Have I destroyed my engine block?

[blueseamonkey]

Is there a separate place for people who've done something really stupid and need to ask if it can be fixed? If so please move this post there. 

As I mentioned in a previous post some months ago, I had snapped off one of the bolts attaching the water pump to the block. In the end I decided to try drilling it out rather than welding something on the end - a big mistake as it turned out...
Someone distracted me a bit as I was drilling a pilot hole and I ended up going too deep - probably about 0.5cm, possibly as much 1cm. At the time I was hopeful I hadn't caused too much damage, but earlier today when I finally got the car started again, oil started to pump out of the hole at rapid rate. 

I've obviously drilled into something I shouldn't have. I will attach a picture with a red arrow pointing out the area of the problem. I am feeling monumentally stupid and know I have potentially cost myself a fortune. The question is, is it worth me taking the block to a machine shop to try and get it repaired? Not so much costwise - labour is very cheap here and machine shops plentiful and fairly competent. But can the damage I have caused be fixed at all, or is the block likely to be permanently buggered? The hole I drilled stayed straight, despite going too far.

Its also worth bearing in mind Golfs - especially Mk2s, are very rare here, so finding a new block is not going to be a case of just going to the nearest scrapyard. If the damage I've caused really is irreparable, then it could potentially end up with me having to put a Japanese engine in as there's probably only a couple of hundred Golfs in the whole country.

Some good news would be nice, but if it really is bad news for my block, has anyone put a Japanese engine in a Mk2, or know what fits?

Here's the pic

[Jimmyrallye]

How big wos the pilot hole ? Could you just not weld over the hole

[molegti]

I would have thought that could be fixed by a machine shop. I wouldn't make financial sense here but if blocks are that rare it probably worthwhile. 

[molegti]

Thinking about it I wonder if PTFE tape around the bolt threads might work?

[oakgreener]

Could you use a bolt long enough to bottom out onto the hole?
Then cut the hex off and fit a nut. I know it's in the realms of bodgery but, 'when in the trenches'

[Chris.]

Cover the bolt in silicone for sumps and leave it overnight.  Hope it works.

[JC]

whatever option you take - remember, you have drilled into something in the engine, be it a basic oilway / return

Swarf will have entered into the oil - so dont run it until you have plugged the leak, and done a full oil n filter change

then PRAY 

[Agreeable Slick]

It sounds like an oilway, and as such will pressurise when the engine is running.

The PTFE will work, for a while, but will blow again. Best option is to either get the hole welded up and then re-drilled tapped, or see if the machinist can turn a plug up, but I'd prefer the first option.

[Diamond Hell]

It might be an oil return, in which case it wouldn't pressurise and all could be gravy.

[danny_p]

welding in blocks is not allways a good idea,  in this case iu would not reccomend it.

basicly you've hit an oil way if it's leacking in quite an enthusiastic manner it's a pressurised one.  bepending on how much block there is between oil way and whre ethe bottom of the hole should be you have 2 choices.

option 1 )tap the hole,  then cover a grub screw in oil resistant loctite and wind it but not so far as to obstruct the oil way.  this it probaly the best solution but also the most involved  as you will have to wash the oil ways out after and will take more effort to do and do so correctly.

option 2 )  cover waterpump bolt in oil resitant  loctite  do bolt up as per normal and job done.  hope no big bits of swarf found there way into the oilway.  downside is  will need to rember this and possobly heat the bolt ( to soften loctite ) if ever need to change waterpump again but it can be consited a permant fix, unlike ptfe or sillicone.

i'd be recomending loctite 243 

this would do you
http://www.ebay.co.uk/itm/Loctite-243-Lock-n-Seal-Thread-Sealant-3ml-Fast-Acting-Secure-Nuts-Bolts-Screws-/251089040081?pt=UK_Crafts_Cardmaking_Scrapbooking_Glue_Tape_EH&hash=item3a7612b2d1