CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Rattling noise when shifting

Soooo, here I am with another topic… :sweat_smile:

My leaky E46 316i has another issue (I noticed this first day) It sometimes makes this rattling noise when shifting from 1st to 2nd and 2nd to 3rd gear (Although it’s less intrusive when shifting from 2nd to 3rd). This NEVER happens in 4th or 5th gear and it doesn’t affect the shifting nor performance but it annoys the living hell out of me. It is best described as flipping a toolbox over but lower pitched. Already let the mechanic check my transmission oil and he put this anti-friction product-oil in it. I thought he changed the diff oil but he didn’t. My dad’s X3 had all kinds of noises and when he changed the oil it all went away so maybe diff oil will do the trick. Someone posted a video on youtube with the exact sound that I’m having, hope someone can help.

the rattling noise you hear is probably a loose heat shield or other metal bracket attached to the engine. The combination of vibration and engine torque produced while accelerating is the source of rattle , assisted by a part that is loose, or contacting the engine.

1 Like

Seems pretty logical actually since the engine obviously produces more torque/has a harder acceleration in lower gears. I’ll check it out, anyone have an idea of where the heatshield in question is located? I suppose it’s around the exhaust of manifold somewhere.

I second the vote for the heat shield/s… Grab a piece of wood and either jack the car up or try to lie on the ground and tap the exhaust with the piece of wood. You may indeed notice a familiar sound when hitting the exhaust all along its length with the wood. If its a shield you will find it in this manner. If not…start looking elsewhere.

The car doesn’t rattle when idling though, only when shifting so I doubt it but I’ll surely try because it kinda makes since in some way. Did you guys watch the video? It’s not exactly a rattle but it’s a weird noise :sweat_smile:

Got back from the mechanic, he took it on a drive and also inspected all the heat shields and the driveshaft. There is no play whatsoever he told me that BMW put this piece in the transmission that limits movement of the components during acceleration and that piece just starts rattling a bit over time. He said he could replace it but it’s a load of work and the noise would just come back in X amount of time which is not worth it. It’s not affecting my gear changes not performance so he told me to just go with the flow. He himself has worked on several E46 and actually owns a 320i and a 330ci and on those you hear it more because there’s more torque.

he said its not worth it? you can pay money to fix a problem. you are happy the noise is gone. but you are not happy you paid money? a rattle EVERY time i shift is annoying.

It’s not worth it because the noise will come back after x amount of time and it just doesn’t interfere with my shifting really and I don’t want to spend a few hundred bucks on something that irrelevant tbh

That is true but I usually get annoyed when something is wrong and when it can damage my car but this is just a piece that has some play in it

If a piece has play in it and it shouldn’t, than something IS wrong, and will eventually cause damage.