Hey guys.

The short of it: 05 JDM evo 9, LSD ACD, mechanical JDM RS rear LSD, 45k miles(I've converted all mileage to miles to make it less confusing), drivetrain is all factory.

I bought the car with 30k miles, didn't think to ask for specific service history (next time lol), no noise. Within the last 6500 miles I've been hearing a noise that is completely dependent on speed, it seemed to be marginally quieter in warmer weather. I'd start to hear it at 35 mph and it would be most noticeable at 40-50 mph but at 60 I couldn't hear it. Any gear, neutral, clutch in or out, accel, decel, cruise, turning, straight, none of this affects it at all, only speed (maybe temp a little).

I was just putting it down to the evos noisy drivetrain but I've just done a 110 mile trip and now the noise is present at much lower speeds, 15 - 20 mph.

The noise: It's kind of a whirring, lack of lubrication sound, or a kind of smooh grind. At low speeds it seems to be a slight pulse, like a rotational issue. There is no vibrations or other feelings coming from it, just noise. I don't think a video would pick up on it but I might give it a go later on.

Done after the noise started:
TC fluid, only around 400 millilitres came out (full is 600), no metal pieces detected
Trans fluid, all good
Rear diff, a fair amount of metal shavings on the magnet
4 new tires, Nitto NT05
Alignment

None of this made any difference to the noise.

Any thoughts, opinions, reccomendations, questions? Fire away.

Cheers guys.


Update: Post 36, clicky.

 

Because racecar?

Evos are noisy unless your transfercase is going out, then they're really noisy.

 

chur brah

The noise doesn't bother me, the fact that its getting worse does.

 

Can you put the car on a chassis lift and run it? That's usually the fastest way to figure this out. If you want a guess based on what you wrote: transfer case. (When has Mitsu ever made a transfer case that didn't have issues?)

 

Once you said pulsating, which I was exactly going to ask you if it sounded like a pulsating whirring sound, I can promise you its a wheel bearing. I had the same issue, it was my left rear. Replaced it and problem solved.

 

FWIW (not really much I suppose ): I'm really hoping for wheel bearing

@Iowa: I don't like the idea of saying TC because it is a weak point, the car hasn't seen any hard launches (only a couple gentle ones) and has only seen high speeds several times, while I've owned it anyway. I definitely won't rule it out though. I can get it on axle stands easily, will that suffice? And just get under there and listen?

@Sven: Given that it doesn't change with turning do you think it is most likely the rear? The noise appears to come from the rear.

 

I would put it on a lift, you don't want the vibration from the wheels spinning while the car is off the ground to knock the car off the jack stands.

 

What he said. I would never get under a running car unless it was on a lift.

Plus, you need more room between the bottom of the car and the ground or else the reflected noises (off the ground) will make it hard to locate the sound.

 

Im not too sure on that part to be honest about turning, mine was blatantly coming from the rear. It was very obvious because it was perfectly audible with your head to the rear seats while driving, and the rear seats would vibrate in conjunction with the pulsating whirr noise from the wheel bearing. The pulse would increase as speed did and the whirring would also get louder.

 

I was wondering about the stability with the wheels in motion, alright then, to find a lift.

 

One other thing you can do is sit in the back while someone else takes the car for a spin, might help you triangulate the noise location.

 

Put the car on a lift, while running, & get a doctors stethascope or whatever its called and listen to both sides & middle of the under carriage... im going thru this as we speak & mine is more of soft scratching/scraping noise thats too low audibly to record...I plan on doing this in the coming week or so Ill let you know if you dont find out 1st... im betting its the wheel bearing although mine makes no change in noise during turns....

 

Hrmm, I'll have to find someone I trust driving my car. Are you in the area any time soon?

I will do this quite soon.


My noise is very similar to yours, I have no change in turning either. I look forward to hearing back from your test, I don't have any baller mates with lifts. I'll be able to find someone who will be able to help, in time. I will do this if I don't diagnose it before I find one.

 

California is close to Australia right?

You see what I did there?

 

in my personal opinion is the transfer case