What Revs Should We Expect?

[Becki]

Hiya we seem to be having few probs with our autobox in our 2.8i cd v6

 

it is changing at very high revs ie 4.5

 

can anyone tell us what the revs should be roughly at 60mph? its sitting at about 3 at this speed does that seem high.

 

when we first start the car its fine and runs ok for about 30 miles then it will start this behaviour of not changing at the correct time instead it changes very high. and it will kick down on its on even on a straight.

 

we are thinking, after reading a few articles on here last night that we could need to do an oil change in the box. could this help?

 

any ideas anyone?

 

thanks Becki

[Comhander]

can anyone tell us what the revs should be roughly at 60mph? its sitting at about 3 at this speed does that seem high.

 

thanks Becki

 

Becki

 

On my 2.3 auto the revs are 3200 at 70 mph. I was told this is the correct level for the AG4 box when I had it rebuilt. Therefore 3000 at 60mph seems about right.

 

As for the changing gear at 4500 this does seem excessive unless you are in sport mode! Mine normally changes up based on speed of car and not the rev level. If driving in granny mode this is normally about 2000 -2500 revs in each gear (35 to 40mph) going into top gear.

 

Regards

[bj2004]

check the oil level in gearbo

[Scorpiorefugee]

This may be a bit off target but many cars suffer in this way if the MAF is a bit out.

 

Try disconnecting it. On some models this will correct the problem as far as changing at the correct speed but can make the changes a bit fierce.

 

This is just a suggestion basd on non Galaxy experience but, in lieu of more experienced input it may help.

 

MAFs can be obtained for about

[NikpV]

can anyone tell us what the revs should be roughly at 60mph? its sitting at about 3 at this speed does that seem high.

 

thanks Becki

 

Becki

 

On my 2.3 auto the revs are 3200 at 70 mph. I was told this is the correct level for the AG4 box when I had it rebuilt. Therefore 3000 at 60mph seems about right.

 

As for the changing gear at 4500 this does seem excessive unless you are in sport mode! Mine normally changes up based on speed of car and not the rev level. If driving in granny mode this is normally about 2000 -2500 revs in each gear (35 to 40mph) going into top gear.

 

Regards

 

 

sounds like its going into 'sports mode' on a tdi this forces it to wait until 4krevs before changing up - iirc its activated by the speed/how far the accelerator pedal is depressed wonder if you have some problem associated with throttle

[Becki]

Hiya all and thank you for all your replies!!!

 

ok firstly where is the maff and how do we disconnect it?

 

secondly what is sports mode and how is it selected/deselected?

 

thank you all again

[NikpV]

look here for location of maf

 

sports mode (at least on my TDi) is selected by how quickly/how far (cant quite decide which) I push the accelerator pedal - eg. coming off a roundabout if I floor the pedal rather than gently increasing revs it goes into sports mode which means it wont change up until it reaches 4k (max for tdi engine) for each gear change this results in max acceleration (and fuel used) - it then defaults to normal mode where it changes up earlier. I dont even know if you have sports mode although if I could afford it I would like to try the 2.8 v6 :wacko:

[Becki]

ok so you are sayingthat the maf is all of the big black thing on the left hand side? i have looked at the removal of it on the tdi engine and its nothing like it on our car there is a plug into it that you just squeeze the sides and and pull it out is that it? does it all have to be removed or can it just be disconnected and left in place? will it cause any damage to the car running it disconnected?

 

where is the best place to locate the auto box under the car?

 

thank you again

[Becki]

hi there

 

ok we disconnected the maf this afternoon and hubby took it out this evening only 15 mils away and it seemed overall better. (not bunnying out of the drive?) also temp gauge didnt go as high as normal either. but what we did notice was that the fan wasnt on at the end of the journey. (is this because the maf isnt connected?) it was working before we disconnectted maf.l or is it purely because the engine temp didnt go as high as normal. the 15 miles were done at a speed of no lessthan 60mp aprta from junctions obviously!

 

we still have to check the oil in the gearbox as we are still not sure that its def the maf.

 

anotehr symptom i forgtot to mention was that when the car does play up bad if we pull up and turn engine off for 1 min and restart it will drive as normal again for about 2 miles then start again. also once it was driving as normal and then it just had no power at all and nothing there when put foot on accelerator pedal. pulled over switched engine off for 2 mins started and drove home the next 20 miles. does all of this sound like the maf playing up or something more sinister?

 

if it is the maf wheres the best place to get one for a 2.8 petrol the ones on ebay are for the tdi versions.

 

thansk again in advance Becki

[NikpV]

hi there

 

 

anotehr symptom i forgtot to mention was that when the car does play up bad if we pull up and turn engine off for 1 min and restart it will drive as normal again for about 2 miles then start again. also once it was driving as normal and then it just had no power at all and nothing there when put foot on accelerator pedal. pulled over switched engine off for 2 mins started and drove home the next 20 miles. does all of this sound like the maf playing up or something more sinister?

 

 

sounds like the transmission is going into limp home mode - max gear is then 3rd iirc

 

I would think that the maf could easily affect temperatures although you may have 2 separate problems could try gsf (german,swedish and french) for maf or fords themselves

[Becki]

sounds like the transmission is going into limp home mode - max gear is then 3rd iirc

 

 

 

ok so if its going into limp mode does this mean then thats its more likely to be a gearbox fault rather than maf?

 

thanks

[NikpV]

nah could still be maf - cheaper to try anyway

 

worth checking th autobox oil though

Edited September 28, 2008 by NikpV

[tiny]

.

 

anotehr symptom i forgtot to mention was that when the car does play up bad if we pull up and turn engine off for 1 min and restart it will drive as normal again for about 2 miles then start again. also once it was driving as normal and then it just had no power at all and nothing there when put foot on accelerator pedal. pulled over switched engine off for 2 mins started and drove home the next 20 miles. does all of this sound like the maf playing up or something more sinister?

 

Has anybody considered the throttle potentiometer? I wouldn't of thought the MAF would give an intermittent fault.

I personally think that a diagnostic check is in order, either a member with Vag-com(anyone local), or ring round reputable independent garages, there's one in Carlisle I use called Auto-tech who specialise in engine management issues a diagnostic from them is around

[Scorpiorefugee]

I am no expert on this and MAFs can fail into different states but it does supply information to the control system about the air flow into the engine and this is only one of the many things which are used to determine fuel injection, ignition timing, gear changing and just about everything so I doubt whether an expert would be able to give you a definitive answer so the only thing that helps is experience of a range of faults.

 

Sadly, unless you are able to get error codes read, the only real way forward is to try by replacement. For what it's worth, a Garage will probably charge the price of a MAF for just guessing as to what the trouble is.

 

I had an auto Ford Scorpio and the MAF caused all sorts of problems and eventually resulted in a wrecked engine because I was too stubborn to buy one 'just in case' because I had no means of proving it. The funny thing is that they frequently do not cause a definitive error symptom or even an error registered in the control system.

 

An easy way forward is to find someone with the same engine and borrow one - not easy I'm afraid. If you can get to it, cleaning with carbretter cleaner can help because they do get coated with fine dust etc after many miles. Typical lief seems to be 50 - 100k miles.

 

The MAF itself is not big but is frequently sold including the housing. Please do not buy one on my say so but you may have to do so to move forward, particularly since you say that the gear changes were better without it. When disconnected the control system will work on default settings which should produce a workable but not ideal situation and some people just leave it off but results do seem to vary greatly with particular models.

[sepulchrave]

I am unclear whether Becki has a 12v or 24v VR6, how old it is and how far its travelled.

 

On the 12v VR6 the MAF is NOT the dominant factor as it is on TDI's, as Tiny states the TPS is far more important although this is much more reliable.

 

The Lambda probe and Ignition components are the most important parts if you have a 12v VR6.

 

The MAF will pick up a few MPG and disconnecting it will richen the mixture enough to encourage a weak ignition system into performing better.