43 replies to this topic

[Yoda]

The heater matrix gets hot and I can't see or feel any sign of leaks.

the hot air does seem to have an odour, but unsure if that's just the smell of the carpet and soundproofing getting blasted with hot air and which is a touch damp from rain water finding its way in somewhere.
 

 

 

I second that Sonikk!

 

 

Us the odour a sweet sort of smell?

 

You can bypass the heater matrix by running a hose from the heater tap back to the rad bottom hose effectively cutting out the heater matrix. then run the car as normal and if the coolant level does not drop then the matrix in the heater probably needs replacing.

 

I would check this first before removing the head.

Edited by Yoda, 22 September 2013 - 05:26 AM.

[carbon]

Other option to consider before removing the head is that the water pump has a slight leak. Had this last year on my 1275 - it was an old cast iron water pump so had been on there a long time... It was only leaking when the motor was hot, if this is the case you are looking for a small drip of water under the car at the radiator end of the engine.

[jime17]

The heater matrix gets hot and I can't see or feel any sign of leaks.

the hot air does seem to have an odour, but unsure if that's just the smell of the carpet and soundproofing getting blasted with hot air and which is a touch damp from rain water finding its way in somewhere.
 
 

 
I second that Sonikk!
 
 
Us the odour a sweet sort of smell?
 
You can bypass the heater matrix by running a hose from the heater tap back to the rad bottom hose effectively cutting out the heater matrix. then run the car as normal and if the coolant level does not drop then the matrix in the heater probably needs replacing.
 
I would check this first before removing the head.

Bypassing the matrix. Good idea. Never thought of that. it doesn't really smell like rad water but id not put money on that.

Pretty sure the water pump isn't leaking. Nothing coming out of the tell tale hole in the pump body.

Thanks everyone for your ideas.

Edited by jime17, 22 September 2013 - 11:23 AM.

[Gremlin]

The back row of cylinder head nuts also hold one set of rocker shaft fixings, so, yes, the rocker shaft must be removed and the valve clearances re-set correctly after re-fitting.
 
Head removal sequence is:
 
Remove rocker cover,
Drain coolant
Remove radiator top bracket
Remove top hose
Remove heater hose
Undo the carburettor connections - fuel, choke and throttle cable
Undo exhaust manifold to exhaust down pipe clamp
Remove plug leads & plugs
Undo the b1/2" AF rocker shaft nuts
Undo all the hear stud nuts
Remove rocker shaft
Remove all 8 push rods
Lift entire head and manifolds and carb from engine block.

Bypass hose?

[jime17]

Just a thought. Is there any merit in clamping both heater pipes before they pass through the bulkhead to rule out the matrix as a source of a leak rather than bypassing it?

It would save a bit of messing about.

[Yoda]

Absolutely. You just need to make sure they are clamped really well without damaging the hose. I use snipe nosed mole grips with 3/8 hose over the jaws, same as when i clamp brake hoses etc.

[jime17]

Thanks Yoda. May the force be with you.

[Yoda]

The force is strong within you, young padewan.

 

Dont forget you can get a small weep from the control tap that can go unnoticed too, this is worth checking as the tiny amount just evaporates and you dont notice it.

[Tamworthbay]

The force is strong within you, young padewan.
 
Dont forget you can get a small weep from the control tap that can go unnoticed too, this is worth checking as the tiny amount just evaporates and you dont notice it.

A trick I was taught years ago for small invisible leaks like that is to use a small amount of clothes die ground up and mixed in grease. Smear a tiny amount around where you think it could be leaking and run the engine for a while. If it is leaking you get a big smear of colour coming away from the offending spot. It has helped me track down mysterious leaks a couple of times.

[jime17]

Thanks guys. I'll try all these suggestions.

Really hoping its not the head gasket. A 2 hour job for me always ends up as a 8 hour one involving rounded bolt heads and sheared studs and other complications I've not got spare time to deal with.

I'll post back with my findings.

[Cooperman]

 

The back row of cylinder head nuts also hold one set of rocker shaft fixings, so, yes, the rocker shaft must be removed and the valve clearances re-set correctly after re-fitting.
 
Head removal sequence is:
 
Remove rocker cover,
Drain coolant
Remove radiator top bracket
Remove top hose
Remove heater hose
Undo the carburettor connections - fuel, choke and throttle cable
Undo exhaust manifold to exhaust down pipe clamp
Remove plug leads & plugs
Undo the b1/2" AF rocker shaft nuts
Undo all the hear stud nuts
Remove rocker shaft
Remove all 8 push rods
Lift entire head and manifolds and carb from engine block.

Bypass hose?

 

If fitted.

[jime17]

Thanks again to you all for your suggestions. I'll go through them one by one simplest through to most complex.... I did ask earlier but it may have got lost in the flurry of replies, but if I remove the push rods, do the followers drop in a void or are they held in place by something?

[Cooperman]

On a 1275 block (except for original Cooper 'S' blocks) they can't drop, but on a 998 they can become dislodged. To prevent this, after taking off the rocker shaft and the head nuts, wiggle each push rod to prevent oil-stickage (is that a word?) pulling the follower up out of it's bore when the push rod is lifted. You can actually tell when the rod is free.

Head removal is a job any Mini owner should be able to do and you only need the normal tool kit plus a torque wrench.

[jime17]

Stickage should be a word if it isn't.

Got all the tools. Will bite the bullet assuming I can't find another source for the leak.

Thanks Cooperman.

[seancv1]

Oil suction would be a better description but stickage sounds better