[michael982]

Im going to look at a 2010 335d tomorrow. I've read a lot about them and plan on doing the swirl flap removal, egr bypass and dpf delete as soon as i get it. It is at a dealership, so is there any somewhat quick or easy way to tell if there is CBU? Other that that looks like the cars are pretty reliable, but any input is welcome. The car is 1 owner, looks to be garage kept and has 80k miles.

[Puerto Rican 335d]

mike step on it and see if she hesitates that could be a sign also, verify her file

[stevers314]

at 80k, it's either on the edge of CBU or just had it cleaned. Possibly someone got fed up with a $5k "maintenance" bill and traded up out of frustration.

See if the dealer will pop the charge pipe off the throttle and scope down the intake. 5x 5mm allen bolts and a flat head screwdriver.

If they will not, get in writing that they will cover any CBU procedures for however many miles you agree on. Otherwise move on to a different car. A ton of 335d's have hit the market lately as leases run out.

[IK6SPEED]

by 80k miles im sure the car had to get it done, ask the owner about it, all direct injection cars will accumulate CBU

[IK6SPEED]

If it didnt, it will hesitate when floored and mpg will decrease and power will be lost.

[Bicax]

Can this hesitation also be felt on DS, or only D?

Also how much does this extend to/affect European cars? Mine has 200.000km and is quite lazy on D, but I've been blaming that on the gearbox.

Whenever I have to pass a car I generally either put it on DS, or manually reduce 1-2 gears before flooring it. Otherwise, on D the hesitation is borderline dangerous/unsafe.

Removing the DPF and remapping it has considerably improved all of this, but I haven't tested it thoroughly enough to be sure if it's completely gone.

[michael982]

Originally Posted by Puerto Rican 335d

mike step on it and see if she hesitates that could be a sign also, verify her file

Im going today to verify the file with a local bmw dealership. I hope everything works out, I know theyre dropping in price but they're still very hard to come by!

[Hoooper]

if it hasnt been cleaned yet, stop on it all the way through one or two gears and it oughta throw a code or be obviously down on power compared to a clean car

[michael982]

Originally Posted by Hoooper

if it hasnt been cleaned yet, stop on it all the way through one or two gears and it oughta throw a code or be obviously down on power compared to a clean car

Ill get on it a few times, if its as nice as everyone says!!

[montr]

You need to get the service, recall and repair history from BMW. This will tell you what has been done on the car.

Also, you need to check for shadow codes and OBD readiness. If codes have been cleared recently and the car has not accumulated enough miles for the self diagnostic, the OBD readiness flag will be OFF.

[Yozh]

Definitely scan it for codes.

[AzureHaze]

Originally Posted by Bicax

Can this hesitation also be felt on DS, or only D?

Also how much does this extend to/affect European cars? Mine has 200.000km and is quite lazy on D, but I've been blaming that on the gearbox.

Whenever I have to pass a car I generally either put it on DS, or manually reduce 1-2 gears before flooring it. Otherwise, on D the hesitation is borderline dangerous/unsafe.

Removing the DPF and remapping it has considerably improved all of this, but I haven't tested it thoroughly enough to be sure if it's completely gone.

So is this "hesitation" due to the awful transmission or possible signs of CBU? This only happens to me once in a while on D and DS mode when launching (soft or hard) from a start but lately I would slightly feel it in manual shift mode. Pretty annoying.

[Nushibo]

I had a rant written but straight to the point is at 80k theres a more than 75% chance of CBU unless the dealer had the cleaning procedure done before in which case the timeframe between the cleaning and current mileage will let you assume severity. Inquire with the dealership about all the service records. IF possible scan the OBDII for code that relate to injectors or smoothness idle controllers. Anything wrong is usually related to CBU. Theres no way to tell from driving unless you've owned the car from start to finish and even so the transmission is a bit clunky lol. SO youre left with electronic checking and looking down the throttle for gunk.

From personal experience 50k and CBU has caused me problems and im getting it cleaned now. IF its made it to 80k the carbon should be reaching critical mass.

So from my personal scale. 0 - 50k miles CBU is minimum and crossing the line to engine problems. If it hasnt been cleaned before 50k mark then youre looking at some issues. Therefore look around for a good shop to clean it. or get bmw/dealership to cover you incase CBU does come lurking. Its a great car but with a great things comes great responsibilities.

If it happens it was cleaned I say EGR and Methanol First before anything else, same thing if it wasnt cleaned and you get the car. That way the meth can run its course and wear down the gunk inside the intake manifold/head. The meth acts as a solvent while the EGR prevents solids from re entering the intake. You might want to look into a catch can too. Basically the oil from the CCV is a glue, egr soot is solid that sticks and creates a clot. Meth breaks apart the clot, EGR blocks the solids and catch can reduces the glue entering if you understand the analogy lol.

[TorqueAddict]

This is how my intake looks like at 678xx km. I bought the car at 47k. 60/40 city/hwy driving.