"pinging" noise while pulling?

[Toypar]

This last weekend I was pulling a 26 ft camp trailer up a 3 mile hill with about a 5% grade. I was in drive at about 2500 rpm 3/4 throttle. About halfway up the hill engine started making a pinging or rattling noise. Noise was kind of like when you run your truck at full throttle for a few seconds and let off to about 1/2 throttle that rattle noise you get. Coolant temp was 200 deg. Quad box was set to stock due to no gauges. Is this normal for these engines? I don't think i was pushing the truck to hard. trailer probably only weighed about 7000#.



Thanks

Dustin





04. 5 2500 quadcab auto

 

[Alan Reagan]

I think the pinging you are hearing is the injectors. Mine was very noticeable before the reflash but then quietened down quite a bit.

 

[Toypar]

So is it normal for third gen injectors to make that noise under load?

 

[SHobbs]

Don't know if it applies to the 3rd gen or not being that there are different injection events, but I was told the pinging was the fuel detonating in the cylinders. Think of it as 6 monkeys hitting the tops of the pistons with a ball peen hammer. Under load there is a lot of fuel going through there.

 

[Nate]

I wouldn't see how detention would be possible on a diesel unless the timing is way off or something like that. Detonation would be the early firing off of the fuel. Since the fuel is injected when it needs to be fired (well supposed to be), detention shouldn't happen.

 

[Alan Reagan]

You have pilot injection where fuel is injected at different stages. It's not detonation like in a gasser but the actual combustion. It's normal. And you are correct, timing has a lot to do with it. With my reflash, there was a significant reduction in the pinging sound. But under heavy load, it's still there.

 

[SHobbs]

By detonation I mean when the fuel explodes. The way I understand it is that diesel fuel detonates in the cylinder the same way gas explodes when fired in the cylinders. Being that diesels are compression engines the fuel detonates in the cylinders. If a gasser was doing this then yes it would be pinging. Saw a post by a member that said the injectors sound like . 22cal bullet being fired when the fuel goes through them and when the fuel detonates (fires) it sounds like pinging.

 

[Alan Reagan]

By detonation I mean when the fuel explodes. The way I understand it is that diesel fuel detonates in the cylinder the same way gas explodes when fired in the cylinders. Being that diesels are compression engines the fuel detonates in the cylinders. If a gasser was doing this then yes it would be pinging. Saw a post by a member that said the injectors sound like . 22cal bullet being fired when the fuel goes through them and when the fuel detonates (fires) it sounds like pinging.

If you are talking about my comment, let me explain. It's not detonation like in a gasser because in a gasser, it is true that is auto-ignition (like combustion) but the pinging in a gasser comes from the irregular burn in multiple areas.



In a Diesel, it is detonation also but with a regular burn.



The pinging noise is typically the sound from the detonation.