91 Eco diesel knock

[DAKOTAKIDD]

Hey guys,  today I took my 91 eco diesel to the store (not used much in the last few weeks--im on vacation and just in and out of the drive way)..So I drove to the store, shut it off came out and then started it up and headed for home (2 min drive).  When I pulled into my street, I was driving slowly ( 2nd gear ) I heard this loud knocking coming from the engine.  My neighbour heard it as well from a distance.. I hit the gas pedal and it went away.  I stopped opened the hood and a brief look showed nothing.  Could have been my imagination but at idle it seemed to be a little louder diesel engine noise than normal.  I revved it over--no knock..Shut it off.  About a hour later I started it up again and went around the block and no knock reappeared.

Do you guys have any idea on what this could be?  Injector knock?  stuck valve?  Should I worry about this or could this be nothing

Let me know what you think.

[burn_your_money]

Injector probably. A little WOT action usually clears the problem. If it doesn't you need to stop driving it or you can damage your engine.

It sounds like you're fine though.

[DAKOTAKIDD]

Hey thanks for the reply.  I revved the engine over quite a bit yesterday after it happened.  I will give her some WOT action when I hit the highway tomorrow am.  If it does come back, does that mean I need to change the bad injector(s)?

[8v-of-fury]

Dump a very generous amount (read: 4L Jug) of Automatic Transmission Fluid directly in to your fuel tank.

Either that, or pull the fuel lines between the pump and filter and run it off of pure ATF. Get the return line good and RED, and then shut it down for a few hours. Start it back up, circulate everything, shut it down and then switch back to the normal hose routing. This has cured many noise issues for me in the past.

[burn_your_money]

It's probably just a bit of gum from inside the pump from sitting. It got stuck in an injector for a few moments but has now been burnt or sent back to the tank. Carry on as normal unless it repeats itself. It could mean its time for new injectors.

[DAKOTAKIDD]

Cool,  Thx for the replies.. I will be using it normally tomorrow again and I will find some ATF and dump in the tank.  I already run an additive because I run it on jet fuel so will running an additive and ATF be a issue together or not?

[vanbcguy]

Probably will be fine but hey you never know. Mix some of everything together in a jar, shake it up and see if it does anything weird (like separating or emulsifying). Very unlikely that it would but if you want to be sure that's what I'd do.

Sent from my HTC One X using Tapatalk 2

[DAKOTAKIDD]

Thanks for the replies.  I also doubt it would cause any issues.  Actually I just dumped a liter in this am along with 5 gal of jet fuel.  So hopefully it wont cause any problems (fingers crossed)  I will fill the tank today (Jet fuel) and keep on trucking.

Cheers