mihaley

hello all, firstly thank you ive gotten alot of great information here from you guys
thank you weistec and thank you rebellion, all the parts ive gotten from both of you are among the best aftermarket parts ive seen, especially after owning an evo x for 5 years

my cla45 hasnt been running right for sometime now and im trying to figure out whats wrong, me and a Mercedes mechanic are both pretty stumped
the car has the following mods

weistec tune/downpipe/anti surge valve
rebellion cat back exhaust/intake/tcu flash

ive definitely elimated the weistec and rebellion parts as the cause

what im getting is an issue under moderate throttle, after 3k rpm under half throttle up to 3800rpm(ish) or so i get a pulsating sound/light feeling
around 3800-4000rpm again under moderate throttle the car loses power and then it comes back, while its doing this for a half second or so you can actually hear it running different sometimes you REALLY feel it, it seems to be better in hot dry air

i threw the following codes 1 time each

p0299 turbocharger/supercharger "a" underboost condition
(i was beating on the car pretty bad when i got this code, the car went into a bit of a limp mode until i restarted it)
the other code i got one time was under normal driving, it was a torque performance code i forget the exact code
car went into limp mode before a restart then ran fine

the anti surge valve isnt on the car right now, its not a vacuum leak, its not the flash, becuase NO one else is having problems with the flash and i sent it back to weistec to verify the flash is fine (thank you weistec for dealing with me)

anyone have any ideas?

Ezec63

Sent you a PM with more details but you are not alone. For other readers out there my car also has the weistec flash tune, anti-surge valve, weistec downpipe/mid-pipe and rebellion intake. The car previously had the rebellion intake and piggyback on for a long time and ran perfectly. After addition of weistec flash and downpipe is when the issue started. I removed the rebellion intake and went back to the stock intake/filter to see if it was causing any turbulence but it did not help and got worse if anything.


I have not thrown any codes yet but the car has been sitting in the shop as we try to figure out what it can be I even switched to a less aggressive 91 octane flash that did not help. Doing research on the symptoms I came across other platforms that describe the same issues we are experiencing and they are attributing it to compressor surge. This is not the surge that is stopped from the blow off valve on throttle lift this is acceleration compressor surge. It happens to me mostly when in a high gear 4th gear or higher (high load) starting off boost at low rpm and as the boost comes on down low it starts oscillating in sound and power.

Ezec63

You can hear it in this video I recorded if you crank up the volume

mihaley

this is exactly what my car is doing also, with the addition to the jolt around 4krpm i get soemtimes

mihaley

and thank you, its a relief to know im not alone and something obscure isnt broken on my car

iamracerX

i have posted this before (more or less) "how is it that post's just drop off with no conclusion?" the last post here was 7-21-15. forums become useless when no one resolves an issue, etc.

mihaley

it was addressed in other threads a bit, the weistec tune didn't run right in east coast weather/elevations, they re-tuned our ecus and it's been fine since