Mk6 Fiesta Zetec S - Engine "coughing"

scratch · 24 Jan 2012 at 13:14

Afternoon!

The gf has a 57 plate Fiesta Zetec S 1.6 petrol which has developed a "cough" when idling, like a gentle misfire but without the loud bang! It's not consistent but can happen at about 5-10 second intervals and as she's looking to sell the car we thought we'd better get it sorted.

Could anyone give us tips on where to start looking? Is it a common thing on these engines? I've had a quick Google and can't find anything obvious but I'm thinking maybe coil packs to start with?

Cheers,
Andy

MatteH Oxford · 24 Jan 2012 at 13:38

If it were coil pack(s) then you would likely have problems throughout the rev range, rather than just at idle. A quick check of the obvious electric things like battery terminals & leads/connections for splits & water/dirt ingress wouldn't hurt. When was it last serviced?. I'd check more simple things next, like the air filter, engine breather pipes/filers & leaks from the intake ducting, inlet manifold & vacuum hoses.

Then move on to the emission control systems, egr etc - these will need a bit of technical knowledge.

MatteH Oxford · 24 Jan 2012 at 13:56

This chap is good. Note that you won't always get a noise from a vacuum leak!

Sonea Fifer · 24 Jan 2012 at 16:16

OP - it maybe worthwhile creating an account and asking on here.

There's quite a few knowledgeable chaps there

Brookert · 24 Jan 2012 at 18:14

Try an ECU reset aswel, disconnect the battery for a period of time and see if theres any difference.

scratch · 24 Jan 2012 at 19:47

Thanks guys. She's got it booked in for a service next Monday as its due one, but I thought I'd take a quick look before she takes it in to try and save her a bit of money.

Will have a poke around to try and find anything obvious, but if nothing jumps out at me then I'll leave it to the garage to diagnose

Thanks once again.

Brookert · 24 Jan 2012 at 21:59

Does anyone else think that Eric the car guy is a legend! His videos are fantastic!!

Overlag · 25 Jan 2012 at 00:42

Brookert said:
Does anyone else think that Eric the car guy is a legend! His videos are fantastic!!

i watched his whole 2hour video on changing a Focus Mk1 clutch... hard work just watching let alone doing it! He's a "honest" guy.

SKYNHEDD · 25 Jan 2012 at 01:08

Fuel filter?

scratch · 13 Feb 2012 at 15:59

Hi guys,

Just as a quick update to this, she had the car serviced and apparently it was running the wrong grade of oil. She can't remember the exact details but they did a full flush, changed the oil filter and filled it with the correct stuff and after a bit of driving around the cough has vanished.

The car is currently up for sale!

Minstadave · 13 Feb 2012 at 16:26

How could they tell which oil grade it was running? :confused:

atpbx · 13 Feb 2012 at 17:11

Minstadave said:
How could they tell which oil grade it was running?

You can tell if its the correct viscosity using various pieces of eqipment.

I doubt your average trained by DVD mechanic has access to this though, so it sounds like blagging from the garage.

Brookert · 13 Feb 2012 at 17:30

atpbx said:
You can tell if its the correct viscosity using various pieces of eqipment.

I doubt your average trained by DVD mechanic has access to this though, so it sounds like blagging from the garage.

indeed.

Who changed the oil before?

thecremeegg · 13 Feb 2012 at 17:47

Well I know if my engine's running the wrong grade of oil because it gets all tappety so maybe they've had a similar problem before?

scratch · 14 Feb 2012 at 12:49

The original oil would have been changed by the dealer she purchased the car from.

The garage that's just serviced it have never worked on the car before so had no reason to lie about what was wrong..in fact it would have been in their interest to string out the fault-finding process to make some extra money. He actually came straight back to us as soon as he'd drained the old oil and said it was too thick.

Brookert · 14 Feb 2012 at 12:51

scratch said:
The original oil would have been changed by the dealer she purchased the car from.

The garage that's just serviced it have never worked on the car before so had no reason to lie about what was wrong..in fact it would have been in their interest to string out the fault-finding process to make some extra money. He actually came straight back to us as soon as he'd drained the old oil and said it was too thick.

seems like a silly mistake for the other garage to make. did she buy it from new?

scratch · 14 Feb 2012 at 13:32

Brookert said:
seems like a silly mistake for the other garage to make. did she buy it from new?

No, she's had it for just under a year so this was the first service she's done on it.