dirt in the plug holes

I don't think it is a serious issue. Think of the old days when there were no boot seals at all. This is the way it is on my '89 LX and it has over 150k hard driven miles on it. There are more 5.0L engines with

200,000+ miles than I can count. My guess is water seepage might cause more harm than grit. Also, a small bit of grit in the combustion chamber would be blown into the exhaust so fast it wouldn't get a chance to cause too much damage.

I've changed a lot of spark plugs and this is completely different. The 4.6 has DEEP, almost vertical holes that are not much bigger in dia then the plugs. The 5.0 had wide open spaces by comparison and for the most part any grit near the plug would fall off as you unscrewed the plug. With the 4.6 if the grit does fall off as you unscrew the plug it's almost guaranteed that a good portion of it will fall in the cylinder. The two 4.6s I did the plugs on had about ten times as much grit around the plug as any other vehicle I've worked on.

Is that something a shot of compressed air couldn't blow out before the plug is removed?

Occasionally, we will see some pieces of grit that can wiggle it's way to the bottom of the hole and wedge itself in between the spark plug and the head - defying all efforts, it would seem, of removal. However, a conscientious worker can remove even the most difficult pieces with common sense and patience.

The usual process (for me, at least).... Blow the top of the engine clear of dust and grit. Remove the COPs and blow out the holes and inspect. Any that have debris, back the plug out one turn and blow again. If there is anything left, I use a piece of thinwall tubing that fits down the spark plug well - serations are cut in the end of the tube so it resembles a very deep hole saw... done deal...

Now, a few side notes.... I don't know why it is, but the moment we start discussing automotive service techs, so many people "expect" that there is an abject lack of integrity. When I need to spend extra time clearing the plug wells of debris, I expect to get paid for my time.... but I will be regarded as a thieving asshole because another shop would have done the job cheaper. OK, so I don't clean the debris out of the plug well (bacuase someone wont pay the extra time), I am now a careless, thieving asshole because, I suppose, the shop down the street wouldn't have found the dirt that I did (amazing how that works).

There are three main reasons why dirt and grit can migrate into the plug holes... In our area, the top of a work vehicle engine often resembles a swamp as dirt and water are forced up on to the top of the engine. As the engine cools, dirty water is drawn into the plug well. A second way involves the careless use of a pressure washer which can drive the dirt into the plug well and the third is failing to practice good housekeeping at the beginning of the job.

I don't think a tech is any more likely to ignore the presence of debris in the plug well than a DIYer.

FWIW, if some small debris does escape the watchful eye, it isn't going to cause any more damage than the errant pieces of carbon that pass through our cylinders every day.... from pieces that flake off the piston and valve stems, to those pieces that are carried through during times of EGR flow.... This is no reason to ignore the pieces that we do see, but it adds balance to those pieces that we don't....

The newer engines can get more grit than the older ones but like Jim stated a little diligence will take care of most of the problem. Mechanics probably see this all the time since most new cars have these types of plug arrangements. I doubt many of them let too much, if any, dirt in the combustion chamber. This advice is better steered at the DIY'ers as they have little experience changing plugs. Plus this is not a task that one completes on a regular basis. Most plugs in newer cars nowadays are good for 100,000 miles easy. Besides, a little grit falling into a combustion chamber isn't going to be the cause of an engine rebuild. It is good that you made us aware of this though.

Michael is quite right... when I first entered this trade, the spark plugs would come out of a car pretty much twice a year.... along with points and condenser. We would clean and regap the plugs but, more often than not, replace the points and condenser... though I've filed more sets of points than I care to remember.

These days, it is rare for our shop to change points (this is SuperDuty diesel land, up here).... It's been about three years since I last had plugs out of a motor in the shop....

One thing worth mentioning, when it comes to Ford cylinder heads, at least, is the importance of torquing the plugs on installation.... This is a sore point with me since I am positive that too many "professional" techs aren't doing this. Spark plug torque valus are listed as 13 ft/lb for the 4.6/2V,

11ft/lb for the 4V engines and (I'm a little leery of this since it seems uncharacteristically high) 25 ft/lb for the 3V engines. Proper torque is essntial if we are to avoid splark plug insert or cylinder head concerns.

Yup. I blew the hell out of them. Also sprayed brake cleaner into the hole and blew them out a second time.

DIY and then you have nobody to blame but yourself. Aside from the fact that some of the rides require the engine to be dismantled just to reach the plugs, that is..... :0)

Speaking of DIY, I'm in the midst of replacing the plugs on my '98 GT. I was rolling right along until I got to the inner rear two plugs on the passenger side.

With some wiggling and moving a protecting bracket protecting some hoses, I was able to replace the rear-most pax side plug with difficulty. However, the next one forward, umm, I just can't figure that puppy out. It seems like I need to remove the fuel rail to get a socket wrench in there. That can't be right, though.

I have never changed my plugs myself before. I used to do it with my dad when I was little, and well, engines were different then -- easy access.

Is there some kind of trick to this? I'm about to go to the store to buy some kind of articulated socket extension, to see if that helps me.

Any pointers are highly valued. I feel like an idiot. 7/8ths of the work done.

-- dave j

No reason to feel like an idiot just because Ford provided job security for shops :0) (Don't get yer shorts in a knot, Warman... :0)

The Mustang II 302 4V w/CA smog and AC I had many years ago was that way. Now I have a car I can darn near stand in the engine well to work on it. Well, maybe not quite that good, but changing plugs is no problem.

I have had a couple of cars where it was obvious all the plugs had been changed EXCEPT one....

The articulated fitting may help. I've even used a couple of them together at times to get into some tight places.

Today I picked up my new steering column from the paint shop. Thus begins the change to power rack and pinion, , PS pump, braided lines, tilt column, cruise control.... DYI..... I imagine by the time I'm done, I will have bruised, scraped, knuckles and used a lot of swear words I didn't know I knew. :0)

In the end, with a variety of extensions to choose from (3", 6", and

10") and the u-bolt articulated thingy, I was able to get all the plugs out without removing anything other than the air duct.

Of course, I did indeed scrape each and every knuckle, but I did get it done, and feel bad for having saved a few bucks. Also changed the wires (nice, no tools) and changed the serpentine belt (which I had thought would be more difficult than the plugs, but with the breaker bar took about 5 minutes.)

Good luck with all your updates!

-- dave j

Get a universal joint and extenders of various lengths for your socket wrench. I can get at all eight on my '97 without removing anything but the plug boots on the wires that way. I just have 3/8th extender set from craftsman and the universal joint as well. Just takes mixing and matching until I have something that can get in there.

On second thought I may have had to disconnect the intake hose... but that's so minor it doesn't even register in memory.