turbo - how do u know if its not working 100%?

[mstar01]

guys my c250td, i looked at the service booklet and there is no mention of any turbo checks (that i cud see anyway) how do i check to see if my cars turbo is working 100% as i never had a td before. Is it a case for me to take it to a garage and for them to "test" it? (not sure how they test it?) or is there some simple component check that a average joe can do

 

[SmartFastUK]

Two major things can affect turbo performance.
1 = Boost pressure (or lack control thereof)
2 = Oil leaking from the seals

To be honest - there is no reason to suspect anything is wrong with your turbo unless you are either leaving a trail of blue smoke, or performance is not as it should be. As long as you leave it to cool off after a heavy footed session then it should last a considerably long time.

 

[mstar01]

Two major things can affect turbo performance.
1 = Boost pressure (or lack control thereof)
2 = Oil leaking from the seals

To be honest - there is no reason to suspect anything is wrong with your turbo unless you are either leaving a trail of blue smoke, or performance is not as it should be. As long as you leave it to cool off after a heavy footed session then it should last a considerably long time.

is there a tool/method to check if:

1. boost pressure is corect (e.g. a part is not working 100% due to age etc)

2. oil leak (there is some oil residue on the engine but i have never and previous owners have never cleaned the engine and its just had a service and dealer said no problems with oil)

 

[SmartFastUK]

You can check the boost level using a boost gauge. This would be fitted to the boost / vacuum pipe right off from the plenum and will give you an accurate reading of your boost levels.
As for oil, best thing to do is to get someone to hold thier hand at the exhaust exit and rev the engine. You will see black spots of carbon and water residue. If ytou wipe your hand with your finger and you see an oil smear as opposed to just the water turning black then you could potentially have a problem.
Expect to see quite a bit of soot and water - check for oil smears.

 

[Glenn Smith]

To check the boost you will need to connect a boost pressure gauge to the inlet manifold, the boost is then measured at a certain rpm, usually 2500-3000rpm under full load, ie 3rd gear pulling up a hill so the revs are only rising slowly, not sure what the figure is on the merc, vw's that I work on run at 0.75bar above atmospheric, even if this is correct performance can suffer if the turbo is worn, a physical check can be made on the compressor and turbine wheels and to check the bearings run smoothly, a degree of experience will probably be needed. Would't worry about the oil unless the consumption apears high.