Impreza's # 3 cylinder spark plug threads are toast

[Legacy777]

Well I've had an exhaust leak, or so I thought for over a year it seems. I never could find the leak. Last weekend I had some weird issues with idle on the Impreza, but it went away. I needed to change the oil, so I figured I'd do a tune up. I got to changing the plugs and found my exhaust leak. The plug was barely tightened. I am amazed at how well the engine ran with it like this!

Anyway, I'm done with this car, and will be putting more of an effort into finding a newer Legacy. However, I do want to fix the Impreza, and have been looking at spark plug thread repair kits. I saw Alex had a similar issue on his Legacy, and bry had a good write-up for a helicoil
http://bbs.legacycentral.org/viewtopic.php?f=5&t=45320

I found this kit, which looks pretty darn good
http://www.timesert.com/html/sparkplug.html

They even have a video
http://www.timesert.com/html/howtosp.html

Was wondering if anyone had any experience with it or suggestions. I don't know if I can find one locally or not. I'm going to have to drive the Legacy to work and back with a leaking radiator...which is another story....

Thanks

[PhyrraM]

The timeserts are good. There is another brand on the market with slightly thicker wall thickness that is also very good. Both kinds require the insert to be a length close to the depth of the plug holes on the heads.

I would not advise a heli-coil type of kit for a sparkplug. Too much chance for damage and leakage.

[Legacy777]

Thanks for the feedback!

Since I'm really just looking to fix the Impreza and sell it, I'm fine with the timeserts, even if there is something with a little thicker inserts. I'll look today and see what I can find.

[Legacy777]

Those Time-serts are not cheap! With shipping, the deep reach tool, and the insert, it was $200. However, I usually don't mind spending money on tools that I will keep and can use in the future

[Legacy777]

Also, just for reference, here is the site where I got the Time-Serts & the specific part #'s. They would be the same for pretty much any Subaru motor since they all would likely need the extended reach handle and the insert is based off the spark plug, which is common across a lot of Subaru engines.

http://www.denlorstools.com/

Time-Sert spark plug repair tool (M14x1.25) - p/n: 4412E - $184.99
Time-Sert spark plug insert (.60" / 15mm) - p/n: 44129 - $2.53
Time-Sert Driver oil (Optional) - p/n: 6010 - $2.99

[beatersubi]

I've had good luck with the Time-Sert kits. Albeit, not on Subaru engines, but the principle is the same and I could imagine all the kits are the same quality. As you have already found, though, they're not cheap.

[Mister Anderson]

I have had to do a spark plug hole repair on my VW bus. The repair has lasted 10k miles and counting. I used an helicoil as the repair. Just an FYI the bus heads run close to 400 degrees Fahrenheit and are aluminum.

[Legacy777]

Got the time-serts this past week and did the repair on Friday. Everything went pretty smooth. When tapping the hole I probably should have pulled the tap out and regreased more frequently. I did end up with a blob of grease shavings in the cylinder. To get that out I partially filled the cylinder with brake cleaner, pulled the exhaust, rotated the engine so the exhaust valves were open, and the grease blob came out. I repeated this one or two more times, and felt confident that everything was out.

Otherwise everything went good, the engine is running good, and no more exhaust leak!

Here are a few pictures:

http://main.experiencetherave.com/subar ... plugrepair