Need HELP! Clacking noise at a cold startup and entire bank 2 misfire

[Los.99]

Hey guys I just joined not to long ago, I’ve bought a 2011 e90 m3 about a year ago and early in July I installed a valvetronic catted midpipe, about a month later towards the very end of August the car started to make a clacking noise at idle and only at idle and then one day it completely went into limp mode, clacking noise was only happening at cold startups from that point on, checked codes(will add pics of them). Clacking noise goes away after first startup or if u clear the codes before starting up but code/codes will come back right after startup, I ended doing my valve covers, vanos covers, spark plugs, bank 2 exhaust vanos solenoid clean and replace seals, bank exhaust CMP sensor replacement but car still is misfiring from bank 2 entirely and clacking at cold starts, I’ve since also removed the midpipe and changed the exhaust gaskets but still nothing. The only code that comes up as of rn is the CMP code(002719)

Any advice or tips would be really appreciated

[spammysammich]

You need somebody with ISTA to run the VANOS test

[Los.99]

Originally Posted by spammysammich

You need somebody with ISTA to run the VANOS test

Sadly I don’t know anyone who has it unless I go to a shop 😭

[Los.99]

Just rechecked the car again this morning and got more codes after switching the primary O2 sensors, 002b46, 002b47, 002b48, 002b49 and 002b4e(cylinders 5-8 misfires empairing with exhaust emissions and misfire impairing exhaust emissions multiple cylinders) and that’s on top of the cylinder 5-8 misfires with cutout. Has anyone dealt with any of these

[Redd]

Full bank misfire usually point to exhaust issue. I would check for exhaust leaks especially at the donut gasket.

[Los.99]

Originally Posted by Redd

Full bank misfire usually point to exhaust issue. I would check for exhaust leaks especially at the donut gasket.

I just replaced the donut gaskets when I did all the other work. Could it be from the headers u think?

[spammysammich]

Check the ground on your bank 2 valve cover.

[Los.99]

Originally Posted by spammysammich

Check the ground on your bank 2 valve cover.

Checked it and it’s good

[Ajolives]

Where is the clanking noise coming from? Did you pinpoint if it’s coming from underneath the car, front of engine, etc.?

I have a Valvetronic midpipe with dual resonators. My untuned car didn’t like it. I would suggest putting the OEM midpipe back on if you have the time to rule out the forward X design causing issues.

I’ve had the clanking on start up and idle before; it was the donut gaskets. Double check the connections, the nuts do come loose, especially with aftermarket exhausts and if you reused hardware. Double check that the exhaust flanges are tight and there’s no gap between them. If you used new gaskets you need to crush them down.

[Los.99]

Originally Posted by Ajolives

Where is the clanking noise coming from? Did you pinpoint if it’s coming from underneath the car, front of engine, etc.?

I have a Valvetronic midpipe with dual resonators. My untuned car didn’t like it. I would suggest putting the OEM midpipe back on if you have the time to rule out the forward X design causing issues.

I’ve had the clanking on start up and idle before; it was the donut gaskets. Double check the connections, the nuts do come loose, especially with aftermarket exhausts and if you reused hardware. Double check that the exhaust flanges are tight and there’s no gap between them. If you used new gaskets you need to crush them down.

Noise was coming from inside the Bank 2 valve covers, I replaced the donuts gaskets already when I reinstalled the factory midpipe but noise is still present and still have misfires, might be taking the car the VT motorworks and have them take a look at it

[Redd]

Originally Posted by Los.99

Noise was coming from inside the Bank 2 valve covers, I replaced the donuts gaskets already when I reinstalled the factory midpipe but noise is still present and still have misfires, might be taking the car the VT motorworks and have them take a look at it

Issue with VANOS system

[Los.99]

Originally Posted by Redd

Issue with VANOS system

That’s my guess right now, hope the shop is able to figure it out quick tbh

[Redd]

The VANOS unit does fail even though it's rare. Just happened to a friend of mine here. New ones are horrendously expensive so he bought a used one off eBay.

[Los.99]

Originally Posted by Redd

The VANOS unit does fail even though it's rare. Just happened to a friend of mine here. New ones are horrendously expensive so he bought a used one off eBay.

I’m hoping that it isn’t but everything is leading towards the VANOS. I’ve checked prices and they’re like $1000 😭

[Redd]

He paid $120 off eBay for a single used VANOS gear unit...

[spammysammich]

Mporium is selling refurbished units individually for $499. I would trust these more than random eBay units.

[Los.99]

Originally Posted by spammysammich

Mporium is selling refurbished units individually for $499. I would trust these more than random eBay units.

Thanks for that info I’ll look into them

[Los.99]

Originally Posted by spammysammich

Mporium is selling refurbished units individually for $499. I would trust these more than random eBay units.

Originally Posted by Redd

He paid $120 off eBay for a single used VANOS gear unit...

Originally Posted by Ajolives

Where is the clanking noise coming from? Did you pinpoint if it’s coming from underneath the car, front of engine, etc.?

I have a Valvetronic midpipe with dual resonators. My untuned car didn’t like it. I would suggest putting the OEM midpipe back on if you have the time to rule out the forward X design causing issues.

I’ve had the clanking on start up and idle before; it was the donut gaskets. Double check the connections, the nuts do come loose, especially with aftermarket exhausts and if you reused hardware. Double check that the exhaust flanges are tight and there’s no gap between them. If you used new gaskets you need to crush them down.

Thanks to u guys for the help and advice, issue has been resolved, just waiting on parts to arrive at VT motorworks. It ended up being my Bank 2 exhaust vanos that was off timing