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Pete. (l33t FS)
Pete. (l33t FS) MegaDork
11/15/20 12:47 p.m.

In reply to Curtis73 (Forum Supporter) :

In GM's defense, the Dexcool issues were from people ignoring coolant leaks, which allows air to get entrained when the engine cools off and sucks air in, which turns it into mud.  They still use Dexcool but their engines are generally better at not developing seeping, ignorable coolant leaks every 30k.

Will
Will UltraDork
11/15/20 5:04 p.m.

I've heard the bit about the heads not having enough threads, but to my knowledge, 4.6 and 5.4 heads are 100% identical (as long as both are NPI or PI, of course). And for some reason I only hear about the 5.4 ejecting plugs, not the 4.6 with (as far as I know) identical heads.

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) MegaDork
11/15/20 5:29 p.m.

Actually, as someone who worked for GM and Saab at the time, I know exactly what causes the Dexcool problem, and it had nothing to do with air leaks.  We were hemorrhaging money on warranty repairs for clogged heater cores, overheating, damage to gaskets, and dead water pumps on vehicles that had zero leaks and LONG before they should have been having problems.  We had some Saturns with under 4000 miles that lost heat, some overheated, and one in particular that clogged some head passages so fully that the steam pressure in the block broke the block.... as in, split it down the middle.  My own Impala went through three heater cores and two water pumps under warranty, long before leaks would have been an issue - the first heater core was replaced at 12,000 miles and change.  The first water pump was done very shortly after that.  The conclusion that GM makes leaky engines is a neat internet myth, but the one-way valves in expansion tanks are constantly letting air in the system.  Air isn't the issue.  People can defend it all they want, but if air... the same stuff we breathe, the same innocuous stuff that is everywhere... is causing your coolant to fail at 4000 miles, I don't blame the air, I blame the coolant.

We lovingly referred to it as "getting all SOJed up."  The diagnosis was abbreviated SOJ for "sandy orange jello."  DexCool is incredibly temperamental stuff, and unless you keep conditions more than perfect, it turns into a corrosive, abrasive pile of goo.

Let's say you get a cat and discover that you are deathly allergic to it and causing your doctors to question whether or not you'll live.  You don't surgically remove your immune system to accommodate the presence of the cat, you flush the cat and get a dog instead.

Streetwiseguy
Streetwiseguy MegaDork
11/15/20 6:44 p.m.
Pete. (l33t FS) said:

In reply to Curtis73 (Forum Supporter) :

In GM's defense, the Dexcool issues were from people ignoring coolant leaks, which allows air to get entrained when the engine cools off and sucks air in, which turns it into mud.  They still use Dexcool but their engines are generally better at not developing seeping, ignorable coolant leaks every 30k.

I still want to know who sold GM those plastic intake gaskets, and how many photos of GM execs in bed with sheep they have on file.

It is the only possible explanation.

vwcorvette (Forum Supporter)
vwcorvette (Forum Supporter) UltraDork
11/15/20 8:31 p.m.

Never had a plug issue in any VW aluminum head I've dealt with in over twenty years and no anti seize. Ever. That stuff is the devil.

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) MegaDork
11/15/20 9:13 p.m.
vwcorvette (Forum Supporter) said:

Never had a plug issue in any VW aluminum head I've dealt with in over twenty years and no anti seize. Ever. That stuff is the devil.

I try to avoid it... I mean, I'll use it where it's needed, but that E36 M3 is the glitter of the automotive world.  IT GETS EVERYWHERE.

accordionfolder
accordionfolder SuperDork
11/16/20 6:50 a.m.

In reply to Curtis73 (Forum Supporter) :

Ain't that the truth, I have it on my rear heim joints spacers as recommended and I swear I'll get it on my hands when I'm not in the garage and just think about applying it.

dean1484
dean1484 MegaDork
11/16/20 7:01 a.m.
03Panther said:
Apexcarver said:

Had mine replaced in a rare "farm it out, I don't wanna deal with the possible fallout" moment. Gave them the truck on a Friday, they oiled it while it was hot and let it sit till Monday and had no trouble.

 

07expedition with 5.4

I did the same with my 03 Grand-ma-quis. At 80K i started getting a stumble if pushed (rare.) I figured prolly not worn plugs, but possibly some fouling from being babied its entire life. The shop had a tech that is known in the area as a bit of a 4.6 enthusiast. Had had no problems prior, and none since... crossing my fingers! Stumble also went away, but 8K later (more little old lady miles) and is back, but intermittent. Still 20.8 mog, so doesn't worry me much.

I would bet it is coil pack related. 

wae
wae UberDork
11/16/20 8:08 a.m.
dean1484 said:
03Panther said:
Apexcarver said:

Had mine replaced in a rare "farm it out, I don't wanna deal with the possible fallout" moment. Gave them the truck on a Friday, they oiled it while it was hot and let it sit till Monday and had no trouble.

 

07expedition with 5.4

I did the same with my 03 Grand-ma-quis. At 80K i started getting a stumble if pushed (rare.) I figured prolly not worn plugs, but possibly some fouling from being babied its entire life. The shop had a tech that is known in the area as a bit of a 4.6 enthusiast. Had had no problems prior, and none since... crossing my fingers! Stumble also went away, but 8K later (more little old lady miles) and is back, but intermittent. Still 20.8 mog, so doesn't worry me much.

I would bet it is coil pack related. 

At a bare minimum you should be able to check where that misfire is happening.  I can't remember if I used FORScan or TorquePro to do it, but if you have it display TID $53 it will show you how many misfires it has recorded for each cylinder.  Mine is a 3/4 ton truck, so it won't light the MIL for misfires which means yours may be different, but I was able to see in there that I had one cylinder that had a crapload of misfires so I cleared the values and swapped the COP module with another cylinder.  Took a quick drive and confirmed that all my misfires were now happening on the other component ID, so I put in a new coil and all was well.

Vigo (Forum Supporter)
Vigo (Forum Supporter) MegaDork
11/16/20 3:09 p.m.

Once you've seen the 3 threads in the head you understand that no different plug design short of perhaps a different sealing washer design is going to help that issue. Slightly overtightening it is the only cost-effective way to improve it without actually using a thread insert. 

As far as anti seize, i'm not against using it on a plug if you know the caveats of lubrication changing the relationship between turning torque and clamping loads, how little to use, and also understanding that it is an abrasive and there are certain places you don't want to add abrasives to. I think a little bit is ok as long as you're not following it up with a severe overtightening. 

03Panther
03Panther Dork
11/16/20 8:51 p.m.

Haven't laid my eyes on my Auto Ingenuity scanner in a couple years. Till it gets worse I'm not too worried (yet!) But moving the coil around is a great plan. My scanner troubleshooting has all been diesel related, so I prolly would not have thought of that. Feel silly knowing I would have missed that... thanks for the wake up tap!

barefootskater (Shaun)
barefootskater (Shaun) UberDork
11/21/20 9:29 p.m.

Well this morning I finally got after it. Motorcraft plugs, just a hint of anti-seize, and slightly over torqued. About 20 miles on new. So far so good. The old ones appeared to be the original units, complete with factory applied "it's tight" paint. 

they were only showing the barest signs of wear, but 15 years/102k miles is long enough. Also threw a new air filter at it just because. 

Vigo (Forum Supporter)
Vigo (Forum Supporter) MegaDork
11/21/20 10:54 p.m.

Sometimes peace of mind is worth more than the parts actually cost. yes

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