Furred up waterways/overheating

[Bigcatfrankie]

Hi Joe,
No, still not sorted.
It's definitely not the radiator as I did a temperature check at top and bottom of the radiator when it was running and there was no appreciable difference.
I think probably the only way forward is more than likely a proper block jet flush through as suggested. As the old girl was 50 years old last week the build up of crud over time is the probable culprit!

[christopher storey]

Isn't your radiator a crossflow ? In which case you may need to measure temperature differential at a different place. In any event , no difference in temperature indicates a rad which is NOT cooling . In a properly working system, when the thermostat is open there should be at least something of the order of a 20Degree C/ 40 degree F difference between exit water and re-entry water

[AshM]

Mine was 50 years old in January.

Had always run really well - nothing untoward on the temperature side of things. Would sit in traffic and the temp gauge would rise, fans would kick in and the temp would drop down. All good.

And look at the state of the block when the engine builder stripped it last year - incredible...

cheers
Ash

[mgcjag]

Thanks for posting Ash....Its exactly as i was refering to in posts above....Its not uncommon to see this in XK blocks.......Steve

[markc555]

Blimey Ash, that's amazing!!!

Did you see the coolant that was drained from yourcars system? Was there ANY sign that there was that much crap in the block??

Steve, my car is a US delivered car with air conditioning which I think had a 13lb rather than 7lb coolant cap. Presumably the greater system pressure allows it to run a little hotter.

Cheers

Mark

[mgcjag]

Hi Mark...I have drained blocks that look just tinged brown but when opened the look like Ash,s block in the video...yes air con 13lb cap as far as im aware...Steve

[AshM]

It was truly remarkable the car ran as well as it did. Was genuinely an engine that has never had any temperature issues.

And half the block was without water...

Robust beasts...

[markc555]

I think I might have to knock out a couple of core plugs to checks or sludge etc before I refit the new pump. Any tips on which one are best/easiest to get at?

Sooo don’t want to have to take the engine out

Mark

[Tom W]

I’ve managed to replace a couple that were leaking without taking the engine out. On the LHS behind the exhaust. I have a tubular exhaust manifold, which does obstruct some access. Mines a long stud block, so there’s a few more core plugs to go at.

[mgcjag]

Hi Mark...if your replaceing the water pump then you can look into the block through the pump opening anyway...Steve

[markc555]

As per Steve's suggestion I tried peering into the block through the water pump inlet/outlet but couldn't see much due the viewing angle. I hit upon the idea of using one of them there endoscope camera thingy's. Got a cheap one from Amazon, connected it to the PC and shoved it in...

I managed to slide in a full 14 inches without protest on the exhaust side and snapped the first 4 images (below)...









I then inserted it in via the thermostat housing and down the first inlet manifold water gallery about 8 inches and took the next 3 pics...







The images aren't great quality and I'm not sure eactly what/where I've got pics of, the base of the head studs I think, but there's deffo no blockages or crud in the those areas

I also checked the fans and while they're both turning in the same and correct direction one is much stronger/faster than the other so I will need to repair or replace that one.

Based on the above I'm 80% happy there's isn't excessive sludge in the block and will put it back together with the new water pumo and see how we go.

Cheers

Mark

[politeperson]

It looks very nice and clean to me, I must say.

[Joes66]

Ho Mark
As I mentioned before
Suspect the radiator
Get a re con radiator or get your one re cored
Bet it's the culprit
Especially as you said it was the same temp at both ends
This says to me it's not doing its job
It should be hotter at one end
Joe