Dual Mass Flywheel (DMF)

[T&T Navara]

Hey guys,

Vehicle is a 2013 Navara D40 ST Dual Cab (2.5ltr Turbo Diesel)

After 66K i started hearing a loud noise coming from the engine so on carrying to the mechanic he said was the DMF making noise and needed to be replaced so I ordered a new one off ebay and had it changed.

After replacing the old DMF with the new one and mounting up the gear box on starting the vehicle the engine check light came on. Had a diagnostic done and it said was the crank shaft sensor, replaced that with a new sensor but same problem the engine check light on and the vehicle won't go faster than 60 kmph. Can anyone help or share some advice on the situation as this is really frustrating its driving me nuts.

 

[Old.Tony]

Welcome to the forum!

A common problem with the CAS is debris (usually metallic) interferring with it. Problem has also been caused by slightly dodgy electrical connections to the CAS and at least one person I know of had a bad ECU earth that caused this.

CAS misalignment causes injection timing errors which will result in fuel being injected too early or too late. If it's too early you'll have a significant amount of noise as the fuel tries to detonate before the piston reaches the top of the compression stroke ('diesel knock') and if it's too late the engine will feel greatly underpowered as the diesel ignites while the piston is already on its power stroke. So if the CAS needs adjusting, you'll know what to look for.

I wonder what an ECU reset will do for you, if it hasn't been done already.

 

[lookskyward1]

If the guy that fitted the new flywheel damaged the crankshaft sensor he obviously did not know that it should be removed before splitting the gearbox off the engine.

It makes me wonder if he fitted the flywheel in the right position?

 

[T&T Navara]

He said that he removed the crank shaft sensor before taking apart the gearbox, and re installed it after putting the box back together.

 

[Old.Tony]

Is the tachometer reading correctly (in your estimate)? The tacho data is provided purely from the CAS. If you get a digital readout, it will vary around the 750rpm mark and the fuel rail pressure will vary in a similar way (it's the ECU testing the HO2S in the exhaust).

 

[T&T Navara]

I checked the tachometer and it is reading correct its idling about 750/800rpm. I also reset the ECU by taking off the battery pole for a while, but what happened after that was, when I replaced the battery pole and started the engine check light did not come on the van was idling but when I mashed the accelerator to about 1500/2000rpm the engine check light coming back on, If I switch off the ignition and restart check light off until I accelerate.

 

[Old.Tony]

It might still be the CAS signal, it would be very worthwhile to clean the electrical connections, and also to check the ECU's earth, even removing it, cleaning it up to guarantee a good contact and then reinstalling. Just for the sake of being complete, check the battery negative cable (both ends) and clean them up, that can cause trouble too.