Stuck in Alamosa (1 Viewer)

[columbu45]

I’m in a 1999 LX470, I had an issue a couple weeks ago that pulled as a P0308, I replaced my spark plugs all around and put a new Denso coil in. It fixed the issue until this morning when driving through La Veta Pass in Southern Colorado on the way to an elk hunt. Flashing CEL, loss of power, got to a Oreilly and they pulled the code as another P0308. I replaced the coil again and it hasn’t fixed the issue. I’m with my dad for a 1 week elk trip starting today and my truck of course s*** out on me. Any ideas?

 

[Trunk Monkey]

Any visible damage to the wiring leading to the coil?

 

[CooCooCaChoo]

Swap coils around, clear codes and see if the code pops back up on same cylinder or cylinder you swapped coil to.

 

[columbu45]

So I cleared the codes, drove the truck around again, and duplicated it. I ended up with just one code of a misfire on Cylinder 6. I replaced the destroyed plug and coil and haven’t had issues since.

 

[94SRUNNER]

Was the plug not tight in the head? Is that why it was destroyed?

 

[columbu45]

Was the plug not tight in the head? Is that why it was destroyed?

Not really, one of the things I discovered when baselining the truck last year was an insert or a collar around the plug for the number 6 cylinder. When I changed them then, I had to find the same design of collar to go around the new plug. The original wasn't corroded at all. But the plug I replaced in the orielly parking lot was just incredibly fouled, completely black and had corrosion. Additionally the bottom of the coil looked like someone put a fire cracker in it. Ill post a picture of the coil and plug in a few minutes.

I think I'm going to need to do something about the head regarding that cylinder.

 

[columbu45]

 

[BuckarooBanzai]

It looks kind of like a helicoil. Used to repair damaged threads. Is it possible a previous owner had a spark plug blow out of the head?

 

[columbu45]

It looks kind of like a helicoil. Used to repair damaged threads. Is it possible a previous owner had a spark plug blow out of the head?

Yeah Im confident that's what it is.

https://www.autozone.com/test-scan-and-specialty-tools/thread-repair/p/oemtools-m14-1-25-fix-a-thread-spark-plug-thread-insert/141512_0_0?spps.s=847&cmpid=LIA:US:EN:AD:NL:1000000:TLS:8367255572&gclid=EAIaIQobChMI4tLh4J-4-gIVpBPUAR1zng92EAQYDyABEgImF_D_BwE&gclsrc=aw.ds

This is the one I replaced it with to get back on the road

 

[columbu45]

There's a better picture of the plug its self.

 

[excessive]

i wonder if the gap was way off, and that caused it to destroy itself?

 

[Mchodl]

What are the manual compression figures for your engine?

 

[JPensyl]

So I cleared the codes, drove the truck around again, and duplicated it. I ended up with just one code of a misfire on Cylinder 6. I replaced the destroyed plug and coil and haven’t had issues since.

lucky you! I had one strip out. i have burned out two plugs and coils in a week and now have to re thread it. now I have purchased everything under the sun for cyl no. five. heli coil, a new plug as well a harness to set things off properly looks like its just a plug issue i am running into an issue getting the tap tool down there because of the spark plug tool socket size...... the tube is the difference between oooh and aw fuuuun

 

[Bomar]

Non OEM coils burn hotter and will cause a potential loose plug to eject itself from head.

That is what I was told from some people I trust and I put a helicoil in that back cylinder and have had no issues in 10 years / 150k+ miles

 

[JPensyl]

Non OEM coils burn hotter and will cause a potential loose plug to eject itself from head.

That is what I was told from some people I trust and I put a helicoil in that back cylinder and have had no issues in 10 years / 150k+ miles

I have it back up and running smoothly, heli coil held better than the factory threads and I am running an oem plug and coil on that cyl now. I took it by my buddies place yesterday and plugged in his obd 2 and cleared the codes with his much newer and nicer reader, mine is old and just for telling an aw s*** cel from an OH NO life is over emergency. I will probably go through and rethread each cyl when I do my next tb wp ht cyl in about 40k.