Tire cupping issue as diagnosed by two different shops due to cheap tires installed by previous owner.

This morning started my car and it produced a lot of clatter and engine right away went into fail safe mode so I had to jump on the bus to get to work. Will scan it this evening to see what codes it's throwing. On the other hand someone here recommended a shop in valley stream and can't seem to find that post. Does anyone know which shop I'm talking about in case it timing chain guides that gave out? So far I got 80567 miles on it.

Scanned the car and a variety of errors. MAF sensor, transmission oil temp sensor, throttle body assembly are some of the more notable ones. Well time to do some shopping.

Error codes are not always conclusive. Some other problem can be causing an error code on a part that is perfectly fine.

Did you clear the codes and see what returns? Could be some old error codes.

MAF won't rattle and there would be other symptoms such as loss of power, engine running rough, etc.

Transmission oil temp sensor bad symptoms are that engine revs but vehicle doesn't accelerate, randomly shifts gears, etc.

Throttle body flap can rattle. Suggest your remove the intake tube so you can see it or use anything that will transform sound, hold one end to your ear and put the other end against the throttle body to pinpoint the source of the rattle. Auto stethoscope is inexpensive.

Troubleshoot, troubleshoot, troubleshoot.

I erased all the codes but as soon as I started it engine failsafe and all engine related codes came back. At idle speed engine rpm varied a lot and when slowing down every time transmission downshifted from two to one rpm dropped below 500 for a second and came back up. I bought new throttle body and maf sensor for $340 which I think isn't a bad price. Will install it once it arrives and see if it solves my issue.

Installed new throttle assembly and new MAF engines purrs like a kitten and has gotten drastically more responsive. Almost feel like a new truck. On the other hand I have a new error code for oil temp sensor in transmission. I'm having a hard time locating part number for this only thing I find is a wiring harness that supposedly has it built in. Does anyone know if it's a stand alone part?

It is not a standalone part. It is integrated into the transmission wiring harness. Oil temp sensor can cause the transmission to have a mind of its own, shifting gears at strange times or staying in a gear when it should be up or downshifting. Replacing the harness is not difficult though you will need to remove the pan. There may be second external sensor, not sure. I suggest checking fluid temperature with an infrared temp reader to see if it is normal at operating temp and you have driven some distance.

Thanks for info. I have new harness new filter oil and gasket already. Just by looking at the harness I couldn't figure out where oil temp sensor was. I changed oil filter in tranny 3k miles ago I guess I'll do it one more time to make sure it lives as long as it can. After changing oil transmission hasn't been acting odd at all other then occasional 2-1 downshift but after replacing throttle assembly that problem disappeared.

Sold my X today. I'm sad I had to do it but as it is for many you really need garage space to work it yourself and a second car. Unfortunately NYC doesn't allow for that. I already regret selling it and this experience let me know what BMW brand offers in terms of driving emotions that others can't match at a price of course. At least I feel good that it went to a good home and will be on the road delivering smiles for many years to come. I'll have to rely on my Ducati for my need for speed until I get myself an M car at some point for a weekend driver.

Good luck!