E92 335D lost mid range power - help
Discussion
Hello all, I'm having an issue with my e92 335d and I was wondering if you could help...
I've seen a massive drop in mid-range power, as if the small turbo isn't spooling up. As soon as I hit about 3,000rpm the big turbo clearly kicks in and there's a big surge of power, but I’m having to drop down a few gears if I want decent acceleration between (roughly) 40-70.
A couple of weeks ago I got a “low coolant” warning, which worried me - although it had only dropped a little bit. I’ve also seen a very small patch of oil under the car as well - equally worrying! I don’t know if these are related to the issue...
From reading around I’ve got a couple of ideas about what it could be, but rather than bias the thread I thought I’d put it out to the PH detectives for their collective wisdom!
Has anyone had this on their x35d before, or can anyone offer any help as to what could be the issue? Thanks in advance!
Edited to add: 2 other things I’ve noticed recently (although this could be because I’m being ultra sensitive at the moment):
The gearbox seems to be particularly rough at changing gear, and it seems to want to change up through the ‘box, rather than hold onto a gear right through the rev range...
A Kia Sportage out accelerated me on the way home this evening FFS!
I've seen a massive drop in mid-range power, as if the small turbo isn't spooling up. As soon as I hit about 3,000rpm the big turbo clearly kicks in and there's a big surge of power, but I’m having to drop down a few gears if I want decent acceleration between (roughly) 40-70.
A couple of weeks ago I got a “low coolant” warning, which worried me - although it had only dropped a little bit. I’ve also seen a very small patch of oil under the car as well - equally worrying! I don’t know if these are related to the issue...
From reading around I’ve got a couple of ideas about what it could be, but rather than bias the thread I thought I’d put it out to the PH detectives for their collective wisdom!
Has anyone had this on their x35d before, or can anyone offer any help as to what could be the issue? Thanks in advance!
Edited to add: 2 other things I’ve noticed recently (although this could be because I’m being ultra sensitive at the moment):
The gearbox seems to be particularly rough at changing gear, and it seems to want to change up through the ‘box, rather than hold onto a gear right through the rev range...
A Kia Sportage out accelerated me on the way home this evening FFS!
Edited by Big Bad Ben on Thursday 15th February 18:44
Likely to be a vacuum leak.
You’ll need to take off the engine cover.
Check the hoses - they are red and blue fabric and run across the top of the little turbo inside a foil wrap.
A common oil leak becoming visible on the floor is likely to be the rear main seal for the gearbox.
Engine oil leaks tend to collect in the undertray.
What mileage is the car ? Mine had all the common faults between 90k and 110k.
You’ll need to take off the engine cover.
Check the hoses - they are red and blue fabric and run across the top of the little turbo inside a foil wrap.
A common oil leak becoming visible on the floor is likely to be the rear main seal for the gearbox.
Engine oil leaks tend to collect in the undertray.
What mileage is the car ? Mine had all the common faults between 90k and 110k.
Edited by Vee on Thursday 15th February 18:47
Edited by Vee on Thursday 15th February 18:59
Vee said:
Likely to be a vacuum leak.
You’ll need to take off the engine cover.
Check the hoses - they are red and blue fabric and run across the top of the little turbo inside a foil wrap.
A common oil leak becoming visible on the floor is likely to be the rear main seal for the gearbox.
Engine oil leaks tend to collect in the undertray.
What mileage is the car ? Mine had all the common faults between 90k and 110k.
Thanks Vee! Is getting the engine cover off as simple as undoing the screws that are visible?You’ll need to take off the engine cover.
Check the hoses - they are red and blue fabric and run across the top of the little turbo inside a foil wrap.
A common oil leak becoming visible on the floor is likely to be the rear main seal for the gearbox.
Engine oil leaks tend to collect in the undertray.
What mileage is the car ? Mine had all the common faults between 90k and 110k.
My car’s on 127k - mostly motorway miles so pretty unstressed, but it seems like it’s a similar story to yours...
MajorBeef said:
I had this in my E61 2005. Turned out to be a perished boost hose.
The one in question was tricky for my mech to find as it was at the back of the engine but a simple fix and not a failed turbo as my pessimistic nature first thought.
Thanks MajorBeef! I’m equally pessimistic so fingers crossed...The one in question was tricky for my mech to find as it was at the back of the engine but a simple fix and not a failed turbo as my pessimistic nature first thought.
Big Bad Ben said:
Just to conclude this - I took my car to Hughes Bros in Derby who investigated and replaced one of the vacuum hoses which had split, for the princely sum of £144.
Now the car is fast again and I can go back to daydreaming about that remap...
I wouldn’t be going back there at those prices !Now the car is fast again and I can go back to daydreaming about that remap...
Eddieslofart said:
I wouldn’t be going back there at those prices !
You've missed off the second half of your post that says how much it should have cost and which garage would do it for that price... 
If anyone has a recommendation for a BMW specialist in the East Midlands that would do it cheaper, I'd love to hear it! Recommendations for decent specialists are few and far between unfortunately.
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