Hesitation/shunting at 3500 to 3700rpm
Discussion
I have just taken the car out for a blast and noticed that there is hesitation/shunting at 3500 to 3700rpm. It idles fine and accelerates fine. It seems to be when cruising or gently accelerating.
I have noticed this before but only in 3rd gear when cruising but now noticed it in 2nd, 3rd and 4th gears.
I am thinking throttle pots as I had something similar after the rebuild 4 years ago. Dom changed the pots and balanced the throttle bodies...I think and/or re set the adaptives.
Could the pots have deteriorated in 3 years and 10000 miles? The car does need a service and tappet check but I wasn't planning on getting this done until the spring. I do want to use the car occasionally on fine days over the winter but want to be sure I'm not doing any damage driving it as it is.
Any ideas?
I have noticed this before but only in 3rd gear when cruising but now noticed it in 2nd, 3rd and 4th gears.
I am thinking throttle pots as I had something similar after the rebuild 4 years ago. Dom changed the pots and balanced the throttle bodies...I think and/or re set the adaptives.
Could the pots have deteriorated in 3 years and 10000 miles? The car does need a service and tappet check but I wasn't planning on getting this done until the spring. I do want to use the car occasionally on fine days over the winter but want to be sure I'm not doing any damage driving it as it is.
Any ideas?
Edited by S6 Devil on Wednesday 14th November 17:21
Walford said:
MAP sensor?
coil pack?
hand brake?
On my car, when in for some work, they found the MAP sensor to be completely useless. You could blow/suck straight through it, no resistance at all. Yet the engine was fine - certainly didn't hesitate. I believe the ecu defaults to an ambient pressure of 1000mb if this sensor fails, so shouldn't cause hesitation...maybe a slight degradation in power if the air pressure is vastly different to 1000mb.coil pack?
hand brake?
A failing coil pack should show on the diagnostics, I believe.
I'd say the best bet would be to get it hooked up to the diagnostic programme, and see if that gives some better clues.
Nick
Edited by nawarne on Thursday 15th November 11:06
That sounds pretty typical of worn throttle bodies.
Even if balanced well, they can soon move out of balance if worn.
Have a look at some of my threads on this, it may help you out...
It's quite possible that if the bodies were worn originally, replacing the pots has masked the problem a while, and they have worn more quickly this time. They have their own internals that would have helped keep the spindles on the throttle bodies steady, but if they were worn it will have accelerated wear on the throttle pots.
Even if balanced well, they can soon move out of balance if worn.
Have a look at some of my threads on this, it may help you out...
It's quite possible that if the bodies were worn originally, replacing the pots has masked the problem a while, and they have worn more quickly this time. They have their own internals that would have helped keep the spindles on the throttle bodies steady, but if they were worn it will have accelerated wear on the throttle pots.
Edited by Robertjp on Thursday 15th November 11:28
Many folks experience shunting/hesitation associated with worn throttle bodies on the Sp6 engine.
I believe several of the usual parts supliers can replace the bodies with overhauled items with sealed roller bearings on the spindles.
Once installed, each cylinder intake then needs to be balanced so that flow to each cylinder is the same.
Nick
I believe several of the usual parts supliers can replace the bodies with overhauled items with sealed roller bearings on the spindles.
Once installed, each cylinder intake then needs to be balanced so that flow to each cylinder is the same.
Nick
Just to update this post. The car has been to Andy at APM. It was very out of tune, the tappets were done so it now drives much better but still with the hesitation/shunting at 3700 particularly in 3rd gear. However, throttle body number 4 is in a bad state, is lifting and needs replacing. 1,2 and 3 seem fine and he thinks 5 and 6 are ok.
I am trying to source number 4 otherwise will be getting all 6 reconditioned. Anyone got a number 4 by any chance?
I am trying to source number 4 otherwise will be getting all 6 reconditioned. Anyone got a number 4 by any chance?
Edited by S6 Devil on Friday 30th November 01:57
To be honest I didn't ask about the tappets, Andy just did them. I was more concerned about the throttle bodies. The car has done 23500 miles.
Dom at Power has a second hand no 4 which I would have thought would be in good condition, I'll ask and see if he has a post 2005 one. What's the difference with a post 2005 body?
I have tried to source a new one but don't think they are available. RG have them listed as POA but when I called they tell me they don't have any neither do they have a reconditioned set available.
Any pointers for where to source a new one?
I am wondering if just changing no 4 is a bit of a false economy. With fitting and balancing I'm looking at 2 hours labour and £60 for the part. STR8 six will remove, refurb, refit and balance for £630 incl.
Decisions, decisions!
Dom at Power has a second hand no 4 which I would have thought would be in good condition, I'll ask and see if he has a post 2005 one. What's the difference with a post 2005 body?
I have tried to source a new one but don't think they are available. RG have them listed as POA but when I called they tell me they don't have any neither do they have a reconditioned set available.
Any pointers for where to source a new one?
I am wondering if just changing no 4 is a bit of a false economy. With fitting and balancing I'm looking at 2 hours labour and £60 for the part. STR8 six will remove, refurb, refit and balance for £630 incl.
Decisions, decisions!
Edited by S6 Devil on Friday 30th November 12:54
S6 Devil said:
To be honest I didn't ask about the tappets, Andy just did them. I was more concerned about the throttle bodies. The car has done 23500 miles.
Dom at Power has a second hand no 4 which I would have thought would be in good condition, I'll ask and see if he has a post 2005 one. What's the difference with a post 2005 body?
I have tried to source a new one but don't think they are available. RG have them listed as POA but when I called they tell me they don't have any neither do they have a reconditioned set available.
Any pointers for where to source a new one?
I am wondering if just changing no 4 is a bit of a false economy. With fitting and balancing I'm looking at 2 hours labour and £60 for the part. STR8 six will remove, refurb, refit and balance for £630 incl.
Decisions, decisions!
Post 2005 throttle bodies were bushed, where they attempted to solve the issue of wear between the spindle and throttle body. Any older bodies with upwards of 25k miles will be suffering the issue to a geater or lesser extent. Dom at Power has a second hand no 4 which I would have thought would be in good condition, I'll ask and see if he has a post 2005 one. What's the difference with a post 2005 body?
I have tried to source a new one but don't think they are available. RG have them listed as POA but when I called they tell me they don't have any neither do they have a reconditioned set available.
Any pointers for where to source a new one?
I am wondering if just changing no 4 is a bit of a false economy. With fitting and balancing I'm looking at 2 hours labour and £60 for the part. STR8 six will remove, refurb, refit and balance for £630 incl.
Decisions, decisions!
Edited by S6 Devil on Friday 30th November 12:54
If im honest i wish i had had mine done at STR8 SIX, but i couldnt afford it at the time. I bought a roller bearing reconditioned set from RG but they needed some work to bring them up to a standard i was happy with - you wouldn't have this issue with STR8 SIX. The set i bought did not mate perfectly with the head and had a slight leak when cold, which caused a further problem in the guise of a misfire that was difficult to diagnose, as it seemed to be there and then gone very quickly.
I would suggest that your other throttle bodies be will worn to some extent and therefore you could just be delaying the inevitable - they will probably all need doing at some point.
Jason will also warrant what he does and will support you if you get running issues - but if you just choose to replace number 4 and you have further issues, it could take you a while to diagnose by yourself - and whilst this may be cheaper, it can be a PITA too - i know, i have been there.
Hope that helps...
Rob
Jason sends the TB's away to Jenvey for sealed (roller ?) bearing upgrade and general re-furb.
Jenvey are well known in the auto sport world for throttle body conversions to a lot of mainstream production cars.
I had my 2004 Tuscan done last year, and following the full service the difference in the car was very obvious. At the time, the car had done about 42K miles.
Nick
Jenvey are well known in the auto sport world for throttle body conversions to a lot of mainstream production cars.
I had my 2004 Tuscan done last year, and following the full service the difference in the car was very obvious. At the time, the car had done about 42K miles.
Nick
nawarne said:
Jason sends the TB's away to Jenvey for sealed (roller ?) bearing upgrade and general re-furb.
Jenvey are well known in the auto sport world for throttle body conversions to a lot of mainstream production cars.
I had my 2004 Tuscan done last year, and following the full service the difference in the car was very obvious. At the time, the car had done about 42K miles.
Nick
I called Jenvey, they do RG's recons and will only do them through RG. They advised that RG are their only customer, no mention of STR8SIX.Jenvey are well known in the auto sport world for throttle body conversions to a lot of mainstream production cars.
I had my 2004 Tuscan done last year, and following the full service the difference in the car was very obvious. At the time, the car had done about 42K miles.
Nick
I am veering towards either getting Jason to do them or buying a new set, whichever is the most cost effective.
Thanks for all the input guys particularly Nawarne and Robertjp. Much appreciated.
S6 Devil said:
nawarne said:
Jason sends the TB's away to Jenvey for sealed (roller ?) bearing upgrade and general re-furb.
Jenvey are well known in the auto sport world for throttle body conversions to a lot of mainstream production cars.
I had my 2004 Tuscan done last year, and following the full service the difference in the car was very obvious. At the time, the car had done about 42K miles.
Nick
I called Jenvey, they do RG's recons and will only do them through RG. They advised that RG are their only customer, no mention of STR8SIX.Jenvey are well known in the auto sport world for throttle body conversions to a lot of mainstream production cars.
I had my 2004 Tuscan done last year, and following the full service the difference in the car was very obvious. At the time, the car had done about 42K miles.
Nick
I am veering towards either getting Jason to do them or buying a new set, whichever is the most cost effective.
Thanks for all the input guys particularly Nawarne and Robertjp. Much appreciated.
When my throttles were replaced/overhauled, I recall Jason mentioning Jenvey as the company that did the work.
I posted on here in June commenting on how the car felt so much more driveable/smoother after the 12K service...Previous visits to Jason had picked up on wear and/or air leaks on the intake side.
Nick
S6 Devil said:
I called Jenvey, they do RG's recons and will only do them through RG. They advised that RG are their only customer, no mention of STR8SIX.
I am veering towards either getting Jason to do them or buying a new set, whichever is the most cost effective.
Thanks for all the input guys particularly Nawarne and Robertjp. Much appreciated.
I thought Jason did his own? that was the impression I got when I had mine done about 18 months ago.I am veering towards either getting Jason to do them or buying a new set, whichever is the most cost effective.
Thanks for all the input guys particularly Nawarne and Robertjp. Much appreciated.
Right, having a dilemma.
I have been offered a set of 2005 bodies from an S spec MK11. Is it worth buying these and fitting without refurbing them or should I just bite the bullet and get Jason to do the whole refurbishment job? Thoughts please?
If I were to buy the second hand set what are they worth or rather what should I offer...I haven't a clue! They come with fuel rail and injectors!
I have been offered a set of 2005 bodies from an S spec MK11. Is it worth buying these and fitting without refurbing them or should I just bite the bullet and get Jason to do the whole refurbishment job? Thoughts please?
If I were to buy the second hand set what are they worth or rather what should I offer...I haven't a clue! They come with fuel rail and injectors!
Not sure if this is No.4, but may be worth asking them ?
http://www.ebay.co.uk/itm/70MM-80MM-THROTTLE-BODY-...
why is this so expensive (630£), if the bodies are ok, there is not much to adjust ?
http://www.ebay.co.uk/itm/70MM-80MM-THROTTLE-BODY-...
why is this so expensive (630£), if the bodies are ok, there is not much to adjust ?
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