One snapped head bolt - any advice

[Keith-how2dewitt]

Hello,
My tintop 2.5 TD has managed all by herself to snap one head bolt near the front left hand side outside of the rocker cover. Anybody suffered this before?
I've got a new set of head bolts and am planning to have a go at extracting the snapped thread section and renewing the one bolt whilst checking tightness of all others. Any advice?

Will also change cam belt while i'm on

Cheers
Keith in North East

[westonwarrior]

is it an exhaust manifold bolt?
if so its common

[Keith-how2dewitt]

No, it's an actual cylinder head bolt. I found it loose in it's bolt hole on a periodic inspection last week. The head gasket isn't leaking by the way.

I know about snapped manifold bolts and squealling manifold gaskets as it had 2 of them snapped when I bought it 6 years ago and sounded like a banshee when first started up. I drilled both out and replaced them with great success.
cheers
Keith

[Simon Jones]

Bear in mind they are stretch bolts so are not really designed to be re-used or 'nipped up' a bit. It may be feasible to replace them one by one following the correct tightening sequence without disturbing the gasket. Not sure - never tried it.

[321Away]

I've seen it a couple of times but they were both toward the rear of the engine, and these snapped during head removal,and getting them out of the block took some serious effort using ED40, heat, and two nuts against each other, that was only possible with the head removed tho as the head bolts arent ever proud so you have nothing to work with??

Julian

[Keith-how2dewitt]

Oh dear, doesn't bode well for my problem. May need the prayer cushions out!

I was hoping to pilot drill the stub with a long series drill and then try to easy out the blighter.

Will post on how I fare as the job is tackled.
Cheers for the reply
Keith

[Keith-how2dewitt]

Well folks, Prayer works! or Im the luckiest bloke driving a Bongo.

Got kitted up in warm togs and set-to removing the top cowling over the engine and then the rocker cover.

Pulled out the top section of the snapped bolt and then quickly realised why it had snapped. All those years ago when I drilled and tapped the hole for the broken front exhaust stud, I'd inadvertantly nicked into the head bolt which will, as you know, have created a small "stress raiser" in the highly stressed head bolt. A number of thermal cycles later the bolt has given up the ghost and sheared across the damaged area. So beware when you drill into the exhaust stud holes folks - don't go too deep.

Now to the good news.
Managed to get the threaded section out by tapping and turning the stub with a screwdriver straight down the hole. The screwdriver end managed to bite into the end of the bolt just enough whilst constantly tapping the handle of the screwdriver and creating a jarring turrning moment to the broken stub. Copious amounts of WD 40 were applied until the stub was now free of the threads and completely loose in the hole. I then went "fishing" for the stub with a piece of blue tack on a long 6mm bolt thread (after first de-greasing the stub end with solvent)
I can' tell you how good it felt as the broken stub came out of the hole but you can probably imagine if you've tackled similar jobs yourself.

Have pulled stumps today as it's dark outside and will probably tackle the cam belt change and check the valve clearances while the rocker cover is off tomorrow.

I'm off to put the lottery on now just in case my luck is holding out.
Regards
Keith

[g8dhe]

You lucky so an so
That never happens to me !

[Keith-how2dewitt]

it never normally happens to me either. But i'll take any good fortune coming my way!

[westonwarrior]

[winchman]

The best tool I know of for this type of job are these
http://www.overstock.com/Home-Garden/Ri ... cid=133635
Expensive but never let me down

[dave_aber]

That's the type I have - needs very accurate drilling but works a treat.

[Keith-how2dewitt]

So,
Today the weather improved so no need to tog up as warm as yesterday.

Anyhow set to and changed the cambelt (2nd time since buying the van) and checked all the valve clearances and all were within tolerance. Not bad considering I have never checked them before.

All back together now and started up first turn of the key. A good days work in my book and enjoyed the task. Only problem was I accidentally leaned on on of the electrically operated plastic valve connector hose points and snapped off the connection where the rubber hose goes on. Had to repair it with some araldite, backed up with some loctite epoxy repair putty for strength. Cant see those electric valves being easily obtainable? but the repair seems good.

Am thinking of blanking off the EGR system in future. Does anyone know if you need to disable the electrics to the EGR valve if you fit blanking plates to the ends of the EGR pipe? or do you just leave everything in place?
Cheers
Keith

[Nevets]

All back together now and started up first turn of the key. A good days work in my book and enjoyed the task. Only problem was I accidentally leaned on on of the electrically operated plastic valve connector hose points and snapped off the connection where the rubber hose goes on. Had to repair it with some araldite, backed up with some loctite epoxy repair putty for strength. Cant see those electric valves being easily obtainable? but the repair seems good

Am thinking of blanking off the EGR system in future. Does anyone know if you need to disable the electrics to the EGR valve if you fit blanking plates to the ends of the EGR pipe? or do you just leave everything in place?
Cheers
Keith

Those plastic valves break just by looking at them sometime

Just buy or make the blanking plates slip them in and all works fine so no need to disturb anything else..

Glad all ok with the headbolt (very lucky)

Cheers Steve.

[briwy]

Am thinking of blanking off the EGR system in future. Does anyone know if you need to disable the electrics to the EGR valve if you fit blanking plates to the ends of the EGR pipe? or do you just leave everything in place?
Cheers
Keith

Left mine connected when I blanked off the EGR. Don't seem to be any problems and keeps the wiring neat and tidy.