Yeah, may be the case - changed the oil a couple of months ago - level is slightly above high mark but it's parked on a camber so need to check flat.. Have also noticed a wet diesel leak off pipe on the injector nearest to the cambelt too.. I also had to nip up this injector a few months back too -

Can't remember when it was last parked pointing steeply down but possibly not recently which could have exacerbated a high oil level...
Air filter is about 12 months old but looks pretty dirty too..

Good course of action:

1. drain oil and replace..

2. remove and clean all turbo / air breather pipes and intercooler

3. replace leaky injector pipe..

[mat_fenwick]

Sounds sensible, although I was hinting at an internal injector leakage rather than the leak off pipes. If the oil level is high you could just drop a bit, then see if the engine has survived OK, monitoring the level closely of the next few hundred miles.

[themildbunch]

Thanks - I didn't know injectors could leak this way! - Lots of stories via google of sumps with too high levels due to injectors leaking...

So it's internal seals not the copper seal and fireseal that may be the problem if it is leaking?

[citronut]

also it has been known if/when piston rings are aged for them to allow unburned fuel past under compression into the sump,

this then brings the sump/oil level up to much and she can run away on her own fluids to the point of self destruction,

regards malcolm

[Brian]

Interesting, not experienced this problem before, but my gut feeling would point to a turbo seal/bearing on the inlet side has let go.

This would allow engine oil into the induction tract, and would account for the rev runaway.

Good luck

[themildbunch]

MMM, that makes sense too and on the inlet side you woudn't notice the usual clouds of smoke... I did shorten the wastegate actuator a little a few months ago as it had never had much boost to speak of - since then it's been what I've imagined a TD to be BUT I didn't get around to checking with a pressure gauge...

Wont' get too depressed yet - I'll drain the oil and clean the pipes out tomorrow and go from there....

[docchevron]

I assume it has the Lucas pump? In which case I'd be suspecting the diaphragm (sp) in the pump. It's a fiddly bugger to do aswell sadly.
If it fails it'll allow diesel up the small pipe to the intercooler (which sounds like you have) and the engine will run directly from the fuel being sucked in through the intercooler.

[themildbunch]

Thanks Doc - That makes sense too - Luckily I bought a recently reconditioned Lucas from Bill O on this forum which would probably be easier to fit than mess with the pump in situ..
Since I tweaked the wastegate actuator the diaphragm has been getting some use which it probably didn't get before which I guess could have lead to the the split if it was pretty old.

This is also what the dipstick said:



A little over the limit - I'm sure I wasn't that slack when I last changed the oil! I can't be sure but I think it has a whiff of diesel to it which could be a leaky injector...

I'll drain the oil tomorrow, clean the pipes and see what's what....

[docchevron]

HOLY SHIT! thats enough over the limit to cause some EPIC issues..
I wouldn't even think about turning it over until thats drained down, and yes, if it smells dieselly then check the injectors..

[themildbunch]

I know - probably a bit exaggerated as I didn't want to move the car to level ground - it was canted over to the nearside on a camber..
Anyway, drained all the oil out and replaced - not 100% sure about diesel smell - not obviously smelling..

Your diagnosis about the diaphragm was spot on though doc - pipe filling up nicely when I got it started again.. Does look extra fiddly to get to on the car.. Have you managed it or do you take the pump off?

http://vimeo.com/42919567

[docchevron]

I've never taken the pump off to do one yet, but it is a bit fiddly, easier with a small mirror and nimble fingers!
bit easier still with the rad out, but it's possible with it all in situ.
the hardest bit really is getting the 3 dinky allen bolts out and back in without dropping the bloody thing into the murky depths of the alternator bracket!

[bill o]

p m sent---bill o