loud diesel knock once in a while.

[rsh4364]

Every once in a while Im having a really loud diesel knock,like a bad injector,but it goes away and doesn't happen again for a while.I have good fuel pressure and it only does it under load,not at idle or even when revving in park.When it knocks loud there is no smoke.It really sounds like a bad injector but only does it occasionally.

 

[bonedoc]

I get a bit of an injector knock when my truck is a little cold and I'm driving it and load it a bit. Only occurs under load and goes away as soon as engine is fully warmed up.

 

[rsh4364]

Mine does it sometimes when cold, sometimes when warmed up to 180.Full tank or 1/4 tank of fuel.I cant make sense of it.

 

[cucvrus]

Dry nozzle stuck. Or it is eating a glow plug. I would say dry sticking nozzle. it happens sometimes because they removed the sulfur from Diesel fuel. If you add a bit of ATF or and additive top the fuel it will take care of it. But do may have a nozzle that is going bad. I have heard it a couple times on certain trucks and others never. It is a real heart stopper when it happens at 70 mph in the passing lane.

 

[rsh4364]

Thanks Rick,I do use power service additive,and added Lucas injector cleaner when noise started.Seemed to help but still happens now and then.I suppose I should get some new injectors.

 

[NovacaineFix]

Every once in a while Im having a really loud diesel knock,like a bad injector,but it goes away and doesn't happen again for a while.I have good fuel pressure and it only does it under load,not at idle or even when revving in park.When it knocks loud there is no smoke.It really sounds like a bad injector but only does it occasionally.

What engine is this in, I'm just curious to know. CUCV or bigger?

 

[rsh4364]

In a 1009.

 

[cucvrus]

Rick bring that truck in here to PA and I will show you how to blow the carbon out of it. It probably has Cobwebs on the intake and exhaust valves. Nothing a good run down I 81 won't clear out. I have that sound happen to me on the highway about 1 time every year. And it gets my attention rear quick. But it goes away with some ATF added to the fuel. Do as you wish. That is the way I fix the knock. Once it happened to me and the next day the truck would not start. Here it was glow plug that the engine was swallowing. Never hurt anything but I thought it was dry nozzle knock but it was louder. Good Luck. Run it hard and maintain it harder.

 

[rsh4364]

Added a qt trans. fluid today,I used to run it in my 85 but didn't run in my 86 1009,til now.I really don't baby this truck I run it at 65mph at 3100 rpms often.So cobwebs should be gone.One of these days Ill make it up there to see ya.My late Mothers family is all from Pa .SummerHill Johnstown area.

 

[rsh4364]

Rick I used to add 1 qt. per fill-up,is that enough? Thanks again.

 

[rsh4364]

Took nice long 75 mile trip one way today for a physical/drug test for new job.And 75 miles back home,first long trip since adding atf to fuel,no diesel knock at all.I guess I will keep adding a qt.at each fill up.It looks like I will be spending this winter in sunny balmy Dayton,OH.