3vze spark plug Heli-coil blew out. I'm hosed, right?

[NerdNoise]

So the thread stripped out a while ago and I had a helicoil placed to fix it. Worked just fine until yesterday it just blew right out of the head. I'm screwed, right? I suppose that either way the head is coming off but then what? Do I buy a brand new one? Can I get this one sleeved? Do I find a used one and have it redone? What are the next steps here? 3.4 swap Thanks.

 

[jynx]

I would say that you are gonna want to put a good head back on there. Another coil will probably be hard to get a plug to fit.

I am curious as to why the coil blew. When installed properly they usually are very solid. Did you install it or have it installed?

 

[NerdNoise]

I had a mechanic put it on. of course it's the back cylinder on the passenger side, but it looks like it stripped out somehow. The plug and helicoil came out in one piece and were laying there attached to the wire. Go figure. I tried to screw it back in but once the engine cooled down it just pops out on the first compression cycle. I remember the mechanic putting in some red sealant type goo around the thread before inserting it but I see no trace of it now.

 

[Tigerstripe40]

I had a mechanic put it on. of course it's the back cylinder on the passenger side, but it looks like it stripped out somehow. The plug and helicoil came out in one piece and were laying there attached to the wire. Go figure. I tried to screw it back in but once the engine cooled down it just pops out on the first compression cycle. I remember the mechanic putting in some red sealant type goo around the thread before inserting it but I see no trace of it now.

The red sealant goo was probably red locktite which releases when it gets hot and sitting next to the exhaust manifold, it will get hot enough to do that.

If the helicoil and plug are coming out with the compression stroke, that suggests to me that the threads cut into the aluminum head have 'wiped' and aren't holding the helicoil together.

The 3VZ just isn't worth doing anything to. -I rebuilt the 3vz in my 91 4Runner and regret not doing the 5VZ swap.

If you're considering a 5VZ swap and can let the truck sit while you do that swap, that is the route I would suggest rather than mess with the 3VZ any longer.

 

[lilevo]

Sounds like it wasn't done right to begin with.

Use a timesert instead. That's a permanent fix.

 

[jynx]

If it is the farthest back plug and if it was done in the truck then there is a good chance that they didn't get it cut in cleanly. Getting a drill in there would be a b$@!* especially on the passenger side, so with the head off it might be salvageable but otherwise you will probably need a new or good used head.

If the rig runs good otherwise I would find a head and swap on and call it good. If the motor is gone then now is the time to swap if you are thinking about going that route.

I am rebuilding a 3vz now because the rig it is going into is too far away to fiddle with a swap right now. But I have plans for a swap eventually, sometimes you do what you have to to get you by until you can do what you really want.

 

[KLF]

It may be that when you get the head off that you could find a machinist with the knowledge and skills to fix it, but it will likely be cheaper/faster/easier to just get another head. I know that Tim at DOA Racing sells them all tricked out, but it looks like maybe he's no longer in business?

http://www.doaracingengines.com/ (Returns a "Account on Hold" message from the provider)

 

[Sam Stewart]

Sounds like it wasn't done right to begin with.

Use a timesert instead. That's a permanent fix.

Word. A machine shop can put a timesert in there. You will have to pull the head tho. If you are wanting to stick with the 3.0 I would buy a head from Dover Cyl Head. They have good stuff and they're reasonably priced.

 

[Tigerstripe40]

It may be that when you get the head off that you could find a machinist with the knowledge and skills to fix it, but it will likely be cheaper/faster/easier to just get another head. I know that Tim at DOA Racing sells them all tricked out, but it looks like maybe he's no longer in business?

http://www.doaracingengines.com/ (Returns a "Account on Hold" message from the provider)

I have a set of DOA's 'head studs' for the 3V-E and took them to my machinist when I had my 3.0 rebuilt. My machinist told me that he wouldn't use the studs and told me that he would not warranty the machine work because the threads on the studs were cut and not rolled on (FWIW, he was happy to use the other parts I brought him for the 3VZ-E rebuild). He showed me an ARP head stud and the quality of the ARP stuff was MUCH MUCH better. Further, the machine shop got me a set of ARP head studs for the 3VZ-E for about HALF of what I paid for the DOA studs.