TDI - How big is your turbo lag?

[VWVirgin08]

Hi all,

Just had my 2001 1.9 TDI Passat serviced today and the fitter told me that the lag on my turbo was much bigger than it should be. I have only had the car for 2 months and being new to the VW world, I just thought that's the way Passats are. When i press the accelerator, there's a 1 to 2 second delay before the car responds powerfully. That may not sound like a long time but it is when you're pulling out onto a busy roundabout and you're waiting for the acceleration to kick in whilst an HGV is bearing down on you!

Does that sound normal? Is your turbo lag the same?

Don't know if this means anything but the guy who sold me the car had a new air mass meter and sensor fitted on it in September of last year (2007)

[LeeTanczos]

didn't think you could get turbo lag as such, because it is a VNT turbo isn't it? Seems to me the mechanic may have embarassed himself really.

Assuming the engine is in okay condition/repair more likely to me that you are demanding power/torque at lower revs than is designed, and the delay is while the engine reaches the lower rev limit for when the ecu is "allowed" to apply boost, and then you finally get your demanded power/torque. this is because the turbo could otherwise stall/stutter and the engine would likely not respond smoothly, not to mention become overstressed.

However, I found on mine a loose large hose clamp (aka jubilee clip!) on the main inlet hose from between the turbo and the inlet manifold... the most visible one in the engine bay from above (can't remember if revealed by removing the top engine cover)

I tightened it up and got quieter engine and more reliable torque/throttle response and much easier driving. prev owner had had the intercooler replaced by VAG so seems they left the hose loose!!! Also he paid for renewed rear calipers which are seizing up again so I suspect that wasn't really done either... or worse... they fitted them with the slider pins dry...???

I find that the ecu will watch for strong throttle demand and I suppose make use of turbo momentum and allow increased power output... I try to explain: if you use strong acceleration in 1st, change up, use strong throttle again, much more power/torque is available much quicker. Makes it worth while driving with reasonably quick gearchanges. With lazy gearchanges this effect disappears and overall acceleration is sluggish. I suppose this is certainly an economy design, allowing strong acceleration only when required, and tending to sip politely the fuel the rest of the time.

Just my 2 cents... and my first post!

[VWVirgin08]

Thanks for the info - I will check the pipes and jubilee clips!