Outer Limits 4x4 Board

Hey guys,

Running a GT2860RS on my SD33T.
It has done 10,000km with the turbo on it. Water to air intercooler and EGT's never pass 550 degrees.
I change the oil every 3500km with Penrite 15w50 for winter and 20w60 for the warmer months.

I noticed a few days back when I was under my car whilst the turbo timer was running down - Investigating leaking rear main seal - as the engine shut off and the turbo started to spin down I could hear a grinding noise, almost like the exhaust wheel is catching on the housing?
The turbo has no weird noises under boost or at idle, it is only when shutting the car down.

I did a bit of reading and this seems to pop its head up on the Ford Forums - XR6T's with larger Garretts on them - No real answers over there though.

When the engine is off there is no oil pumping around, and the BB turbo shafts balance themselves with oil pressure? When the engine shuts off and the oil pressure drops, the shaft is no longer balanced?

This really applies to anyone with a Garrett BB turbo who may know the noise I am referring to. If it helps, I can take a video tomorrow and YouTube it.

Cheers guys.

I had a Garrett BB (big sucka GT4294r) on my rb30, you could hear a slight noise after shut down , but you could only hear it when there was very little ambient noise (late at night when it was quiet)

If your noise is something you have to really listen for in the engine bay, it just well could be normal , if your turbo is still spinning free for a while after shut down i doubt the bearings would be stuffed .


Maybe you can pull the intake pipe of the front of the Turbo and turn the impeller by hand and see if it rotates free and smooth ?

04off wrote:I had a Garrett BB (big sucka GT4294r) on my rb30, you could hear a slight noise after shut down , but you could only hear it when there was very little ambient noise (late at night when it was quiet)

If your noise is something you have to really listen for in the engine bay, it just well could be normal , if your turbo is still spinning free for a while after shut down i doubt the bearings would be stuffed .


Maybe you can pull the intake pipe of the front of the Turbo and turn the impeller by hand and see if it rotates free and smooth ?

It doesnt free spool much on shut down - Perhaps 6 seconds or so and then stops dead - Grinding comes before it stops :(
I did a few tests today and I believe the exhaust wheel touches the housing on shut down when the oil pressure drops. You can hear it from under the bonnet, under the car and also from the exhaust.
It is a definite grinding sound and this is what is slowing the turbo down so quick when the motor stops.

I pulled the intake off and the turbo moved freely with my fingers and did not seem to be hindered by anything.
I felt for movement sideways - A little but hardly.
I felt for movement back and forth .... At first there was what felt like a considerable amount and then it was normal.
I think the shaft movement back and forth is my problem.

Will have a chat to PGS, MTQ and Garrett next week and see what we can do. It is only 10,000km old and only ran 15-20psi - 20 psi was in bursts and never a constant load.

Cody

How long did you expect that garret BB rubbish to last mate!!!!

UGOTNUFN wrote:Cody

How long did you expect that garret BB rubbish to last mate!!!!

Longer than 10,000k!!

I will get a sound clip up.

Suggest a turbo for me then. Quick spool, able to pull 20psi if required that I can use my existing dump pipe with.
Something with a .55 exh housing perhaps?

I suggest the 1HDFTE turbo

360deg thrust bearing, superback comp wheel, similar turbine size, 46/65 comp wheel (GT2860RS is 47.2/60) and the right size exhaust housing.

Turbo is off.
Busted knuckles, lots of swearing and early morning beers....

Off to MTQ we go!

New turbo is here:

Here are some photos:
Shows my new inline oil filter with 85 micron filter - Nothing is getting through this sucker.
Also picked up a 4-7psi Facet electronic fuel pump.

As the rear seal is much like piston rings, the coked oil has pretty much made the ring stick thus causing the oil to leak. You can see the wear on the rear of the shaft from the coked oil.







This photo shows the coked oil trapped between the CHRA and the heatshield.



Munched!