How do I tell if my turbo is healthy?

[leftcoastmark]

Hi all,

I have a 1995 Jetta turbo diesel.  I bought it about 6 months ago with 240,000km on it.  It has had the IP rebuilt about a month ago (the IP was leaking).

When I bought it (and it hasn't changed), I noticed that the turbo sound is different from the '85 Jetta TD I had before, and it's different from the TDI's, and also most other turbo diesels I'm used to (Ford trucks, etc.). Whereas the 85 and TDI's have more of a high pitched whistle, my turbo has a lower pitched one.  I know this is an awkward way to describe it, sorry.

Also, it takes about 4-5 blocks before I hear that sound (after I start it up cold).  

The fuel mileage is ok (about 670km on a tank, in 95% city driving) but not great.  Very little smoke out the back end unless I really rev the snot out of it, in which case there is a reasonable amount of smoke - so I think that part of it is ok.  It has ok power but it's been a while since I've driven one so I really have no basis for comparison.

No oil consumption between oil changes.  I'm running 5w40 Diesel grade (I think - my mechanic changes it) non-synthetic.

Any thoughts on how I can see if the turbo is acting the way it should?  Should I consider a boost gauge?  If so, any recommendations on what brand, etc.?

Thanks for whatever help you can provide.  Let me know if I can provide any more details on the engine or turbo.  

Mark

[jtanguay]

Hi all,

I have a 1995 Jetta turbo diesel.  I bought it about 6 months ago with 240,000km on it.  It has had the IP rebuilt about a month ago (the IP was leaking).

When I bought it (and it hasn't changed), I noticed that the turbo sound is different from the '85 Jetta TD I had before, and it's different from the TDI's, and also most other turbo diesels I'm used to (Ford trucks, etc.). Whereas the 85 and TDI's have more of a high pitched whistle, my turbo has a lower pitched one.  I know this is an awkward way to describe it, sorry.

Also, it takes about 4-5 blocks before I hear that sound (after I start it up cold).  

The fuel mileage is ok (about 670km on a tank, in 95% city driving) but not great.  Very little smoke out the back end unless I really rev the snot out of it, in which case there is a reasonable amount of smoke - so I think that part of it is ok.  It has ok power but it's been a while since I've driven one so I really have no basis for comparison.

No oil consumption between oil changes.  I'm running 5w40 Diesel grade (I think - my mechanic changes it) non-synthetic.

Any thoughts on how I can see if the turbo is acting the way it should?  Should I consider a boost gauge?  If so, any recommendations on what brand, etc.?

Thanks for whatever help you can provide.  Let me know if I can provide any more details on the engine or turbo.  

Mark

you should give the engine a chance to warm up before utilizing the turbo.  thick oil has higher shear so it puts more friction on the shaft, which is why it doesn't spool as quick when cold.  once the oil warms up it thins out and voila, you get a quick spooling turbo.  the turbo in your '85 is also much larger than the one in your car now...  with a smaller engine  :lol:

i've never heard of 5w40 non synthetic...  if you switch to synthetic you'll notice that your turbo spools up quicker when cold.  the best way to see what the turbo is doing is to buy a boost gauge.  sound alone is very difficult to discern at times.  go with the cheapest boost gauge you can buy.  i went with one from princess auto for about $20.  works great and no buzzing sounds.

who rebuilt your injection pump?  did they do a full rebuild or was it just a re-seal? it might need to be calibrated.  your injectors might need to be rebuilt as well.  because your car should be capable of 800km/tank+ if you drive it right.

because your new here i think you should be warned of the 1.9 AAZ crank nose problem.  just a quick check will give you a good idea if yours is going.  check the crank pulley while the engine is running and if its wobbling, its on the verge of coming right loose and possibly wrecking the engine.

[leftcoastmark]

...i've never heard of 5w40 non synthetic...  if you switch to synthetic you'll notice that your turbo spools up quicker when cold.  the best way to see what the turbo is doing is to buy a boost gauge.  sound alone is very difficult to discern at times.  go with the cheapest boost gauge you can buy.  i went with one from princess auto for about $20.  works great and no buzzing sounds.

Thanks.  Probably my mistake on the oil grade. I plan to switch to synth at my next oil change.  I always used Shell Rotella D in my last car and it ran fine when I sold it at 370,000km.

who rebuilt your injection pump?  did they do a full rebuild or was it just a re-seal? it might need to be calibrated.  your injectors might need to be rebuilt as well.  because your car should be capable of 800km/tank+ if you drive it right.

because your new here i think you should be warned of the 1.9 AAZ crank nose problem.  just a quick check will give you a good idea if yours is going.  check the crank pulley while the engine is running and if its wobbling, its on the verge of coming right loose and possibly wrecking the engine.

Thanks.  I had it rebuilt by a mechanic shop here who does pretty much nothing but VWs.  It was a reseal, not a complete rebuild.  He said that it looked somewhat worn, but he wasn't overly concerned.  I didn't think to ask him about the turbo issue.

I'll get my mechanic to check the wobble - thanks, that's good info.

Any idea what the boost pressure should be on this turbo?

Also - are there any common problems with the turbos on this engine?  

Thanks for your help.

[leftcoastmark]

How hard is it to add a boost gauge to the car?  Is there a port on the turbo manifold that you can just screw a sensor tube into, or does it require drilling into the manifold?