The Dispatch | Expert | Scudo Hub

TeddyMcB

Member

Registered: 2022-11-21

Posts: 15

Diesel knock on cold start, Lift Sensor?

Hi all, I have a 2005 Dispatch 1.9 diesel face lift with a diesel knock on cold start which quiets down as the engine heats up but not completely. It started suddenly and sounds like rod knock but it is not. I believe it is diesel knock because it does not knock when coasting in gear, no fuel being used at this time. If I rev the engine, it knocks as I push the accelerator but stops briefly as I take my foot of the accelerator again no fuel being used during this brief time. Back knocking on tick over. So after reading a lot both here and online I see the Lift Sensor on the injector 4 is a possible cause. I note disconnecting it makes no difference to the Knocking and this also makes me believe it is the culprit. I measured the resistance of the sensor which is 100 ohms and that is what a good sensor should read. I traced the 2 wires back to the ECU and both have continuity to the connector (Pins 2J and 3K) of the ECU. However, I have not yet checked if connections make their way to the ECU circuit itself. (Through the multi plug connector) After checking the wiring diagram the pins (2J and 3K) are the correct ones. I have no warning lights on the dash when engine is running but they do come on with ignition as I would expect. So my questions are
1: Could the Lift Sensor be faulty and still read 100 ohms?
2: If the lift sensor is faulty would I expect to see a light on the dash?
3: Is driving it with the knock bad for it I wanted to take it for a spin and get the Injector cleaner I added to the tank to do its thing.
I don't have the van long and it had passed its annual test about 500 miles before I got it so should have been running well then and I drove it for about 3 weeks with no sign of Knock before this started.
Any thoughts please?