changing plugs and leads, not as easy as it should be!

vibe666

bought a 97 fiesta and got it checked out before we bought it. performance at the top end is sketchy at best, but i was told that this was down to warn plugs and leads.

anyway, decided to get a haynes manual and have a go myself. my stepdad is a mechanic (although not in ireland unfortunately, or i'd be going to him) so i've seen him do plenty of this type of thing, and habve helped on several occasions so i thought i'd be grand.

the only problem is, that i can't get the plugs out (they seem to be rusted into their sockets, and the distributor cap is behind the engine almost underneith the head where i can't get to it without jacking the car up and sliding under it. not somethign i enjoyed (just had a quick look) as the sump sits right on my chest, and i'd pop like an orange if the jack (the noe for changing tyres) decides to go on me.

so anyway, this is me just about given up on this little project, and wondering if anyone knows a good/cheap mechanic in either the blanch area or the city centre who could fit my nice new leads and plugs for me?

thanks.

Dades

Yeah you don't want to snap off the plugs trying to get them out. Big problem if that happens. Better to give it to a mechanic who can use some solution or heat or something to get them out.

And I wouldn't climb under a car to mess with anything unless it was on a pair of jackstands. You can get a pair pretty cheap in any motor store, and might just avoid getting popped like an orange.

Only mechanic I know near town is in Ringsend (not your neck of the woods I suspect).

andyg

if you went to the trouble of getting the Haynes manual you might as well try and change them yourself. The plugs can be loosened by spraying some WD40 around them. Wait a few minutes and they be easily removed with a spark remover.

The problem of the jack giving way can be solved by placing a cavity block (or a large block of wood) under each wing of the car when you jack them up.

Squirrel

I definately wouldn't be under a car held up by a jack, you should get a pair of axle stands, WD40 could work but otherwise bring it to any mechanic, they'll know what to do

vibe666

good advice andyg, might give it another go tonight.

some WD40 and i'm gonna go and get me a bigger spark plug spanner, as the one i have is just a cheap one. might be worth investing in a proper torque wrench maybe. only thing is i'm not going to use it after i've swapped the plugs till next time. could do with some compressed air too to blow out the sockets properly. managed to get 95% of the crap out with a screwdriver and a good hard blow, but i don't want to drop crap into the hole.

milltown

No need for a torque wrench for this imo, especially if you only plan on doing it the once. WD40, and a half decent plug wrench/socket should do it. If you have been trying with the engine cold it may be worthwhile warming it up. The alloy head should expand more and quicker than the steel thread on the plugs. Just mind your hands though. And always pull towards yourself!

vibe666

i'd been using it warm, but i'd driven home about an hour earlier, os maybe i should try running it for a couple of minutes from cold and try that way.

BrianD3

Soak the plugs with WD40 and leave it a few hours to penetrate. For loosening the plugs try a decent length T-bar + extension + deep socket. You'll get more leverage with this than with a normal plug socket. Don't use a torque wrench, it's not the right tool for the job. Also are you sure the plugs have rusted in, they might just need more torque to remove than you have anticipated. I remember the first time I changed plugs I was surprised at how much force I needed to use.

But I dislike changing plugs because like you I worry about a number of things happening - breaking a plug, crossthreading it, dropping something in through the plug hole. I think with experience you just get a "feel" for the right way to change plugs without any of these disasters happening.

vibe666

so if i went into halfords get some WD40 and asked for a tbar, extension and a deep socket i should be okay? i could do with a couple of those little metal ramps that they sometimes use, but i'd bve nuts to go and buy some just for that. maybe i could find a high curb somewhere handy!

AMurphy

Does this have a cast iron or Aluminium head?.
They could rust into a CI head, or corrodeinto an Al. one. Either way, First see if you can vacuum out the holes with some large diameter plastic tubing taped to the end of a house vacuum.
Then get the engine as hot as you can bare to handle and while still hot crack them loose, then when it has cooled down to warm apply the wd40 or penetrating oil and work that in.
You could run the engine up to hot again, to make them loosen up a little in the threads.

Get a professional or good quality plug socket, extension and "T" or breaker bar.
While you are in the store, get some antisieze grease also, u'll need it for the new plugs. Also if they have them, get a plug thread dressing tap, and 6" of stiff rubber tubing that you can stick the insulator of the new plugs into, about 1/4" bore.
And some insulator or electrolytic grease.

After you get them loose, vacuum or blow out the debris again and then remove them completely.
A few bits of dust may fall in, dont worry over it, it will blow through pretty fast, however the little nipple at the top of the plug is another matter.

if you want to make a cheap plug thread dressing tool, take a plug with a clean thread and cut down beside the electrode with a saw, making 2 slots along the length of the thread. Remove the burrs with a needle file, blow the dust & metal filings out of it and there you have it, run this in and out of the plug hole and the slots will pick up the debris.

I'll leave you to figure out and set the electrode gaps.

Apply antisieze grease to the threads of the new plugs, if not already coated.
Stick the 6" of tubing over the top of the new plug. Holding the plug with the tubing, thread it into place. By using the tube and your fingers, you will never X-thread a plug. Once in the proper thread, you can screw it down all the way and require the "T" bar only to tighten them. btw, some plugs, with 90° tapered sealing faces do not require torquing, to 90° from hand tight.

I'll leave you to figure out the plug wires bit, however before you attach them to the plugs, get one of the old plugs and smear the insulator with the dielectric/insulator grease, then insert andd coat the inside of the plug connector insulator. Then attach to the plug in the engine. Do the same with any insulator shrouds that may exist at the dist cap end.

byte

I'd guess it'd be important not to swap the wires when replacing either, or timing might be off if wired from distrib cap to plug wrong?

milltown

byte wrote:

I'd guess it'd be important not to swap the wires when replacing either, or timing might be off if wired from distrib cap to plug wrong?

Correct!!

Also, worrying about plug gaps is pretty much a thing of the past. Modern plugs are pre gapped, just have a quick look to make sure thay haven't got a knock that has closed the gap. Again this is pretty unlikely as they should come with a little cardboard tube around the end to protect them.

AMurphy

Many of them are pre-gapped, but not all, And many of the dist caps and wires are perenumbered, but again, not all. So don't assume they are pregapped, unless you bought them pre-gapped.

vibe666

ended up getting a local machanic to do it for me. €50 not too bad if you ask me to save the hassle. i'd have spent that on tools i reckon.

running like a dream now anyways, so thanks for all the help though.

something i did notice tho, was that the difference in gap on the plug i did manage to get out and the new ones was huge (about 3 times wider on the new one).

got it fixed anyway, and didn't cost much.

thanks again.

fletch

What engine is in the Fiesta? I've a '98 Escort and it has a flat spot about 4,500 revs. I'm wonderin would replacing the leads help this?
I've already replaced the plugs with NGK V-grooves and noticed it runs smoother.

AMurphy

vibe666 wrote:

.....
something i did notice tho, was that the difference in gap on the plug i did manage to get out and the new ones was huge (about 3 times wider on the new one).

......QUOTE]

Thats what happens when they have not been either adjusted or changed in ~20Kmls. Leave them in there long enough and the tip erodes completely....

The larger gap makes them harder to spark, hence misfiring goleor, particularly on a lean mix.

Capt'n Midnight

The Atheist wrote:

Yeah you don't want to snap off the plugs trying to get them out. Big problem if that happens. ...
And I wouldn't climb under a car to mess with anything unless it was on a pair of jackstands. You can get a pair pretty cheap in any motor store, and might just avoid getting popped like an orange.

You're not wrong there, memories of a unscrewing half a spark plug, - the core came out, :eek:

Argos also do the stands, and make sure that you can't get caught if the car rolls down off the stand !

sirlinux

if it's a 1.3 fiesta with the endura engine they have a common habit of the block rusting a little and the plugs sticking like you discovered, dealers have been told to put copper grease on the grooves of the plugs to solve the problem!! Anyway loosen up and tighten the plugs a few times a year should stop it happening, i know a poor unfortunate who ended up needing the plugs drilled out of the head after they stuck and snapped.

AMurphy

sirlinux wrote:

..... i know a poor unfurtunate who ended up needing the plugs drilled out of the head after they stuck and snapped.

Nasty. I thought I'd end up that way once, i was doing a DIY tuneup for a friend, one very difficult to get at plug on the rear bank of a X-ways V6 broke. Eventually I got it out, without stripping, etc.
Only on inspection did I figure out why. It would appear everyone prior to me, had either ignored or given up on removing that single plug, they obviously knew the difficulty, the car was probably running on 5 cyl for years before I got it.