Clunking noise when accelerating

[TominMO]

My Festy has just started making a clunking noise, only when accelerating. Doesn't seem to be connected to steering or suspension. From the driver's seat, it seems to be coming from inside the engine bay, near the center of the firewall. The harder the acceleration, the more noticeable the noise. I'm thinking rear tranny mount?

[fastivaca]

I'm thinking rear tranny mount?

That would be my first guess too! Another thing to look at is your sway bar to body bushings. If they're loose the sway bar is able to move forwards and backwards which I'm sure would result in clunking.

Ian

[william]

I heard that when you gave me a ride . I thought ball joints/pinch bolts or worn rack.

[TominMO]

I heard that when you gave me a ride. I thought ball joints/pinch bolts or worn rack.

I'll check that stuff out too.

[TominMO]

All this stuff is pretty easy to check out; but what is the symptom of worn rack bushings, when I am in the wheel well looking around?

[2jzkilla]

Is it just 1 clunk or or is it hammering with the speed of the engine?

Turn the wheel all the way to the right and reach down on the passenger side and see if you can get any play up and down under the boot. If it isn't shredded. It takes some muscle. If there is play more then just a tiny wiggle it's probably getting bad. Even if there's no play could also be inner tie rods.

[TominMO]

Is it just 1 clunk or or is it hammering with the speed of the engine?

Turn the wheel all the way to the right and reach down on the passenger side and see if you can get any play up and down under the boot. If it isn't shredded. It takes some muscle. If there is play more then just a tiny wiggle it's probably getting bad. Even if there's no play could also be inner tie rods.

It clunks continuously when accelerating, stops when I let off the gas. I'll look around tmw and report back. In fact I get similar symptoms with my Aspire, which is now in the garage for other stuff, so I'll look at that one too.

[2jzkilla]

Sounds like mains to me. Or connecting rod.

[TominMO]

Sounds like mains to me. Or connecting rod.

Seriously doubt that.

[william]

Tom I heard the clunk just once when first taking off and while pulling into the parking lot that's why I said rack or ball joints .
What you are Describing sounds almost like axels? But I've never had an axle clunk on anything but turns

[TominMO]

Tom I heard the clunk just once when first taking off and while pulling into the parking lot that's why I said rack or ball joints .
What you are Describing sounds almost like axels? But I've never had an axle clunk on anything but turns

Right, I discounted axles for the same reason. Plus, all axle boots are in good shape, so no grease leakage or dirt getting in. Axles were new when Greg did the motor swap ~5 years ago, and the Festy is only one of several cars I drive.

I could believe worn ball joints or the bolts that hold them in. But my LCA boots are in good shape, as are the tie rod end boots. I'll know more tmw.

[TWFodor]

When mine was doing something similar, it was because the lower rad support had rusted through and caused the engine carriage to drop on the sway bar. It probably isn't your issue but worth a check

[WmWatt]

Don't know about automatic transmission but with a manual you can let out the clutch in forward and reverse and listen for engine mounts. When my control arm pinch bolt nut loosened the knock was on bumps not acceleration or decelleration.

[TominMO]

When mine was doing something similar, it was because the lower rad support had rusted through and caused the engine carriage to drop on the sway bar. It probably isn't your issue but worth a check

This car is pretty rust-free, esp. in front. But one more thing to be aware of, true.

Don't know about automatic transmission but with a manual you can let out the clutch in forward and reverse and listen for engine mounts. When my control arm pinch bolt nut loosened the knock was on bumps not acceleration or deceleration.

I'll look into that. I do know that all my pinch bolts are there and tight, on both cars. But the bolts may be worn where they contact the ball joint indent. I think on the Aspire it may be a ball joint/pinch bolt issue. But I'll go thru everything suspension and steering related on both cars.

[TominMO]

Checked out both the Festy and Aspire today. On both cars, everything seems fine as far as rubber boot integrity/no grease showing, on the LCA and tie rod ends (I replaced the tie rod ends and steering boots when I bought the cars). Pinch bolts seemed to be doing their job. Front sway bar mounts are on tight. Festy engine mounts seemed to be fine as far as I could tell.

However, after lifting the tire off the ground, when I grabbed it at 9 and 3 and wiggled it, on both cars the driver's side moved. So probably inner tie rod, possibly rack. On the pass. side, the Festy seemed pretty tight but the Aspire was loose. On both cars, the driver's side was worse. The Aspire has ~183K miles, the Festy has much less, and was mostly an RV tow car. All inner tie rods (and the racks) are original AFAIK.

Interestingly, if anything the Aspire seemed to be worse, since it was loose on both sides. But I just drove 2400 hwy miles in it and it seemed good, no noise at all and steered fine.