New automatic Cmax help needed

[Howsey bear]

Hi all please can you help me I    recently sold my CMax 2.0 tdci    manual and brought another 
Ford CMax 2.0 tdci but it being a automatic model. 
The problem I am having is I can pull away without any problems most of the time but every now and then when I go to pull away from a stand still or just from a junction etc I seam to be getting a judder from the car on pulling away as if I have got kangaroo fuel in it (sorry about the description but is is the best way of explaining it ) but if I put my foot flat down it will stop juddering But pull away like a  rocket. 

Please can someone help me on how I sort this out as I have never had a automatic before and now being disabled I need a good car and think this is just down to me or is it the cars clutch slipping?? 

[Tdci-Peter]

3 hours ago, Howsey bear said:

seam to be getting a judder from the car on pulling away as if I have got kangaroo fuel

Is the idle steady (constant rpm & even engine note), and if pulling along with the smallest possible throttle opening, is it steady? (I am not sure if an auto can be driven on idle, with throttle pedal fully released, like a manual can, but that would be a good test).

Uneven idle might be: fuel system, sensor, or EGR problem.

If it only happens on pulling away from stopped, then it is more likely to be a transmission problem.

Post a reply here, someone on this site may be able to advise better then.

Peter.

[Howsey bear]

Hi Peter thanks for the reply it is idling at just under 1000 rpm and will move off with the throttle fully released. I think it could be me but not really sure as if I put my foot down hard on the throttle it will take off and stop juddering. 

[Tdci-Peter]

23 minutes ago, Howsey bear said:

it is idling at just under 1000 rpm

That sounds a little high. Normally these diesels should idle at 800 to 900 rpm, though it may be a bit faster on a cold engine. The no throttle pull-away test eliminates the driver's right foot from the process.

Is that with the transmission in neutral? And aircon off?

And is the idle nice and steady?

The pcm (engine computer) controls idle speed directly from the crankshaft sensor. There is no adjustment. If the idle is high, or unsteady, then something is making the pcm raise it.

(You have not given the year of the car, not sure if new means new (2016) or new to you.)

If under warranty (new or used), do some more tests to pin down the uneven pull-away, and report it to the dealer.

And for any car past or near the end of the Ford warranty period, I would always recommend getting a diagnostic aid (scanner). A cheap generic OBD2 type (I got a "U480") will show EGR & other engine related faults. More sophisticated aids like FORScan will also check out the transmission module, and can monitor rpm & injector settings etc. If that light does come on (it will sometime), it is just so nice to have at least a clue as to why.

Post here if you want more info. Car year & transmission type might help.

Peter.

 

 

[Howsey bear]

Hi peter I got the U480 and all has come up with no faults at all so I think it is down to just how I am driving it and hopefully it will get better in time as k get use to a  automatic car. As you asked in the last message the car is a          Ford C-Max 2.0 tdci and 2010 model thanks for help 

[Tdci-Peter]

2 hours ago, Howsey bear said:

I got the U480 and all has come up with no faults at all

I am sure you will not regret having a diagnostic aid handy. My U480 dropped through the door one morning, and that very afternoon, after changing the filter, the light came on with an error!

Just a couple of points about these things:

The codes are only a guide. The car software has to make assumptions sometimes, and it is not 100% right. But they do point you in the right general direction, and in 90% of cases, they are right.

If you are likely to take the car to a garage for repair, do not clear the codes. If you know the cause, and it is not urgent, then clear the code (& put the light out), to see if it, or anything else, re-occurs.

A generic device like the U480 will only read basic engine related codes, normally. But these are the most frequent.

Please keep us informed of any changes or other problems, should they arise!

Peter.

 

[kev 2010 s-max]

Hi, just wondered if you had a resolution to this one, it sounds very similar to my problem. I have just bought a 2010 s-max 2.0 tdci, and when I hit approx 2000 revs, the engine appears to chug. Not violently, but enough to know something is wrong, and applying normal throttle, can take a few attempts to move up to next gear. As you describe, I can power through it, but even then, when the engine is cold, it still chugs through gear changes 2 & 3. Any help appreciated if you think it's the same problem.. thanks Kev

[Tdci-Peter]

12 hours ago, kev 2010 s-max said:

when I hit approx 2000 revs, the engine appears to chug.

The original post was related to pull away at low rpm. Gear changes at 2000 rpm sound a bit different.

Have you tried slowly releasing the throttle once the car has reached normal gear up-shift speed? This might break the cycle causing the judder or chug, and allow up-shift

I would start by checking the engine mounts, both ends of the engine should barely move when pushed firmly by hand in a fore & back manner.

But then a rather large range of possibilities could cause uneven power: Sticky EGR or EGR throttle valve, sticky turbo actuator, one dodgy injector, or some faults in the transmission. Without error codes (DTCs) to go by, it could be hard to diagnose.

 

[kev 2010 s-max]

Thank you. I had one injector changed last week, so I'll see what they say when it goes back in next week. No fault codes showing at all which has confused everyone who's looked at it so far. I'm actually hoping it's injectors or transmission as they'll be covered under the warranty. Thanks again for your help.

[Tdci-Peter]

2 hours ago, kev 2010 s-max said:

I had one injector changed last week,

Check that they re-coded the changed injector properly in the pcm. If the calibration factor is wrong, it could give uneven running, though this is likely to show up at idle or low rpm.

It needs Ford IDS (or the Forscan system) to re-code the injectors.