Ford Mondeo - Car Losing Revs (Power)

decmatt · 17 Oct 2019 at 19:16

Hi

My Ford Mondeo is on around 116k miles, just recently it has started losing revs when doing motorway driving,

When in 6th for example at 70 is is usually on 2.5k revs, but ever 4 seconds or so this drops down to 2k revs and it has to accelerate again... This is really noticeable and the car judders when it happens.

When using cruise control on this speed, and it active going up a slight motorway hill will cause it to lose enough power to turn off the cruise control.

MPG also seems a lot worse as a result.

Not a clue what is wrong with it, I took it to a Ford garage (and mentioned it when it has a service a couple of hundred miles ago) but they said they couldn't find anything... I don't think they took looked tbh.

Any ideas whats wrong?

Cheers

(Car is a Ford Mondeo TCDI 2L Diesel 2013)

Video - https://imgur.com/T5t7f1h

Drumroll · 17 Oct 2019 at 19:33

Maybe the DPF is full?
Or EGR failing?

acemastr · 17 Oct 2019 at 19:44

Is the speed dropping when it goes down to 2k rpm?

Malt_Vinegar · 17 Oct 2019 at 19:47

Get the codes read, see what its throwing up on.

decmatt · 17 Oct 2019 at 20:43

acemastr said:
Is the speed dropping when it goes down to 2k rpm?

When it gets to about 2.5K

Sorry understand, doesn't drop in speed majorly just revs (and a thud in performance)... Maybe a 1-2Mph drop but I don't notice too much

decmatt · 17 Oct 2019 at 20:47

Malt_Vinegar said:
Get the codes read, see what its throwing up on.

i read the codes (only using a £5 thing and Toque off play store) and the only code was an issue with the Active Grill Shutter... But it has always had that code

Lopéz · 17 Oct 2019 at 20:54

decmatt said:
When it gets to about 2.5K

Sorry understand, doesn't drop in speed majorly just revs (and a thud in performance)... Maybe a 1-2Mph drop but I don't notice too much

How can it take a "thud" in performance but not really slow down. I'm not sure I understand what's actually happening.

500rpm in 6th in a Mondeo is going to be a fair old drop, must be 10mph or so?

Edit
Just checked, a 500rpm drop in 6th gear is approximately 18mph of speed loss!
Your report can't be accurate.

decmatt · 17 Oct 2019 at 21:05

Lopéz said:
How can it take a "thud" in performance but not really slow down. I'm not sure I understand what's actually happening.

500rpm in 6th in a Mondeo is going to be a fair old drop, must be 10mph or so?

Edit
Just checked, a 500rpm drop in 6th gear is approximately 18mph of speed loss!
Your report can't be accurate.

It gets up to around 2.5k revs, then drops down, I keep my foot on the accelerator (maybe I compensate it) and don't see a huge drop in speed

I have a video a passenger took I will try and get drop a few days ago, but it has got worse... Will get it off him

decmatt · 17 Oct 2019 at 21:12

This is a GIF of the salvageable video, tried to crop and stabilise it...

This is me staying constant on the accelerator, so maybe under 500 and more 250 on a motorway in 6th.

it was a lot worse today (looked about 500 revs but just me in car so couldn't record).

https://imgur.com/T5t7f1h

Clarkey · 17 Oct 2019 at 22:43

Bizarre. Are the engine revs actually changing or just the dial is dancing?

decmatt · 17 Oct 2019 at 22:47

Clarkey said:
Bizarre. Are the engine revs actually changing or just the dial is dancing?

Its definitely changing, it knocks out the Cruise Control and I can audibly hear it (and feel it in the engine)

bremen1874 · 17 Oct 2019 at 22:53

Clutch slipping?

In 6th there's no way the revs could be changing that quickly if the engine is actually connected to the wheels. Even if it could it's be throwing you around the car.

decmatt · 17 Oct 2019 at 22:58

bremen1874 said:
Clutch slipping?

In 6th there's no way the revs could be changing that quickly if the engine is actually connected to the wheels. Even if it could it's be throwing you around the car.

Thanks - Did you manage to see the short GIF? Are there any checks I can do?

bremen1874 · 17 Oct 2019 at 23:07

I saw the video and it is weird. I drive a 2.0 TDCi Mondeo myself and don't think I could make it do that if I tried. At that speed in 6th it just wouldn't react that fast either flooring it or lifting off completely.

Surprising that it isn't showing any error codes.

decmatt · 17 Oct 2019 at 23:11

bremen1874 said:
I saw the video and it is weird. I drive a 2.0 TDCi Mondeo myself and don't think I could make it do that if I tried. At that speed in 6th it just wouldn't react that fast either flooring it or lifting off completely.

Surprising that it isn't showing any error codes.

Thanks

Exactly! Driven this for 100k miles since I got it, this is definitely strange (also the Ford eCheck came back all green 300 miles ago)

Scania · 18 Oct 2019 at 11:30

decmatt said:
Thanks - Did you manage to see the short GIF? Are there any checks I can do?

Looks like clutch slip, you test it by selecting as high a gear as possible and flooring the throttle, ideally on an uphill section of road,if your revs rise but speed doesn’t then your clutch needs it’s last rites.

Chris1712 · 18 Oct 2019 at 11:40

Is it auto or manual?

decmatt · 18 Oct 2019 at 12:07

Chris1712 said:
Is it auto or manual?

Manual

Dogbreath · 18 Oct 2019 at 12:45

If the engine RPM is actually changing without significant impact on road speed, then it's almost certainly the clutch slipping. 6th gear is where it's most likely to happen, and 116k seems not unreasonable for a clutch if it's spent quite a few of those miles doing start/stop city driving rather than mostly motorway.

Any strange smells after a drive?

lordrobs · 18 Oct 2019 at 14:07

Don't most cars use a combination of engine and road speed to calculate in the ECU what gear the car is in? If that goes out of whack (I.E if the clutch starts slipping) the ECU may think you've dipped the clutch hence the cruise control cutting out.

I'd do the classic high gear at 30 mph, pin the throttle, look for the revs changing while the speed remains relatively stable. To confirm that the clutch is on its last legs.

Ford Mondeo - Car Losing Revs (Power)

Transmission breaker