Car Surging At Idle When Warm? Check This

[towsw001]

Hey guys,

Now im assuming that the problem im about to describe could also present in other ways, and Im not the most knowledgeable about cars but I know enough to describe my problem in enough detail to help anyone else who presents with a similar issue. The reasoning im posting this is because I scowered these forums looking for an answer to my problem and couldn't find anything that worked. Also since fixing the issue, ive learnt that it has been pretty uncommon thus far. My car has just ticked over 100,000km so it may be something that shows itself as cars clock up more kms. In saying that, im sure this has also happened before in different ways, but this is my story. Car is 2008 G6ET with 100,000kms, no modifications. Also posted in g6et section but figured would be easier to find here.

Also, I still recommend testing the easier and cheaper items first, such as coil packs, inlet manifold gaskets, fuel pumps and filters. Also sometimes just taking your car into ford or another decent mechanic to hook up a computer will get you on the right direction. However, this didn't work for us. Even fords computers couldn't pick the issue. Anyway, read below for how it presented.

1. Car started surging at idle after a short drive for no particular reason. Hadn't given it a squirt (on that particular drive), although at the time I only had the car a short time so had tested the waters a little bit. Turned it off, restarted, still surging, crapped myself (in that order).

2. Now when I say car surging, I mean a proper shaking of the engine, and hence the car, more noticeable when in drive for obvious reasons. RPMs were stable at 550-600rpms, although did hesitate slightly when throttle initially opened. Surge disappeared after about 1000rpm and hence drove relatively fine. No major loss in power that I noticed at the time.

3. Car didn't surge when cold. Took about 3-5 mins for car to start surging, which increased gradually over about 30secs to the point I was having nightmares about it. Important note.

4. Changing of simple stuff like coil packs, fuel filter, inlet manifold gasket (which did have a leak and bolts were loose) failed to make a difference.

Answer: Variable cam timing solenoid and phaser (for me anyway) (exhaust)

We did eventually get a computer code to show up (will chase up the actual code soon) which pointed us to the solenoid. We replaced it which didn't fix the problem. However when we placed the solenoid in another FG we got the code to come up. So replaced the phaser which stopped the timing issue and hence the surging.

After my mate being on the phone to the engineers in Melbourne, we discovered that apparently, only one of the solenoid and four of the phasers have ever been sold by ford. Now this is what ford said, unsure of truth. However after posting this might find some others had the same issue.

Now the reason the issue didn't arise when cold is because as many would know the solenoid and phaser work on oil pressure, hence become evident once the car warmed up.

Hopefully this helps someone trying to diagnose their issue, if not rule one this possibility out.

[nick d]

Sounds like you have checked all the areas that may be checked.

I know my 500hp Ckleveland had a camshalft problem when 600rpm idle or less, knocking shaking meant complete pulldown but was only the cam thank god but you may be right with your answer.

Maybe some of the others guys sponsors might be able to help. Would like to hear the end result.

[towsw001]

It's all sorted now. It definitely was the phaser and solenoid. However as it turned out this wasn't the cause of the problem. They failed trying to compensate. The original problem was a mistake when the engine was put together. The timing was slightly out and hence the variable timing was compensating up until now. Once this failed the surge appeared due to the bad timing.

And now that it is fixed, wow do I notice a difference. Goes so much harder.

[ratter]

the timing would have been correct from the factory, it is common for them to jump teeth

[aussie1926]

My Old xr6 ute had a simular proble it had the cams tight in there holdeer things ford replaced the whole head under warenty

[rbjet]

My car started doing a similar thing yesterday but then it was fine today. Then I went to give it a bit of stick and traction control kicked in pretty hard and the car started to run like crap and surge. I took it home and turned it off.

Reckon I might have a similar problem mick?

[turbotrana]

any more details on codes, part numbers and prices on the solenoids and phasers

[nick d]

From reading all of the above, just curious how many kms have most of the cars that you guys own are surging?

Curious cause I have herd all sorts of kms that this can happen, is it becoming very common with these cars.

[rbjet]

My coils have done less than 20,000km but they aren't genuine.Checked them today and number 3 is dead.