BXProject

[Bx Bandit]

Got a mild diesel clatter or it even sounds a bit tappety between about 1500 - 2500 rpm. Pretty sure it's nothing to do with tappets.
Not the beginnings of turbo bearing failure is it?

[Philhod]

Sorry you have a clatter Bandit. Hope it soon gets better

Usually when the turbo is beginning to fail you get a chirping/ whistle, (high pitched) which generally lowers as it deteriorates. Provided it is not short of oil it could be 12 months between first and last.
If that Turbo you gave me was any good, it's only in bitz, I could re assemble it for you should you need it back.

[Bx Bandit]

It has been sounding like an ambulance is chasing me, but the TGD went on like that for years, but you've reminded me that the tone does get deeper with time!

When I had the Hurricane in '97, it developed a proper fucked turbo, like a grating sound in boost. What I have now sounds like it could be the beginings of that.

I just can't think of what else it could be.

Thanks for the offer of returning the turbo Phil. You bring me on to part two of a related dilemma but you've no need to return the KKK unless Vanny wants it back at is was his initially.

If it turbo, I assume it'll carry on for a bit anyway? Even though it'll sound like a tractor having an epileptic fit?

But, I'll need a turbo for the 2.1. Why not use the original 2.1 turbo I hear you say!!!

Well, mostly as it wont fit without some buggeration and even then it'll force me into a front mount i/c which (possibly) I'm keen to avoid!

The turbo on the 2.1 was a GT15. Looking on Garrets website the GT15s are more suitable for 1.0L to 1.6ltr engines (although petrol ones I assume?) I've not done any of the flow calcs yet but based on the max rpm a petrol vs diesel engine will reach, then (2.1 x 4000)/6000 = 1.4, which means the GT15 is about right .Oh bugger, that's blown my theory, I had thought the GT15 was too small for the 2.1......

With that setup it's all down low and rather have slightly longer legs in the turbo department. A GT17 seems about right possibly, based on what other manufacturers have used for smaller (than 2.1) engines but I can't find a compressor map or any info. There don't seem to be any compressor maps anywhere for manufacturers vehicle turbos

[Bx Bandit]

arse bangers, the GT15 turbo off the Xantia has more play than a playful puppy at play time.

Anyone overhauled a turbo????

[Philhod]

You need a press for the spindle and quite often they are peened in as well after fitting.
Unless your detail fitting skills are up to it I would suggest stripping a scrapper fitst.


What about the one on the Picasso? It meets a fair range of mapping from 90 to 138bhp
(ok an I/C gets added) but it meets the blow requirements. It also has asymmetric vanes.
This gives push from 1800 revs right up to 4000. Albeit a bit short on torque low down

[Bx Bandit]

I have press, but not done one. Have two to practice on. Just realised I put the 'overhauled' post in as there was a GT17 going on ebay for next to nothing but in need of a refurb. Ideal I thought. Fuck - got side tracked and forgot to bid It's all over now

[Philhod]

Start by removing any delivery pipes etc and draining out any residual oil. Then remove the compressor (air end) Once thats off you will have to examine how the shaft is secured, there are lots of methods, and remove any mechanical locks in place. (peening is just one example) then it should press out. This could take some pressing as some Garrets were coated in blue loctite Garret used to provide a new shaft with the turbine (exh end) already fitted, along with a bearing kit.

[Bx Bandit]

There are kits of varying and indeed probably dubious quality on eminge, some up around the £100 mark Is it the bushes or shaft that wear? I would of thought bushes but why supply the shaft?!

[Philhod]

Because on the earlier ones you generally had to wreck the thing to strip it (loctite)!!!!

I've even torn the metal and left that fucking stuff in place

[docchevron132]

I've seen some very worn shafts, albeit usually from engines where the owners would arsehole to a stop from speed then switch the engine off.
I often wondered about fitting an electric oil pump to keep feed to the turbo until things had cooled down a tad / stopped spinning.
Then I thought fuck it and went for more beer.

[Philhod]

You mean you are going to pump beer in to cool things off


The central chambers on Garett's and KKK's are big enough to cope provided that you stop normally; ie; pull up at parking speed, then just switch off.

[docchevron132]

Depends how hard you drive I guess.

I've heard tell before that the lack of oil flow with the motor switched off can mean the remaining oil boils it's nuts off and does little to lube the turbo whilst it arseholes round at a fair few thousand RPM?

[mat_the_cat]

Plus, if the turbo is really that hot, even if it has stopped spinning the oil sat there can turn to carbon which doesn't lubricate quite as well...
I think the BX manual mentions to leave it idling for a while if you've been caning it, although perhaps not in those very words. I haven't seen that mentioned for a modern TD, so it may be that the problem is less/not there with modern oils?

[Philhod]

The only real changes are the central chamber is a little more offset and slightly bigger.
It should stop spinning within 20 secs too and carbon powder lubricates quite well actually Mat. Not that it would ever get to that stage as the casing cools quite quickly.

[Bx Bandit]

Well it's getting worse, not noticeable on cold though. It could also be the CRB as I'm sure the noise follows the engine revs as opposed to the noise lagging behind the rpm...........if that makes sense.

[Philhod]

What's the Criminal Records Bureau got to do with it?

[mat_the_cat]

carbon powder lubricates quite well actually

Graphite would, yes. But heating oil till it carbonised wouldn't form graphite...

Whether the turbo would be hot enough to carbonise oil sat in there after turning off I don't know for sure. But I'll leave it running for a short while just because it gives me that warm glow of satisfaction looking after my turbo.

[docchevron132]

Having trashed 3 turbo's in as many thousand miles I'm more inclined to drive with some mechanical sympathy these days.

[Philhod]

it gives me that warm glow of satisfaction looking after my turbo.

....knob!!


It doesn't even boil.... unless you are running verrrrry retarded.

[mat_the_cat]

Who are you calling retarded?