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-   -   Spark plugs seizing on high mileage engines:myth or fact? (http://www.diychatroom.com/f46/spark-plugs-seizing-high-mileage-engines-myth-fact-162823/)

toolaholic 11-10-2012 11:52 AM

I had no problem removing all six spark plugs from the 3.1 v-6 ( 1999chevy lumina 96,000 miles) despite my mechanic friend telling me I'm opening Pandora's box and some plugs may be seized in the aluminum head. I purchased Crc freeze off and a lisle spark plug thread chaser. I even contemplated using a impact driver. All came out easy w/ a 1/2 drive ratchet. Old plugs had oil on threads(leaking valve covers?) which he says was my saving grace. any thoughts?It's my teenage daughter's car and I want it to be reliable. Some old plugs had the platinum blown off the ground. Electrodes were good yet. Glad I changed them. New wires too. Thexton engine mover made it possible.Did I get lucky?

noquacks 11-10-2012 03:19 PM

Just what I learned- no reason plugs have to "fuse"/sieze just cuz high mileage. If maintained well (who knows if your previous car owner did) shouldnt be a problem.

D-rock 11-10-2012 03:56 PM

I've seen more spark plug boots/wires coming apart more often then plugs seizing in the heads. If replacing spark plugs I would suggest also doing wires on 100,000 mile service interval engines unless coil over style.

toolaholic 11-10-2012 04:10 PM

Quote:

Originally Posted by D-rock
I've seen more spark plug boots/wires coming apart more often then plugs seizing in the heads. If replacing spark plugs I would suggest also doing wires on 100,000 mile service interval engines unless coil over style.

Yeah I put ac delco professional wires on w/ dielectric grease in the boots.

cjm94 11-10-2012 04:46 PM

The ford 3 valve engines have issues with the plugs breaking off. But most others your more likely too have a plug come loose and blow out than seize in.

ukrkoz 11-10-2012 06:09 PM

1. you did put dab of Antiseize on the threads, right?
2. Your plugs are located in the side wall, going into combustion chambers at slight angle? Correct me if I'm wrong, there should be no head gasket where they at. Where's oil coming from then? Dripping from valve covers down?

toolaholic 11-10-2012 06:33 PM

Quote:

Originally Posted by ukrkoz
1. you did put dab of Antiseize on the threads, right?
2. Your plugs are located in the side wall, going into combustion chambers at slight angle? Correct me if I'm wrong, there should be no head gasket where they at. Where's oil coming from then? Dripping from valve covers down?

Anti seize yes. Maybe plugs replaced before and coated w/ oil to install. I hear this is done. Torqued to 130 inch lbs. spec is 132. Probably a little tighter than factory spec due to anti seize Lubing threads.

toolaholic 11-10-2012 06:39 PM

Quote:

Originally Posted by ukrkoz
1. you did put dab of Antiseize on the threads, right?
2. Your plugs are located in the side wall, going into combustion chambers at slight angle? Correct me if I'm wrong, there should be no head gasket where they at. Where's oil coming from then? Dripping from valve covers down?

Oh and it has the dreaded o ring distributor plug leak. But most oil leak goes toward the back of engine. You are correct as to plug location.

digitalplumber 11-10-2012 09:06 PM

Happens on certain year model f150's.

rusty baker 11-11-2012 12:34 AM

More common on aluminum heads than the old heads.

Fix'n it 11-11-2012 10:24 AM

Quote:

Originally Posted by cjm94 (Post 1049039)
The ford 3 valve engines have issues with the plugs breaking off. But most others your more likely too have a plug come loose and blow out than seize in.

yep. those should be removed and cleaned or replaced every 20k or less.
way to go ford.

imautoparts 11-11-2012 10:27 AM

Quote:

Originally Posted by Fix'n it (Post 1049549)
yep. those should be removed and cleaned or replaced every 20k or less.
way to go ford.

Which is not very likely, since the spark plug change interval on a 5.4L Ford V8 (the ones most affected by this issue), is 100,000 miles.

ukrkoz 11-11-2012 10:37 AM

which he has GM engine, not Ford.

1. so, you have oil getting into chambers from somewhere, and drizzling onto threads. The way they are situated, oil either drips from the top and seeps onto the threads, likely, from valve cover gasket. So scope for those leaks. Or, you have oil getting inside the chambers, and not burnt completely during combustion, and sprayed over threads. Most of a plug is inside sticking out, you have what - maybe 3 full threads in the engine head?
2. yep, heard that too. so this what happens. if you do NOT have continuous lubrication with oil, and put some oil onto plug threads to "lubricate" them, as it gets VERY hot, oil cakes and THAT will definitely bind plug to threads. Done it. That's why they came up with anti seize. Which is, basically, metalized powder in liquid form. Should also be used on lug nuts.
3. what you better off doing now is figuring out where that oil is coming from. As it will keep killing plugs. Or you will have to clean them every so many miles, and by that, you'll screw up plug seats sooner than necessary. Unless they have steel jackets, but somehow I doubt they do, as my 5.3L Vortech doesn't.

Fix'n it 11-11-2012 10:37 AM

Quote:

Originally Posted by imautoparts (Post 1049552)
Which is not very likely, since the spark plug change interval on a 5.4L Ford V8 (the ones most affected by this issue), is 100,000 miles.

indeed, beause the owners don't know about this issue. UNTIL they get a $800 tune up bill. :laughing:

toolaholic 11-11-2012 11:38 AM

Quote:

Originally Posted by ukrkoz
which he has GM engine, not Ford.

1. so, you have oil getting into chambers from somewhere, and drizzling onto threads. The way they are situated, oil either drips from the top and seeps onto the threads, likely, from valve cover gasket. So scope for those leaks. Or, you have oil getting inside the chambers, and not burnt completely during combustion, and sprayed over threads. Most of a plug is inside sticking out, you have what - maybe 3 full threads in the engine head?
2. yep, heard that too. so this what happens. if you do NOT have continuous lubrication with oil, and put some oil onto plug threads to "lubricate" them, as it gets VERY hot, oil cakes and THAT will definitely bind plug to threads. Done it. That's why they came up with anti seize. Which is, basically, metalized powder in liquid form. Should also be used on lug nuts.
3. what you better off doing now is figuring out where that oil is coming from. As it will keep killing plugs. Or you will have to clean them every so many miles, and by that, you'll screw up plug seats sooner than necessary. Unless they have steel jackets, but somehow I doubt they do, as my 5.3L Vortech doesn't.

Thanks for your informative reply. You are a very knowledgable guy. I researched putting the plugs in and it went fine. Guess I'll look into the oil issues.


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