I found this interesting.

[tony rodaway]

Hello guys.
I have always loved watching clips/videos about landcruisers.
I have watched this guy for a long time now and I find him interesting but the wife disagrees.
I found this clip interesting even tho it's not my model or even my year.
But after watching the clip related to most landcruiser engines.
I was quite shocked to be honest as even the machanic in the clip (ex toyota machanic) was shocked.
If you like information on landcruisers then find time to watch.
Most of those on here will have already heard of this guy.

 

[mwhtc]

I saw the video and I thought for 200,000 miles and it does that then it's not so bad. But then I've done a lot of research and reading on the Rover K-Series which, we all know, is well known for it's head gasket.

On the K-Series, it originally used an elastomer head gasket and Rover engineers tested it for 40,000 miles and reported no problems. Head gaskets started to "go" at 60,000 miles. 2 things tended to happen. One scenario was that the engine would suffer an overheat moment (ran dry of coolant as an example) and the elastomer would go beyond the rated heat and move/detach from the gasket, allowing things to mix together. The other scenario was that due to age the elastomer would detach from the gasket and allow things to mix together. There was another thing with the inlet manifold that would make it look like a head gasket failure when it wasn't, but that's by the by.

The fix which was devised by Land Rover was to fit a multi-layered steel gasket instead of the original elastomer gasket, along with stronger through rods (as the engine is like a sandwich) and the introduction of steel dowels instead of the plastic ones originally used. There was also a relocation of the thermostat so that it operated on water leaving the engine rather than operating on entry to the engine. Thermostat positioning aside, the MLS, dowels and through bolts resolved the issue. No one really suffered from head gasket failure after this, and this was incorporated in to the N Series engine and featured in the MG6 by SAIC. No head gasket failures reported there either. Although the MG6 it has more problems than that!

In any event though, if the engine suffers from an overheat scenario then the head gasket will suffer regardless of the engine or design of head gasket. You can't expect an engine that's abused to not crap a head gasket. It's always a risk. With the K Series it's internal water capacity was fairly low anyway, so if there was a leak you'd know about it fairly soon. With this, if the owner isn't refreshing the coolant then that's not the fault of the engine. And the reaction of the mechanic surprised me when it came to this, like he expects the engine to deal with crappy coolant.