Cooling System Problem Review - Chapter 7
 

previous - https://landroverforums.com/forum/ge...ter-6-a-51033/

Chapter 7 - Coolant Reserve Container and coolant tests

The cooling system is "closed" and has a reserve container that allows expansion of the heated coolant and some small quantity of reserve. There is a fill cap that is also a pressure vent, it will vent at about 18 PSI. The coolant reserve container should be white plastic, if you have one of the older black ones it should be replaced, they are known to crack and cause immediate coolant loss.

Venting is a sign of overheating usually, but cap can go bad and allow boil over to happen at lower temperatures.

Small leaks are detected by coolant level dropping from a reference point in the container. Normally no loss should be noticed week to week. Leaks can be caused by gaskets, head gaskets, hoses and clamps, and even devices like the radiator.

A pressure tester can be rented or borowed from auto parts store, and the system pumped up to 15 PSI, then watched for leaks or decrease in pressure.

There is a chemical test for exhaust gas in coolant that can be run, it almost certainly will confirm an head gasket leak. The sample of gas bubbles from the coolant reserve container will make the fluid change colors if exhaust is present. However, an HG can also leak exteranl and internal to oil pan. Usually if a dramatic HG leak to coolant, there will also be a gurgle sound from water lines under dash that feed the heater core, and white smoke from exhaust. But the gurgle can also just be air in the cooling system that needs to be purged.

Question. If you are going to use a coolant that doesn't use water, and doesn't increase pressure.[ due to not having any water in it] Does that have a negative affect on this type of cooling system?

The straight antifreeze coolant does not have the thermal transfer performace of water and antifreeze, so the vehicle will try to run hotter. The no water coolant people tell you that running hotter is a good thing. Making a Rover run hotter on purpose might not be an experiment to do. But if one was to do it, they would ceratainly want better instrumentation, being able to see coolant temp and after maket oil PSI would be good. It is common for overtemp Rovers to have low oil pressure (gets thinner above normal temp range).

And if you can do such a test, and report back data, perhaps of a period of months, that would be good. If a specialty coolant helped overheating Rovers, that could be good. But keep in mind that the block and the gasket don't really notice the formula. The physical small size of the gaskets around the water passages from the block don't change.

Also, I guess there will still be pressure in the system, as the water pump makes pressure.

I have a pal with a BMW motorcycle that is an "oil head", it uses oil instead of coolant.

Nope, no pressure what so ever. The pump provides flow, not pressure. The pressure comes from the water in traditional coolant mix becoming steam. With waterless coolant, you can open the cap at temp with very little pressure escape at all.
I wonder what the temp increase is? I realize this is an older thread, but I'm interested in finding out more about the waterless coolants.

Okay, so I just found out the Evans waterless coolant runs at about 230 degrees. Doesn't the normal temp of the land rovers run close to that?

Only if your head gasket is about to blow or the block is cracked. In a D1 or D2 the engine temp was moved up to 192 from 180 to help meet stricter emissions rules. Many owners install a 180F stat to keep things cooler. Not as much heat in winter time.

A normal older design engine in any vehicle should run in cool weather at temperature of the thermostat plus maybe 5 degrees. The stat opens and closes to keep the block cool. Once you are running 15-20 F above opening point the stat is wide open, and control of cooling shifts to heat in (block and load) and what the water pump and the radiator can cause to be transferred elsewhere.

In Rover's design for D1 and D2, the electric boost cooling fan(s) are supposed to come on at 212F to supplement cooling. This would be normal if you pulled off the freeway and into a drive thru lane at burger doodle. On the freeway at 60 mph you have 5280 feet per minute of airflow thru the radiator from forward motion. At idle, maybe 800 feet per minute from clutch fan (if it is working).

And the Evans won't "run" at a particular temperature, that is determined by physics, and it is hard to run less than mechanical thermostat opening temp. Now pure coolant will have different heat transfer characteristics than 50/50 mix of glycol base coolant. If you put pure coolant in your car it won't run as cool. My pal that dirt track races around the southeast runs straight coolant and on the track it can hit 290 ish. Life of motors is short. Leaks no issue as it is a dirt track. So the Evans while "could" run at 230, but the other parts of the engine will decide if it gets there.

Most owners find themselves installing head gaskets after running the engine for extended periods at high temp. The old 1963 design Buick engine was built with a 180F stat in mind. Wild swings of temperature make it hard on things like heads (which warp, and anything beyond 2/1000ths exceeds flatness spec. That's half the thickness of printer paper.) The head gaskets get eaten away by coolant issues, electrolysis, and rust. They are very thin to start with in the space between coolant passage and front or rear exterior of the head.

To add to the chaos, Rover makes poor quality instruments. The heat gauge will point to normal while engine is overheated. See pix below.

In short, if you are running 235F, your engine components won't like it for long.

Wow, that really isn't nice!
Is there a replacement for the gauge or switch? I'm assuming that must have been a problem with this vehicle, as the cooling fans are connected to a toggle, and the previous owner had the head gasket redone, and the heads serviced.

Depending on D1 or D2 the fan relay is controlled differently. But that is only for 212F and AC. In A D1, turning on AC should bring fans on at any temp. As for gauge, many find the Ultra Gauge to be a handy device, it can reset codes and display other live data. In the D2, the gauge is driven by the ECU, which takes coolant sensor data, runs some calculations, and tells gauge where to point. From about 130 - 230F it points at 50%. So you can't see that you are running warmer than last week on same road.

whilst you guys are on the subject..... how cold is too cold for water temp.
I recently did in line stat mod with a 170 for sbc and i am running at 177.
I am thinking that might cause lowered mpg in an already thirsty brick.
any thoughts?