Lately I've noticed increased noise from my diesel at idle and when accelerating in drive, after coasting . Yesterday after pulling a two horse trailer for 1 hour at 120km/h (75 mph) - about 6,000 lbs, I heard a rhythmic knocking sound from the engine while it was idling in P. THis sound gradually went away after I started driving. The increased noise while adding throttle is more of a rattle than a clatter (which I have not noticed previously). In general, the engine clatter seems to be getting louder. I have to drive 600 miles to Minneapolis in 3 weeks to pick up a new gooseneck horse trailer and wouldn't like to be left on the side of the road with engine problems if this noise isn't normal. As I am new to diesels, sometimes I'm not sure what is combustion noise and what is valve clatter - however I know enough to knw that the knocking noise wasn't anything good. The truck has 7,000 miles on it. This is my first diesel ... any ideas?

 

More than likely its just diesel noise, but I would swing by the dealer to document the noise just to be sure. Valve adjustment should not be nesessary at 7K miles.

 

Thanks for the reply Geico, but at this point the knock is intermittent and I don't think the dealer will spend the time to go on a lengthy highway trip waiting for the noise to appear. It's clear that this noise has just started though and the engine definately doesn't sound the same (noise wise) as it did a 1,000 km ago.

I'm not too concerned about documenting the noise as the engine has a 7 year - 100,000 mile warranty, which will expire long after I've sold the truck. Whatever breaks is DC issue from a cost point of view.

My question is more related to whether this knock is something that is likely to leave me stranded. For myself, I don't really care, but when I'm hauling $150,000 worth of show jumpers, being broken down in the middle of nowhere isn't an option.

 

I only have 16k miles on mine, but so far I've been able to bucket 'new' noises as noted below. Other's opinions and experiences very much welcomed.

1. Increased noise when cold and when starting - better grade of fuel and/or a cetane boost helps. I use Stanadyne as it seems to be the only fule additive that has a number of OEM approvals.

2. Increased ticking/clickety-clack noise - need an oil change and/or better grade of oil. For me Delvac 1300 was quieter than whatever the dealer oil was, and Exxon XD-3 Elite, a synthetic blend, was quieter yet.

3. Knocking, even when warm, especially under lugging conditions - change the fuel filter, and consider changing fuel supplier.

 

The noise you are hearing could be fuel related. Have you tried running some fuel conditioner? I used some Power Service and it cured my engine noises. I had a dirty injector causing a loud ticking sound at idle and low rpm. A double dose of PS cured the problem.

 

I agree with SBishop. Mine was doing exactly the same thing as yours. and fuel conditioner took care of it.

 

If the noise comes and goes it probably is fuel related. Going on your trip to haul your trailer should be good for it. A few WOT will help. If you have mechanical noise it will always be there. Not too many (if any) CTD have had catastrophic mechanical failure stranding someone on the side of the road.

 

From what I have read, there are quite a few 03 +04 's with injector hold downs working loose. This causes a knock at idle and just off idle.
Look into it.

 

I've got a similar knock from my engine as well (24,500m). Have been running PowerService additive for about three tanks now and it hasn't seemed to make a whole lotta difference. The fuel filter has been changed recently, oil and air filter too...My knock seems to happen right under 1500RPM. At higher RPM it's not too prevelent but I can tell a bit of difference in the sound of the engine....

I'm considering taking mine in but afraid the dealer "won't find anything"...

 

Thanks J-Fox. What you are describing si the noise I am experiencing (I think). I'll check with the dealer on this tomorrow. The noise is intermittent and I'm wondering if I am doing any damage driving the truck if in fact the problem proves to be a loose injector hold down?

My attitude with respect to fuel additives, etc. is as follows: If it didn't need them for the first 6 months, it shouldn't need them now, unless the owners manual says they should be added.

Thanks for the replies.

 

When I first start my 04 it's nice and quite. Then after a little drive down the highway with the A/C on. at a stop light the dam thing sounds horrable. Real klanky Knock and its loud. I was thinking it was bad diesel.

 

I am having that same problem, a knocking noise at idle or low rpm. I just dropped mine off at the dealer. Where can you buy Power Service?

 

Wal-Mart