Boost at 4000rpm?

[S38p2012blkedition]

Hope this post is in the right place..

Hello everyone. First post on the forum

have owned my s3 black edition 2012 for 2 years now. Never had any problems until I took it to the local vag garage who are mates of mine.

to put a long story short:

> car went in for major service, timing chain and belt change and a full service ect
>came back with a misfire on idle turns out car was out of timing by a tooth..
>garage re did job on the house and fixed the misfire by putting timing right
> now the s3 doesn’t boost until 4000rpm in all gears, but when she does she boosts fine and strong

>will be sent off on Monday to audi specialist who is up to speed with current situation as lads at garage are unsure what is causing the boost issue,

>they had it for a week trying to solve it, plenty road tests and other tests but are at a loss with it - if it’s diagnosed as a fault on their end they are good lads and will take care of it but we are all at a loss so I have turned to the forums to see if anyone has any idea what might be causing this issue?

thanks

 

[nluk100]

Have they scanned it for error codes? Late boost is usually a boost leak somewhere so you can do a visual inspection of the intercooler lower boost pipes (usually easy to spot these as you'll see oil reside near the connectors), but could be a multitude of things i.e. split DV, vacuum hose split / disconnected.

However, the fact that it was OK before the service suggests that something wasn't put back right.

 

[S38p2012blkedition]

Have they scanned it for error codes? Late boost is usually a boost leak somewhere so you can do a visual inspection of the intercooler lower boost pipes (usually easy to spot these as you'll see oil reside near the connectors), but could be a multitude of things i.e. split DV, vacuum hose split / disconnected.

However, the fact that it was OK before the service suggests that something wasn't put back right.

Thanks for reply.

was scanned on vagcom and all that came up was a boost problem - will get the specifics for you by tomorrow

Apparently there are no leaks as was smoke tested and other tests which i was present for

also a live test was done with vag com in car plugged in whilst running and they are unsure what is causing the issue - something about 95% boost requested at 2-2.5k rpm but just nothing happening until over 4K then boosts fine - with what little range

Common sense suggests that as it’s never had this problem before at all that yes something wasn’t put back properly. As was the case also with the timing which caused a misfire on idle for a month as previously mentioned.

I still drove it then and had no boost problems. Only since they re did the timing.

as I understand that job is back engine which is where the turbo is? So potential for something to be knocked or unclipped ect?
Thanks