Ah yes, supporting the engine!   Maybe you could fabricate a U-shaped bit of flat steel bar with some holes at just the right spacing to allow it to be bolted into a couple of the holes in the bottom of the block, to act as a dummy sump. Then you could trolley-jack under/onto that to support the engine from below, without an engine support across the wings? Might give more/better access for most of the job?

 

Edit: a bit like this:

 

 

 

Could be a handy tool?

 

Edit2: On the other hand, don't suppose you want to leave the sump off for any longer than you need to, in case crud gets blown into the engine off the road.

True, never thought of that, would be a quick tool made up of wood from what I'm thinking off, don't have any metal lying around the garage at the minute.

So I had a very quick look this morning. Put a bar in the top and eased it slightly. It snapped back tight so I knew somthing had a hold.

I relied straight away I had missed one of the 3 big bolts beside the engine mount, the one that's about 2" deep in the case, duh!

Checked again for others countersunk into the case and noticed one hidden behind the crank pully also.

It still took a little persuading to get off but once past the lugs it came straight off. Couldn't see anything obvious wrong with the chain but spent all of about 30 seconds checking before closing the bonnet again.

Jobs on hold, a head bolt managed to snap being taken out, I can only assume it's a common fault.

All other head bolts came out no trouble apart from the very front left one (bottom right as your working, closest to the coolant housing) all the bolts are a nice black still apart from this one which is really rusty! I'll take pictures tomorrow possibly to show everyone. Such a shame.

At least there's a bit sticking out of the block to try to get hold of.  Wire-brush the crud away, a few taps on the top with a stout hammer to try to break any corrosion bonding between the threads, plenty of plusgas round it a couple of times a day for a few days,  then big pair of grips and try to work it free? 

 

Trouble is, even if it comes out, what's the thread in the block going to be like? Steel bolt in alloy threaded hole + moisture; never a good combination.

That's my worry... I've already wire brushed it and put wd40 on it. Going to heat it up as much as I can, get the block nice and hot and cool the stud down, then use a proper stud extractor. It's a snap on one and works a treat!

Keeping my fingers crossed it's going to work. Can't be bothered with any messing around now, if it doesn't come out it'll be getting scrapped. Or put together missing a head bolt...

I've no idea how it's happend. The bolt goes down past the egr valve though so it's possible it's just been getting hot/cold hot/cold for the past 13 years?

I did think that must be close to the drilling in the head that takes the exhaust gas from port 3 to the EGR adaptor on the end of the head.  I wonder if there is a defect in the head casting that means the EGR gases (which will have a significant steam content, good for corroding I'd imagine) are communicating through into the head bolt hole in the head? May be able to see that if you take the adaptor bit off the end of the head; or just by looking down the headbolt drilling with a bright torch?

Nah, just looked at a spare head I keep under my workbench, and there's a fair distance between those things.

 

Two other possibles though - well three if you include gasket leak, but I guess you 've looked at that?

The main coolant passage out of the end of the head gets quite close to that headbolt drilling, if you stick your finger in you can tell that you're only a few mm away.

 

But my new favourite theory...one of the three mounting holes for the coolant flange is actually drilled right through into that headbolt hole! for no good reason that I can see  . If the o-ring seal stops fully sealing that plastic flange to the head, steam/water may be getting down that thread? Still seems a bit far fetched TBH. 

Spoke to my engineer and he says no chance, get a new block.

It's been heated up with oxy and then poured a little paraffin over the bolt. It's all been cleaned out and wire brushed as much as I can, gave it a little knock about to try and free it a little.

Will be heated up and cooled a few times tomorrow before giving it a try. It's a one chance thing so giving it every chance. I'll keep you posted.

It is usually just the exhaust valves that wear, correct?

Or do all 12 valve guides wear and the inlet valves wear out also?

As far as I know, the exhaust guides wear more than the inlet guides.

Yep, that was my thought.

All 12 will be checked and replaced regardless if need be.

What do the exhaust valves look like? Any sign of burn-out or cracking on the ones of cyl 3?

Nothing at all, a lot of carbon looking build up (black, orangey, browny) type stuff.

Speaking to my engineer he explained to me that when the valve guides wear the valve doesn't always come back straight into the head and over time makes it an egg shape (extreme) I couldn't see anything off looking or different from each cylinder.

He's got the head now anyway and giving it a look over, I'll post pictures of it when it's back all looking new. It's getting a very light skim at the same time to keep it 100%

Fyi the valves cost about £5 each and the valve guides cost £5 each supplied and fitted. A charge of £30 for stripping down the head and grinding the new valves in and £20 to pressure test, skim and clean.

So if all 6 valves get changed and all 6 valve guides (that's what I've requested, hoping the inlet are fine) it will cost me £30 for the valves, £30 for valve guides, £30 fitting and grinding and £20 for skim, it's cost me £110.

And around £200 for parts.

I'll say £350 for the full job with a service kit at the same time so all in all not bad....

..... This is providing the snapped bolt comes out!

I got all 12 guides done, with seats re-machined to match and a minimal re-facing skim, with no other replacement bits for a shade over £150 on this spare head I've got. I did the disassembly/re-assembly myself, I think, but it's a while ago now. I think the per guide price was a fair bit more, and things are generally priced higher down my way... :'(

Would be £170 for me getting all 12 done, which I'm tempted to do anyway, but if the guides are all fine with no wear on them I'm happy with just reseating the valves to make sure they all sit 100% home. That's with new valve stem oil seals also I should add.

I'll also add....

The throttle body is manky! Looked ok'ish from above but is coverd under the butterfly. Gives me a good chance to clean all the inlet manifold, throttle body and egr valve while I'm at it. Anything els you can think of?

I was thinking earlier that it was a bit concerning that the valves don't seem to (definitely) explain the low compression on pot 3. Would it be good to check piston rings on that cylinder?

Then I was lying in the bath and thought "maybe the corroded headbolt was so far gone that it had lost enough of its strength/preload that the pressure was leaking out of that corner between block and HG, or head and HG, or both?"

Just another wild theory from uncle Wino...

I don't think it would have lost its strength enough to loose it's force. That theory is flawed as the result is because of the theory!

As for piston rings.... It's crossed my mind, but I really don't have it in me to go further, it's bad enough doing this.

Keeping in mind I could have just left everything and just put a timing chain on it and drove it as it is.

I'm thinking for my snapped bolt...

- Clean it up

- Cut head off new bolt

- Weld threads to snapped stud

- Tighten down with High strength nut with the rest of the new head bolts.

I'll find out more tomorrow about piston rings, valve play and guide wear, as well as the stud removal.

Hehe, I didn't mean the bolt corroded, leading to the coolant leaking onto the bolt and corroding it.

I meant *something* caused the bolt to rust, which weakened it, which then caused pot 3 to leak its compression and give a low result on your test.

 

Your headbolt welding plan...

...I guess you're much too young to know what tennis-star John McEnroe was famous for yelling at the court officials?

I almost used google, but that's cheating. So yes I'm to young

https://www.youtube.com/watch?v=ekQ_Ja02gTY

 

at about 0:14...

 

Ok ok! I'm clutching at straws here. I've been told I need a new block, that ain't happening! At least not this week anyway

I seen its part of a repair kit on peugeots to do a similar thing, I don't see why it wouldn't work just as well as a bolt

Clean up the top off the broken stud with an angle grinder and MIG weld a big fat nut to it then brute force it out and repair the thread if necessary with a long or double short Helicoil insert, I always chase block threads through with a plug tap before refitting anyway, it gives much more accurate tightening results.