advice needed

[rgemmell]

I have just been out to drill a hole in my thermostat in line with recent thread. I finished this (with new gasket), started to fill up and thought 'this is taking a lot of water'. At the back of the vee, water is running out near to what looks like a core plug under the coil. Could it be this plug or the head gasket or something else? The strange thing is, it was not losing any water before I did the stat and it is definitely not the stat thats leaking. Note- it is leaking without the engine running.
Can't understand it. Can any of you knowledgeable guys help me out?

Regards to all on the Forum

Robbie

[nib]

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Robbie

Check it aint the top hose joining the thermostat housing you took off.

[NickA]

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I'd check you've got the termostat and corresponding pipe work connected up leak free first. Are you sure it's not leaking at the front and running to the back of the block? It'd be quite a coincidence if a core pug just happened to fail.

[rgemmell]

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Thanks for replies guys. Just gone out to double check and definitely not keaking from around stat it seems to be at back of block. Started the engine and after about 1 min developed a pronounced clicking sound! Switched it off sharpish!

Robbie

[NickA]

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If it's leaking without the engine running it's got to be quite a big leak as the coolant not under pressure. Core plugs usually rot from the insidebut as they're recessed into the block it'd be obvious if they were leaking as they'd be full of fluid. Just to check are we talking about this core plug, the one in front ofthe distributor hole?





Other places that would wet just back of the block are the inlet manifold gaskets and the heater connection that runs down the right hand side of the V. Could this have been twisted loose as you were doing the thermostat?

[rgemmell]

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Nick, the centre of the core plug (as your pic) is not wet, it seems to be running around it. Any thoughts on clicking noise?

Robbie

[NickA]

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If the cores plugs center's not wet I can't see how it would be a core plug, I'm still much more inclined to think it's something you've disturbed when changing the thermostat. I think you'll need to dry the whole area and then watch carefully to see if you can spot the source of the leak.

I'm assuming the clicking's a seperate issue, any clues where it's coming from?

[rgemmell]

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NickA wrote:

If the cores plugs center's not wet I can't see how it would be a core plug, I'm still much more inclined to think it's something you've disturbed when changing the thermostat. I think you'll need to dry the whole area and then watch carefully to see if you can spot the source of the leak.

Nick, difficult to see the source of the leak but it is somewhere under the carbs on offside maybe inlet manifold. I will need to take the carbs off to get closer look. Is this a difficult job - had car 3 years and only jobs have been simple servicing issues.
Any advice from yourself or others much appreciated.

Thanks
Robbie

[DJT]

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Robbie,

Did you struggle to get the thermostat housing off? The only connection I can make between doing this job and a sudden water leak is that you may have inadvertantly caused a marginal inlet manifold gasket to fail when undoing or tightening the thermostat cover bolts. Seems unlikely, but..........

Just occurred to me whilst typing. The two thermostat bolts are different lengths. You haven't put them back in the wrong place so the longer one has bottommed out before squeezing the gasket? Again, unlikely, but I am struggling to come up with something feasible connected with the work you have done.

As for removing the carbs, this is easy. Just remove the brass vacuum spigot from the base of the r/h carb and undo the nut that secures the carb pedestal to the inlet manifold. Lift the whole lot away and rest it on a protective cloth on the air intake in front of the windscreen. No need to disconnect any cables, but you may have to remove a HT lead or two if they are intertwined with the choke cables.

Dave

[rgemmell]

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Dave.
Bolts on correctly and the stat housing came apart easily. I think its been an unfortunate ciincidence.
Is the inlet manifold gasket easy to replace once carbs are off?
Sorry if these questions seem silly - I've not done these jobs before!
Thanks for your help.
Robbie

[DJT]

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Morning, Robbie,

The inlet manifold is fairly straightforward. The only issue is which gaskets to use. There are various thicknesses available and it really depends on whether the heads have been machined, by how much, and if the manifolds have also been machined.

I have always used standard gaskets and had no problems, however I have only done the manifold on its own a couple of times. More often with one or more heads off which makes things a bit easier.

Make sure also that you use quality gaskets. The OE ones were cream and had a slit in them to allow water to seep into the vee rather than the engine if there was a leak. Payen ones are available from most suppliers and the ones I would use if the OE ones aren't available.

Clean up all the faces. Check the threads in thebolt holes are good and helicoil any that are in doubt. If they are good, check that the tops of the holes are flush with the face and haven't pulled up. Can be a good idea to countersink them slightly to remove any raised lips.

Last timeI did these gaskets I used a product called Stag Wellseal. This is a brown liquid gasket sealer and is available from some of the suppliers and on Ebay. Stick the gaskets to the manifold first. As I was in no hurry I then dry fitted the manifold to the heads (but not to full torque) and left it overnight. This ensures the gaskets are firmly stuck in place on the manifold. I the removed the manifold, checked everything was aligned, then applied Wellseal to the engine side of the gaskets and fitted the manifold, tightening the bolts down evenly and in stages.

I would not use silicon based sealer. If you do, then use it sparingly as any that squeezes into the engine can find its way into narrow waterways and start a blockage. If you can't get Wellseal, the Blue Hylomar will do the trick.

Check the tightness again after a few hot/cold cycles and nip up if necessary. There are a couple of bolts you cannot get a socket on and these have to be tightened by spanner. Check the spanner on torqued bolts to learn how tight they feel and then apply to these bolts.

Dave

[rgemmell]

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Many thanks, Dave, you're a star! Got email from LDparts and have re-registered with them so will order gaskets and sealant today.

Robbie

[Mark S]

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rgemmell wrote:

water is running out near to what looks like a core plug under the coil. Could it be this plug or the head gasket or something else?
Robbie

Your leak won't be from this core plug - it onlyleads to a void around thejackshaft.The hole wasthere to support the mould usedduring casting of the block.

I would still favour what has recently been worked on and go for a positive diagnosis of where the leak is coming from before disturbing the manifold gaskets and all that that may entail.Wash and dry the whole area,dust with talc, refillandsee where thewater is running from.

Mark.

[rgemmell]

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Got the inlet manifold off and the leak was from a failed gasket. Another problem has occurred - one of the top set screws holding the inlet manifold to the head has sheared with about 5mm sticking out from the head. I have made a dam from plasticine and left it soaking in Wd40 overnight and will try mole grips on it tomorrow. Have any of you guys any thoughts on these possible further approaches
- drill and try an easyout
- drill the stud out and tap to a slightly bigger diameter (could make it metric and therefore use a high tensile set screw). Is there enough material in the head to allow this?
-or are there any other suggestions?

Robbie

[stustag]

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Get yourself one of these from Halfords etc it's made by Sykes Pickvant and come as indivual sized extractors i.e. 6mm does 6mm studs.

Stuart