Threaded cylinder head - suggestions please!

Maz · 12 Jun 2010 at 16:56

Afternoon guys,

Got a scoobie as a toy, anyway taking it apart to mess about with and one thing I've noticed is the previous owner must have overtightened a spark plug and threaded the head! Anyway he resorted to tightening the plug up with some sort of sticky stuff!

Anyway do I have any other option other that resorting to replacing the cylinder head?

Thanks

Dogbreath · 12 Jun 2010 at 16:59

I guess you mean he's stripped the thread rather than threaded it? You can get a helicoil fitted to salvage the head.

Maz · 12 Jun 2010 at 17:03

Yes sorry Dogbreath, thats exactly what I mean.

I've thought about Helicoil, due to engine layout on the Impreza do you think it would be possible to fit a helicoil without removing the head?

As it's a boxer and the stripped thread is on the cylinder on nearside and the cylinder furthest from the front of the car I think this is going to be a very difficult job!

Jonny ///M · 12 Jun 2010 at 17:37

I'd imagine getting that done would need the head off?

Surely metal bits inside the combustion chamber = not good.

Maz · 12 Jun 2010 at 17:59

Jonny ///M said:
I'd imagine getting that done would need the head off?

Surely metal bits inside the combustion chamber = not good.

Defo not!

Hmmm, now I need to whip one of the heads off, renew gasket and may aswell do the timing belt while I'm there!

And I thought his Scoob was cheap!

Dogbreath · 12 Jun 2010 at 19:11

You can helicoil a head without removing if there is enough access, you just have to use plenty of grease on the tap to hold the swarf and clean /regrease it regularly.

I imagine access is a bit tight on the Impreza is a bit tight though, removing the head would make it much easier.

Maz · 12 Jun 2010 at 19:15

Looks like I'm removing the head, doing a head gasket and timing belt aswell as new plugs and possibly coil packs

horseunderwater · 13 Jun 2010 at 05:39

Oh dear what other damage has the nob done to it? (previous owner / mechanic)

Ev0 · 13 Jun 2010 at 12:04

Bet you're glad you bought that instead of the MR2 now

Hope it gets sorted ok

Maz · 13 Jun 2010 at 15:08

It's an old car and I did buy it very cheap! So I'm not too upset about having to do the work!

Ev0 · 13 Jun 2010 at 19:50

Think of it as a bit of fun

Maz · 13 Jun 2010 at 19:55

Ev0 said:
Think of it as a bit of fun

My idea of fun isn't removing a rethreading a cylinder head!

This car is also LPG converted so the 20mpg it does shouldn't be too hard on the wallet!

Ev0 · 13 Jun 2010 at 19:59

LPG? Quite cool, how does/did it go compared to normal petrol?

Maz · 13 Jun 2010 at 20:31

Defo notice a difference in performance, but not massive and it's very easy to turn off!