Somebody told me that vinigar is good as it disolves rust, I am not sure though. And yes it is an iron head.
With HCS/Endura engines I now have a policy with rusted plugs to leave them till they develop a miss fire, the chances are in my low milleage ownership the plugs will last the life of my ownership so it is not worth the potential hassle and expensive of a cylinder head repair just for sake of routine servicing.
Mine are rusted in, but there engine runs very sweet and not even a hint of a mis fire so I am leaving well alone!
|
|
Just wondered if plugs were treated with copper grease ( when the car is fairly new) if this would alleviate this problem, or is there a risk of plugs unscrewing themselves and blowing a hole through the bonnet ???
|
|
|
First of all Dont Worry !
I broke two out of four plugs on a Ford Ka, same engine as used in some of the older Fiestas. The problem is that the sparkplugs have tapered seats instead of the more normal washer arrangement and they become rusted in. WD40 will not work, its not really a freeing agent in the way that Plus-Gas is but even Plus-Gas didnt work for me.
I read all the various postings about how to remove these broken plugs, some quite drastic including using a MIG welder. I thought a lot about how to do this, here is my step by step cautious method which turned out to be very successful.
I start from the position of having broken the plug. The top part of the insulator is in my hand, the rest in sitting in the plug itself.
- Make up a vacuum hose small enough to go down the spark plug hole. I put a rubber plug into my normal vacuum cleaner hose, drilled a hole in it and inserted a length of small diameter clear plastic piping.
- Use a small masonery drill and a sharp pick to chip away at the ceramic insulator in the broken sparkplug. I tried turning the engine over to see if it would blow out the ceramic insulator but that didnt work for either plug. On the other hand, as soon as I had chipped away enough to expose the electrode I was able to grip that with a pair of long nose pliers and lift the electrode and the ceramic out in one go. In the case of the other plug I had to chip away much further until I got down to the inner shoulder at which point I was able to draw out the electrode and the last bit of the ceramic dropped down to be held by the earth electrode. So no bits fell into the cylinder but I was careful to use the vacuum after every bit of chipping.
- Put a small twist of tissue down the open plug until it rests on the earth electrode so nothing else can fall down. (If the tissue should fall into the cylinder it will be burnt up anyway).
- Take a 12.5mm drill (B&Q sell that size) and drill down into the sparkplug a distance of about 9mm but definitely not more than 10mm. This measurement is made from the surface of the broken plug to the cutting edge of the drill, NOT the point of the drill. (Make up a rod with a sliding cable tie to act as a depth gauge). Drill a bit and then measure the depth and so on. I cleared swarf with the vacuum cleaner but also magnetised a 6 inch nail in order to lift swarf off the tissue paper at the bottom of the plug hole. (To magnetise a nail put it onto a magnet for an hour)
- the purpose of this drilling is to ensure that the upper part of the broken plug is thin-walled down to a point just BELOW where the plug seats into the cylinder. The 12.5mm diameter means that the drill will remain inside the plug body and will not break out and risk damaging the seating area of the cylinder head. The depth of 9mm ensures that the hole is drilled below the level of the seat but stops just above the threaded part of the plugs. The result is that the wall of the plug at this point is now only about half a millimetre thick.
- Then take a narrow cold chisel/punch/drift etc and bend the top of the plug body inwards. Its very restricted but I found as soon as I had got a bit of each side bent inwards and hence slightly opened from the surrounding cylinder head, the whole of the top half of the plug broke away at the thin walled part just above the thread which I mentioned above. It could then be lifted straight out.
- I removed the thread part of one plug (that still remained in the cyclinder head) by just sticking a screwdriver down into it and turning it out by by hand. The other plug was more stubborn and because of the previous drilling out and also the fact that the upper part had just been broken out, there is very little depth in the plug body before the internal shoulder narrows the internal diameter. So I took an 8.5mm drill and drilled out the shoulder to a point just above the piece of tissue paper. This was enough clear depth to hammer in my extractor and then the screwed part came out straight away, including the bit of tissue paper with one or two bits of swarf on it.
- With a fibre optic cable I checked the inside of the cylinders for any other swarf or debris but there was none to be seen but I stuck down my little vacuum tube just in case.
So the final result worked out well. That was a year ago and since then there has been no sign of any swarf in the engine oil or filter so I count it as a great success and much easier than taking the head off and sending it away to a machine shop.
|
Two more things to remenber,
1 Allways clean the area arround the plug before trying to remove it.
2 When removing the plugs, (Or trying to!) use a "T" bar, and not a ratchet. With a "T" bar you can use both hands so giving a more even force.
If we have them break, we put a good fitting bolt down the hole, and then weld it onto the broken end of the plug. Then use the bolt head to unscrew the remains of the plug.
We have never yet had to remove a head by using this method.
|
Hello all,
Thanks very much for the replies...!
>Just wondered if plugs were treated with copper grease ( when the car is fairly new) if this would alleviate this problem???
I believe it does - but I don't know whether this one has been treated with it. (But it will be once the plugs get removed!)
I'll go get some proper penatrating oil and air-cleaner to clean up before actual removal.
I think if they do break then its off to machine shop - i'm not a garage so don't have great skills or lots of tools to some of whats been suggested...!
Cheers all,
James
|
We also got my sister's Ka spark plugs out using the "fold over" method. It is only the taper seats that seize. Once you break the taper, the threaded part will come out unbelievably easy - as mentioned above, a screwdriver wedged in is normally enough.
The cylinder head corrosion on this Ka is horrendous. Big chunks of the head are literally flaking off.
|
Well James, I'm not a garage either but I do have a Black and Decker drill, a screwdriver, a hammer and a pair of pliers which is about all you need. Plus a vacuum cleaner.
One of the contributory reasons why these sparkplugs break is that they are often done up too tightly. For example, if you use a torque wrench to do them up to the specified torque (which is only 17 Nm) you'd be surprised at how 'light' that seems compared to doing them using a plug socket and handle.
A bit of copper grease on the seat might be a good idea for the future but make sure none of it goes onto the threads. Grease on the threads encourages overtightening without the operator being aware. Thats why (unless specifically instructed otherwise) bolts are always torqued up dry, ie without any grease on them.
|
Hey Claude,
Good advice - thanks
James
|
|
It's a fair time since I've worked on this engine and I've forgotten what the clearance is around the plugs. If there's enough see if you can get a well fitting ring spanner on them instead of a socket. This avoids some of the twist effect of a socket.
|
|
|
|
One of the contributory reasons why these sparkplugs break is that they are often done up too tightly.
Yep, people always blame the design for poor workmanship.
I just nip mine up 5 degrees from the point they hit the seat. Never had a problem.
|
|
Ive never had this problem either, although I in my time owned 5 cars with the Bobcat engine in... could it be because I spray the leads and plugs with WD40 regularly?
|
hello all,
Update : 48 hours soaking in WD40 and a 18" breaker bar proved just the job. Got them out cleanly.
Engine has been sick for a bit - the plugs were tarred black!
New plugs installed with copper grease on the top (not the thread!) - and torqued to 17nm as specified. The old ones were overtightened!
Cheers all
:-)
James
PS - oh - interestingly this is Fords suggested method arround this issue. Leave to soak in penatrating oil....!
Edited by Javalin on 29/11/2008 at 16:42
|
|
WD-40 is NOT a penetrating oil!!-and does not claim to be tho' some of it's clones do.
|
WD-40 is NOT a penetrating oil!!-and does not claim to be
Er, yes it does.
According to the WD40 website "WD-40 is the ultimate multi-purpose problem solver. WD-40 cleans/degreases, penetrates to loosen up stuck parts , prevents corrosion and is a light lubricant."
Cheers
DP
|
Well done! I think you had a lucky escape...
I know that WD40 is available in every sort of shop including your local newsagent and hence anybody would be forgiven for thinking that it is the answer for everything. But its not specifically a releasing agent unlike, for example, Plus-Gas. The clue is in the title, WD stands for Water Displacement and the product was primarily designed as a drying agent, preservative and inhibitor. Its a great product, the manufactuers describe as the "ultimate multi-purpose problem solver". But I always keep a tin of Plusgas for things that are REALLY stuck because it is specifically designed to release rusted fastners. It doesnt lubricate or preserve or do any of the other things that WD40 does so its chemical formulation can be much more targeted. (For example acetone which you wouldnt want to be spraying over your electrics).
|
perhaps the WD40 wasn't the key - maybe the breaker bar and being a bit more brave....
I like being lucky.
James
|
|
|
|
|
I am not having much luck with a similar problem I have with a plug on a Fiesta .
Now drilled out to 13mm and have the end electrode and remaining thread in the cylinder , I had any amount of attempts with a stud exractor and it was in solid. I now need a source of suitable helicoils for the Fiesta even at 13mm I fear its a drill too far , although a plug screws in , it would never hold or be gas tight. Assuming the hole needs to be a little larger yet to accommodate a new coil , I can then extract the remaining end of the spark plug and drill to size and fit coil.
So does anyone know where I can source these coils or can there be a nother plan?
Pat
|
|
yes thanks , I was only trying to avoid taking a cyl head off , but looks like the inevitable has happened, I have another engine with bottom end damage so it is the only way forward. I have not enough info on this engine , and looks like a haynes is necessary to complete some knowledge not available at this stage.
|
|
|
|
|
|
