Pinging diesel
 

Hi folks,

Just collected my GC from my mechanic. It has had German remanufactured injectors fitted. The engine runs fine, except under load at low revs it has a pinging sound. I do not think the injectors are leaking, as there is no smoke coming out the exhaust. Once it starts to accelerate it is happy. Just mainly the initial take off from still, is when I hear the ping. Not lead footing it, just a normal take off. Any ideas?

Thanks, Dave.

My mechanic had assumed the ECU would automatically rebalance the new injectors. He checked the output of each injector with the scanner, showed all were very equal, figure of the output being in RPM. He then decided to select new ECU on the OBD scanner, this seems to have fixed the problem. First driving off there was pinging, but the more I drove the quieter the pinging became. After 5 minutes it was perfect. Great Mercedes technology.

Most ECU's have a re-learn function. Happens with transmissions as well. It never hurts to put a dose of injector cleaner through as well to clean the pump etc. The composition of diesel changes over the seasons and so the ECU is probably compensating for that as well.

Hi.
Did your mechanic recode the new injector? There will be a number on the injector that needs to be entered into the ecu using the scan tool.

Thanks Brit, yes the recoding was done.

I reported in my last post that all had become good by doing a ECU reset.
The Jeep was then not used for about 4 days. On starting it up again, it was sluggish, in fact quickly established the engine would not rev beyong 2,000 RPM, even with my foot flat to the floor. No engine light, but I quickly turned back and parked it. Now waiting for my mechanic to visit again.

Could be a dirty egr valve.or split in turbo hose.My money on a blocked egr,causes pinging . Fairly easy job on these to get off.Did my mates JGC diesel a couple of years ago his was blocked up.

Thanks greatly bjm, will tell my mechanic.