timing chest to block leak from missing water pump bolt

[justustwo]

Hi all from a very wet and windy Cape Town.

Now that I have put you all in good spirits knowing an old Brit is shivering down here I need some helpful advice on my ‘NEW’ Defender 110 200tdi(1993).

I have had the vehicle 2 months and been slowly giving it a good service and clean up before I use this as my everyday vehicle instead of my series 3 (R6),but 2 weeks ago my clutch went on my S3 so now am pressing ahead to get it up and reliably on the road .

I did a cambelt change along with water pump (no problem with previous water pump but just for piece of mind), got it all back together and started and ran well BUT I noticed a small leak the next day( a constant drip) coming from the outer right side bottom of the water pump (the one closest to the alternator-as shown)

When I changed the water pump this bolt was missing(but it did not leak) . When I tried to put a new bolt in it did grip so put( a 75mm) bolt in as stated in the manual.

This has now started leaking through this bolt hole(must be along the threads)and now subsequently through the gasket where the timing chest joins the block. I did try taking the bolt out and filling with some blue hylomar before putting it back but still had a constant (very slight ) drips . (I think I must have disturbed someone elses handiwork with me putting a bolt in

Decided I did not want to trust in trying to seal further and tonight I have taken the timing chest off (with help from the tech archives here)and the thread in the block looks to of had the first 5-7mm stripped but further in I can see a good clean useable thread. I don’t think I would want to trust drilling and re tapping to larger size as the chest looks very thin of excess metal material for a larger thread

My questions are:

why is the manual correct that bolt length stated is 75mm long ?? that means its only going into the block @5-10mm .There seems to be room for at least another 10mm (its already threaded there )before it would be liable to break out of the block and into the water passage way.???

I was going to put a longer piece of threaded bar in and get it bonded in then put timing chest over and in position and get it all bolted up with a flanged nut then cut off any excess.

Should the back of the timing chest be oily-mine was-(Yes/No)???

I will put new gaskets on IP ,chest & water passage to chest ,I keep seeing things about a small round washer sized gasket going somewhere at the back of the timing chest to block but am not sure exactly where ,even on the manual its hard to see where it goes(Where)???

I put the gaskets on with a little smear of blue hylomar thinking this is the best(its expensive!)but would RTV be better(Yes/No)???

Will put new seals on chest for IP and camshaft

Will also put 2 new ‘O’ rings on camshaft pulley securing bolt and washer.

Have already done the crank pulley seal(behind the small crank timing pulley) and I shouldn’t need to replace as its only run for 10 mins max(Yes/No)???

By the way I have also heard that there is possibly an ‘O’ ring on the crank behind the small crank timing pulley but there wasn’t on mine and did not put one on is this right(Yes/No)???

Thanks all for any advice and a big thank you for the great forum

[Retroanaconda]

I recently had the front of my 200Tdi off to fix a very similar issue, the bolt that you had a leak from had long been snapped and I was tired of the leak. I drilled the snapped bit out of the block and re-tapped for a Helicoil thread repair insert, which enabled me to re-use the standard M8 bolt.

I can answer some of your questions:

• Yes the back of the timing chest is supposed to be oily, the cavity between it and the block is open to the sump at the bottom.
• The round washer-style gasket goes between the chest and the block where the bolt for the timing belt tensioner goes - note that this is a different location on Defender engines to Disco engines (the blocks are the same and have both holes - the timing chests differ).
• Your crank pulley seal should be OK as you suggest if it's only run for a while, so long as it is damage free.
• Hylomar is OK to use, as is RTV. You shouldn't need any in theory if the mating surfaces are OK and you're using decent gaskets. A smear of grease is useful to hold gaskets in place in this instance. I use a thin smear of RTV however on the water pump bits, as the mating surfaces are not so good on mine. As it is on mine there is a very small weep from the bolt to the left the one you have a leak from.
• Not aware of an O-ring on the crank timing pulley. Two on the cam pulley though as you say, one large and one small.

Hope that helps. I have a few photos of my engine in various states of disassembly if you need reference.

[western]

Yes, the 75mm bolt length is correct.

no O rings on my crank pulley, last time I replaced my timing belt.

[justustwo]

thanks very much chaps ,both your replies have answered all my questions and will get parts today and crack on with it .