TRANSIT MK7 engine "rocking"

[joarnes]

Hello everyone
I wonder if someone can point out the right direction to go to solve this problem.
I have a 2010 Transit FWD, 85hp. 5 speed manual. When I drive with steady throttle and the engine revs between 1500 and 1800 the engine starts "rocking" like hell.It is only between this RPMs and in all gears. If I let go of the throttle its stop "rocking" and if I give more throttle its stops "rocking", and, if I activates the Cruise Control it goes smooth and steady in all speeds and all rpm`s.
This has come over time. I have changed the engine mountings, read out fault codes (had code P1409 on EGR who disappeared when I "blankt" it) and now I have code P1103 because of that "blanking" but no engine-error light and the code disappears when I erase it.
The engine starts easy (cold and hot) ,idling smooth, runs good, no smoke, no loss of power and good mileage I think, (35-42 mpg). All filters and fluids are new. ODO is ca 15000 miles
I have read of the car with a Delphi program and cant find anything specially to point the finger at.
I might get to change the MAF sensor, the MAP and perhaps more but I hope any of you have experience with this problem and can point out the exact fault and the solution.
John

[Altransit]

Mine does it too, has done for a few years, off and on.
It's been discussed on here a few times, but no-one has reached a conclusion, mainly because the fault seems to manifest itself to different people, in different ways.
Some people think it's mechanical, some think it's fuel, and some think it's electronic.

A couple of other people also claimed that it disappeared when on cruise (I don't have cruise, to confirm this), so that would seem to eliminate mechanical and fuel problems, leaving a possible electronic or mapping issue.
My theory is that it could be the pedal itself, but it doesn't annoy me enough to stump up the cost of a pedal just to find out, because I just change down a gear and avoid that rev range

[joarnes]

Mine does it too, has done for a few years, off and on.
It's been discussed on here a few times, but no-one has reached a conclusion, mainly because the fault seems to manifest itself to different people, in different ways.
Some people think it's mechanical, some think it's fuel, and some think it's electronic.

A couple of other people also claimed that it disappeared when on cruise (I don't have cruise, to confirm this), so that would seem to eliminate mechanical and fuel problems, leaving a possible electronic or mapping issue.
My theory is that it could be the pedal itself, but it doesn't annoy me enough to stump up the cost of a pedal just to find out, because I just change down a gear and avoid that rev range

Thanks for the answer.
The throttle pedal is one of the things who has been in my thoughts to. I shall continue searching for a solution for this problem and if i find it I´l post it.
John

[Altransit]

if i find it I´l post it.
John

That would be most welcome, there are many threads on here with no conclusions, and it doesn't help the collective

[ned]

Silly question but how do you know the engine is rocking?

Only asking as my van does a weird gear stick shaking thing only in 5th between 1500 - 2200 rpm

[tranmx2]

Engine gearbox mounts.
Engine cold, low rpm/power - moving off across a slope.
Worn UJs, hangers, splines.

[knobby1]

Engine gearbox mounts.
Engine cold, low rpm/power - moving off across a slope.
Worn UJs, hangers, splines.

It's primarily a FWD thing.

Lord Knobrot

[Altransit]

Engine gearbox mounts.
Engine cold, low rpm/power - moving off across a slope.
Worn UJs, hangers, splines.

How would running on cruise stop it happening though

[metalworker0]

Engine gearbox mounts.
Engine cold, low rpm/power - moving off across a slope.
Worn UJs, hangers, splines.

How would running on cruise stop it happening though

Had similar with engine mounts

They make little shakes, your foot on the accelerator pedal then turns them into a larger shake, then foot sort of gives throttle a tiny blip, within half a second that feeds back into the engine mount again, then back into your foot...so self perpetuated at certain revs.

When in cruise control there is no foot amplifying the little shakes

Just an idea and experiment ...try a lump of sponge under your ankle to see if it stops it happening.

all the best..mark

[joarnes]

Silly question but how do you know the engine is rocking?

Only asking as my van does a weird gear stick shaking thing only in 5th between 1500 - 2200 rpm

I placed a wireless reversing camera in the engine compartment and a screen inside the car

[joarnes]

Engine gearbox mounts.
Engine cold, low rpm/power - moving off across a slope.
Worn UJs, hangers, splines.

How would running on cruise stop it happening though

Had similar with engine mounts

They make little shakes, your foot on the accelerator pedal then turns them into a larger shake, then foot sort of gives throttle a tiny blip, within half a second that feeds back into the engine mount again, then back into your foot...so self perpetuated at certain revs.

When in cruise control there is no foot amplifying the little shakes

Just an idea and experiment ...try a lump of sponge under your ankle to see if it stops it happening.

all the best..mark

In my case all the engine mounts are new, but only for the fun of it I shall try your suggestion with a sponge. And if that works, I will know that it is in the accelerator pedal the fault is to find.

[ned]

Silly question but how do you know the engine is rocking?

Only asking as my van does a weird gear stick shaking thing only in 5th between 1500 - 2200 rpm

I placed a wireless reversing camera in the engine compartment and a screen inside the car

That’s not a bad idea, I might try that, my issue is so sporadic I may have to fit a go pro or something to see what it’s doing, it’s usually when the engine is warm, I’m not sure if the symptoms are the same as yours, it’s like when you go in to 4th instead of second but more violent, bloody ford

[joarnes]

Engine gearbox mounts.
Engine cold, low rpm/power - moving off across a slope.
Worn UJs, hangers, splines.

It's primarily a FWD thing.

Lord Knobrot

A strange thing, I changed the gearbox oil and the oil in the gearbox was more like dirty water and at that time I only had 80w90 mineral oil available. With the 80w90 mineral oil the shaking went away but came back when I switched to 75w90 synthetic gear oil again. Maybe just a coincidence or just in my head but trying a single grade mineral oil is in the plans if nothing else works.

[amlav]

Have the same issue on my 2006 MK6 (rwd). It is happening mostly when car is just rolling and just push and release the accelerator pedal gently to keep the car at constant traffic speed . Pretty much at same RPM like yours . Usualy I either accelerate a bit more or deccelerate a touch and it goes away .
Never bothered to look in to it but I think is to do with the accelerator pedal sensor . As far as I researched it the sensor seems to be an hall effect sensor and it pushes out some variable voltage depending on pedal position . So far it didn't bother me enough to look in to it . It is doing it for years .

[joarnes]

Have the same issue on my 2006 MK6 (rwd). It is happening mostly when car is just rolling and just push and release the accelerator pedal gently to keep the car at constant traffic speed . Pretty much at same RPM like yours . Usualy I either accelerate a bit more or deccelerate a touch and it goes away .
Never bothered to look in to it but I think is to do with the accelerator pedal sensor . As far as I researched it the sensor seems to be an hall effect sensor and it pushes out some variable voltage depending on pedal position . So far it didn't bother me enough to look in to it . It is doing it for years .

Accelerator pedal is on the shopping list