1st Gen R53 Cooper S Most liked posts in thread: P0171, P1237, and now P1688. Help appreciated!

First get rid of the ALTA silicone tubes or IC couplers because they all leak and cause boost leaks. The OEM black flexible rubber ones make a much better seal.

Second fix / replace your crank damper, because if that thing goes on you have a tow truck # available.

Replace it with an ATI OEM sized Damper or the Fluid Filled Damper that is available. (I forget the name of it)

After those things are corrected then let us know how everything is. Things should be a lot better but you could have a throttle body seeing the end of its life but I would not replace it now since you have two bigger issues above that need to be addressed first that could resolve all the problems.

 

you have to be really careful when installed the DT BPV...if you arent you can crack that inlet tube...also check your vac hoses coming from and to the Intake manifold, inlet pipe and supercharger...if you get a cracked one it can cause a inconsistent boost pressure and could cause a shutdown..i chased a P1776 code which tuned out to be a cracked rubber vac boot...replaced the boot and all was well again...instead of the ATI damper look at the Fluidyne(thats the name of it Dave) damper that Rmw sells...less expensive than the ATI and its SFI approved...i had one in my car for over 100k miles with nary an issue...

 

You definitely have a positive and a vacuum leak possibly on the charge pipes and possibly a vacuum leak at the intake. Id suggest you smoke the both intake and exhaust.

 

Yes , im currently finishing up an r55 that we bought from the auction,had to do a complete rebuild. Although it was turbo and not super charged the symptoms and dtc are almost identical. At first it just idled rough and a constant barage of fuel trim codes. Gradually became worst more turbo lag and decrease in boost pres. Then smoke. I smoked the turbo and intake system , found the oil feed li e for the turbo leak even while engine off , thinking that it was the oil dripping on the impeller that caused the start up smoke but it was not. Finally and very reluctantly , having only 52k miles on it i checked the piston rings by smoking from the bottom through the oil dipstick and surprised to see smoke coming out of # 4 , took the engine appart expecting bent or melted rings but found a cracked piston. Im trying to figure out how to attach pictures so i can show you what happened to the piston and engine before and after rebuild.

 

actually they are different joker...smoking a 2nd gen exhaust you may need to do because a turbo is spooled by exhaust gasses so if you are getting a leak and back pressure it can leech power from the turbo... where as the 1st gen uses a supercharger and all of the boost is in the intake side...like i said i had a leak in my R53's exhaust for awhile and all it did was smell funny...didnt cause any issues beyond that and i had a RMW street header with a magnaflow exhaust...bout as high flow as it gets but a R53 needs backpressure but a 2nd gen is hurt by that same back pressure

 

in nismo's case if he is getting inconsistent boost pressures/vac he needs to smoke the intake side only...its pretty easy to see if you have a leak in your exhaust system...because there is already high pressure gasses just feel for a leak and give a sniff... also i wouldnt go so far as to do a compression test...there are codes that will throw for cylinder misfires and low compression...pull your spark plugs and look at the color and see if there is any damage to them

 

I just resolved a P0171 on my Mini last weekend. It was the rear O2 sensor.
Pulled it and it was fouled pretty bad.

Replaced both. Not cheap.

But the code is gone and it's running smoother than it's run since I bought it!

Don't know if you checked YouTube for this code. Lots of info.
[ame="http://www.youtube.com/watch?v=Ujt56nnw-2k"]Here's a good one that shows how to diagnose/troubleshoot it.[/ame]

Good luck.

 

Good news Chads a good guy.

 

:cornut: No help here so I'll just Bump.

Jason

 

Glad you got everything worked out and are running at WOT again with boost.