Stationary Low RPM vibration between 1000 -2000 R32

[dtorreal]

Hey Guys

I have a 1994 R32 GTR which I have owned for years. It's always been silky smooth yet the other day I started it and the car felt weird. 

Stationary at low RPMs between 1000-2000 the car vibrates. You can feel it through the seat but mostly the steering wheel. No knock, no smell, no issues driving just this weird vibration. Above 2000 you don't feel it anymore. Not sure if it goes away or can't be felt due to higher revs. Car just finished a 400KM drive a few weeks back without any issues. 

I have seen this problem on many forums including SAU and nobody ever posts whether it gets fixed. Hoping this time someone can give me feedback or has fixed it so we can update the forum with a fix.

 

 

[joshuaho96]

How is the idle? Are all injectors flowing properly? I recommend running a cylinder balance test where you disable injection on each cylinder at low idle and see if any one of them seems to have a weak influence on idle RPM, they should all drop the same amount of RPM when you turn it off.

[White GTS-T]

You've owned it for years, have you ever replaced the engine mounts? I'd be checking and testing all the engine mounts first, including the gearbox mount.

[dtorreal]

On 2/6/2022 at 7:42 AM, White GTS-T said:

You've owned it for years, have you ever replaced the engine mounts? I'd be checking and testing all the engine mounts first, including the gearbox mount.

No I haven't. I was thinking this could the case but wouldn't there be rock in the engine when starting?

[dtorreal]

On 2/6/2022 at 7:36 AM, joshuaho96 said:

How is the idle? Are all injectors flowing properly? I recommend running a cylinder balance test where you disable injection on each cylinder at low idle and see if any one of them seems to have a weak influence on idle RPM, they should all drop the same amount of RPM when you turn it off.

Idle is perfect. No hunting, very smooth. I haven't done the cylinder balance test yet why would it only do it at low RPM?

[Duncan]

Yes, if the engine is vibrating but running smoothly it is probably not a missfire.

I'd check all of the accessory belts carefully, and make sure all of the accessories are mounted properly, eg power steering pump is tight. There are lots of other rotating bits that could come out of balance (eg, the harmonic balancer itself) but at least you can check those easily. If you have a timing light, check the base timing against the balancer too, if it is miles off it may be the balancer

[r32-25t]

I had this issue with mine for years, turned out to be the balancer 

[WantGTR]

agree with @r32-25t. i had a similar issue, slapped on a new ATI, engine was smoother than ever.

[WantGTR]

if it does end up being a balancer, hopefully you havent damaged the keyway on the crank. best to get a new keyway as well.

[dtorreal]

On 2/7/2022 at 1:22 PM, WantGTR said:

if it does end up being a balancer, hopefully you havent damaged the keyway on the crank. best to get a new keyway as well.

So the balancer can damage the keyway immediately or does it take a while. Problem hasn't been an issue for long 

[WantGTR]

On 07/02/2022 at 7:48 PM, dtorreal said:

So the balancer can damage the keyway immediately or does it take a while. Problem hasn't been an issue for long 

Depends how bad the vibration is guess. if the balancer bolt backs out or the balancer is bouncing around it can do damage yes.

[BK]

Last year this happened to me...

If balancer has become faulty and loosened after being tightened to 460nm + there is sometimes another cause. The most overlooked part that makes them come loose is not the bolt or balancer itself, it's the rubbish lower factory timing gear and shields. They seem to crush after extended use or under high loads.

Ross have an excellent billet full replacement for this which I have now used.

If the balancer needs to come off I strongly suggest inspecting the lower timing gear area. Dead give away for being crushed is when the back of the balancer is touching or almost touching the lower timing cover.