checking a 20 CDTi Turbo

KeirL · 30th November 2019, 09:34

Hi
I've my turbo off the car currently (2005 20 CDTi Tourer) and before I put it back to test it fully I wanted to check what I can whilst it's on the bench. Below is a picture as it currently is so do I need to break it down any further to test it properly or is this sufficient.

The haynes manual says to check the body for cracks - all good on that one and to spin the turbine or compressor wheel for shake or roughness. As it is, I can only get to this end (see below) and here is my question.

https://i1347.photobucket.com/albums...psntvpjcnd.jpg

How freely should this spin? If I put a small socket onto the nut as shown below I can turn the vanes with little effort but they don't spin freely in the way that you could spin a bicycle wheel - is this correct?

Also - there is zero 'play' on the shaft whereby the haynes manual says there should be a little bit of play as this is a 'floating' shaft.

I hope all is ok but wanted to make sure this is what I sould expect to find when testing on a bench.

many thanks
Jon

T-Cut · 30th November 2019, 10:10

Some background reading: https://www.google.co.uk/search?safe...4dUDCAo&uact=5

TC

Sheraton · 30th November 2019, 10:43

Someone can maybe confirm if it's a Journal Bearing used on the Diesel Turbo - if it is a Journal Bearing it won't spin freely without an Oil Supply

Better to check for excessive Shaft play with your finger

From what you have described (I'm assuming Journal Bearing) it doesn't sound like the Bearing has failed

Paul.

KeirL · 30th November 2019, 11:20

Thanks Paul
The manual states that the shaft is pressured lubricated by an oil feed pipe and that it's 'normal' to have some play.
So I can get why it might be stiff to turn without the pressurised oil being present, but I would then expect to be able to feel some play as the shaft is effectively 'floating' within the oil.

Perhaps the play on these is just very minimal

T-Cut · 30th November 2019, 16:11

The normal 'float' is not more than 5 thou, probably less. I wonder if you could detect it by hand. The CHRA assembly should turn quite easily, but you'll not make it 'spin' like a bike wheel. It 'floats' in an annular/cylindrical film of oil at high pressure. Without the pressure it isn't floating as such.

TC

trikey · 30th November 2019, 18:19

Quote:

Originally Posted by T-Cut

The normal 'float' is not more than 5 thou, probably less. I wonder if you could detect it by hand. The CHRA assembly should turn quite easily, but you'll not make it 'spin' like a bike wheel. It 'floats' in an annular/cylindrical film of oil at high pressure. Without the pressure it isn't floating as such.

TC

If you can feel any play in the shaft then it will need a rebuild to make it 100%

T-Cut · 30th November 2019, 18:57

Quote:

Originally Posted by trikey

If you can feel any play in the shaft then it will need a rebuild to make it 100%

I agree. However, there are several references on the forums which promote the idea that a palpable slop is 'normal'. I believe that's misleading, but almost everyone has an opinion and some (IMO) are misguided.

TC

sworks · 30th November 2019, 20:01

Most manufacturers state some play is acceptable and it reduces when oil fed. A few also state that it’s only excessive if the vanes touch the housing.

Mike Noc · 1st December 2019, 07:51

Quote:

Originally Posted by KeirL

Hi
I've my turbo off the car currently (2005 20 CDTi Tourer) and before I put it back to test it fully I wanted to check what I can whilst it's on the bench. Below is a picture as it currently is so do I need to break it down any further to test it properly or is this sufficient.

How freely should this spin? If I put a small socket onto the nut as shown below I can turn the vanes with little effort but they don't spin freely in the way that you could spin a bicycle wheel - is this correct?

Also - there is zero 'play' on the shaft whereby the haynes manual says there should be a little bit of play as this is a 'floating' shaft.

I hope all is ok but wanted to make sure this is what I sould expect to find when testing on a bench.

many thanks
Jon

Sounds good to me - they don't spin like a bicycle wheel but should move freely with light finger pressure.

These Mitsubishi turbos are the most reliable and long lasting I have come across.

There isn't an easy way to check the seals with it on the bench, but we have owned cars with 188k and 245k miles on the original turbos, and mine is currently at 401k miles and still good.

.

KeirL · 1st December 2019, 08:26

Brilliant - thanks Mike.
It'll go back on soon and it sounds hopeful all should be good.

30th November 2019, 09:34	#1
KeirL Regular poster Rover 75 Tourer Join Date: Apr 2008 Location: Beckley Posts: 54 Thanks: 4 Thanked 11 Times in 5 Posts	checking a 20 CDTi Turbo Hi I've my turbo off the car currently (2005 20 CDTi Tourer) and before I put it back to test it fully I wanted to check what I can whilst it's on the bench. Below is a picture as it currently is so do I need to break it down any further to test it properly or is this sufficient. The haynes manual says to check the body for cracks - all good on that one and to spin the turbine or compressor wheel for shake or roughness. As it is, I can only get to this end (see below) and here is my question. https://i1347.photobucket.com/albums...psntvpjcnd.jpg How freely should this spin? If I put a small socket onto the nut as shown below I can turn the vanes with little effort but they don't spin freely in the way that you could spin a bicycle wheel - is this correct? Also - there is zero 'play' on the shaft whereby the haynes manual says there should be a little bit of play as this is a 'floating' shaft. I hope all is ok but wanted to make sure this is what I sould expect to find when testing on a bench. many thanks Jon

30th November 2019, 20:01	#8
sworks Been absent for a while… Rover 75 Tourer, Classic mini Cooper S, Abarth 595 competizione, MG TF and a Hyundai Tucson PHEV Join Date: Feb 2007 Location: Cumbria Posts: 13,065 Thanks: 1,033 Thanked 1,686 Times in 1,040 Posts	Most manufacturers state some play is acceptable and it reduces when oil fed. A few also state that it’s only excessive if the vanes touch the housing. __________________ ................................................. 'Marmite' Possibly one of the most famous 75 tourers produced! left the production line as the last of only Three Rover 75 tourers produced in Trophy Yellow. 48 hours later Longbridge closed. The last sold ordered 75 Tourer. Paid for by the Phoenix Four and handed over by John Towers to the Warwickshire Northampton Air ambulance service as a Rapid Response vehicle

30th November 2019, 10:10	#2
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,752 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	Some background reading: https://www.google.co.uk/search?safe...4dUDCAo&uact=5 TC

30th November 2019, 10:43	#3
Sheraton Posted a thing or two Rover 75 1.8t Join Date: Oct 2015 Location: Edinburgh Posts: 1,377 Thanks: 384 Thanked 409 Times in 267 Posts	Someone can maybe confirm if it's a Journal Bearing used on the Diesel Turbo - if it is a Journal Bearing it won't spin freely without an Oil Supply Better to check for excessive Shaft play with your finger From what you have described (I'm assuming Journal Bearing) it doesn't sound like the Bearing has failed Paul.

30th November 2019, 11:20	#4
KeirL Regular poster Rover 75 Tourer Join Date: Apr 2008 Location: Beckley Posts: 54 Thanks: 4 Thanked 11 Times in 5 Posts	Thanks Paul The manual states that the shaft is pressured lubricated by an oil feed pipe and that it's 'normal' to have some play. So I can get why it might be stiff to turn without the pressurised oil being present, but I would then expect to be able to feel some play as the shaft is effectively 'floating' within the oil. Perhaps the play on these is just very minimal

30th November 2019, 16:11	#5
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,752 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	The normal 'float' is not more than 5 thou, probably less. I wonder if you could detect it by hand. The CHRA assembly should turn quite easily, but you'll not make it 'spin' like a bike wheel. It 'floats' in an annular/cylindrical film of oil at high pressure. Without the pressure it isn't floating as such. TC

1st December 2019, 08:26	#10
KeirL Regular poster Rover 75 Tourer Join Date: Apr 2008 Location: Beckley Posts: 54 Thanks: 4 Thanked 11 Times in 5 Posts	Brilliant - thanks Mike. It'll go back on soon and it sounds hopeful all should be good.