Gotta agree with you here. I think part of the reason they were there in the first place, was because chrysler used cheap plug wires. (Hence, the routing TSB as well.) I have seen motors where the boots were MUCH closer to the manifolds, and there were no heat shields, and no problems either. Still had to replace plug wires eventually, just like any other engine that had the shields.

 

Well I'll leave mine in then, but before i take out the spark plugs when i do anyway I am going to use a vacuum cleaner with a end big enough so the spark plug fits inside it that way i can suck all the sand and dirt out before i remove the plug.

I was kinda pissed after i used a can of air to blow it all out only to find a good pinch or 2 of sand still there after i took the spark plug out. I got most out with duct tape, but alot of it went into the spark plug chamber looked inside and saw grains of sand on the head. I couldnt do anything about it but put the plug back in after inspecting it and start the engine. I drove it some with good revs to blow the crap out, havent checked the chamber again but i havent had a problem since so im pretty sure it just blew out the exhaust from compression

 

Canned air is more for blowing dust and such out of delicate electronics, it doesn't really have the oomph for this particular application. I don't think a vacuum will be very effective either.... best bet is a compressor, with reasonably high pressure air. (90 pounds or so.)

 

I had the very same issue as the first poster in my 2001 Ram with the 318. After several hours of fighting the tube, it finally came out and I found it had practically fused to the head with rust. In fact, it appeared that rust was the culprit for deforming the ID of the tube in the first place and prevented my socket from fitting over the spark plug.

It took way more effort than some folks have described to remove the single tube I was fighting with. I used PB Blaster, screw drivers, pliers, two different Vise-grips, etc. etc. I would say to anyone trying to remove their tubes that your experience may vary from the "norm"!

As for the tube being there/not being there, I know as a "low-poster" I have no clout whatsoever, but I made a conscious decision to leave mine in, even buying a new one from Chrysler to replace the one I had destroyed during removal. I have a tendency to believe that some protections are there for a reason, and if the tube will prevent the wire from falling against the exhaust manifold, I'm leaving it there. I find it hard to believe that Chrysler engineers sat around and said "well, our wires are total trash so we need to put all the extra money and effort into this motor to make the tubes and install them at an engine plant." It would have been far easier to spec a better set of wires from the get-go if they were the true problem.

Anyway, my 2 cents...

Dave

 

See that's just it though. The bean counters don't look at what is "best", that look at what costs the least...... do we pay a few bucks more for better plug wires, or, do we spend a few cents on heat shields, so we can save the money on the plug wires?

Ya gotta remember, the trucks aren't designed with longevity in mind....

There are many many motors out there in the world with plug boots (the part the h/s are designed to 'protect') much closer to the manifold, with no h/s at all..... We have many members here on the forums that have removed them, with no ill effects. (of course, they replaced their plug wires with wires that are of higher quality as well.)

 

Excess heat is the enemy of engines and engine parts. The heat shields keep the spark plug boots cooler, no matter what quality the wires are. To deny this is to deny physics.

I'm having a hard time believing that every manufacturer that included spark plug heat shields in their designs did so just to save money.

The question comes down to whether or not you're willing to take one minute to blow out the shields with compressed air when you change your plugs every 50,000 miles or so.

If you don't have a compressor, you really should have a portable air tank that you can refill at most gas stations. Compressed air is a wonderful thing to have on hand.

***

A few links about spark plug heat shields:

http://www.classicchevy.com/chevy-sp...1957-1966.html

Chevy Spark Plug Wire Heat Shield Set, Small Block, 1957-1966
•Reproduction Of Original
•Protects Wires From Heat Damage

http://www.boostplanet.com/spark_plug_wire_shield.htm

The Spark Plug Wire Heat Shield offers the ultimate protection for spark plug wires and boots from conductive and radiant heat.

http://www.k-huhn.com/dodgeram/sparkplugs/ (good pictures including air gap between boot and shield)

Some notes:

1. you may have heat shields on your head to protect the wires - possibly on the drivers side. Do not attempt to pull these off - leave 'em on, your
wrench *will* fit down that hole.

 

Using advertising to 'prove' a point isn't really effective. Marketing claims are one of the least reliable sources. (look on ebay at all the two-wire chips that claim 50 horsepower, and 10mpg increases.....) Also of note, you first link is for classic cars, and is more geared toward restorers that want everything 'original'.

Do you think the heat shields that are on our trucks are still effective when they are full of crap trapped between the tin, and the plug boot? Or, does that crap not conduct heat??

If you think that any manufacturer doesn't pull stunts of this nature to save a buck or three per unit, guess again. When you are talking hundreds of thousands, if not millions of units of production, you are getting into some serious money.

 

I respectfully disagree with your assessment that the heat shields typically become so full of debris that their functionality is significantly affected. I've never had to blow out more debris than the volume of a pea, if that. YMMV if you're off-roading ~and~ mud can actually fill them up.

"Do you think the heat shields that are on our trucks are still effective when they are full of crap trapped between the tin, and the plug boot? Or, does that crap not conduct heat??"

And even if they were to become filled with crap, they still would keep the boot cooler because they would still reflect much of the radiant heat. Yes, the crap would conduct some heat, as would the best insulation known to man.

How heat-conductive is the average "road crap"? I'm not sure. It might be equally or more effective at insulating than the air gap it displaces. (The air gap you said wasn't there; "having them actually contacting the plug boots probably doesn't help matters any ..... The plug boots are indeed in contact with the metal tubes". How much "crap" are we talking about if the boots contact the tubes?

I stand by my opinion that having heat shields will reflect much of the heat from the manifold away from the boots, keeping them cooler and making them last longer.

Lastly, I again reject your notion that they are present merely as a cost-cutting measure.

 

We should be careful here. If we aren't, we might prompt a government study into the heat conducting properties of road crap.

My point is, basically, the heat shields cause more problems than they solve. Sure, they may extend the lifespan of the plug BOOTS, but, the rest of the wires still degrade at the regular rate. It is a very rare occasion that I have to replace a wire set because the boots are bad.... (at least, at the sparkplug end....) heatshields or no.. More often than not, it is because the wires have broken down at some other point, and are arcing to some other object, or, another plug wire. So, keeping them in there gives them the opportunity to trap crap, which it will then do its best to drop it into the combustion chamber, can make plug changes more challenging than they really need to be, while removing them may, or may not shorten the life of the boot. A part which rarely fails in any event.

 

Brian -

I am now confident that we've given any readers of this thread ample testimony regarding our respective views on this issue, arguably one of the most crucial decisions facing any car or truck owner today. (Not! )

If I ever come across a definitive article entitled "Thermal Conductivity of Road Crap and Its Effect On Spark Plug Heat Shield Efficiency", I'll be sure to forward it to you.

I applaud your civility throughout, and offer my sincere wishes that your spark plug boots always be as cool as The Fonz, if not cooler.

Best Regards, John D