Henryv

Got my truck back today!!!!!!!!! Man, I know its been said before, but STEALers (and they earn every bit of that word) SUCK!!!! Ok, comparison time:

stealer invoice: Inspect and found #5 ign coil damaged. remove ign coil and found spark plug missing. further inspect and found thread damaged. all threads gone. needs ign coil, spark plug, rt side cylinder head replace. customer declined recommendations (of course freakin retards). They didnt give me the paper the guy scribbled the quote to fix it on like I thought they would but it was TOTAL: ~$4000.

indy shop: #5 spark plug popped out, melt ignition coil. spark plug hole stripped. r/i right side valve cover, tapped and installed heli coil, replaced tube seals, valve cover gasket, spark plug and coil. TOTAL: 459.00 and thats including the towing fee of 60 which i'll get back when i contact the ins co making it 400 total.

Sounds like the idiots just tried to drop in a spark plug and since it didnt work figured I needed a new cylinder head. It took the shop about 3 hrs to tap the coil. He said they do these often and that imports are the main culprits every time. Also mentioned that causes can be that the vehicle might be running too hot from being too lean, or have a leak somewhere, which can cause the plug to blow but more likely its from the plug either being loose or crossthreaded and over time vibrating free and blowing out. In my case it was the latter.

slightly off topic but looking on the bright side, they checked for exhaust and vacuum leaks and found none, checked all the other plugs and they were all secure and fine, and checked to see if I was running lean or rich but I wasnt (which isnt that great because it means that my mpg woes are permanent and due almost totally to my environment of nasty stop and go traffic and hills on every block since I've done most of the other maintenances). Basically the trucks running great. Thanks for all the replies everyone. So relieved getting the truck back but then again would have been alot better had I not stopped in the the stealer first.

4RUNR

Cross threaded. Makes sense.

Btw, I have to commend you for good spelling and the use of paragraphs. Such a rarity.

arjan

The 4runner is running and he passed the spelling test. It must be a good day!

Good to hear it all worked out for a reasonable price.

mt_goat

One step cooler plug?

MTL_4runner

I had never heard of this before as a problem (I had done many helicoils and never run into one with detonation problems) but I did a search and it seems that this has become some sort of an engine builder tip over the years.

You should still be able to inspect the plug for any hotspots in might create and rectify if needed:


Here is another good article explaining the hot vs cold plugs:
http://www.kreidler.nl/forum/sparkplugs.php

Seems that the Ford 5.4L blows plugs constantly and thus they talk about heat conduction here:
http://www.f150online.com/forums/arc.../144734-1.html

This is what a plug looks like when you let it run too hot for too long.


I think as long as you take the plug out again after a few miles (say 50-100) you should have a pretty good idea how it is tranferring heat with the new insert by reading the plug itself (best way to tell how well the engine is running). .....and finally always use antiseize on any plug that has been repaired!

mt_goat

I don't know, but I trust EB's knowledge is far superior to mine on the subject and that was his recommendation. Just thought he might have forgotten about it.

Henryv

Had I known I would be graded, I would have paid more attention, especially with my grammer.

Anyway, I was driving it around last night and it felt great. Babied it a bit, like you would after healing from a broken bone, but had to open it up a little at certain points and so far so good. As for the cooler plug, I did remember about that and asked the mechanic but he basically told me the same thing mtl said. In his experiences he didnt have anyone run cooler plugs and they all held up fine. The procedure he described sounded pretty complete though, as he tapped the coil and used some sealant on it as well. I might check on it sometime (or let someone else check on it since I cant tap another coil if it screws up again) but I'm thinking it should be ok.

Bob, if youre still following this thread, after your rebuild, did you run a cooler plug in that cylinder? If not, how has your runner held up in those 4000 miles since the rebuild?

MTL_4runner

I thought your advice (or mention of someone else's) was quite valid. Obviously a poorly done helicoil or even a loose plug can cause heat problems for sure. Also just because I haven't seen it, doesn't mean it doesn't exist either...again best way to verify is to pull the plug after a few miles and check (look for a slight brown color for proper combustion).