HELP! Blown Heli-Coil Fixable? Or am I screwed?

Hey Everyone!
I drive a 2000 Tacoma SR5, 4WD.
Today (Christmas Eve..... ugh) I blew out a spark plug. To make it worse, it was one that had blown out earlier this year and had been replaced with a Heli-Coil. I texted some pictures to my mechanic and he is worried that a second Heli-Coil won't work. I don't completely trust him though, he hasn't been completely straight with me in the past. I don't understand what is going on. Do I need to replace the whole head? Is it maybe something worse? I am scared because my Tacoma is my baby and I am worried there is a deeper problem that I may not be able to afford or might be above my limited skill as a mechanic.
Any advice?

 

Time-sert. Cheaper to just get a head.


edit: Never mind, it says first time repair only. He was doing a big favor trying the first time. It's under a lot of pressure every cycle.

 

30ish years ago I had a spark plug port/hole that was welded and retapped. It was in an aluminum head. It held for years, I eventually sold and lost track of the vehicle. YMMV.

 

So replacing the head would end up being cheaper in the long run? I guess I am just worried about why the same one blew twice in 8 months. Idk if it was your truck what would y'all do? I am at a loss and i dont want to just throw it at a mechanic unless absolutely necessary.

 

Just the kit to try is pretty expensive. Like 300 expensive + time. These aren't rare heads. Welding and rethreading would prob. be foolproof fix but cost double what a head swap would be. Figure that head is coming off no matter what.

 

Because it wasn't fixed, just band-aided.

 

I also wonder why the first repair failed was it not done correct ??

The few I have patched (Band aided ) over the years are still going strong years later if they failed I am sure I would have been told.

Where does the truck live ??

What kind of shape is the rest in??

Mileage ?? Time for a timing belt ??

Going into Surgery what else might need doing

No friends that can help OP instead of paying the going Labor rate ??

 

That was the issue with the 02 I just bought, my mechanic showed me the heli coil was blown out. He retapped the hole but didn't trust it so he found me a used head for 250$ worth the peace of mind imo
He also changed the timing belt and water pump while he was in there because it was all open.

 

I don’t think this was a bad problem on Tacoma’s but look at the F150 forums. I know there were several years of them designed with only 3 threads holding the spark plug in. They spit them out all the time. I’m sure they used everything possible to try and fix them

 

From a mechanics perspective, a Heli-coil is only intended to be used as a temporary repair until a complete repair can be made, I don't care what anyone say's. Especially if you are using the Heli coil in a situation where the area is under, high stress, pressure, or temperature. bite the bullet and get a new head. Inspect the head before installing it, especially if you are getting it out of a bone yard. I only use a Heli coil to get me out of a bind, until I can get the replacement part in my hand. BTW, I have been a certified CAT diesel mechanic for over 25 yrs.

 

I've seen a number of Honda J-series V6 engines eject the plug on #4 cylinder. It happens.

 

It was an issue with the earlier 5.4. a friend lost 3 different cylinders in his expedition over the 4 years he owned it. They were all fixed with a coil. I lost 0 in my f150, 1 year apart in manufacturing years

 

Clearwater cylinder heads https://www.cylinder-heads.com/

Check them out for a fully refreshed head. If doing one, do them both. Assuming the truck is worth spending the $ on.

Miles and condition of things you don't mention factor into making the 'best' solution.

 

At work we have installed Time-Sert thread inserts in dozens of Ford Triton 6.8L V10's. But we only install inserts one time per cylinder. If a plug blows out a second time in the same cylinder, the motor gets cylinder heads.

 

Honda likes to blame the ejected spark plug problem on using anti-seize (or lubricant) with nickel plated NGK spark plugs. They claim the plugs can be over torqued when a lubricant is used. If that were the case, I don't see why #4 is the most likely to be ejected. This is not my personal opinion or experience so YYMV.