ZT turbo HGF - 12 months later turbo problems

[Lates]

Evening gents,
We look after a nice clean 04 plate ZT 1.8 turbo. The first time we seen the car was around 12 months ago for a slight thirst issue.Had drunk a small amount of coolant over a couple of months prior to repair.The head was removed,skimmed and rebuilt and the car has been as good as gold until a couple of months back when starting to suffer a light hesitation ( almost a misfire ) Absolutely no coolant losses.
We had it back and carried out the due 60K and had another look, no fault codes, plugs are new,coils good,vac pipes in good condition, so on an so forth.
Almost head scratching time so I asked him to pop back a week later so I had time to arrange some new vac pipes / BCV ( just in case ) / inlet gasket etc. In the week leading up to coming in I received a video showing a fair amount of smoke from the exhaust and a drop in engine oil. End result - turbo removed and inspected the bearings, absolutely shot to pieces.Now I know how the oil escaped the system but why should a low mileage clean car eat the bearings - long shot but could that much anti freeze contamination cause 12 month later failure ?

[Karsten]

Had that with a CX500Turbo in the 80's.
Low mileage, rider didn't even pushed the envelope, but...
...did not allow the turbo to cool down properly.
Got home after a ride, parked the bike in the back and that's it.
The still too hot turbo burned the oil in the bearings, which then burned the bearings.
Solution: idle the engine 30 seconds to one minute after the ride to allow the oil to cool the turbo bearings ... never had any problems then...

[JohnDotCom]

The Handbook states for all the Turbo models Diesels included to leave engine running for at least 20 seconds before turning off when parked.

[Greeners]

Back in the 80's there used to be a product out called (I think) a simmer switch. It allowed you to get out lock the car and the car would then run for another 60 seconds before turning the engine off.

If you attempted to drive off in it without putting the keys back in, it would stall.

There was some debate as to whether they were legal or not, as it could be classed as leaving a vehicle unattended with the engine running.

[Mike]

A while back I had a Monty Turbo Diesel 7 seater estate(with iirc the Perkins engine). Great car. I recall always leaving the engine at idle for 30 secs to let the oil drain from the turbo (the handbook advised this). I wonder whether the 1.8T handbook advises the same or similar.

loved the Monty - was reasonably fast and always left the car behind in a cloud of sooty smoke when I booted it :rofl:

[Greeners]

And here's one in the flesh

http://www.potn.co.uk/p1623002.htm

[Lates]

It was a perkins Mike and yes they did like to smoke a bit ;)

The ZT is driven sedately after a mild blat and allowed to cool a little before switch off, the only logical issue the car has had is hgf 12 months back :shrug:

[Mike]

It was a perkins Mike and yes they did like to smoke a bit ;)

The ZT is driven sedately after a mild blat and allowed to cool a little before switch off, the only logical issue the car has had is hgf 12 months back :shrug:

I'm guessing then that the Turbo unit didn't appreciate the HGF and coolant sharing its oil?

[Lates]

I'm guessing then that the Turbo unit didn't appreciate the HGF and coolant sharing its oil?


That is my thinking, no fluid mixed on hgf just water down the exhaust so my theory is it degraded the oil feed and bearings have picked up ?

[dustybin]

Good posible answer, but then with so many hgf´s on 1.8´s,garrett should be making a fortune out of supplying new turbo´s,, Maybe the best action to take is get garrett thenselves to check the turbo out, my guess would be metal or bearing fatigue, or somthing being sucked into the turbo, or maybe the oil feed pipe has a blockage...lates, if the exhaust gases are mixing with the oil feed to the turbo, then there was no way of stopping it failing..

[MartinW]

Although the Rovers use OAT coolant systems, normal glycol based coolants will react with oil to form oil balls or coolant droplets in the oil. These can range in size from 5-40µm and with a very high level of hardness that can lead to premature bearing failure.

In addition here, as discussed above, if the oil is not a high quality oil and the engine not left to idle before shut down, I guess the two issues may have caused the problem. Which does beg the question - what are the state of the main and big end bearings?

[Ti Rich]

Isn't the turbo on these water cooled? - if so possible air in cooling pipes to turbo casing the bearing to run hot?

[Phil]

Whats the price for a turbo on these?

[dustybin]

Not all turbo´s are water cooled, so they should be able to cope without it and the water pipe to it is a straight drop from above so any air would travel up in theory...i cannot believe a few drops of water in the oil would destroy a turbo, be very carefull then when doing a head gasket, garrett´s are one of the best, fitted as standard to scania´s now,still think it´s just metal fatigue or lack of oil supply...

[Phil]

It's not unknown for the old shape Isuzu dieseled civic to chew through a turbo in 10,000 miles, It isn't usually bearing failure though its normally they start overboosting.

[Roverron]

That is my thinking, no fluid mixed on hgf just water down the exhaust so my theory is it degraded the oil feed and bearings have picked up ?

I'd agree with that.

The 30second rule in my view is only of use in letting the turbo spin down before the oil pressure drops.
It is totally ineffective for cooling the turbo.
Heat soak from the turbine housing will raise the temp of the bearings when the engine is stopped. However, modern oils can cope with this - provided they are not contaminated!

Ron

[Lates]

Turbo back on and up and running briefly, give it a shake down tomorrow see if the hesitation has gone as we were a little too busy today to finalise the job.

[Lates]

Touch wood all is well and the tubby has now departed with his owner. Replacement vac pipes were required, small mark / split on one of the pipes to cure to hesitation.