Incipient turbo failure?

[Thrumbleux]

While replacing my wastegate actuator I checked the compressor end of the turbo for play - and there is some. Odd, as 1500 miles ago during engine rebuild it was absolutely fine. Possibly the low grade oil I ran for 1000 miles to aid bedding in the rings has caused this though the oil analysis merely said that wear metals were in accordance with post rebuild bedding in - no mention of yellow metals which presumably turbo bushes are made of.
Anyway, given there is play, better to replace it now before it fails and puts compressor debris right through the engine core? Is that a typical scenario when they fail - or is there some other symptom that gives prior warning?
Any reason not to replace it with the cartridge in the link below? Any other suggestions anyone?

http://www.ebay.co.uk/itm/GT1238S-tu...3D231911230028

[bob-in-dav]

I've used a couple of those cartidges without issue apart from one thing. If you have a look at the 4th picture in the advert, it shows the side that the oil feed and return pipes bolt up to. Be aware that the machined surface is not as wide as the original and requires the removal of a small amount of metal from the side of the flange which is attached to the pipes in order to get the two to mate up squarely.

[Thrumbleux]

Thanks BID.
The cars you have fitted them to - did you come by them with the turbos already blown (and known to be) or did you have a turbo fail on a car you were running? In either case, what was the sign/symptom and did compressor debris cause problems? I'm just a bit paranoid about how much longer I can run mine for. How long did it take for delivery of new turbos?

[tolsen]

With sensible driving and a fully functional wastegate, there is no reason why your turbo should not outlast your car.

As for bearing play, this can be considerable but depends on where you measure.

Image shows my spare China KKK KP31 copy turbo. Measuring radial play on cylindrical part of compressor wheel nut. Radial play 0.38 mm. Axial play was nil.

Below image shows my knackered turbo. It failed many years ago due to fatigue crack in turbine. Radial play 0.42 mm. Axial play 0.10 mm.


Turbo bearings last for years. It is vibration and over revving that cause them to destruct. Have yours rebalanced if you are worried.

[Thrumbleux]

On mine, the (radial) play is noticeable at the end of the compressor shaft when moved by my finger. I think it's shot.
If it fails, which impeller first makes contact with its housing - exhaust or compressor? Will it let oil past its seals before internal conflict between impeller and housing?
Any views on the unit in my link?

[tolsen]

Radial play should be quite noticeable at end of shaft. Without play there would be no room for the oil.
Does it spin freely? Not touching housings?
Why not measure your radial play?

[Thrumbleux]

I'd have to strip it to measure with a dial gauge and if I break anything I'd be grounded until a replacement turbo arrived - which isn't really an option.
Play is at a guess into mm territory and hard to get hold of to turn but it is turning as freely as can be expected. It has sat for a week or two and oil will have drained but having it drained of oil in the past there was no play then - or what was there was compatible with 'oil film'.
Will I get warning - eg burning oil and smoke - before it disintegrates, is my concern. I'm not for compressor debris passing through a newly rebuilt engine.

[tolsen]

You can visually inspect compressor wheel with tik pipe off. Spin it with a suitable short piece of hose. Confirm it spins freely and not touching housings when applying radial force. Excessive axial play is a warning. Axial play should be barely felt. Use a pencil or other stick to measure radial play. See photo especially shot for you:


Using pencil as a lever indicator with ten times advantage. Distance between pencil marks at rubber end is 4.5 mm. Radial play becomes thus 0.45 mm. Pretty accurate in my humble opinion.

[Thrumbleux]

I've just put it all back together after replacing the wastegate actuator. Holding the end of the compressor shaft with needle-nose pliers I can feel clicking both radially and axially and can see the movement by eye. Sufficient to say it's shot?
How long, and with what (if any) warning before failure is catastrophic?

[tolsen]

No reported whistle would indicate compressor is ok. Measure play and research what is maximum.

[Thrumbleux]

No reported whistle would indicate compressor is ok. Measure play and research what is maximum.

You might just have hit the bull's eye there.
I'd completely forgotten that the last time out (the trip the wastegate actuator fell apart during) I noticed a bit of whistle I hadn't recalled noticing before but forgot about it when I lost boost (and the whistle) when the wastegate actuator fell off.
Waiting for an E-clip from SmartMods (tomorrow surely) and will give it a short(ish) drive then. If it's whistling - new turbo ASAP.

[tolsen]

Just in case you were wondering. Soup depicted in post 8 is of course Lidl's best instant tomato soup. Best soup to get your brain windings spinning.

[EmilysDad]

Why isn't it Heinz? I bust a gut at work making the best tomato soup money can buy ..... & you buy Lidl's :-(
;-)

[tolsen]

Lidl tomato soup and plenty of Queen Margot whisky is what I call good medicine.

[tolsen]

Soup for the body and whisky for my soul.