MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: Adrenaline on November 13, 2014, 04:18:55 pm

Title: boost has lowered slightly
Post by: Adrenaline on November 13, 2014, 04:18:55 pm
Hey guys last week i went ko4 with a custom tune from Driver motorsport ...first 2 days the car was pulling really hard and was peaking a strong 1.8 bar .Now the car feels a litle bit slower then before peaking only 1.45 to 1.5 bar of boost after scanning i have got boost pressure control valve n249 mechanical malfunction  intermitent cleared the code and swapped the Dv with another one no codes but same boost numbers 1.5....So what can be the issue here can it be a boost leak?
Title: Re: boost has lowered slightly
Post by: cooljimy84 on November 14, 2014, 09:29:25 am
Have a look at the front PVC (or is it PCV) and the rear, as these won't show fault codes, but will drop boost a bit. Front one is easy to test, there is a guide on here somewhere.
Tho the rear one i've not seen a test for, but assume its the same kinda set up with a one way valve.
Title: Re: boost has lowered slightly
Post by: Adrenaline on November 14, 2014, 04:23:40 pm
Ended up being the oil pan it was missing a small joint on its end so when boosting boost was escaping ...boost back to nornal 1.7 1.8 bar peak
Title: Re: boost has lowered slightly
Post by: jason_rmh on November 14, 2014, 04:55:08 pm
How did you track that down? Good work!