Morris Minor Owners Club

1971 1098
Just taken the head off to change the head gasket because of thick white gunge on the rockers and Its in a right mess
Looks like some one has used red hermatite to seal it.
I have taken some pics.
So looking for advice on the state of the pistons and bores and the red stuff

Was the thick white gunge the only reason to remove the head?
There's more then one reason for white gunge with a car.....
Though if you've found red sealant in, there something's not right...
Seeing the photos would be useful for comments.

Sorry, here are the pics

"Mayonnaise" inside the rocker cover is a common problem that is normally due to blocked engine breathing pipes exacerbated by short journeys when the engine never properly heats up.

If of course there were other symptoms as well, oil in the coolant, low or inconsistent compression readings, poor power, white smoke from the exhaust, then a failed head gasket is the likely reason.

People use all kinds of gunk on head gaskets and it is not necessary. It just makes a horrible job to clean it all off!

Providing you are careful to stuff the bores with rags or paper towel and to prevent the red gunk from going into the oil ways and waterways (which could conceivably get blocked) then you should be able to scrape it off. A window scraper such as used to remove paint from windows is a good tool to help clean up the mating faces of block and head.

Stephen

I just saw the photos which were not there when I typed my reply.

That sealant will easily scrape off. Use the window scraper I suggested and finish off with a green pot scourer lubricated liberally with WD40. The scraper only costs a few pounds and uses ordinary Stanley knife blades.

https://www.stanleytools.co.uk/product/ ... ss-scraper

Stephen

She started loosing water with no visible signs of a leak and a lot of water from the exhaust on start up
That with the white gunge I figured its best to take the head off and check,
Looking at the head gasket it seems to have a lot of corrosion at no 4 cylinder.
We are planning to her touring Devon and Cornwall later in the year so we need it running perfectly
Thank for all you replies.

Nax wrote: ↑Wed Apr 29, 2026 7:52 pm She started loosing water with no visible signs of a leak and a lot of water from the exhaust on start up
That with the white gunge I figured its best to take the head off and check,
Looking at the head gasket it seems to have a lot of corrosion at no 4 cylinder.
We are planning to her touring Devon and Cornwall later in the year so we need it running perfectly
Thank for all you replies.

Sounds like a very good to reason to do the head gasket. The copper head gasket that is part of the ESM decoke set is good but there is an even better quality one available from Minispares. This is the type I fitted before touring in the Netherlands a few years ago. https://www.minispares.com/gug702506hg- ... minispares

Remove the studs before trying to scrape off the old sealant. They should come out easily using the two nuts locked together technique.

Check for "pulled up" threads once you have removed the studs. The blade of the scraper will catch on a pulled up thread and if it does, lightly countersink the thread. Grease will catch any swarf and can then be wiped off. Take care to clean out any muck or liquid from the stud holes with paper towel as in theory, the block could hydraulically crack if a stud is screwed in to a hole containing liquid.

Stephen

Thanks for the advice, I've got the block all cleaned now but 2 of the studs refused to budge even with the 2 nuts trick So i let them be
I cleared the stud holes with wd40 and then vacuumed it out worked a treat
Just got clean the head up now and re grind the valves.
couple of questions
where can I buy some washers for the rocker pedestals ? a couple of them where missing when I took it apart
I tried ESM but they are out of stock
Also missing where the collet clips, Are they really needed?

Unless you are revving the engine to high numbers the collet clips are not required. BMC latterly deleted them as they considered them surplus to requirements.
When you say washers do you mean the plain washers, the spring washers or the flat plates that go across the top of the pedestal?

Nax wrote: ↑Thu Apr 30, 2026 3:12 pm Thanks for the advice, I've got the block all cleaned now but 2 of the studs refused to budge even with the 2 nuts trick So i let them be
I cleared the stud holes with wd40 and then vacuumed it out worked a treat
Just got clean the head up now and re grind the valves.
couple of questions
where can I buy some washers for the rocker pedestals ? a couple of them where missing when I took it apart
I tried ESM but they are out of stock
Also missing where the collet clips, Are they really needed?

These interactive line drawings are useful and even if you don't want to buy from that particular supplier, you will have found out the part number.

https://www.moss-europe.co.uk/en-gb/cyl ... 17--02--01

Stephen