engine squeal and loose spark plug

Hello Everyone,

I have a dilema and I thought that I would ask for some advice. My 71 is almost completely stock, except for the spoilers and tires and rims. Basic 302 2v auto with air and 57,000 miles. First problem, I changed the spark plugs a month ago and now third plug on the passenger side keeps backing out. Secondly, the engine idles almost perfect with no strange noises. Then you rev up the engine and a terrible squeal can be heard. I checked the belts, and tightened them a little just to be safe. Well, the noise is still there. So, now I'm thinking is it the flex plate or the torque converter. Both are original pieces to the car, I don't beat on the car I might have a little fun but I never power brake it. The car had the original 14" size tires until last year when I finally changed to the 275-50-15 tires, I wonder if that put too much stress on the car? Any help would be great, I don't often get a lot of time to work on the car and if I know how to find the problem it saves time fixing it.

I would drain the trasnsmission fluid and change the filter to start with. Low fluid levels can make all sorts of sounds.

A squealing belt is a distinctive sound and I know of nothing else that sounds like that...you should not have more than 1/2" of movement in belt when tight. Was there oil around the plug when you pulled it out? How much torque are you applying? Did it have the compression seal? You can switch plugs with another hole and find out if the plug or the hole threads are at fault.

Remove the belts and see if the squealing goes away. Then, add back one belt at a time until the squealing returns.

Would definitely do the trans flush....TAKE YOUR OWN TRANS FLUID IF YOU HAVE A GARAGE TO IT.

Remove the belts and see if the squealing goes away. Then, add back one belt at a time until the squealing returns.

Would definitely do the trans flush....TAKE YOUR OWN TRANS FLUID IF YOU HAVE A GARAGE TO IT.

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{thumbs up} thats what i would do....Long as you dont run it long with out the fan belt...Could be belt or even a pully going bad....Btw...Flex fan or fan with a clutch? The fan clutch could be going out......little bit of oil will make a belt squeel for a long time sometimes....I know a freind who made the mistake of painting his pullies...And the paint was so slick they squeeled till the belts got ruined...lol

If not that..I would check and replace the transmission oil filter...And like others said.

as for the plug..You mite have to run a thread case down it....And a very thin lock ring....Some one could of messed up the threads along time ago...Atleast its not blowing out the hole yet...You mite be able to save what is left of the thread....thats what i would do...Worse case senerio...You will have to buy a Healey coil kit...And healey coil fix it...Worst of the worst if that dont work "it should"...You will have to get a new 302 head.

Remove the belts and see if the squealing goes away. Then, add back one belt at a time until the squealing returns.

Would definitely do the trans flush....TAKE YOUR OWN TRANS FLUID IF YOU HAVE A GARAGE TO IT.

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{thumbs up} thats what i would do....Long as you dont run it long with out the fan belt...Could be belt or even a pully going bad....Btw...Flex fan or fan with a clutch? The fan clutch could be going out......little bit of oil will make a belt squeel for a long time sometimes....I know a freind who made the mistake of painting his pullies...And the paint was so slick they squeeled till the belts got ruined...lol

If not that..I would check and replace the transmission oil filter...And like others said.

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Nice catch on the fan clutch...you can also get a can of belt dressing to find the squeal

Regarding loose spark plug, does it have a washer?

I think the plug has a washer, but I will double check to make sure. I will try to remove the belts and see. I just bought a trans filter kit and will tackle that in the next few days. I'll get back with the results in a few days.

Sounds like old dry belts. Many times the belt will look fine, no cracks or anything, but when you rev it, you will get a high pitch shriek, almost like a crow is being tortured under your hood!

Trans won't make noise if it's not in gear. If it's a flex plate, you will usually get a tic, much like a lifter noise that will speed up with RPM, but it won't squeel.

Sound's like you need new belts to me. Like Wolvy said, pull the belts off, fire it up and then rev it a few times. If no noise, there is your problem.

I would just get all new ones at that point. If one is bad, the others are probably shortly behind it and the last thing I want to do, is do something twice when I could have easily done it once!

Unless of course, I'm drinking a scotch, then I make an exception to this rule.

Also, you can try swapping out the loose plug with a tight one, and see if everything stays tight.

Kind of like trading in your 40 year old wife for a 20 year old...kind of.

Been waiting a long time to get that comment on here...wasn't going to touch the dry belt/lubricated belt post.

Hey Wolverine, what if the 40 year old engine block just needs a "bigger" spark plug to fit properly!? hehe

Hey Wolverine, what if the 40 year old engine block just needs a "bigger" spark plug to fit properly!? hehe

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Well...there are other options...

Good advise guys.

Regarding the tires... It's not stressing your car more and isn't part of the issue.

Good news, as of today the Mustang has been fixed and is running. The noise was coming from the power steering pump, I removed all of the belts one at a time and it ended up between the power steering pump or the water pump. Both were on the same belt. I replaced all of the old rubber hoses on the car and the water pump nipple was dissolved so I replaced the pump. I also installed new headers and dual exhuast, and flushed the trans and installed a new filter. This lead to about two weeks of problems, with the trans.. Seems the new fluid and filter caused a valve to stick, but it is all corrected now! Thanks everyone for your help.

There should not be any type of washer on the plug. Ford uses a tapered seat to seal the plug to the head. Other than that, the suggestion to swap it into another cylinder is a valid test.