Cylinder head and tappets

[meganwilkinson2008]

Hi having power washed my engine to find oil leaks i have found i have a leak from the cylinder head just above the water pump.I just wondered if anyone has had the same problem any advice on removal i e is it very difficult and is it possible to leave the tappets on. Also have looked in my manuals and found it states two different tappet gaps one says 012 cold in the handbook and the other says 015 cold in the manual.my car is a 1098 traveller.wanted to know which one it is. Any advice would help many thanks.

[Chipper]

Removing the 1098cc head is a piece of cake, relatively speaking.

Drain the radiator (remove bottom hose, drain into a suitable pan), remove top hose to thermostat housing and either the heater valve itself or the hose and cable to it, also the loosen the jubilee clip on the brass pipe where it goes into the bottom radiator hose. Remove the inlet/exhaust manifold/carb assembly.

Undo the cylinder head bolts - no need to remove the rocker assembly, which is held on by separate bolts. Lift the head - beware, it's quite heavy, so careful not to put your back out! It may need some cajoling to get it to come loose - tap with a mallet or club hammer on the sides.

Carefully inspect the head and block mating surfaces, and the condition of the head gasket to find out why it was leaking.

If you're lucky, you may be able to get away with just cleaning the head and block with wire wool, fine emery paper, etc., and fitting a new gasket (Payen are good). However, you may need to get the head/block skimmed.

This You-tube clip may be useful, to give you an idea of what's involved:

https://www.youtube.com/watch?v=z7Nge8DuO0o

12 thou was the A-series tappet setting for years (some, including myself, still use it), however, I think with the introduction of unleaded fuel, it was suggested to set them to 15 thou - something to do with increased duration for the exhaust valves to cool down or similar...

[meganwilkinson2008]

Great many thanks for the reply very helpful and thanks for the link brilliant.

[philthehill]

If you have not changed a cylinder head gasket before I would advise removing the rocker gear and push rods before lifting the head as there is a good chance that you may bend a push rod and if the rockers are still attached to the head when you come to refit it all you will need a dozen hands to ensure that the push rods are not trapped.
For an extra 5 minutes work it is better to remove the rocker assy/push rods as was done on the 'You Tube' video .

[bmcecosse]

The rocker shaft retaining nuts should all be loosened anyway - before loosening the head nuts. You won't need to go near the 'tappets' - just shoogle each push rod before lifting it out to prevent it lifting the cam follower (sometimes incorrectly named as 'tappets') out of the block. Are you really SURE the oil leak is from the head/block joint? This would be most unusual - although not impossible. Oil running down from the rocker cover is much more common - and it can then run round the head/block join.....giving a false impression of where the oil is leaking.

[alexmcguffie]

Given the oil gallery going up into the head is at front right of the block when looking under the bonnet then it could be coming from there. As you've given it a good clean then I guess you are pretty sure thats where its coming from.

I'd never take the head off without removing the rocker shaft and pushrods first. Be sure to release the rocker shaft nuts evenly though as rocker shafts have been known to snap otherwise.

[bmcecosse]

"known to snap" - I've never heard of that - but I suppose with super strong springs it's a possibility!

[meganwilkinson2008]

Hi many thanks for all the advise. Think I will power wash it again to make sure. All I can see is oil coming from above the water pump and running down but its definitely not the rocker cover. Many thanks

[Chipper]

You could try just nipping up the head bolts to 44lb/ft and seeing if that does the trick, before you go removing the head.

[bmcecosse]

It is possible for that oil gallery to leak out past the gasket, but unusual - the pressure there is relatively low.... Is oil getting up to the rockers ?

[meganwilkinson2008]

Hi yes oil appears to be getting up to the tappets. Its all a bit strange, thought it was the timing chain oil seal till i power washed it, but the leak is above the water pump.Will try and power wash it again over the weekend to make sure.

[alexmcguffie]

It is possible for oil to be getting to the rocker shaft while there is still a small leak from the cylinder head joint.

[bmcecosse]

Very unusual leak though...so unusual I've never seen it on here or any of the Mini forums.... Try to see if it isn't oil creeping round from the cam follower covers.... I wouldn't use 'pressure washing' - just careful wiping with a rag may show better where the oil originates. It has been known for the oil passage drilling in the side of the head to weep some oil from the rivet that closes it off on some heads.

[meganwilkinson2008]

Hi ok will give it a good wipe with clean rag and see if i can find where it is coming from.seems to be quite bad now as i have a few drips after been left for 15 to 20 mins. Got to get to the bottom of it i hate oil leaks and use my traveller every day . Many thanks will let you know how i get on.