Classic Hifi Care

My Ranger has almost 100K on its second set of spark plugs. Time for replacement. Last time I just bought 4 new ones and changed 'em. Since then I read a scary story somewhere about tapered-seat plugs breaking off. I've never had a spark plug break off, but it's scary to think about. Any comments on changing out tapered-seat plugs?

My plan was to use a T-handle on the socket wrench so as not to put sideways pressure on the plugs, as might happen with a regular ratchet handle.

Chris Campbell

I've never twisted a plug off in my life. Believe me, I've tried. I used to remove them with the engine COLD with an impact gun. The only ones I'd be worried about is a Ford 4.6 liter V-8. Your Ranger should present no problem. Take them out with the engine cold, using whatever means of leverage you choose. Put anti-seize on the threads, put them back in. Done.

Chris, is your Ranger 4 cylinder one with 8 spark plugs like mine?

Bill

William wrote: ↑Fri Oct 21, 2022 12:52 am Chris, is your Ranger 4 cylinder one with 8 spark plugs like mine?

Nah, this one is one plug/cyl. but 4 valves/cyl. The old one was the two plugs/two valves model.

I always laugh about this. When I was a kid, if you had an aluminum engine with double overhead cams, 4 valves/cyl., and fuel injection, it was a race car engine. Your truck probably had an inline 6, maybe overhead valves/pushrods if it was a newer model, or an L-head 6 if older. But now the race car engine is in a truck.

Chris Campbell

I had a customer back in the 1980's who bought one of the first Merkur cars in this part of the country. It was a horrible little heap of advance technology, built by Ford of Germany in Koln. But it was powered by the Ford 2.3 liter "Pinto" engine. It had a huge turbocharger and intercooler and put out like a billion horsepower, compared to the standard 2.3. I believe a version of this engine found its way into the Ford Thunderbird TurboCoupe models. Anyways, to make a long, sad story somewhat shorter, he mercifully wrecked the Merkur. He bought a used Ranger and transplanted the Merkur engine into the Ranger. The thing was so fast it wasn't safe to drive. He had to haul weight in the bed to keep from burning the back tires off. That 2.3 liter four that Ford built for so many years was a great engine. Almost bulletproof.

From March 20...


Re: Spark plugs
My truck has the tapered seat plugs. Removed (?) them cold. broke 3 sets of threads off in the head. Had to tow the truck to my mechanic, who admonished me to never try to remove that type plug with the engine cold. That will be my plan from here on out.

I wonder if he might have broken them off for reasons other than removing them cold. I was taught the reason you remove plugs cold is due to the expansion of the metals in the head and in the spark plugs. Aluminum heads were more important that you removed the plugs cold. I wouldn't remove plugs from cast iron heads hot. Maybe somebody has found a different/better way of removing spark plugs then they did in my day.

Tapered seats are nothing new. The Ford FE series of V-8's in the early 1960's were one of the first I can think of with tapered seats, albeit 18mm seats. Chevy started using tapered seat plugs with the 1969 models.

I broke them. I've never had anything like it happen before. They just cut loose.

Did the spark plug itself break, or did you pull the threads? We may be talking apples and oranges.

My comments pertained to preventing thread damage. Actually, physically breaking the spark plug itself may be a different matter. I have broken the porcelein many times, particularly on nailhead Buick V-8's with air conditioning. #1 plug is almost impossible to remove without breaking it unless you have a wobbly spark plug socket. I don't remember ever breaking a plug off below the gasket or tapered seat. I have pulled threads. Some not my fault. After you tear down an engine and replace the head on your dime, you learn to be careful.

I've broken quite a few porcelains too. But the idea of breaking the steel threaded part was surprising to me. I am wondering if, instead of calling the tow truck after breaking one, it might be better to just take it to the shop for a plug replacement while it's still running. Geez, that seems stupid. Kinda like having somebody else ump the gas.

Chris Campbell

Hiring it done would certainly be preferable to breaking a plug then having to pay for a tow on top of paying someone to do the job.