[Audi A3/S3] turbo is overboosting and going into "limp mode".!

[daninsyd]

hi all.. newby here... anyone with a s3 had this happen before? it goes hard but then the turbo cuts off around 5000 and it remains in limp mode to protect the engine, when u check the fault codes it says " maximum boost reached".. overboosted.

im running a APR chip , FMIC , rs4 BMC, 3 inch turbo back exhaust, porche brakes and 13.7 quater mile.

thanks

[Mollox]

sure it doesn't say "Charge Pressure: Upper limite exceeded"?

Have a very good look at every hose (under the plastic engine cover too) - look at bends, clips and joins and look for a hole as your starting point

[daninsyd]

think it said "overboost intermittent" something like that..

[kalheer]

I had a similar problem on my S3.. took it to stealers and he fixed some faults on my ECU.. said it was over-boosting and engine would back of to protect it.. but then i checked some pipes under the bonnet and found one that was split and hanging off.. one of the small ones.. under the engine cover.. seems to have sorted my one out..

[Mollox]

Well if you have a holed hose then its very likely that the ECU can't read boost properly as the vacuum system has been comprimised. Because of this you'll have a difference between requested and actual boost - if the car reads boost too high then it'll knock into limp mode (the most frustrating thing on earth) as a precautionary measure.

Limp mode on boost pressure issues is normally hose-related

[daninsyd]

thanks for the advice guys!