Focus diesel running rough

Not badly, but enough to upset my partner who drives long distances in it, & so is not happy doing so of late.
Car was fully serviced last month, and has been tested on two different plug in diagnostics (generic unit & a brand new snap-on unit) to see if any fault codes could be discovered – none have.

Were at a loss, so is my mechanic, because it does drive and work seemingly fine to us, but the g/f whose has it for 3 years+, so knows it intimately, says it’s just not right. I’ve been more aware that I didn’t think it was right myself as a passenger & having driven it again today since the service, I’m of the opinion it doesn’t feel right too.

Any idea’s?
The mechanic is friend so doesn’t want to just start swapping parts like a main dealer, but has suggest another place with facilities for more indepth testing of the injectors and such like (I dunno exactly what).
This will be our next port of call, but wondered if anyone else had similar experiences?

1.6 focus, late 2007 model.

A Diesel running rough but not flagging any fault codes is generally fuel related, i.e. the actual Diesel that is being used, (could be contaminated) could be the injectors (build up of carbon), I would possibly try some fuel treatment to start with, run that through (approx 200 miles) then see how you get on.

We use a product called Tunap, which is very very good!

Gunged up MAF? Give that a clean up then give it a good rag down a motorway to get it nice and hot to get rid of any soot deposits.

As andydicko says, some injector cleaner in a tankful of diesel can work wonders. Worth a try, roughly about £7 or so.

I would go with MAF, try taking it out and clean with electrical cleaner let it fully dry then try it, it could be completely knackered and I do not think it would show up on diagnostics

Fuel treatment was suggested by some-one, but I thought of them as snake oil, but it’ll be worth a go I suppose.
Any idea where joe public would find Tunap, and which exact product do I need? As there website ain’t very helpful & the catalogue interesting…

Will try that 1st and then go and ask my m8 to look at the Mass AirFlow Sensor.

Cheers all!

z1ppy, where are you mate? Tunap is only available through the trade (so to speak) I think the one you’ll need is 983

Stourbridge ways…

Ah, bit too far away mate, I would try a motor factors, they may not do Tunap but I’m sure they do something similar, it ideally needs to be a solvent based treatment, not oil based as when you burn oil Ash is created!!

Don’t go to Halfords though, someone like, Brown Brothers, Euro Car Parts, etc……

No problem… oh any chance of confirming that product number? As I can’t see that one in their catalogue.

If fuel related try some BG244 from http://www.powerenhancer.co.ukit’s more expensive than the Halfords shelve stuff but it really does work.
If when you are starting the car it feel like the engine is missing then more than likely it will be injectors. Usually accompanied with white smoke when starting on a morning. BG244 will sort most dirty fuel/injector problems otherwise it will be diesel specialist for the injectors cleaning or replacing.
Sluggish to get going when you put your foot down can the MAF or dirty air filter. Clean the MAF as above but be careful the wires are very thin and a replacement part expensive.
Sluggish with lots of smoke could be a split boost pipe or worse case a faulty turbo.
Italian tuneup only costs the fuel and can sometimes clear up small problems such EGR, DPF buildup.

Got the wrong one, the 983 is to clean the diesel!!!

Injector cleaner is Premium 127

No smoke, and brand new ford air filter (suggested by a couple of ppl), as the old one pattern one was a poor fit.
The pattern one had actually vibrated looser since the last service, so maybe indicates more crap was getting to the MAF, now it’s been suggested.
Turbo pipes have been checked and turbo declared as running fine (as much as you can without dissembling)

Cheers for the alternative fuel additive suggestion.

EDIT: Thanks for checking Andy

Car was fully serviced last month, and has been tested on two different plug in diagnostics (generic unit & a brand new snap-on unit) to see if any fault codes could be discovered – none have.

Was the fuel filter changed?
Find someone with IDS (Ford’s own diagnostic tool).Lots of these in the trade these days so no need to go to the main dealers.

Marko

Marko yes fuel filter was changed too, though she did report it seemed better after the service but went down hill again not long after – maybe I’ll ask him to check it again (due to crap in the tank).

There are some fake filters around. The fuel filters fall to bits and restrict the flow of fuel. Not saying it is so in your case and I’ve never seen it myself, but it may be worth having a look.

Hth
Marko

Just got rid of a Focus diesel, the shitest car I’ve ever driven 😕

I just got rid of a Focus diesel ’54 plate 1.8 TDCI – one of the better diesel’s I’ve driven. 😉 Sold it to a guy who had put 150k on his ’02 Focus estate diesel. one of the injectors was on the way out, and he was balking at the £600 price tag to fix it. So let’s hope it’s not an injector, eh?
Sounds like there are wiser heads than mine giving advice, so best of luck.

If all else fails I’d recommend Carwoods for good diesel diagnosis work! They’re the official people for manufacturers like Delphi. I’ve taken quite a few of our works vans to them and they’ve saved us a fortune over main stealers wanting to swap parts around!

Can I hijack this for a moment please?

My Passat 2.0 TDI 140 is fine except for one very specific instance. You start and drive off fine, but then if between minutes 1 and 4 or so you drive in 2nd or 3rd under really light throttle, like going down a driveway or side street, it starts to misfire sporadically every few seconds, which can cause quite significant jerks. It’s always done it off and on since I had it, which is over 42k miles.

I’m at a loss – I’d thought it could be the injector wiring being faulty or the injectors, but either would have thrown a code I think (there are none, had them checked) and I’ve just recently had the injectors changed.

Molgrips

Our Touran suffers from this. It’s very random and has stopped completely at the moment. When I check for faults it always shows a MAF (Mass Airflow Sensor) fault – described as ‘implausible’.

I just live with it, but you can try running it with the MAF sensor disconnected to confirm that the MAF is the issue.

Hth
Marko

Ah, thanks Marko. Mine comes and goes too – it was predictable when I got the car, then disappeared after lots of motorway runs, then it came back after towing our van to Germany.

EDIT: I’m back from google for the 50th time, and someone suggested checking the water drain on the fuel filter. I’ve never done this on this car, perhaps I should!

Cheap diesel=poor running eventually.
Run some STP injector cleaner through with a tankfull of posh diesel then stick to posh diesel. the extra mpg you will get from the posh diesel is almost the same in cost as cheap diesel with, say Millers addetive in it overall.
The majority of low boost pressure hose faults will cause the car to switch to limp home mode so make sure you check all the small bore low pressure rubber air hoses as well as the large bore rubber inlet hoses for any small holes or cracks. I know that on my VW when hoses have cracked with age or persihed it throws up an air inlet manifold pressure regulation fault code.
If it has gone on to limp mode you can temporarily reset the air mass meter by disconnecting the multiplug (wired into a sensor close to the airbox) leave it for five minutes then reconnect.
Just another limp home but still with full rpm acceleration tips for split low pressure turbo pipes is a simple puncture repair kit (keep one in the boot) and some nice large patches- got me out the mire for a couple of days recently when the large bore inlet hose developed a 1″ long crack/split!

mpg you will get from the posh diesel is almost the same in cost as cheap diesel with, say Millers addetive in it overall.

Buying separate cetane improver is cheaper than buying BP Ultimate, for instance. Especially if you buy plain 2-EHN in bulk off the internet, which is what cetane improver is.

you need to get comfy with the phrase “italian tune up”

Not my car, and I do try that when I get to drive it alone, and I can’t afford to replace it for her, if I broke it.

She is a safe sensible driver, when I’d tried to convey the occasional thrashing will do it the world of good, it doesn’t go down well, apparently.

Quick update, too early to completely confirm the issue is cured, but after cleaning up the MAF she reports it feel much better..