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        General >> Problems >> 2.3 valves sticking
        
(Message started by: chico40 on Jul 10^th, 2006, 6:32pm)

Title: 2.3 valves sticking
Post by chico40 on Jul 10^th, 2006, 6:32pm

Hello everyone, this is my first post so go easy on me!
First of all I have to come clean - I don't have a Scorpio, I have a Galaxy. But I do have the 2.3 engine as fitted to the Scorpio. I'll try to make this as brief as possible.
Car was difficult to start and was misfiring. Removed plugs, gap on no.3 was closed right up. Reset gap, still misfiring. Suspected/leads/coil packs but put car to local garage for second opinion. Garage diagnosis was sticking valves. They dosed it with petrol and oil additives and got it running much better and reckoned it would get better as it was used. Car conked out on way home but managed to limp home on low revs. With a bit of persistance got it running again much better but there was still a misfire. Phoned garage next day and they wanted to take head off for decoke but suggested I check plugs again. Checked plugs and gap on no.4 was closed right up! Spoke today to a very nice man at NGK who had never heard of a plug closing up by itself and reckoned only plausable explananation was that something had struck it.

Is sticking valves a recognised problem with the 2.3? (correct oil was used)

Any ideas what is hitting the plugs? As far as I am aware the head has never been off. I don't know the head design, is there much clearance between the piston and plug at TDC? Is it possible the pistons are so coked up that they can hit the plugs? Again as I don't know the design is it possible a stuck valve can strike the plug?

Apologies for infiltrating your forum, I have tried on a Galaxy forum with little response. I have also searched on here and found little reference to my problem.

Thanks in advance

Title: Re: 2.3 valves sticking
Post by Octavian_P on Jul 10^th, 2006, 6:52pm

Hello, and....wellcome :)

I happen to own a 2.3 engine scorpio and till now i have never ever heard about something like this, nor sticking tappets, nor spark plugs that gap themselves. How old are the spark plugs, maybe they have had it and need replacement.

Title: Re: 2.3 valves sticking
Post by Kjetil S on Jul 10^th, 2006, 6:55pm

Maybe the wrong plugs are fitted? I believe Scorpioen84 got a wrong set recently, where the plugs were too long. Luckily he noticed before it was too late.

Title: Re: 2.3 valves sticking
Post by chico40 on Jul 10^th, 2006, 7:11pm

Deffo the right plugs - confirmed by NGK.

Plugs have been in a while but not past their sell by date, anyway NGK state that gaps should open up slightly with age - they have never heard of a gap closing by itself

Title: Re: 2.3 valves sticking
Post by sector-9 on Jul 10^th, 2006, 10:08pm

If the plugs are being hit by something then I'd expect there to be marks on the electrode and it'd have to be such a high level of carbon build-up that the compression ratio would much higher and the engine pinking and possibly overheating - a compression check will show this. Of course the easy way to tell is to gap them correctly, fit and turn the engine over a few times by hand then take them out and compare. I don't think this is the problem though.

I'd definitely be tempted to change the plugs, possibly for a different brand, and see how you get on.

Darren

Title: Re: 2.3 valves sticking
Post by cossie_al on Jul 10^th, 2006, 10:51pm

[quote

I'd definitely be tempted to change the plugs, possibly for a different brand, and see how you get on.[/quote]
[]
I had an old suzuki gs 750 when I put new plugs in (champion) I whent to kick it over and it locked. Checked the plugs against the manual and they were supposidly correct, fitted a set of the equivalent ngk's and all was fine.

Title: Re: 2.3 valves sticking
Post by hellblue on Jul 10^th, 2006, 11:44pm

I have NGK pfr6b in my 2.3 ........24mm from washer to tip of plug. YOU have got an air filter fitted ??. Take out the plugs & use a pen light, to look on the piston tops even a magnet pen. Have known lumps of carbon to shut plug gaps years back but not these days. Any noise from engine??Take off the pipe from air filter to throttle body, open throttle,anything in iether??

Title: Re: 2.3 valves sticking
Post by jonnycab on Jul 11^th, 2006, 12:45am

If it were a very high carbon build up then I would imagine the engine would be pinking very badly. Also, to build up so much carbon in a reasonably modern engine then it must have been running rich for a long while. The mpg would also be pretty poor I would have thought.
If the vehicle has been serviced properly at the right intervals then the mixture shouldn't be rich & carbon shouldn't build up that badly :)

Title: Re: 2.3 valves sticking
Post by Spannerdemon on Jul 11^th, 2006, 7:34am

When you say "Closed right up" is the gap closed because of deposits of carbon or oily deposits, or do you mean that the electrode has actually been physically closed?

As your guy at NGK has said, the only explanation for the second reason is that something must have struck it.
Whether crown of the piston , valve, deposits on the top of the piston or whatever. Electrodes simply can't close themselves that quickly.

Then I read your post again.

You say that first the No.3 cylinder had a closed gap, and then you go on to say that after the garage had cleaned them and put them back it was No.4 cylinder had the closed gap.

That is LOUDLY suggesting to me that you have three plugs which are correct, and one which is not (possibly fractionally longer), and that it got put back into a different plug hole (No.4) after being re-set. I'd check ALL your plugs to make sure they are all the same. I'd also go along with what has been said here, and change the plugs anyway. A difference of only a few mm can be the difference between a smoothly running engine and an expensive engine rebuild. A set of plugs is dirt cheap compared to that! :o

If, of course, the gap is closed up because of 'muck' then you're going to have to take the head off to investigate further.

It's also possible that NGK have inadvertantly suggested the wrong plugs for your particular engine. Check, and double check, for the same reasons. :)

Title: Re: 2.3 valves sticking
Post by chico40 on Jul 11^th, 2006, 8:52pm

Thanks for all replies so far.

The plug gap was physically closed i.e. the side electrode was touching the centre electrode. I fitted new plugs after discovering the gap closed hoping it was a duff plug. Haven't done many miles yet but fingers crossed, car seems to be running ok now. Plugs (new and old) are NGK PFR6B-11's. Old plugs appear to be identical when measured with a vernier. Plug holes are so deep in head that looking with the naked eye may be difficult but I'll have a go - may even see if I can borrow a borescope from somewhere. Common factor is that plug gap closed while being run with sticky valve(s) though why it would happen I can't figure out. MPG has never been that great (mid 20's) but I guess it's all I can expect for a big car.

Title: Re: 2.3 valves sticking
Post by jonnycab on Jul 12^th, 2006, 12:13am

Going by what Spanners suggested about the 3rd plug being put back in the 4th plug hole & bending up again. How easy was it to reset the gap on that plug?
It could be that the electrode has a very minute hairline crack where the bend is, or it could just be particularly weak at that point.