Changed Plugs

[ejstith]

Well just changed the spark plugs on my PT. I used Autolite APP5263 double platinum and gapped at .040. Is that .040 from a Chrysler service bulletin or just somebody's idea? Everything I see still calls for a .050 gap. The Champions I took out 2 of them were gapped at .065 and two were gapped at .062. No wonder I got a check engine light, rough idle and lousy gas mileage. Anyway, it does idle better and I hope it picks up the mileage a little. I didn't take the intake manifold off. One of the gussets on the intake made it a problem to get a deep well socket in the (#2) hole so I just took a dremmel tool and ground off enough of the plastic gusset to get the socket in the hole. Also put MSD 8.5 mm plug wires on it.

[CREWZIN]

You were able to get plugs and wires off/on without taking off the upper intake? You must have the Turbo or Turbo Lite but even then I thought you had to remove the intake for the wires. Learn something new everyday.

Chrysler themselves brought out a TSB (Tecnical Service Bulletin telling the dealer mechanics to change the gap in the NON-Turbo to .040in.

So, if you followed the .040in gap you must have the Non-Turbo. I'm confused, which do you have? With the Turbo PT's the gap should be even smaller.

[Matt42]

To paraphrase a mens' suit ad, you are gonna love the way your PT runs.

[quicksilverdon]

Your turbo lite is like mine with the plastic manifold - I hear the earliest '05 turbos came with the metal intake - which was even easier, but the plastic is supposed to breathe better. I put two swivels on and was able to do plugs with no grinding of the minifold.
I gapped at 0.038, because I have read that turbo guys recommend smaller - as Crewzin noted, there was a TSB that said to change the 0.050 to 0.040....
From what I've read, the gap widens with time - yours probably weren't gapped so large when they were put in....

[Mean Green]

Sorry to pop your bubble, but you do not use platinum plugs in a turbo car. Because a turbo car runs hotter than a na one the tips will eventually melt. Platinum plugs work great in a na (non turbo) car. In my turbo car ('05 SRT-4 w/same engine as PT GT) I use the stock Copper Plus plugs gapped at .035. I'm running 350 hp so your 180 hp car should be gapped at .040 the same as I used with my 280 hp PT GT.

[ejstith]

Well it's gonna have to live with it because I'm not gonna take 'em out anytime soon. If the tips melt then the tips melt but it ain't gonna do it in the next couple of days and if they do they are guaranteed for 5 years. I just took a dremmel tool and ground that gusset where the socket would go down in there then put a universal on it with an extension. Put the plug on a piece of hose and screwed it in. Didn't have to grind it very much. Was a pain in the ass gettin' that plastic cover off of the top of the manifold though. But all in all not too bad .. Not as bad as a V-6 Buick I used to have and trying to get to the back set of plugs and on my Lincoln Navigator I don't even know where they are but I'm gonna have to tackle it pretty soon. It will be worse than this was.

[Mean Green]

Originally Posted by ejstith

Well it's gonna have to live with it because I'm not gonna take 'em out anytime soon. If the tips melt then the tips melt but it ain't gonna do it in the next couple of days and if they do they are guaranteed for 5 years. I just took a dremmel tool and ground that gusset where the socket would go down in there then put a universal on it with an extension. Put the plug on a piece of hose and screwed it in. Didn't have to grind it very much. Was a pain in the ass gettin' that plastic cover off of the top of the manifold though. But all in all not too bad .. Not as bad as a V-6 Buick I used to have and trying to get to the back set of plugs and on my Lincoln Navigator I don't even know where they are but I'm gonna have to tackle it pretty soon. It will be worse than this was.

No, they won't go that quick, but you'll know when one does.

[ejstith]

Originally Posted by Mean Green

No, they won't go that quick, but you'll know when one does.

I'll address that problem when it comes. These are not the platinum plugs with the tiny wire in them. To look at it you couldn't tell it from the plugs that came out of it. We will see "said the blind man to his deaf dog" ..

[Mean Green]

Originally Posted by ejstith

I'll address that problem when it comes. These are not the platinum plugs with the tiny wire in them. To look at it you couldn't tell it from the plugs that came out of it. We will see "said the blind man to his deaf dog" ..

Then there is more to fall into the engine. It's your car. I hope the blind man can see when the deaf dog keels over and chokes to death.

[Matt42]

Originally Posted by Mean Green

Sorry to pop your bubble, but you do not use platinum plugs in a turbo car. Because a turbo car runs hotter than a na one the tips will eventually melt. Platinum plugs work great in a na (non turbo) car. In my turbo car ('05 SRT-4 w/same engine as PT GT) I use the stock Copper Plus plugs gapped at .035. I'm running 350 hp so your 180 hp car should be gapped at .040 the same as I used with my 280 hp PT GT.

I'm curious about this, but not in a way that disagrees with your results. I don't have a turbo, y'see. Platinum metal has a much higher melting point than steel, iron or copper or any alloy of them. Platinum alloy wire is used in laboratories to hold crucibles that are being heated in super-hot flames. At least in theory, the platinum electrodes should stand up to temperatures much higher than can be generated by the spark or in the cylinder.

I used the single electrode thin-wire Bosh platinum plugs in a Saturn S series with poor results. That was due to electrode recession into the insulator from the scavenger firing during the exhaust stroke. Others have reported poor results in PTs and TCs for the same reasons. That's why I am using the double electrode iridium plugs where there's a round plate of iridium on each electrode. These are working well but I don't have enough miles yet to say that they work over the long term. Iridium has similar temperature resistance, and is known to us geological geeks as a platinum group metal.

On the assumption that the poor results in Turbos were with dual flat plate electrode platinum group metal plugs, what went wrong?