Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: iansoutham on 28 August 2014, 21:11:34

Title: Slight misfire
Post by: iansoutham on 28 August 2014, 21:11:34
Guys

Just after a second opinion if I may please?

Randomly, and only when starting from cold, i.e. overnight or left all day @ work, the car starts fine but has a slight misfire for a few seconds, which stays if you rev the engine lightly. It then clears itself and runs fine. It does not do it every day, or even every time you start. Weather does not appear to make much difference to likelihood of it happening.

Water level is not going down, the spark plugs are recently changed and when removed, were dry and evenly coloured. Fuel economy is good (23-25mpg round town and 40mpg+ on a run.

The car is an X20XEV MFL with slushbox.

There is no water in the oil, it does not appear to smoke from the exhaust. Short of me dragging it into work for a sniffer test to confirm headgasket situation, or swapping HT leads out for new set (have not checked on an ohms check, but may do over the weekend).

Thoughts?
Title: Re: Slight misfire
Post by: ffcgary1 on 28 August 2014, 22:55:49
Could just be the start of DIS failure or a lead showing its age, these are the starting areas for misfire symptoms.
Title: Re: Slight misfire
Post by: iansoutham on 30 August 2014, 18:39:33
Well, I have put a nice new set of leads on today. Tomorrow will be the check and if still there, I'll swap the coil pack with the Cavalier one and try again
Title: Re: Slight misfire
Post by: iansoutham on 01 September 2014, 20:12:25
Looks like I need to swap the coil pack over. No misfire yesterday and none this morning, but misfire from cold for about 5 seconds until it cleared itself this afternoon after work.
Title: Re: Slight misfire
Post by: iansoutham on 02 September 2014, 20:02:05
Coil pack is swapped, and what a right, diddly, awkward place that is in on the 2.0 engine.

Next is to see if it works
Title: Re: Slight misfire
Post by: iansoutham on 05 September 2014, 18:30:43
Well, for anyone that is interested, the answer has been found.

After checking everything else and checking things like the coolant temp sensor readings on a Tech2, I put it into work this afternoon and borrowed the block tester. Lo and behold, it went green after a short period. Looks like the head gasket is starting to weep.

Oh well, another head to be removed.
Title: Re: Slight misfire
Post by: Broomies Mate on 05 September 2014, 19:49:53
Sorry to hear that mate, but someone of your knowledge and ability will have it ticking over smooth in a few hours.

Best of luck!  :y
Title: Re: Slight misfire
Post by: iansoutham on 05 September 2014, 20:20:27
Sorry to hear that mate, but someone of your knowledge and ability will have it ticking over smooth in a few hours.

Best of luck!  :y

Wouldn't say I am looking forward to it. Was bad enough doing the same on the Cavalier, and that had easier access. TBH, I am thinking of putting a small amount of a liquid radweld type product in, getting the bits over the period of a month, including a spare head and then do it when I feel like it.