[dcbuckmiller]

My son has a 2010 BMW 335xi with about 105k miles and hired his so-called mechanic friend to modify the exhaust system and install some type of blow off valve. He left the project incomplete and now the turbo lost power. I took it to a professional mechanic for evaluation and repair estimate and this is the inspection report:

Vehicle arrived after someone installed catless downpipes, and attempted to install a blow off valve. Left multiple ports open including where map sensor should be installed. Hose clamps all loose, vac lines no where near routed correctly and had HVAC tape holding intake pipe to throttle body. Underneath Vehicle found all the o2 sensors just hanging not installed in down pipes, and plugs for o2 sensor locations not tightened at all. Whoever attempted the install on the downpipes cut a reinforcement section out of the subframe instead of dropping subframe. Will need replacement subframe and stiffening plate, downpipes need to be removed to have o2 sensors installed. Turbos are also leaking oil from case halfes of turbos so would rec turbos at the same time along with all new o2 sensors as the have been subjected to road debris.

The repair cost quoted was 10k and likely exceeds the value of the vehicle. What options do I have with this car?? Please help!

[StradaRedlands]

[trohde78]

Originally Posted by dcbuckmiller

My son has a 2010 BMW 335xi with about 105k miles and hired his so-called mechanic friend to modify the exhaust system and install some type of blow off valve. He left the project incomplete and now the turbo lost power. I took it to a professional mechanic for evaluation and repair estimate and this is the inspection report:

Vehicle arrived after someone installed catless downpipes, and attempted to install a blow off valve. Left multiple ports open including where map sensor should be installed. Hose clamps all loose, vac lines no where near routed correctly and had HVAC tape holding intake pipe to throttle body. Underneath Vehicle found all the o2 sensors just hanging not installed in down pipes, and plugs for o2 sensor locations not tightened at all. Whoever attempted the install on the downpipes cut a reinforcement section out of the subframe instead of dropping subframe. Will need replacement subframe and stiffening plate, downpipes need to be removed to have o2 sensors installed. Turbos are also leaking oil from case halfes of turbos so would rec turbos at the same time along with all new o2 sensors as the have been subjected to road debris.

The repair cost quoted was 10k and likely exceeds the value of the vehicle. What options do I have with this car?? Please help!

It would depend on how nice the car is, and if it's worth saving. That quote also seems a bit high for a used subframe, turbos, and some O2 sensors. A very detailed inspection by that mechanic though, so they do seem legit. I'd be thinking closer to $5K, assuming all of the other parts are OK, and just need to be installed correctly. It's also likely that the turbos "lost power" because there are all sorts of air leaks now with things not being installed properly (or at all), and they were probably already leaking oil before all of this happened.

[Wolf 335]

If your car drove fine before your friend started doing this then your turbos are fine.

Get a new charge paipe, two new bypass valves, a map sensor and vacuum lines. All those you can put in yourself in 2 hours time. Cost no more than $500
If the old parts are ok then just reuse the old parts - free.

Subframe you can source from a junk yard or get a new one and have the shop install it. At the same time they can tackle the dowpipes and O2 sensors. $1500 max at the shop.


Not sure how they came up with $10K, unless they are buying parts and having the dealer actually do the work.

If this work is all thats wrong with the car, I'll buy it off you for $4K.