Paulyy

I don't know how long it's been doing this but time to investigate.

When i drive, it's fine. When i go WOT at say 3k rpm and when you hear the induction noise, the car shakes with in sync of that noise. It's not a huge shake but you can notice it. and i think in deceleration too.

Different to the 1 tooth out of align balance shaft shake. a lot less then that.

The steering wheel doesn't shake. The CAR does.

Ideas?

I'm thinking could be the exhaust shaking the car or the noise?

Paulyy

B-U-M-P
No one have ideas?

lee101315

That's not an easy problem to diagnose on a forum...

So does it feel like a misfire? What type of noise is it? Metallic? Is it more of a thumping noise on the frame?

Paulyy

No other noises. no grinding feel. nothing like that

think of an unbalanced wheel that shakes the car. but it's faint but noticeable. except this happens during load

lee101315

If it happens under a load, I'd check the transmission mount and the axles. Maybe the transmission is moving to the side under load and straining the axles.

Paulyy

I did the poly fill on my trans mount. if that helps? or the cause?

lee101315

If you filled the bushings with polyurethane, it's probably not loose. You have to do some more driving to narrow it down. When you mention a tire shake, you feel the steering vibrate violently, and you mildly feel it on the floor of the car. Where do you feel it the worst? Is it an engine misfire? Do you feel the rear of the car hop?

Paulyy

The car shakes with in time of the engine exhaust noise.
not a miss fire. or missfire type of sound.
not violently. no steering shake. but the body shakes.

I'm thinking it could be the engine mounts.

jmj951

Any chance the clutch is slipping when boost kicks in? I have a very similar shake that only occurs when I'm hard on the power, which I think is the clutch. I can force a similar shake if I take off really hard from a stop. The shake does not start right away, off the line. I only feel it when boost starts to kick in.

Paulyy

I can't say i have clutch issues. Holds strong. i did drive the other day and i did smell clutch... but i was fully engaged driving and hadn't changed gears before and after the smell came and went. I'm thinking it was in the air.

JET951

Sounds like the exhaust may be touching the body somewhere. the engine will twist more so under load, it only takes a slight touch and you will feel what you describe. Get it on your hoist and use a lever side to side on the exhaust. We have seen similar issues around the WG tie in area on some of the aftermarket exhausts.
Regards
Sean

Paulyy

Thanks Sean, I'll have a look!

User 52121

I'll second this - especially if you recently had the trans mount out. Check your axle bolts.

Years ago I had a funny shimmy/shudder/wub-wub-wub kinda feel throughout the chassis under hard accel as the car passed through 3,000rpm and it turned out I had a couple axle bolts backing out.

Paulyy

I'll check that too!

Paulyy

I had it on the hoist. I know what my down pipe sounds like hitting the chassis,
My wastegate tie in isn't near the chassis. that's more of a clunking noise.

I checked the axel bolts and they're good. still tight. the mount i filled with polyurethane (different stuff to the one you guys use in the states) could be the wrong one, who knows. But i have a feeling it could be the trans