Rhythmic pulsating at 1500rpm

[Greystroke]

Hi guys, wife and I just pulled into Braidwood on the first day of our travels around aus and noticed that the engine was making a rather distinct rhythmic pulse at when idled at 1500rpm. Not noticeable at all when driving only when idle. Thought it might be an air leak in the fuel line but haven't been able to find anything yet. We have a good old hj75 with a 12ht (so not sure if this would be better posted in the 60s series section). Will try and get an audio of it if needed.

 

[coldtaco]

well, hopefully you are not idling at 1500rpm's. Try 800 or lower.

 

[Greystroke]

Haha no not idling at 1500, just happened to put my foot down when we stopped and felt the engine vibrating. Just peculiar that it only happens at that rpm, going up to 1600 seems to make it stop.

 

[coldtaco]

hmm, then I don't know, might be normal. My 2H has something similar when you first start it and set idle to about 1200rpm right away until it warms up.

 

[ozcrusier]

Probably best to get a audio but check your turbo air pipe as it may have blown one of them off or split a pipe.

 

[Greystroke]

Checked the turbo pipes, couldn't see anything wrong there. Got a recording of it hopefully this will help Untitled

 

[coldtaco]

next time turn your blinkers off

 

[Greystroke]

Let me guess you can't hear anything with the darn indicators going can you...

 

[coldtaco]

Let me guess you can't hear anything with the darn indicators going can you...

Second time I could see how the instrument cluster was shaking. Was still kind of hard for me to hear the engine good, but it did sound odd, maybe like missing? Have you driven it at same rpm to see if it does it too? Is it only at 1200-1500rpm? Did you try higher rims?

 

[AndrewHadji]

i had a similar sound, it was my fan about to fall off, two of the bolts had vibrated loose. Easy to check if thats what it is

 

[Greystroke]

I'll have a check of the fan bolts. Did discover the small hose connected to the turbo actuator was split, have replaced that now but didn't make any change to the pulsing. Taco, much higher revs and it goes away, and it doesn't seem to happen when driving. Totally stumped.

 

[roscoFJ73]

. We have a good old hj75 with a 12ht (so not sure if this would be better posted in the 60s series section). .

Normally diesel related queries go in the diesel forum.

 

[AndrewHadji]

I'll have a check of the fan bolts. Did discover the small hose connected to the turbo actuator was split, have replaced that now but didn't make any change to the pulsing. Taco, much higher revs and it goes away, and it doesn't seem to happen when driving. Totally stumped.

Yep, not saying its it, but noticed it at a stop light, at higher revs it would go away, pulled over and saw 2 bolts missing