PCA Forums

Went to change the spark plugs on an old '94 Chevy Cavalier, 3 out of 4 no problems. Then I get to the last one.

*SNAP* goes the spark plug. Some idiot thought it was a great idea to not use a normal socket wrench... Therefore they cross-threaded the damned thing, making it hard as hell to even remove.

So in short, it is important when you or people you know go to take their cars in for a tune-up. Find a place you know is competent enough to do these kinds of jobs right. Otherwise you run into problems like this when helping out a friend or family member.

I was taught to NEVER start the plug with a wrench. I hope you get it fixed.

The late model ford 4.6 and 5.4 liter motors had a shanked section on the sparkplug to prevent them from cross threading and also due to the distance the plug had to be recessed in the head in order for the tip to make it to the combustion chamber....in return for this great advancement......you guessed it, upon removing the spark plug, 80% of the time the smaller shanked section breaks off the plug and becomes lodged. Removal proceedure? Yup, pull the head and drive it out with a drift....purchase new head bolts...and reinstall. So how much does the average tune up cost on one of these? And when did a tune up become nothing more than changing the sparkplugs? My idea of a tune up is changing the air filter element, fuel filter, distrubtor cap and rotor if equipped, oil filter/oil change, and of course replacing the spark plugs. Then again this was the good ole days when cars werent made completely made of plastic(I own an avalance, I can say this).

Never cross threaded a plug in my life. Like above, do it by hand till the end & all is good. Get it snug with the wrench & give it 1/4 turn past. Done.

I do know that aluminum heads are the bane of mechanics everywhere though. The different expansion rates of steel vs. aluminum means that if you don't wait for both to equalize in temperature you ruin something (usually the aluminum threads).

I thought a tuneup was new points and the gap adjusted, timing adjusted, idle air screw adjusted, and main jets adjusted? Then again im old.

Pugsley wrote:I thought a tuneup was new points and the gap adjusted, timing adjusted, idle air screw adjusted, and main jets adjusted? Then again im old.

you must be really old j/k ive never seen a car w/o electronic ignition. have fixed some lawn mowers with points though.

When I worked on my 1971 El Camino, when replacing the plugs, I put a little motor oil on the threads, and always hand started them. Same goes for the oil filter. I put a little motor oil on the rubber gasket, then hand tighten only.

Now with my Ford F-150 2001 Crew Cab, I let a shop do it because:
1. I'm lazy and rather not get my hands dirty
2. I don't have the proper tools since the motor has coils for each plug
3. They last a long time before needing replacing

Executioner wrote:When I worked on my 1971 El Camino, when replacing the plugs, I put a little motor oil on the threads, and always hand started them. Same goes for the oil filter. I put a little motor oil on the rubber gasket, then hand tighten only.

Now with my Ford F-150 2001 Crew Cab, I let a shop do it because:
1. I'm lazy and rather not get my hands dirty
2. I don't have the proper tools since the motor has coils for each plug
3. They last a long time before needing replacing

Hope your truck doesnt have the 4.6 or 5.4 in it.......


Also, the afore mentioned expansion rates of aluminum vs steel has been more than just spark plug problems. When the cylinder head expands due to heat, it expands at a much faster rate than the engine block. Most blocks are made of cast iron except for some foriegn cars and performace cars. This difference in expansion rates causes whats called the "scrubbing effect" on the head gasket. Eventually the gasket will blow. When an aluminum headed engine is overheated, the weakest point in the gasket (where most scrubbing occurs) will give and the rush of coolant and combustion causes the head to cool far too rapidly in that area which in turn warps the head. Thought some of yall might be interested......

Oh, yeah, the gasket thing too. Though, I didn't want to get off topic (not that I'm free of that problem).

Key Keeper wrote:Hope your truck doesnt have the 4.6 or 5.4 in it.......

Mine has the 4.6 V8. I have 101,000 miles on it and no problems yet. What was the issue with the 4.6 or 5.4?

On my 71 El Camino, I use to blow head gaskets by #1 cylinder. GM made the width of the gasket/head so short that over time it would start to leak coolant. I knew when it happened because the motor began to miss, and you had water vapor coming out the tail pipe.

Cast Iron or Aluminum, I always use antiseize on plug threads. I learned that from my turbine engine days...

MRCOMPUTER wrote:Cast Iron or Aluminum, I always use antiseize on plug threads. I learned that from my turbine engine days...

Same thing here, I managed to get the spark plug in just fine, just the overall stupidity of the person who did it previously, kind of annoys me.

MRCOMPUTER wrote:Cast Iron or Aluminum, I always use antiseize on plug threads. I learned that from my turbine engine days...

Yup, this works good. I did learn one thing about antiseize compound, when you mix it with saltwater it turns into a conctrete like substance....anti seize????

Got the Comanche.. and a tune up is coming soon. Plugs.. Wires.. Cap.. Oil change.. (Air filter is good.. just checked that) and a fuel filter.

When I did the Clutch Master Cylinder last week.. I had a nut where I couldn't get to it.. put it in the socket.. put the extensions on.. and ran it down by hand.. then the ratchet to tighten.. just the way I was always taught to do it..

Pugsley wrote:I thought a tuneup was new points and the gap adjusted, timing adjusted, idle air screw adjusted, and main jets adjusted? Then again im old.

Remember, the thickness of a business card for that opposed 4!!