Please Help Diagnose a Front-End Rattle whilst Accelerating.

[BongOutBienMorts]

Dear Bongonauts,

Please help me diagnose a Front-End Rattle heard while accelerating. VIDEO LINK: https://imgur.com/a/AUj7cAU

I'm having to sell-on my beloved Bongo, she is in great shape overall but has this one issue which I'd like to resolve before selling.

The rattling noise happens strictly when accelerating: when revs are at approx 2300-2400RPM. Above and below that she purrs like a kitten (or rather; chugs like a tractor - but a happy one).

It's a rapid, high-pitched metallic ticking/clicking/clanking/rattle - a bit like somebody rapidly playing the triangle.

Seems to be coming from below on the front passenger side. - Video attached - (please excuse how short it is... my dad was on the accelerator and he is deaf as a post... - so it was a battle to get it at all...)

- Video was taken whilst stationary (in Park). It's been suggested that it could be a universal coupler on the drive shaft - but would that still make the noise if stationary>??

1995 2.5 AFT dual battery (Northern Japan Style),

Many thanks in advance for your thoughts, advice, and time.

Bing.

[teenmal]

Its not easy trying to diagnose a sound on a video , to hazard a guess ,main bearings, cam shaft /valve train / exhaust warm up valve etc etc.

Personally I would check the oil level then do an oil pressure test. When you mentioned your dad , one of the finest mechanics that I ever worked with was a Deaf and Dumb Lady ,absolutely amazing.

[BongOutBienMorts]

Thank you. Can we eliminate any of those guesses based on the fact that it only happens at 2300-2400 PRM?
- I'm inexperienced, but it feels oddly specific to me that it only makes the noise within those parameters??

Thank again!

[g8dhe]

I suspect that it occurs at those speeds because the vibration at that speed matches the resonant frequency of the thing making the noise.
You might be able to pinpoint the source by using a rod/screwdriver/pole to touch various items and put your ear to the end rather than listen to the noise as it echoes around the entire space.

[teenmal]

Thank you. Can we eliminate any of those guesses based on the fact that it only happens at 2300-2400 PRM?
- I'm inexperienced, but it feels oddly specific to me that it only makes the noise within those parameters??

Thank again!

You can eliminate most guesses if you have an experienced diesel mechanic look at it, guessing is the most expensive way to go. Have you checked the oil and oil pressure , that's a cheap guess.

[BongOutBienMorts]

Thanks all.

- My normal mechanic suggested it was the coupler on the drive shaft - but said he could not guarantee it. His suggestion was to tell the buyer that "it's always been like that" - but that everything is fine... but I just can't imagine myself buying a car that sounded like this... so I don't know why someone else would

- My problem is I'm currently out of the country (so can't check oil right now) and have a small time window to diagnose, fix, and sell, when I return.. - So I was hoping to get some extra ears/eyes on the problem to help save time. I understand checking oil pressure is not something I can do myself?

I have a bongo-friendly friend who can access my bongo and do simple checks (oil etc) - but I don't think I can ask him to get down then with a stethoscope .

@Teenmal - is your mechanic still working? - Sounds like an interesting subject for a radio show...

Thanks again

[BongOutBienMorts]

Thank you. Can we eliminate any of those guesses based on the fact that it only happens at 2300-2400 PRM?
- I'm inexperienced, but it feels oddly specific to me that it only makes the noise within those parameters??

Thanks again!

You can eliminate most guesses if you have an experienced diesel mechanic look at it, guessing is the most expensive way to go. Have you checked the oil and oil pressure, that's a cheap guess.

I got my friend to check the oil level and it's about half. - Any insights from that?

[teenmal]

Thank you. Can we eliminate any of those guesses based on the fact that it only happens at 2300-2400 PRM?
- I'm inexperienced, but it feels oddly specific to me that it only makes the noise within those parameters??

Thanks again!

You can eliminate most guesses if you have an experienced diesel mechanic look at it, guessing is the most expensive way to go. Have you checked the oil and oil pressure, that's a cheap guess.

I got my friend to check the oil level and it's about half. - Any insights from that?

Yes that's a step in the right direction , when was the vehicle last serviced /oil change and filter ?? Obviously it needs to be on the full mark, then note if there is any difference to the sound. If not a pressure test . The pressure test is a very simple straightforward test that your mechanic should be able too carry out.