Intermittent Rough Idle On 2011 Fg N/a Xr6

[Boog72]

Hi All,

We purchased a 2011 FG XR6 last year through a Ford dealership in Brissy (had 22000kms on the odo). When my missus took it for a test drive she drove it out of the dealership and got out on the road, pulled up at the first set of lights and whilst in Drive with foot on the brake the idle went very rough to the point it would almost stall. She spoke to the salesman sitting beside her that there is something wrong with this car and that she didn't want this one. He stated the normal 'well fix that, it won't be a problem'. The missus was ok with this. Took delivery of the car and this time I was with her. I drove the car out of the dealership and it done the same thing at the same set of lights. I took the car straight back and told them there was a problem with it and booked it in.

Diagnosis was low volts code came up so they put a new battery in it. Within a week it done it again. Took it to another dealership....couldn't find the fault and no codes. Spoke to the dealership and they said it just needs a good drive with good fuel! Our cars have run only on BP ultimate or 95 and it still has the same fault. I drove the car from Brisbane to Perth (to give it a good run) and it is still doing it.

After 2 months of its last visit to a dealership I took the car to the nearest Ford dealership here in Perth and they couldn't find a fault or get it to run rough on cold start or under normal conditions. Took it to another dealership and they finally found that there was a problem with the car.

Thoughout this process I have the CRC involved in our case and the dealership we are dealing with now have been very patient and trying everything to find out what it is.

We carried out a carbon clean, replaced coil packs, checked PCV valve, checked all vacuum lines for leaks, all sensors checked, inlet manifold removed, had all the injectors flow tested, checked timing gears and tone wheel to see if a tooth has broken and timing chain has skipped a tooth, checked solenoids to see if they were gunked up, identified it's not a bodgy diaphram in the brake booster as it only does it now and then!!

The dealership has no other option but to remove the head to see if there is a sticky valve or problem with it seating however Ford CRC have advised me that they "don't pay for the removal of the head".....so I have to wear the cost of $1800 to remove the head...all of which will not guarantee we will find the issue. I am at wits end with this.

I am in the position that we shouldn't have to pay for anything as the car was defective from the day we purchased it. The warranty ran out in July 2014 however the car has been in the shop and had the case open prior to the warranty running out so it is still covered for this problem.

Most occassions the car runs beautiful, it is regularly serviced, never thrashed hard and is the 3rd FG we have owned. Admittedly it is the 1st n/a XR6 we have owned as the last one was a FG XR6T ute which ran flawlessly.

Has anyone had the same issue with intermittent rough idle and had it fixed???

Cheers

Tim

[barnz]

It certainly sounds like a jumped chain but apparently not, have the solenoids been replaced or just checked?

[aiboart]

If the car idles perfectly in N or P then perhaps it is not idle as such.

A bad engine mount can present as a really bad shudder-stutter etc. and this will in general be only in evidence only when the driveline is under load, say in D (or 1) or possibly R.

Often positioning the car on a gradient (such as a hill) when in D can make the problem worse because of the way that the engine weight is directed towards the engine mounts.

[FiftyOne]

Doesn't help you heaps but I've got an OBD data logger from ebay. Plug it in & just let it log, wouldn't know it's there. Probably the best way to see what happens when it plays up

[turbotrana]

I had a problem with a 2009 FG Turbo with it stalling at lights and the revs dropping when comming to a stop. I resolved mine but to cut a long story short I blame the way Ford tune the vehicle can make the return to idle a bit unsettling at times. Is your idle unsettling at times?

I don't have a full understanding of what is going on but I can make it not do it.

Mine would do it a bit when I would drive up an inclined drive then come to a stop. Now this probably will not make any sense to you but will put it out there for those that do.

When going up the drive the fuel trim would trim to take fuel out in closed loop. It would be maybe -7% fuel trim. Then you would come to a stop but the idle areas of the map like to be in the +tve territory and it cant trim down quick enough. Then you would find a 16+:1 air fuel ratio coming back to idle and the idle would struggle until it closed loop to stoich. Otherwise the trims in most situations were +/-3

So now when I tune I make sure I avoid this situation to make sure I have +tve trims around the idle/light load areas. Did that make any sense!!!!.

My story is a bit more complex than that but you may be barking up the wrong tree if you think its mechanical is my main point.

[Rab]

Probably not the same, but I had very, very intermittent, very, very rough idle occasionally when pulling up at the lights etc Felt like it was going to stall maybe once or twice a week

Months going back and forth to Ford to fix under warranty - they never found it, even had the "specialists" looking into it.

Could never replicate it when I wanted to

Turned out it was an out of balance/dodgy thermo fan - intermittent because they weren't on 90% of the time. Wasn't even a hard drive, just a random cruise to the shop or run on the highway could trigger it though.

The blokes at Pitlane finally diagnosed it when I'd all but given up hope - still took a couple of returns to Ford before they finally agreed and put in a new one.

[f-wolf]

TPS Throttle Position Sensor ??

http://toofin.org/symptoms-of-a-bad-throttle-position-sensor/

Edited 03/10/14 07:31 AM by f-wolf

[xr6tForMe]

Re. "Removal of head is not covered"

It has been a long time since my basic legal studies, but I don't believe the principles could have changed, so:

They need to fix it regardless of what the fix is.

If it is "pull the head off", or "replace the diff", or "replace the engine", then that is what they have to do and cover.

Putting it another way, why would everything else they have done be covered, but not the head removal?

The obd data logging sounds like a good idea to me. It could possibly show a sensor is intermittently going bad.

They CAN fix it -they just have not put enough effort into it yet.

[elie]

I have the same problem I have had the car since new and from day one I have had the problem and only now that the car isn't under warranty I have taken it to my preferred mechanic and has found that the car on cold start runs on 5 cylinders with cylinder no. 4 cylinder not firing and as soon as the engine reach's warm temp. it runs smooth and all 6 cylinders

Edited 29/03/16 11:27 AM by elie

[Craig 351]

Get a can of Subaru upper cylinder cleaner. get engine up to temp turn engine off. spray half can thru throttle body directing hose towards front & rear of manifold. start car for about 5-10 seconds just enough time to get cleaner sucked into cylinders then turn off. spray rest of can into manifold as before directing flow front & rear let sit for 10 minutes. than start car it will run rough so give a little bit of throttle as cleaner is burnt off it will run like normal. this cleans the inlet tracks, valves intake & exhaust & piston crowns you car will idle better have better fuel economy & will be more responsive.