Spark Plug Thread Repair

[LS_rolf]

Hello together,

I have a 1998 LS400 with a blown out spark plug thread, now I want to repair this one with a good and cheap method,

preferred without removing the cylinder head.

I found several repair kits in the net, the favored seems to the Time-Sert System.

Has anybody experience with that, or are there other recommendations to repair that thread.

I talked to an engine mechanic, and he told me that is important not to harm the valve seat inserts with that "operation"

A picture of the cylinder head from the bottom would be helpful to get an idea how the distance is between the spark plug thread and the valves.

Any comments and may pictures would be appreciated.

Thanks in advance Rolf

[SRK]

First thing is good and cheap don't go together. However you can get good and "reasonable". Forget the "Time-sert". Use a Heli-coil only. The cost of the kit is about the same as what an experienced tech will charge to install it. If you have never used a heli-coil, don't practice on a Lexus. Practice on a trashed head from a Corolla or something. Or a lawnmower.

So if you have no experience, get a person skilled in their installation to do it. With a heli-coil properly installed, it's better than new, and no, the head won't have to come off.

[lenore]

the time cert is discussed a great deal on the Ford F150 site...Excellent repair according to everyone. Highly recommmend it. Heli coil is ok, but no where as good as the time cert for a solid permanent repair...

[LS_rolf]

Hi all,

thanks for your tips,

the thread is repaird with a bushing, no time-cert,another system.

A motor mechanic came along, looked with a tool in the spark plug hole, an in the piston chamber,

drilled a new thread, with lots of grease on the thread driller,

cleaned everything with brake cleaner, let the engine run for 10 Seconds,

inserted a bushing with locktite,

inserted a spark plug, and thats it.

was finally done in less than an hour.

Now I hope that it is ok for the next 200000 Miles :)

I will update this entry is something happends.

RGDS Rolf