1.9 TDI ALH needs to be reved above 2200 rpm at every start

Hey there fellow TDI owners,

I have a 2002 Caddy with the ALH engine that has been showing some unusual behavior. When I start the engine it is really powerless, if there's a slight uphill I cannot accelerate, that is until the rpms get above approximately 2200 then it wakes up and has normal power. It's like there's a blockage that gets equalized at higher revs, so maybe a valve? Air related?

It doesn't matter hot or cold, if I turn off the engine and then start up again it has to be reved to 2200 before regaining power.

It has been 100℅ consistent over 5000 miles, been doing long hauls and haven't had time to look into it.

Any ideas guys? Would be much appreciated. Thanks.

Norado said:

It doesn't matter hot or cold, if I turn off the engine and then start up again it has to be reved to 2200 before regaining power.

Click to expand...

After you start and rev above 2200 RPM, does the engine function normally after that until you shut down/restart? Or does it continue to have no power below 2200?

I wonder if this has anything to do with the anti-shudder valve?

I had this issue confusing me. For me it turned out to be the vanes sticking and at a certain point after starting the car they would break free and be fine after that. It wouldn't even always act up after being turned off. Check vane operation with your hand or a mightyvac. It's a simple check and shouldn't take long.


Sent from my iPhone using Tapatalk

I had this issue confusing me. For me it turned out to be the vanes sticking and at a certain point after starting the car they would break free and be fine after that. It wouldn't even always act up after being turned off. Check vane operation with your hand or a mightyvac. It's a simple check and shouldn't take long.


Sent from my iPhone using Tapatalk

It works perfectly fine at all revs after it has been above 2200.

Anti shudder valve sounds like an excellent hypothesis, I will inspect it.

http://forums.tdiclub.com/showthread.php?t=128812
Maybe same problem as described her only not stuck in completely shut position.

When you say vane operation are you referring to the turbo itself?

Does your car have a mass airflow sensor? Could be bad.

Yes, I do have a mass airflow sensor, and I've just cleaned it with an electronic cleaner. I also found that the wiring to N239 (anti shudder valve right?) was faulty, changed these to no avail.

"Check vane operation with your hand or a mightyvac." I was able to move the rod underneath the vane actuator, so that doesn't seem to be the problem.

AnotherPerson, for you the vanes broke free "at a certain point", for me this is ALWAY the exact same point, 2200 rpm. That leads me to believe it's an electrical problem, or even the ECU?

"Limp mode is a generic 'reduced power' mode, that results from any number of potential engine problems. (resulting in reduced fueling & N75 operation)"

Am I in limp mode until I reach 2200 rpm?

I'm not gonna throw too much money at this problem, as it's not really a big issue to rev the engine at start up, but it does tickle my curiosity.

N239 is the anti-shudder valve solenoid, not the valve itself (picky, picky).

What was faulty about the N239 wiring? Are you sure you have it fixed now, and the valve is operating normally? You can see the actuator arm without disassembly; I suggest you watch it as someone first starts the car and lets it idle, then revs above 2200 RPM, then shuts off the engine. I'm not sure, but I think it should be open always except for a couple of seconds at engine shutdown. I can check mine this evening if you need me to, but I bet you can also find that info online.

In my experience, limp mode sometimes will reset itself when the car is turned off/back on. Usually though, once a code is set which causes limp mode, limp mode stays until the code is cleared. I've never known limp mode to go away without at least cycling the engine off/on. Do you have access to a VCDS scanner and can check codes?

Your location is Chamonix-Mont-Blanc, the ski resort? In that case, I don't know how to help you find a VCDS near you -- but your local auto parts store might have a scanner that at least would read DTC's.