[BurrNinja]

It started about a month or two ago. I keep hearing a rattling noise like a ticking coming from underneath the car. Not sure if its in the rear or the middle of the car. Well I tried seeing if anything was loose without taking the plastic covers off from under the car didn't notice anything. When I am driving it starts about 37-40 mph, i hit bumps and i hear it rattle like something is definitely loose. I did notice one of the rattle clips on the brake caliper is a bit loose, so i took it off bent it a bit to add a tighter fit no success. The opposite side rattle clip is way tighter against the caliper then the side i bent so not sure if that causes it. I then thought to check my differential which was a bit low on oil, filled that up no change. Its really bugging the hell out of me.....

Any ideas what can be causing this annoying rattling?
Btw its a 2008 328i

[rick100]

Catalityc converter tends to rattle once it starts going bad. Have tou tapped them to see

[BurrNinja]

Originally Posted by rick100

Catalityc converter tends to rattle once it starts going bad. Have tou tapped them to see

So, i tried testing back pressure my exhaust tips were hot af so i used my shirt and hand to plug it with little to no back pressure... Fuck me... replacing the cat asap. Must be why my car gets hot quick, and would this be a possible low idle cause? Also before i felt more back pressure and heard no rattle, but now theres rattle and little to no psi.

[W37V]

Originally Posted by blackwidow328i

So, i tried testing back pressure my exhaust tips were hot af so i used my shirt and hand to plug it with little to no back pressure... Fuck me... replacing the cat asap. Must be why my car gets hot quick, and would this be a possible low idle cause? Also before i felt more back pressure and heard no rattle, but now theres rattle and little to no psi.

If your mid cats are gone, Unless there is a sniff test in your state, just get rid of them - it's cheaper. Get Afe mid pipes and you should be good to go. No need to do tune or anything as there are no sensors past headers.

[BurrNinja]

Originally Posted by W37V

If your mid cats are gone, Unless there is a sniff test in your state, just get rid of them - it's cheaper. Get Afe mid pipes and you should be good to go. No need to do tune or anything as there are no sensors past headers.

With the cat going bad/or already is. Will this cause what problems im having with low idle, poor performance at low rpm? Also im sure its the reason why my car gets hot pretty darn quick.

[W37V]

It could be, but I think clogged cat would give you more issues at higher rpm as that is when you are pushing more exhaust.

When you say hot, what do you mean by that? It could be failing water pump.

Have you scanned for codes (shadow codes)?

[BurrNinja]

Originally Posted by W37V

It could be, but I think clogged cat would give you more issues at higher rpm as that is when you are pushing more exhaust.

When you say hot, what do you mean by that? It could be failing water pump.

Have you scanned for codes (shadow codes)?

Maybe im just worried about it a little to much as far as being hot, im not totally used to the change from having a Honda to a BMW. HUGE jump, and way better performance so i should expect the engine to heat up quicker then Honda "not sure", but it hasn't over heated. There are no major codes stored/shadow codes that i have seen with the programming. Im just trying to trace down why my car is ticking at higher mph, and just today it isnt as loud. I Know i need an alignment, which car swerves a tiny bit to the right and wobbly steering wheel.