Hi I have a 2001 1.9 diesel beetle, my question is sometimes when driving up the mountain, I live at 6800 ft elevation, the car will seem to go into a 'limp' mode, wont go above about 40 mph. I'm driving the car easy, not bombin' the mountain, outside temp is about 60 degrees, no lights appear on the dash. This only happens once in awhile, and once the car is shut off and then started again the problem stops. Is there an EGT sensor that could possibly be limiting fuel flow that could be going bad? Any other ideas?

 

Possibly an oxygen depletion wherever you're going and the ECU not keeping up with the change? You've got me on this one really...

 

Something to check out is the air shut-off components of the intake system. The system has an air shut-off valve or flap in the intake manifold that closes when the engine is shut down. Shutting down the air prior to fuel reduces the shock associated with diesel engine shutdown. This is a vacuum operated system controlled by a air shut-off valve vacuum/solenoid. The system resets each time you shut down and restart. A check of the vacuum lines and or the solenoid is in order. If the flap is inadvertantly closing somewhat the exhaust will be sooty when it happens and power loss occurs. A good check of the vacuum pump is also in order due to the load put on at high altitude (less differential pressure). Another item to check is the wastgate actuator linkage. If it is binding or stuck from lack of lubrication it will not allow the turbo to spin up enought to produce the pressure needed thus loss of power. Hope this helps a little.

 

Nice mauso. I'm not very well versed on a diesel at all. Turbo gas engine I know inside and out but diesels are a whole different beast. Glad someone here has an idea there.

 

Thank you for your resonse to my problem, I've looked into it based on what you said and had another question for you.I could not locate the air shut off flap in the intake ststem that you refered to. The actuator linkage on the wastegate seems to be free, can move it by hand, however I did find 2 electronically controlled vacuum switches, one goes to the wastegate actuator, located on the drivers side firewall. Question is what is a good way to test these, problem is only intermitant, swithes appear the same could i 'switch the switches' and see what happens? Thanx for your help, I'm getting closer to solving this one!

 

The air valve flap is incorporated into the intake manifold flange along with the EGR valve. It is vacuum operated as is many of the controls on this engine. A hand held vacuum pump can check the actuators to see if the diaphragms are leaking. The ECM controls all of these and the vacuum supply should be checked if there is a problem. Good luck and keep trying.