Something wrong on idle after huge service...

220316 · 4th February 2015, 10:35

UPDATE:
A faulty spark plug was to blame, it had a very small crack and was overlooked due to the plugs having just been replaced!

Year: 2005
Model: ZT
Engine: 2.5L V6 Petrol
Mileage: 104,500 KM

Hey guys, after just having the major service done (with a tonne of extra things also) I have noticed an odd sensation at idle. I'm no expert but it feels like it's misfiring, or stuttering. I can feel it throughout the whole car and the engine almost seems to stop for a millisecond before continuing on.

This only happens for the first 5-10 minutes of running (it seems to clear up and run fine after about 10 mins)
This only happens when the car hasn't been run for at least 30 minutes (doesn't matter if the engine is still warm though, still does it)
Have just had a major service with new inlet manifold, timing belts, water pump, spark plugs, idler pulleys & thermostat + housing.
The problem wasn't apparent before the service was done

Here is a link to a video of the issue occuring which I recorded after fitting some ridiculously bright reverse lights. You can here the exhaust pausing/stuttering, as I mentioned earlier when behind the wheel you can feel it!
https://www.youtube.com/watch?v=UHmCNSjoEBE

I've only had my ZT for a few weeks and have spent far more coin than I had ever intended.

suffolk boy · 4th February 2015, 10:39

if your car was ok b4 the work done it the work may have caused the issue.so my money is on a air leak from the new manifold.or the valve timing is a tooth out.spray around the inlet manifold with wd40 and see if the engine note changes

kaiser · 4th February 2015, 11:20

Are you also loosing water?

Avora · 4th February 2015, 11:27

Have a quick check of your oil level when the engine is cold. Worth a check, and can easily be misread on the V6. Otherwise might be the timing off as said before.

220316 · 4th February 2015, 11:33

I haven't checked any levels other than coolant which appears to be just fine.
There are no drips that I can see, although I did notice a damp-ish spot near the washer-bottle (I'm assuming that's what it is) when I removed the front bar today, however it had been raining earlier and I assumed that was the cause.

Here is the area that appeared damp. Around the circled area, but under the bash-bar.

Number 6 · 4th February 2015, 11:36

The OP states that it only manifests itself on start up and goes after 5 or 10 minutes running,so I would not think it would be the timing out.If it was it would happen from start up and be there all the time surely

I would think inlet manifold leaking into the cylinders

Avora · 4th February 2015, 11:37

Hmm, I agree. Perhaps a coil is overheating?

220316 · 4th February 2015, 11:38

Quote:

Originally Posted by Number 6

The OP states that it only manifests itself AFTER 5 or 10 minutes running,so I would not think it would be the timing out.If it was it would happen from start up surely

Maybe I wrote it poorly, but the issue happens for the first 5-10 minutes of running. After that amount of time all seems to be fine.

*EDIT*
I have just re-worded the original post, apologies for any confusion.

Number 6 · 4th February 2015, 11:43

Quote:

Originally Posted by AAY441

Maybe I wrote it poorly, but the issue happens for the first 5-10 minutes of running. After that amount of time all seems to be fine.

*EDIT*
I have just re-worded the original post, apologies for any confusion.

No it was not you I miss read it

bl52krz · 4th February 2015, 19:05

could be a spark plug breaking down or a coil pack. I would go for the cheap option first.... Spark plug. Had this on my SD1, also different time a spark plug lead two weeks old was breaking down.

4th February 2015, 10:35	#1
220316 Regular poster Join Date: Jan 2015 Posts: 47 Thanks: 11 Thanked 8 Times in 3 Posts	Something wrong on idle after huge service... UPDATE: A faulty spark plug was to blame, it had a very small crack and was overlooked due to the plugs having just been replaced! Year: 2005 Model: ZT Engine: 2.5L V6 Petrol Mileage: 104,500 KM Hey guys, after just having the major service done (with a tonne of extra things also) I have noticed an odd sensation at idle. I'm no expert but it feels like it's misfiring, or stuttering. I can feel it throughout the whole car and the engine almost seems to stop for a millisecond before continuing on. This only happens for the first 5-10 minutes of running (it seems to clear up and run fine after about 10 mins) This only happens when the car hasn't been run for at least 30 minutes (doesn't matter if the engine is still warm though, still does it) Have just had a major service with new inlet manifold, timing belts, water pump, spark plugs, idler pulleys & thermostat + housing. The problem wasn't apparent before the service was done Here is a link to a video of the issue occuring which I recorded after fitting some ridiculously bright reverse lights. You can here the exhaust pausing/stuttering, as I mentioned earlier when behind the wheel you can feel it! https://www.youtube.com/watch?v=UHmCNSjoEBE I've only had my ZT for a few weeks and have spent far more coin than I had ever intended. Last edited by 220316; 18th April 2015 at 11:44..

4th February 2015, 10:39	#2
suffolk boy This is my second home fiat panda Join Date: Sep 2009 Location: haverhill Posts: 6,720 Thanks: 96 Thanked 586 Times in 526 Posts	if your car was ok b4 the work done it the work may have caused the issue.so my money is on a air leak from the new manifold.or the valve timing is a tooth out.spray around the inlet manifold with wd40 and see if the engine note changes __________________ fiat panda 1.2 eco

4th February 2015, 11:27	#4
Avora Loves to post MG ZT-T 190 Join Date: Jul 2014 Location: Penrith Posts: 441 Thanks: 89 Thanked 69 Times in 56 Posts	Have a quick check of your oil level when the engine is cold. Worth a check, and can easily be misread on the V6. Otherwise might be the timing off as said before. __________________ ZT-T 190

4th February 2015, 11:36	#6
Number 6 This is my second home Rover 75 tourer Club CD/Limo Tints Join Date: Nov 2008 Location: Meneac Posts: 6,759 Thanks: 5,007 Thanked 1,609 Times in 869 Posts	The OP states that it only manifests itself on start up and goes after 5 or 10 minutes running,so I would not think it would be the timing out.If it was it would happen from start up and be there all the time surely I would think inlet manifold leaking into the cylinders __________________ ] "I started out with nothing, and Ive still got most of it left!" Last edited by Number 6; 4th February 2015 at 11:40..

4th February 2015, 11:37	#7
Avora Loves to post MG ZT-T 190 Join Date: Jul 2014 Location: Penrith Posts: 441 Thanks: 89 Thanked 69 Times in 56 Posts	Hmm, I agree. Perhaps a coil is overheating? __________________ ZT-T 190

4th February 2015, 11:20	#3
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	Are you also loosing water?

4th February 2015, 11:33	#5
220316 Regular poster Join Date: Jan 2015 Posts: 47 Thanks: 11 Thanked 8 Times in 3 Posts	I haven't checked any levels other than coolant which appears to be just fine. There are no drips that I can see, although I did notice a damp-ish spot near the washer-bottle (I'm assuming that's what it is) when I removed the front bar today, however it had been raining earlier and I assumed that was the cause. Here is the area that appeared damp. Around the circled area, but under the bash-bar.

4th February 2015, 19:05	#10
bl52krz This is my second home Rover 75 cdt club + Rover 2.5 KV6 Conni SE Join Date: May 2008 Location: Birmingham Posts: 11,401 Thanks: 6,587 Thanked 2,262 Times in 1,729 Posts	could be a spark plug breaking down or a coil pack. I would go for the cheap option first.... Spark plug. Had this on my SD1, also different time a spark plug lead two weeks old was breaking down. __________________ Great Barr, Birmingham.