Hey guys, I've been lurking on these forums a bit for a while since I got an '86 6.9 IDI, but I decided to finally join..

I noticed that there is a grindning kinda noise from the engine when I cut the ignition.. It always seemed to be there atleast a little bit as long as I had it, but today it sounded even worse than usual so it has me a bit worried... I would take a video, but i'd need to borrow a camera as mine doesn't seem to have any audio.

The truck was sitting for quite a few years before I got it, but it was being started up every week or so.. I drove it for about a year, but then I had to let the insurance lapse and its been sitting again for a while, but I've been starting it every week or so..

Theres are a few little problems that I don't think are related, but I might as well mention them. The CDR valve needs O-rings. I had bought a replacement online, but it didn't come with them and I already had it all apart so i just used the old ones.. It ran great after for maybe an hour after, then it started burning oil again.. I haven't gotten around to replacing them yet.. Also theres a small air leak into the fuel lines.

Maybe im just being paranoid, but should I be worried at all?.. The truck does have ALOT of mileage, a bit over 500,000kms, but it was always well maintained by my uncle (previous and first owner) and it was mostly highway driving.. It seems to run fine though, but I can't take it on the road to really test it.

Thanks for any help

 

A bit more info in regards to the grinding? Is it a consistent grinding noise (continuous) or reciprocative? Any hints as to where in the engine bay you hear it coming from?

First thing I'd do is remove the belts and fire the truck up and then shut it off again and see if you hear the grinding. I would place my bet on alternator bearings or some other accessories bearings.. A/C pump, PS pump, Alternator, Vacuum pump and Water Pump would all be candidates...

 

Thanks for the reply.

There seems to be no sound while its running, but then again its a pretty loud engine

I went out and started it again and got my brother to turn it off while I had my head under the hood and I could not hear the sound anymore. I did this several times and even while in the cab as usual and nothing..

Before when I heard it, it sounded like a little grind as the pistons came to a halt after cutting the ignition.. it always sounds a bit rough as this happens, and im sure thats normal, but Im sure I heard a bit of a grind a few times before... Thats the only way I can really explain it..

It might be that it only happens when the truck has been sitting for a while.. I've been away for a bit over a week so it was 2 weeks since it had been started.

Im almost certain its not any bearings in any of the pulleys, as I could not hear anything from them while under the hood.

I will let it sit a few days and start it up again and see if I can replicate the sound...

But Thanks for the help, I will post again in a few days when I start it up again, but if anyone has any other ideas on what it could be I'd like to hear them.

 

Check your fan clutch, that's what it was on my 84. When I shut the truck off it would make a weird grinding noise for a few seconds and then stop. After further investigation the bearings in the fan clutch were coming apart and turning into powder... that could have been bad. If it completely comes apart, the fan will come off and tear up all kinds of things onder the hood.

 

This is why you just get a direct bolt fan lol!

 

is it a manual truck? could be the though out

 

throwout bearing will not cause grinding....unless its gone completely to pieces....

 

old thread

 

XD I just seen that haha