VIN No. 1867

[Rissy]

I had what you had. By the time I’d drilled out the shaft of the bolts, a light waggle of the Y-pipe loosened it straight off the remanence of the bolts, allowing the funny angle you need to get the Y-pipe to, for it to get out of the valley. Once out of the way, I literally unwound the stubs of bolt with my fingers. After all the drilling, they were naturally loosened off. I think it was mostly just the bolt shafts being bonded to the Y-pipe. The bolts only go into the block by about 8-10mm from memory. Try using a reverse drill bit. That might help to unwind the bolt as you drill.

Just my 2p worry of course. I’ve been where you are now. I can only tell you of my experience. It all worked out nicely for me because I took my time and was careful. So that’s why I’ll advise the same.

[Chris P]

Your choice about the water pump of course. Its been my experience that once you start using the car regularly the water pumps can and will fail. Its so easy to get at now and for the sake of say £120 (or so) just not worth not doing it. But its your car.

[Rissy]

To echo Chris P, when I was in my VOD, nearly 9yrs ago now, I had no intention of changing the water pump. I was in there for all the other reasons. Just by the sheer nature of draining down the coolant, just as I’m sure you have had to; the seals on my water pump had chance to dry out. Only when I was finished the job I was there to do, I filled all the coolant back up again. Only at that point did I realise I had an issue with the pump, that wasn’t there beforehand. I gave it a chance to settle and reseal. It didn’t.

Back in I went, after buying a replacement pump from Ed. Double the time. Double the hassle, double the inconvenience.

You may not have had a reason to change the pump before; but you may have now. You just don’t know it yet.

[Justwatching]

(06 Feb 2024, 23:37)Rissy Wrote: The bolts only go into the block by about 8-10mm from memory.  

That's a concerning thought. Might need to re-think the crowbar approach after all as I'm putting quite a lot of force on it.

[Chris Williams]

As Chris wrote it's difficult (but not impossible) to get the Y pipe out with the remains of the bolts still in there. Think I would be tempted to put a washer over the hole with a nut sitting on top and try to mig weld the nut to the remains of the bolt.

[Justwatching]

(07 Feb 2024, 20:28)Chris Williams Wrote: As Chris wrote it's difficult (but not impossible) to get the Y pipe out with the remains of the bolts still in there. Think I would be tempted to put a washer over the hole with a nut sitting on top and try to mig weld the nut to the remains of the bolt.

Sound plan, but I don't have a welder. I've managed to get the Y pipe off using Rissy's suggestion of drilling it out. I did it in gradual steps and paused for sessions of beating it with a hammer and levering with the crowbar. Eventually it let go and left a promising amount of stub. 

   

The longer stub came out with vice grips, but the shorter one broke off nearly flush. I've left it for the time being to preserve my mood. 

I did get the spilled coolant and muck out of the valley. As per initial impression, looks alright. 

   

[Rissy]

That's really good that you managed to get the Y-pipe out by lifting it up and away from bolt remanence. I'm perplexed on how that was possible. My memory was telling me that the Y-pipe has to be moved horizontally by a rotational angle and then lifted up one leg, then the other. I seem to remember mine not being able to be lifted straight up from the valley even after drilling out the stubs of bolts. Maybe my memory from over 8yrs ago isn't good enough...!

Well done anyway.

Small reverse drill bit for that persistent stub now.

[Rich Hanlon]

well done indeed, great progress. I like the bit about 'preserving the mood'.

Often much easier after a break and with a clear head, but I fond that very difficult to do at the time!

[Guinney1971]

great progress, I remember doing that job 20yrs ago..... I still have nightmares......

[Justwatching]

This has become such a fiasco...

Since my last post, I got a bolt extractor set, drilled a pilot hole and wound the extractor in. Problem was, no matter how tight I clamped the extractor in the drill chuck, it always managed to slip. 

For plan B, I acquired a different set of extractors with hex heads. Well it didn't slip! It snapped off inside the stud instead...

Chris had suggested welding a nut to the broken stud, so filled with desperation and anxiety, I went to my parents house and retrieved an old welder they bought me 20 years ago to repair my first car. Dusted it off (literally), repaired some wiring and had a practice session with scrap metal before turning it on the DeLorean. 

   

Unfortunately, this also snapped off. I welded the nut on a second time, but same result. 

I think we're on plan D now...

I've accepted the stud can't be removed without destructive methods. I've started drilling the lot of it out. Progress is painfully slow. Hopefully it will get easier once I get past the hardened extractor. 

This is how it stands at the moment.

   

[Rissy]

In my own humble experience, stud extractors are rarely worth the metal they're made from. Take a measurement of a complete bolt from that hole (from memory, you use two shorter bolts and two longer bolts, so you might need to check a vender website for the length required for that hole - if they give that information away), measure the depth of the Y-pipe plus the engine casing hole to ascertain the difference in depth of the hole compared to the length of the bolt. That should give you an idea of how much empty space there is beneath the broken part before you hit the casing. Use this as a guide for how much you can allow yourself to drill it out, depth-wise. Use a reverse drill bit. You might get lucky and have it wind out as you drill. To aid with this, heat up the the outside of the casing hole with a mapp gas welders torch before each drilling session.

Great care needs to be taken now (but you know this). Frustration is counter productive, all of the time. As soon as you feel you're losing it, then down tools and walk away and come back another day. Longer time spent now, can potentially save you MUCH more time later.

Just my 2p.

[Chris P]

Sound advice Chris...ive done a couple in a similar manner. If I remember correctly, I ended up with slightly larger diameter bolt/stud.

[Guinney1971]

I'll echo Rissy's words here, I remember 20+yrs ago tackling the manifold studs and heads on #2292 with
the help of friends at the time.
We had studs snapping off, then trying to drill them out and going through the water jacket on the heads, resulting
in buying a pair of refurbished cylinder heads from a PRV guru that we knew through the Renault Owners Club
in Manchester.
The VOD/Y Pipe area was a nightmare too.
The engine is now under a bench, whilst we decide what to do with it (keep bits for #6772 or sell it), as its got
block rot and a 3.9 V8 is replacing it.

[Chris Williams]

I think your doing well there, nice clean straight drill hole. Can only echo whats been wrote above never had much success with any stud extractors either. As ChrisM wrote above follow his advice and you wont go far wrong. Especially the walking away bit!

[Justwatching]

Many hours later...