Page 1 of 1
Hesitation on acceleration (maybe)
Posted: Thu Mar 08, 2012 3:53 pm
by dirtymonkey29
I have a 54 plate E53 3.0d sport, today I had it fully serviced, oil, fuel, air, pollen filters and engine breather(oil seperator) done also. Now I don't know if it's because I've spent the day driving a Citroen C1 all morning and I'm just imagining things but the X5 doesn't feel as responsive pulling away or accelerating as it did before. Not really had a proper test after collection as I came straight to work after collecting it and traffic was bad. I will get to try it better going home tonight.
If it is hesitant is there anything obvious I can check before I take it back and get it looked at? It's a bit of a drive away as there a decent independent that I use when I have the need to put it in.
Re: Hesitation on acceleration (maybe)
Posted: Thu Mar 08, 2012 4:10 pm
by X5Sport
As the filters have been played with there's a pretty good chance that one of the turbo vacuum control pipes has been left disconnected so you're running without enough turbo boost. It's a fairly frequent 'miss' by service techs.
Look on the left side of the engine and see if everything has been reconnected. Bottom left of this image, just visible is one end of the vacuum regulator/reservoir bottle - makes sure all the small pipes are all attached at
both ends.

Hesitation on acceleration (maybe)
Posted: Thu Mar 08, 2012 4:24 pm
by dirtymonkey29
Do I have to remove that hidden screw at the back to get that cover off? I was thinking vac hoses too.
Re: Hesitation on acceleration (maybe)
Posted: Thu Mar 08, 2012 4:39 pm
by X5Sport
Might be able to see everything with a small (make-up compact) mirror? Used the piccie as it happens to be one from when I changed the filter.
Hesitation on acceleration (maybe)
Posted: Thu Mar 08, 2012 10:15 pm
by dirtymonkey29
Ok.... on the way home. Put foot down to stop point but not to kick down and it seems to take 5-10 seconds before it takes off. Would a disconnected vac hose not throw a management light? Will be sticking the scanner on in the morning I think
Re: Hesitation on acceleration (maybe)
Posted: Fri Mar 09, 2012 10:35 am
by X5Sport
sorry, only just got to this.
No, you won't get any warning lights. And yes, a disconnected vac tube will cause that as it affects the turbo controls and will reduce the boost as the turbo isn't getting the right data about 'demand', so may not be spooling up fully.
You aren't the first of us to have had similar things happen straight after a service, especially one involving the air filters. It's easy to knock one of the tubes loose as they are that side of the engine and close to the covers that get removed, and that probably costs you 30% of your engine power at a guess.
You may also be seeing a lot more smoke on acceleration too as the mixture will be too rich.
Re: Hesitation on acceleration (maybe)
Posted: Fri Mar 09, 2012 12:33 pm
by dirtymonkey29
No waring lights but bmw scanner is showing "manifold pressure regulation"
Cant hear turbo spooling up like usual and power is ruduced, not massivly but enough to notice.....example gentle acceleration does nothing but revs increase slowly then it suddenly picks up....notice power loss on hills though.
I cleared fault code this morning then took it back to the garage to get the book stamped and the mechanic to fix it but hey only have sales in today (really small indy). Just went out to read codes again and the same "manifold pressure regulation" message is back.
Off out to get engine cover off now before it rains, just hope i can get away with taking of the 5 torx screws and no need to mess with the hidden ones at the back.
Hesitation on acceleration (maybe)
Posted: Fri Mar 09, 2012 3:45 pm
by dirtymonkey29
Resolved.... The vac reservoir was missing the connection on the right.
Re: Hesitation on acceleration (maybe)
Posted: Fri Mar 09, 2012 5:04 pm
by X5Sport
Excellent news. Hope you now have all the power you need - or at least have available that you should - again..
Time to give the Indy a slap around the head and get them to do a quality check BEFORE putting the car back together!!
I had a hugely apologetic call from someone senior at my BMW Dealer this morning after yesterday's 'incident' where they swapped the winter tyres out for the summer ones and also cleaned the car - but their valeter left black bootprints on the cream leather on the front and rear seats!!!

It was very rapidly sorted out, but...
Apparently someone from their new valeting company thought it was a great idea to stand on the seats to clean the roof!! I wasn't pleased (it's a public forum so I'll not put what I actually felt or said!!). The Dealer will now also 'quality check' all cars coming back from the valeter to make sure it never happens again.
Re: Hesitation on acceleration (maybe)
Posted: Fri Mar 09, 2012 6:09 pm
by jaynana
Talk about dealeer services!!
I make a fus§ if my 3+ daughter stands on seats with shoes on.
What you have is not even a child a fully grown adult.. Well, 'grown' apart from in the brain maybe..
Its not even cleaning up afterwards, its the fact that they shouldn't be doing it in the first place!!
Hesitation on acceleration (maybe)
Posted: Fri Mar 09, 2012 11:57 pm
by dirtymonkey29
Powers back, mpg on the obc dropped to 22mpg in the few short drives I did in it. Now it's fixed it's back up at 30 or so. Service boss and mechanic was off. Only a cleaner and sales man in but i rebooked to go back in Monday incase I couldn't sort it. Will be an interesting phone call Monday morning.