Caddy 1.9 PD BLS Abgasrückführungsrate zu hoch. | Posts 16+

TDI-GTI-4-Motion wrote:

So, the EGR valve is definitely not working correctly. As long as it is active, the air mass is kept close to the target value. But as soon as the EGR valve is deactivated after 34 seconds, the air mass suddenly fluctuates between 360-440 mg/stroke. Was das AGR valve ersetzt wurde, ein hochwertiges neues Teil oder ein gebrauchtes Teil?

Okay, I was only focusing on the maximum value. Let's see if the EGR pipe is properly attached to the module, and if the EGR module is functioning correctly and nothing is loose.

Best regards, Rainer.

"I replaced the ZMS (flywheel) today. The part was so corroded that I couldn't access the screws. After burning away the hub with a plasma cutter, I was able to replace the part. The vehicle runs much smoother after replacing the ZMS. However, I haven't been able to eliminate the jerking in the partial load range, up to about 1400 RPM. The driving behavior is now acceptable, and given the high mileage (294,000 km), I'll continue to drive it like this. When I last refueled, I added a fuel system cleaner to the fuel, which is probably starting to take effect now."

Hi,

Since the data from the idle speed control system is correct, the system cleaner won't help either.
You can also check the engine mounts and see if there's excessive play anywhere in the drivetrain.

Best regards, Rainer.

Hello, I'd like to revisit this topic. The Caddy now has 306,000 km on the odometer. I recently drove about 1,000 km on vacation. When I accelerate after driving through a town, the engine runs extremely rough up to about 2000 RPM. The top speed and driving behavior above 2000 RPM are fine.
"There are no error codes stored in the diagnostic system. All values are normal except for those related to the idle speed control. The values are fine at idle, but at higher RPMs, they go completely out of range. The engine sounds like it's only running on three cylinders. The gears in the transmission are making a lot of noise. The problem gets worse after driving for a longer distance. The engine no longer has a dual-mass flywheel; I replaced it with a standard flywheel."
The engine is in its original condition, with no modifications or performance enhancements.
Maybe someone else has an idea.

Matthias.

The term "idle speed control" is aptly named because the values are logically only relevant when the engine is idling.
At higher speeds, the idle speed can no longer be adjusted, so moon values are completely normal and irrelevant.

The engine's performance had been steadily deteriorating. I checked the valve timing again. During the dynamic valve timing test, I ran the engine without the pressure pipe connecting the intercooler to the intake manifold.

While inspecting it, I noticed that a cylinder was misfiring. After removing the valve cover, I identified the defect in the camshaft. Some of the lobes were missing up to 3mm of material. The valve lifter for cylinder 3, exhaust side, was worn through.

After replacing the camshaft and hydraulic lifters, the engine runs perfectly again.

Thank you for your feedback.

Thank you for your feedback!