R33 Rattle At Low Rpm And Bump After Accelerating

[Brad13]

Hey guys just wondering if anyone can shed some light on a couple of issues I'm having with my 96 S2 R33 turbo manual. I have a weird rattle noise when I accelerate at low rpm. It goes away after say 1500-2000 rpm but anything lower than that doesn't sound very good. It doesn't seem to affect the way it drives but I would still like to determine the problem here. My hicas light does come after going for a drive, stopping for a bit, wand then once the wheel is turned the bloody lights comes on and doesn't go away. Not sure if this has anything to do with it because the rattle noise is always there regardless. Steering isn't affected when the light comes on either, power steering all works fine.

Another problem is that after I accelerate and back off, I get a bit of a bump that almost feels like a push in the back. Kind of like the feeling you get in bumper cars when someone lightly runs into you from behind.

I have no idea if any of these are related at all, but they're issues I want to get sorted out so I'd really appreciate and help or advice you guys can give me!

[Hadouken]

This could maybe be described as backlash from the diff.

As for the rattle have you checked the simple things? Ie heat shields etc?

[Brad13]

Thanks man, I was under the impression that the bump could be diff related. Is there a fix for it or will it need replacing?

As for the rattle, I haven't checked heat shields. To be honest I had no idea where to start with this, I would've thought the rattle would be there all the time not just in the low rpm range if it were that. Any in particular that are more likely to be the culprit?

[breaker1845]

Chances are you can't hear the rattle after 2000rpm and it could still be there or its due to vibrations at idle and low rpm. Noises are usually very hard to identify just by sound unless its unique.

If you can do more testing and try and eliminate variables it may help. Or getting under the car and putting load on the engine to see what happens.

Can you hear the noise in neutral or just while in gear? Possible heat shields on exhaust or something? Need more information to help you out.

For the 'bump' issue, it could be diff related but can't confirm. Have you serviced the diff recently and checked all the moving parts are alright?

[chiksluvit]

Gearbox rattle? Does the whole car vibrate?

If so then possibly spigot bearing, should've been replaced when changing clutch

[Brad13]

I can't hear the noise in neutral, it only ever happens at low rpm. You can feel a bit of a vibration through the seat but it's not too violent. No feedback or vibration through the gearbox either, that all seems ok!

It's hard to describe the sound, it is what I would expect a loose heat shield to sound like so I'll definitely check that, thanks.

I've only had the car for a couple of months now so I haven't checked out or serviced the diff yet. Still trying to sort out some of the problems that were there when I bought it.

[GTSBoy]

If the diff has lash it's either wear, which you can't do anything about (usually) apart from replace CW&P, or it's collapsed a crush spacer or similar and is now out of adjustment. If left like that it will wear until you have to throw it away also.

[Hadouken]

You may be able to get a bit extra life out of it by putting in some redline oil.

[kingtube69]

The vibrating you have at low RPM sounds exactly like mine and my mate also has an R33 with the EXACT same rattle. I have tried many things but can't seem to work it out.. If you get help with this I want help too.. Just letting you know that it's not just you having the issue. Also we have the clunking diffs too hahaha.

[Brad13]

How annoying is it?! Such a painful sound man haha. There are a few things like the heat shields and rear diff I need to check a bit closer once I have a chance to get it up on some stands. What have you tried so far? Just so I know a few things I can eliminate.

I've also realised I'm missing an exhaust bolt/nut at the top of the dump pipe. Not sure what size these are and I didn't know whether you could use any type of bolt due to the heat it'd have to withstand. Are you missing any as well by chance?

[kingtube69]

How annoying is it?! Such a painful sound man haha. There are a few things like the heat shields and rear diff I need to check a bit closer once I have a chance to get it up on some stands. What have you tried so far? Just so I know a few things I can eliminate.

I've also realised I'm missing an exhaust bolt/nut at the top of the dump pipe. Not sure what size these are and I didn't know whether you could use any type of bolt due to the heat it'd have to withstand. Are you missing any as well by chance?

I'm not missing any bolts but I've tried manifold heatshield, Turbo heatshield, bumper, grill etc.. I haven't checked any other heatshields but I noticed my rear engine mount is a bit shot.. Check yours as well to see if there is excessive movement and let me know.

[kingtube69]

I just received my transmission mount in the mail so I'll change it tonight and let you know if that helped at all because it certainly needs replacing

[Brad13]

Sorry to drag this thread up again but has anyone had any luck with the rattle? I've checked my heat shields and the transmission mount seems ok.

Still a bit stumped as to what else I should be checking??

[kingtube69]

No dice, mine is still the same but I haven't driven it for three months now.

My car goes in for a tune in the next few weeks so I might get them to look at it then.

[scotty nm35]

Get it on a hoist and start thumping parts to replicate the vibration, if it's exhaust it shouldn't be hard to hear. Run the car on the hoist if it makes the noises at idle, and use the hose in your ear trick to pinpoint where it's coming from.

[Brad13]

I've had it up on stands a few times and checked over the exhaust & mounts with no luck. It doesn't affect the way it drives but does vibrate a bit. Only makes the sounds under a bit load in 1st or 2nd usually, so it might be hard to replicate the sound on a hoist as well.

It's doing my head in trying to work out what it could be!

[ErOR]

I have the same noise when taking of sometimes and I believe it's something to do with the clutch. I'll be doing the whole clutch job in a month or two and am interested to see what I can find regarding this noise.

[Milkmun]

Hey man, ever end up resolving the problem? Mine starting to do the same;

- low rpm noise and vibration

- goes away when boost kicks it/higher rpm

- no noise on idle

- coasting then clutch in still makes noise

- revving in neutral no noise

- revving in gear no noise

[ErOR]

Hey man, ever end up resolving the problem? Mine starting to do the same;

- low rpm noise and vibration

- goes away when boost kicks it/higher rpm

- no noise on idle

- coasting then clutch in still makes noise

- revving in neutral no noise

- revving in gear no noise

The rattle that I had was coming from the exhaust heatshield just after the manifold. It's a 2 piece heatshield there if I remember correctly and it was just touching. It would only make the sound when taking of in low rpm.

[Brad13]

I haven't solved it unfortunately, I haven't checked that manifold heat shield though I'll definitely have a look at that. Your symptoms are literally the exact same as mine though