I had a thread awhile back discussing my concerns of power loss. Its very hard to explain as the car drives well, and still has power, but I knew then (but thought maybe i was imagining it) and now I really know that there is something lacking.

The aux pump was an issue back then and that got replaced and i didn't notice any noticeable difference so i was just thinking i was imagining things. But ive had so many encounters that prove there is an issue.

One example was side by side against a standard xf no super charged and it almost kept ride by my side, i hope it was 5.0 and not 3.0 lol..

Then some encounters where i had similar experiences when i first got the car and performed much better against same type of cars.. \

Last night a new ish Mercedes S500 (stock/standard) pulls up next to me and kills my take, KILLS me. And I know the S class very well, and this should not have been the case, In fact when i first got my car i tore quite a few s63 and other amg 63 body styles out of it.

I know it sounds ridiculous but this is driving me nuts and I have no idea how to find out the the root of the issue.. But I really want to have my car performing as it should.. Any help sniffing out the issue here would be greatly appreciated.

Thanks guys

 

To elaborate a little further, car still feels quite fast, but definitely lagging in normal mode, in sport mode it picks up but also feels very jumpy. When on the free way and cruising about 70 it can pick up pace and get to 100-110 very quickly, i dont know if this information is relevant or not but just putting it out there

 

Have you modified the exhaust at all? I removed my center pipes for true dual pipes last year. It felt sluggish and I finally had an X-pipe installed in the new straight pipes and it has much more low end power.


How many miles does your car have now? It could be suffering from direct injection valve fouling.

 

i did have my mufflers removed but the above issues became apparent before that but that probably adds to the issue so I may have them back on or do an x-pipe ?

Its on 103k miles now, is there a remedy for direct inject fouling?

 

I would say at 103K your valves are very carbon fouled. There are a few threads on here that show this.


I think the only way to clean this up is to remove the heads or at the very least pull the supercharger/intake manifold and start cleaning.

 

Read this thread.


https://www.jaguarforums.com/forum/x...charged-94489/