Another turbo bites the dust...

[tsh]

Right then... Tim couldn't explain this, so any ideas...

Turbo II, new (turbo i) engine. After about 200 easy miles, loss of boost and lots of smoke on lifting off. Quite a sudden transition between good and bad.

£200 and a weekend later, replaced the turbo. All seemed good again - for another couple of hundred miles - then ditto.

Stripped the original turbo. Some wear on the compressor wheel where it had rubboed on the housing. Exhaust side bearing decidedly loose.

So what's causing this? It's costing me £1/mile at the moment, and thats just for turbos.

Sean

[Fish]

Sean, whenever a turbo'd engine lets go, you should as a matter of course send the turbo's off to be cleaned and checked over.

The slightest bit of metal in the oil way on the turbo can be enough to throw the blade in to the housing.

Dan

[tsh]

The original engine didn't actually let go, it just stopped starting (o-rings gone). Still doesn't explain why the 2nd turbo died.

Sean

[MikeLMR]

For a turbo to fail like that (sounds like bearings) you have to be starving it of oil or feeding it with swarf , did you replace the oil feed line and drain line when you did the rebuild ? maybe a turbo pre filter would be a good idea , then at least you know the oil its recieving is clean (+ you can clean it out to find if any swarf is making it that far)

Turbo's are very simple devices , theres not a great deal to go wrong as long as they have a good oil supply

Mike

[tsh]

The turbo certainly seems to be getting oil... I didn't replace any of the oil hoses, but i wouldn't be getting swarf out of a new engine would I? Even if that killed the first turbo, surely it would have been picked up by the filter before the 2nd one went?

The only thing that looks a bit odd is the downpipe. When I took it off, there were big flakes of metal coming off it, looking like it had got very very hot. Is this a clue to what happened? Can't see anything much wrong with the way the engine runs though.

Obviously can't tell now if some of the blades broke before the bearings went, or the bearings gave up first.

I don't really want to put on another turbo without working out what's wrong, since there wasn't much warning before the turbos packed up.

Sean

[MikeLMR]

Its usually good practice to replace the oil lines in case they are either damaged or full of debris from the engine failure , did you replace the oil cooler too ? or at least have it flushed

Where did you get the turbo from ? can you send it back to them for a professional diagnosis, it may have been bad luck and it was a faulty turbo ... having said that you;ve had two go in the same way. Could be a coincidence I suppose.

Mike

P.S new engine produce a fair amount of metal shavings as the bearings bed in etc.

Hows the oil pressure ?

[tsh]

No, I didn't think of flushing the oil cooler. Oil pressure is good, even at tickover it's reasonable - and the oil still looks clean (but then it ought to!)

The turbo came from Rx Motors, so I guess there is a chance that there was a problem with it - but I'd like to be sure that nothing else is up before i go back and ask for another! Two turbos in succession (and taking it easy since the engine's new) just seems too suspicious.

Sean

[finite]

I've got a turbo in very good condition for a turbo 2 that I can sell you (89-91 so it fits on the later manifold). £200 it's yours.

[antnicuk]

Not trying to teach anybody to suck eggs, but, the T11 turbo feed lines are solid metal, with a coupling by the water pump. Check your oil feed pipe by disconnecting it from the turbo, pull the egi relay and turn the engine, you chould get oil pumping out, if the oil line is crushed this could cause your turbo to fail. If in doubt you could have a stainless braided hose made that will banjo bolt to you original outlet and attach to your turbo, this will also allow you to have an in line filter put in aswell. I had one made when i put a bigger turbo on my T11, it was about fourty pounds. Hope this helps.

[Grizzly]

This may sound a Dumb thing to say but have you checked the gaskets are the correct way around and has the Banjo (engine) bolt got a Copper washer on each side?

I take it the Oil presure on the Engine is good? Did you fit a Ft oil cover gasket? I belive the new Cover o rings are designed to eliminate the Cover gasket if you have fitted both a new style ring and gasket you'll see a drop in presure?

Chris