L322 Oh Dang it - This is a bit more serious - Head off time I think....

So following on from a previous post - well not so much following on, more of, oh that's more important....



Wow - thats fecked.....

Took the acoustic cover off, the coil cover looked a little 'displaced' so I took the coil cover off and shone a torch down the plug wells and saw this:



Hmmmmmm......

Then took Coil 8 out and found this:



Then looked closer at the plug hole, and found this:



No thread visible........dropped the plug back in and it feels like it just slips straight down.....

So, what has happened is by the looks of it as this stage, the plug threads have stripped, blown the plug into the coil pack and shattered the stem.....also the pressures of running at speed when this happened has distorted the coil cover.....it happened while the other half was driving back from seeing me at lunch on the M3....(insert shocked face emoji here)

Fun.

So the question is, as the plug hole is deep in a well is it possible to helicoil? Is it possible to helicoil an M62 plug hole in the first place...??

Would you just replace the head with a replacement - or is a helicoil a decent enough repair for plug holes?

I know they have been done on head bolt holes and on Rover V8 plugs holes - but my (so far) limited research hasn't come up as conclusive...?

Love it....!!!!!

@Saint.V8 You certainly know how keep yourself and us entertained It's way above my pay grade but good luck with it and I shall enjoy learning from you, yet again.

Looks like a right monkey tightened those plugs in there!

So that's both RR out of commission!

Surely the RR Saint can confobulate something together!

Surely swapping on a new head wouldn't be too difficult?

Blimey......

if you were stuck in the desert you'd tap a helicoil in, in-situ, all that's needed is swarf control and piston positioning.

JB-Weld and some buffing compound?
Why not at least try a helicoil first? - Plan "A". If it works you are a hero and it was relatively inexpensive. Hoover out all swarf most thoroughly.
If its not a winner.... then Plan "B". New/exchange/recon head.

My concern is

a) swarf
and
b) limited access as it is no 8 under the ABS ECU and etc (can barely get my hands in their to get the plug in and out)

Would be soooooo much easier than taking the head out.
................

Yes, both RR out of action.......bugger, we will sort it never fear, Saint s here!!!!
.................

Luckily we have the baby BMW and the 110

Head off is quite a task I'd imagine, if it were me I'd lower that piston to a tad below TDC, then make room (if poss) to tap a new helicoil in 'in-situ'. Some grease in the bore would catch the swarf.
A hoover/vac condensed down to 1/4" tubing would surely suck up the debris and one of those camera thingy's would be good for final inspection.

Reckon you are about to find out if you can Helicoil an M62.
Even if it works then you will never trust it so just go for new head.

A helicoil is a permanent repair.

If it's possible, try and get one of those spiral fluted taps for the helicoil, that way the swarf should be long strings that come up the tap rather than get pushed down

Would it be possible to tap a thread and pop the helicoil onto the plug? Then screw her down. Job done.

Hi ant, it was pretty easy pulling the heads off our little project but a helicoil is a pretty good fix if you can get access as you say. We must arrange to meet up so I can return your can locking tool kit and a bottle of what you drink. Were having another go tomorrow to button things up on my mate RR now we have sorted the cam that was 180 degrees out it purrs like a tiger just a banks rattle to sort at some point were holding its not a bent valve.

The swarf is what i'd be worrying about tbf

Doo said:

Would it be possible to tap a thread and pop the helicoil onto the plug? Then screw her down. Job done.

Click to expand...

no they have to be fitted first

doesnt look like a much manouvering space for a helicoil, no matter what method to stop swarf getting into the chamber i'd be paranoid of something residual getting in and damaging the bores its a feck and half but i would pull the head. helicoiling is going to easier on bench with room rather than risk a bad helicoil in situ. and if it doesnt helicoil then the head is off to get a replacement. and you know that no FOD will happen in the chamber

Henry_b said:

The swarf is what i'd be worrying about tbf

Click to expand...

That's easy. A length of dowel about 6 to 8mm diameter, a small hole drilled through and a small length of wire inserted through and twisted around tight, some blue tac wrapped around that so the end of the dowel resembles a match stick, then poke into the hole to stab at the swarf to pick it up. Wouldn't worry too much about teeny dusty sized bits as they'll get blown out the exhaust or burned off. It's aluminium after all.

buy correct plug repair helicoil kit, tap hole, fit helicoil ,vac clean ,fit new plug, as good as new, i have some different length tap wrenches not hard to make

Doo said:

That's easy. A length of dowel about 6 to 8mm diameter, a small hole drilled through and a small length of wire inserted through and twisted around tight, some blue tac wrapped around that so the end of the dowel resembles a match stick, then poke into the hole to stab at the swarf to pick it up. Wouldn't worry too much about teeny dusty sized bits as they'll get blown out the exhaust or burned off. It's aluminium after all.

Click to expand...

Doesn't look like there is enough space for all that, let alone the helicoil fitting kit.

Henry_b said:

Doesn't look like there is enough space for all that, let alone the helicoil fitting kit.

Click to expand...

I have to say I don't know the engine bay involved, but I have used this method to great success for getting swarf out in the past.