2.0 Focus TDCI Engine Malfunction

[Mattm926]

Hi everyone - i was driving home from work today and coming upto my home i put my foot down in 3rd and as the turbo engaged it immediately jolted and then 'engine malfunction' showed on my dash. So as i came to the lights before my road i stopped and turned the engine off and then it would not start again. Just turned over until after about three trys it made a clicking sound. So i gave up pushed her back and called green flag. They subsequently told me i had a flat battery and without seeing the malfunction they had no advice for me, the fella even red lined it to no avail.

I drove to the gym before and it was fine. Turbo perky as usual and no weird noises (for a diesel with 107000 miles on it)

Any advice would be welcomed.

2009 Ford Focus 2.0 TDCI Titanium

Thanks.

[Mattm926]

UPDATE 

Started fine this morning but the turbo is much louder than usual, can hear the whistle with windows up and radio on. Turbo is very laggy hitting 2300 revs.

 

[TomsFocus]

Sounds like it's in limp mode.  Get the fault codes read so we have a rough area to start with.  

[Mattm926]

Thanks Tom - getting the fault codes read this afternoon. Will let you know!

[Mattm926]

Turns out there was a crack in the small pipe to the Air Flow sensor - just been taped up for now whilst i source one. The battery also only holding about 60% hence why it wouldnt start again i guess.

 

would a crack in the MAF sensor cause turbo delay and lag? 

 

 

[Tdci-Peter]

1 hour ago, Mattm926 said:

would a crack in the MAF sensor cause turbo delay and lag? 

I am not sure where the crack is, or the small pipe. The MAF (air flow sensor) is directly after the air filter. The pipes here are not pressurised, so small leaks would have little effect.

A faulty MAF might cause lack of power and delay. Sometimes just un-plugging it partly cures the problem. It will put the engine warning up with a MAF error, but if the car runs better with no MAF, then the MAF is likely to be faulty.

The MAP sensor (boost sensor) mounted on the throttle valve at the front of the engine can also have similar effects.

A code reader would help in identifying codes, doing tests, and clearing the codes to see what returns. They are very cheap and easy to use these days.

The bit marked 12B579 is the MAF in the picture.

[Mattm926]

Code reader came up as ‘air - mass sensor’

i will take a picture of what they pointed out tomorrow when it is light. It is running a lot better with no lag on the 10 mile journey home. 🙂

 

Thanks for the replies

[Mattm926]

There you go - the crack is at the top of the pipe where the tape is.. also my bad its 1.8 diesel, just changed from a 2 a month or so ago!🙂

[Tdci-Peter]

1 hour ago, Mattm926 said:

here you go - the crack is at the top of the pipe where the tape is.. also my bad its 1.8 diesel, just changed from a 2 a month or so ago

That is the MAP (pressure sensor).

SNAP! - I had exactly the same fault just over a week ago. Except it was the thinner tube that had almost broken in two. I am not sure when it happened, but my turbo performance seems to have leapt back to as good as new since fixing the leak. It was getting decidedly dodgy before.

As soon as you said small tube & air, I thought of that, but I looked up 2.0l MAP sensors, and they are plumbed direct in as I expected, so no small tube!

I would not take the fault code too literally. The ECU compares the MAF readings with calculated air flow from rpm & MAP sensor & air intake sensor. So it will have to guess where the error is, unless the MAF reading is completely out of allowed range. This is a common problem with DTCs, but it does give a good idea of the general area to look. Just note the code, clear it and see if it comes back with the leak fixed.

[Mattm926]

1 hour ago, Tdci-Peter said:

That is the MAP (pressure sensor).

SNAP! - I had exactly the same fault just over a week ago. Except it was the thinner tube that had almost broken in two. I am not sure when it happened, but my turbo performance seems to have leapt back to as good as new since fixing the leak. It was getting decidedly dodgy before.

As soon as you said small tube & air, I thought of that, but I looked up 2.0l MAP sensors, and they are plumbed direct in as I expected, so no small tube!

I would not take the fault code too literally. The ECU compares the MAF readings with calculated air flow from rpm & MAP sensor & air intake sensor. So it will have to guess where the error is, unless the MAF reading is completely out of allowed range. This is a common problem with DTCs, but it does give a good idea of the general area to look. Just note the code, clear it and see if it comes back with the leak fixed.

Ahhhh i see! - apologies im not great with cars!

yeah to be honest even with just the tape on the turbo feels much better! 

Did you manage to get a new tube? My garage reckon i can only buy the full unit..my have a trip down to the scrap yard.

https://www.ebay.co.uk/itm/FORD-1-8-TDCI-FOCUS-MK2-C-MAX-GALAXY-MONDEO-MK4-IV-MANIFOLD-ABSOLUTE-MAP-SENSOR-/261205812189  🙂 Is that the correct part?

[Tdci-Peter]

37 minutes ago, Mattm926 said:

Did you manage to get a new tube? My garage reckon i can only buy the full unit..my have a trip down to the scrap yard.

On mine, the thin tube had gone at one end. I have just cut it a bit shorter and re-used the tube. I also have boxes full of bits of tube & hose if I need, I work with pressure sensors!

Scrappy may be the best bet, with the bit of hose like that, if it looks & feels ok, it is ok. Not like the sensor, where calibration and stability details really matter.

Part 4M51-9F479A, or 1338678, seems to be just the sensor.

Part 4M51-9F479B, or 1352477, seems to be the complete assy with hose & bracket.

See: https://ford.7zap.com/en/car/50/no/23/1559/15545/67799/

The site you gave is a bit odd, it lists the sensor number (A or 1338678), but the photo is the Assy, and their compatibility list stops at 2008 for the Focus. But it looks the right part, it seems from the number it is the right sensor, with the hose. But £43 is a lot to pay for a tiny bit of hose! The "official" Ford sites price is well over £100 though. Crazy.

The inlet manifold temperature should stay below about 100C, so a bit of silicone hose and suitable clips would suffice. Pressure is only 1.5Bar (22PSI) above atmosphere too, so not too demanding.

[Mattm926]

I see - scrappys may be the best bet.

The mech I used try to say i need that correct part as it is a specified length for accuracy! Smelt funny when he said it.