N47 down on power

Sexual Chocolate

Any suggestions or opinions here folks ?

08 N47 320d

Quick back round. Car down on power the last good while. Dynoed @147hp with egr and dpf off (gutted same day) before power remap was applied.

Garage suggested new turbo but couldn't guarantee fix. Actuator test on ista/inpa was fine.

EGR blanked, map and MAF replaced by myself. Made a bit of difference but not much.

Added some Wynns turbo cleaner in with fuel.

Then began getting Internal DDE Control Unit codes:

4C2F
4C2E
4C29

I believe these are related to the remap and overboosting.

Remapper told me not to worry about codes, I'm bit sceptical here though.

Dynoed again @180hp with remap. 🀦*♂️

Had boost leak test carried out by different garage and that came back fine. 🀯 I believe they also checked how turbo was boosting and said it was fine though not sure if at idle or was test driven. Was recommended to get a Hydrogen engine clean. Haven't done that yet though.

Didn't drive car for 10 days, then when driven again it was driving much better between 1800 - 3000 rmp. That lasted a week until I went on a long trip and it's back to it's old ways again.

I'm now thinking it's either clogged intake ports or sticking turbo vanes, more so the vanes.

Is that possible without a fault code ?

Torque figures seem fine from what I can tell just HP is down.

stratowide

I had similar problem with a 05 e90 320D.

Don't know if your engine has one but mine had a crankcase breather fitted.sometimes called a vortex filter.

Its up under the bulkhead on top of the cylinder head.

Was convinced it was the turbo too,changed it out and made a huge difference.

Might be worth a look.

PaoloGotti

Your torque is not fine. You can’t have HP without torque. HP is just torque at speed (rpm) and your rpm is fine. Your torque is lower but crucially drops off after 3k rpm.

I can’t offer any further advice, just often see torque vs HP misunderstood.