RLT

Can someone tell me what causes a diesel engine to 'rattle' especially when you stick your foot down ?
Always been meaning to ask someone about this for years.

RLT

Brashanic

To put it in a nutshell, the diesel "rattle" and the knock/ping of a gasser are essentially the same thing. The difference is a diesel is designed for this "detonation" to happen constantly, while with a gasser detonation is a sometimes-destructive event.

the loudness of your rattle is mostly related to the cetane level of your fuel and your injection timing.


i googled it for you and this seems to be a decent description.

RLT

So its the actual noise generated by the compression/explosion of the fuel in the engine, is that correct ?
It has always sounded like a mechanical metal on metal type sound to me with this 2.8CRD.
I remember back when diesel engines started to become more 'popular' for economy reasons, over here, usually for higher milage use cars, company cars etc, they sounded like a 'bag of hammers' compared the the petrol engines.
Over time they've become very refined / quieter.
I had a V8 Expedition for 5 weeks in the States two years ago and you could hardly hear the engine.

Brashanic

yeah i think in my own words that most of the noise is caused by compression. the rest is injectors and valve train.

i think the refinement in sound comes from direct injection which tend to be quieter.

leolito

Plus remember the pressure from the compression is sometimes almost 3 times what the gasoline engines have ... so much for a "hammer"

4x4 schrottie

Hello
I think the rattle sound is from the EGR Valve wich one you have, the old had 3 holes in the side and the new only one.
Have anybody problems with the Turbo Tube?

leolito

No(t yet), but I did get my EGR replaced ('08), the distinct rattling + associated vibration was around 1800 RPM. Not that it helped much ...

RLT

I've got an April 2009 build, but got no clue to what EGR valve is installed.
Can you request a new one under warranty ?
Do get quite a bit of rattle when I push my foot down.
Is the valve design especially for the 2.8CRD or is there better after market ones available ?

RLT

Also exactley where is the valve located.... ?

leolito

Sorry for the delay to reply.
I tried to get mine changed, but to no avail. It seems "if it not broken" they don't replace it

The EGR is located at the rear of the engine, on the right side facing the Jeep. It looks like a round tube with a small pipe coming out of it.
In this pic you can see it in the far right, right under the coolant tank pipe. The finger points at the small pipe you can "close" with a screw in order to disable it.

RLT

Thanks for the reply.
Will you get constant noise / rattle from the EGR especially when accerating ?
What happens if you disable the EGR with that screw ?

RLT