Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: kcl on 10 January 2012, 09:30:23

Title: Loose spark plugs
Post by: kcl on 10 January 2012, 09:30:23
I was tracking down another coolant leak on my 2,6, I suspected it would be the oil cooler which I had to "repair" in the summer because any new parts were not available on Finland etc.. (the leak appears to be the DEFA block heater, new seals ordered, hoping to have it sorted). So, to my issue: while plenum was off I checked the spark plugs, which I had replaced some 25000 km ago (and for sure were triple checked for correct fitment and torque) and I thought to look at them just for curiosity. And what I found  :o :o :o Number six cylinder plug had come loose and the whole plug and plugwell were black!!! I had read here that plugs work loose but had never really thought that it would happen to me!

Makes me wonder how many Omegas, given the 120 000 km plug change interval for quads, have one or more plugs loose causing misfire, poor fuel economy, failures to coil packs etc WITHOUT anyone noticing it.

So, do make sure you check the plugs and make sure to have them torqued up corretly at least once a year to avoid this kind of a mess. Luckily my coil pack seems to be ok, it was just painful to clean the plug well from the black scrud.
Title: Re: Loose spark plugs
Post by: feeutfo on 10 January 2012, 09:34:04
Yes have found a couple loose recently on various members cars, including my own a while back. 25nm i believe?
Title: Re: Loose spark plugs
Post by: kcl on 10 January 2012, 09:36:31
Yes have found a couple loose recently on various members cars, including my own a while back. 25nm i believe?

25Nm IIRC. Also the good old method, 1/4 turn more when the washer meets the head is still good... But why they come loose? I've never ever seen a loose plug on any other car and I have had dozens... though they have had only 10-20 000 km intervals for plugs...
Title: Re: Loose spark plugs
Post by: Marks DTM Calib on 10 January 2012, 10:04:14
I have seen the quads loose before and this is one of the reasons we recommend ignoring the 80K service interval (as they work loose long before this is reached).

I cant recall seeing the same on a twin but cant see why it would not happen.

I always fit the plugs to torque and then go around a econd time to check, they normaly nip up a little further (I suspect the seal ring compresses slightly)
Title: Re: Loose spark plugs
Post by: 05omegav6 on 10 January 2012, 10:22:59
Quote
Probably coincidence, but fitted GM twins to mine at 160k and within 2k it had destroyed one plug and all the others were loose

I change the plugs every 20k, and apart from that one incident, always use Quads. You pays your money...

:y
Title: Re: Loose spark plugs
Post by: feeutfo on 10 January 2012, 13:03:25
Cookie monsters where twins, pots 1 and 3 loose. The rest had water contamination as well as oil and where a bugger to get out with rusty threads. Pot 6 especially as its under where the scuttle leaks.