Make a donation

Author Topic: Down on power?  (Read 1563 times)

Offline JoshB

  • Always Involved
  • ****
  • Thank You
  • -Given: 4
  • -Receive: 7
  • Posts: 158
Down on power?
« on: July 10, 2021, 08:08:53 am »
Hi all,
Had my car on the Dyno yesterday and it didn’t make for good reading...


Car feels fine, pulls well enough. During the run there was a couple of puffs of black smoke from the back...?
Torque’s not a million miles away (although a tad late) but it’s well down on horsepower and at a low RPM.
Only audible note is a sucking noise on acceleration, I don’t have an induction kit fitted.

As I mentioned, the car seems to pull well enough. Part of me wants a 2nd opinion!
I’ve ordered a new divertor valve just in case. The only other thing I can think of is the CAT, the cars only done 20k in the last 8 years...

Any other ideas?
Getting too old for this...

Offline GVK

  • Won't Shut up.
  • *****
  • Thank You
  • -Given: 1
  • -Receive: 61
  • Posts: 786
    • GVKmotorsport
    • Email
Re: Down on power?
« Reply #1 on: July 10, 2021, 08:49:06 am »
Needs checking out on VCDS data logging etc, and fault codes.

May have a boost leak too hence the noise?

Decent fuel as well? 98 ron?

Sometimes can black smoke oif misfiring or pulling timing due to crap fuel.

Get some liqui moly fuel cleaner through it too, great stuff.
« Last Edit: July 10, 2021, 08:53:55 am by GVK »

Offline GVK

  • Won't Shut up.
  • *****
  • Thank You
  • -Given: 1
  • -Receive: 61
  • Posts: 786
    • GVKmotorsport
    • Email
Re: Down on power?
« Reply #2 on: July 10, 2021, 09:49:36 am »
I know you didn't want to mod it but a remap would give you 250hp and more fun once fixing whatevers wrong witth it to give factory 200ps.

Sent from my Pixel 4a using Tapatalk

« Last Edit: July 10, 2021, 10:42:02 am by GVK »

Offline JoshB

  • Always Involved
  • ****
  • Thank You
  • -Given: 4
  • -Receive: 7
  • Posts: 158
Re: Down on power?
« Reply #3 on: July 10, 2021, 12:13:40 pm »
Cheers, it is still on supermarket fuel at the minute... Once that’s run through though it’ll be VPower only from then on.
It’s just the sudden drop off after 4800rpm that bothers me though. Not that I regularly drive it anywhere near!
Getting too old for this...

Offline GVK

  • Won't Shut up.
  • *****
  • Thank You
  • -Given: 1
  • -Receive: 61
  • Posts: 786
    • GVKmotorsport
    • Email
Re: Down on power?
« Reply #4 on: July 10, 2021, 12:33:32 pm »
I rev mine to 7k all the time  but then I'm a bit nuts

Fuel will do it they are meant to run on 98 minimum  and if you have s diverter valve leaking that will lose power too

Sent from my Pixel 4a using Tapatalk


Offline GVK

  • Won't Shut up.
  • *****
  • Thank You
  • -Given: 1
  • -Receive: 61
  • Posts: 786
    • GVKmotorsport
    • Email
Re: Down on power?
« Reply #5 on: July 10, 2021, 12:37:23 pm »
Invest in a VCDS cable from Gendan.ci.uk invaluable for these cars to check how they are running.

Sent from my Pixel 4a using Tapatalk


Offline GVK

  • Won't Shut up.
  • *****
  • Thank You
  • -Given: 1
  • -Receive: 61
  • Posts: 786
    • GVKmotorsport
    • Email
Re: Down on power?
« Reply #6 on: July 10, 2021, 02:32:36 pm »
Me again, make sure the fuel filter has been changed, mine was changed last year and hd the original date stamped 2007 filter on it, it had mud inside.

Offline pudding

  • Global Moderator
  • Just look at my post count
  • *
  • Thank You
  • -Given: 2
  • -Receive: 670
  • Posts: 8229
Re: Down on power?
« Reply #7 on: July 17, 2021, 07:02:55 pm »
Was it really 28.5 degrees in the dyno cell?  That might have something to do with it.


2007 ED30 | 2009 TDI 140 | 2016 BMW 330D

Offline GVK

  • Won't Shut up.
  • *****
  • Thank You
  • -Given: 1
  • -Receive: 61
  • Posts: 786
    • GVKmotorsport
    • Email
Re: Down on power?
« Reply #8 on: July 18, 2021, 04:36:05 am »
IATs in the 50s?

Offline pudding

  • Global Moderator
  • Just look at my post count
  • *
  • Thank You
  • -Given: 2
  • -Receive: 670
  • Posts: 8229
Re: Down on power?
« Reply #9 on: July 23, 2021, 10:16:24 pm »
Easily. The air temps in dyno cells are waaaaay hotter than an intercooler would see out on the roads.  The ECU starts pulling timing quite aggressively past 45 deg C intake temp and adds fuel for component protection, which might explain the black smoke.  It 'guesstimates' EGT temps from some kind of funky algorithms and dumps fuel in.  It doesn't have an actual EGT sensor like the old BAM TT engines had. 

Having said all that, 112@ the wheels is terrible.  I think there is some other underlying issue there.
« Last Edit: July 23, 2021, 10:17:59 pm by Pudding »


2007 ED30 | 2009 TDI 140 | 2016 BMW 330D