Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) coolant level

Hi, I have a 1988 +8 rover 3.5l.
How do you check the coolant level?
I have squeezed the top pipes when cold and no squelching heard nor any liquid in the expansion tank.
No visible leaks.
Also what coolant is best used?

Thanks

I use this in my Roadster without issue - click for source.



It can be used neat as I did since old coolant was found to have same -40°C protection although this allows for some dilution if required.

Not familiar with +8 but typically there should be some coolant remaining in expansion tank after engine cools.

I think the expansion tank is like that on my T16 +4. There should be a level indicator inside if you shine a torch in & look

Assuming the plumbing system is similar to my 1998 car , there should be coolant in the expansion tank on the bulkhead. There is a marker in the tank which is visible if you shine a torch. The fluid should just cover this marker.

If there is nothing in the expansion tank I would assume that the rest of the system is not full and therefore you will need to do a bit of delving into the radiator , hoses , thermostat housing , and engine block drains, in order to ensure that :-

1 You don't have any tiny leaks
2 you don't have an air lock in the system somewhere.

Does the engine come up to temperature OK? It might be worth checking the operation of the thermostat if not (be warned access is not the easiest on injection cars)

Perhaps the best place to start would be to first fill the expansion tank to the level marker and then remove the radiator cap , and run the engine for a while until it reaches "normal" operating temperature. Keep topping it up so that the coolant is clearly visible in the radiator. Unless an air lock is present in the block this should bleed any air out. The level in the expansion tank might vary a bit, but that is usual.
Now that the air is (hopefully) out of the system put the radiator cap back on, and try again . This time the level in the expansion tank should remain at a very similar level AFTER the system has cooled down

The recommended fluid for the Rover V8 was always Bluecol which should be changed on a 2 or 3 year basis It is a concentrate which is diluted with (preferably distilled or dionised) water according to the amount of frost protection desired.

This is one place to purchase it :-

https://www.mymotorworld.com/blueco...I6AC8C2Za7MW-KGLfBJ72_idyJRoCoqUQAvD_BwE

However more modern formulations are probably now perfectly acceptable

Is this the same as G-12 coolant?

I have a mid 80`s +8 with a plastic expansion tank which has a very definite water level marked on it.

Over the years I have been on Morgan forums there has ever been chat cropping up from time to time on expansion tanks and their purpose, water levels, types of cap and what cap goes where.

I suspect if you visit GoMoG you will find plenty of detail.

I suspect the height that the expansion tank is fitted relative to the rad top tank may be important. Also that the spring loaded pressure cap is fitted to the expansion tank and not the rad, the rad cap having no spring and just containing a rubber seal in order that expanding and contracting water can move freely between the rad and expansion tank as and when required.

As for coolant levels, on my +8 when cold the level in the expansion tank sits right down at the level of the tube that connects to the rad, and after a run the coolant has expanded into the tank and sits at or near the level indicator arrows moulded into the tank.

Whether any of the above might be considered accurate or not...? All I know is that my car with standard rad and standard engine spec has never overheated even when Italians were fainting in the street due to heat exhaustion when we toured there in the middle of Summer some years back.

Good luck in your choices..

Yes I believe it's the same as G12 but longer life (minimum 5 years)

See here and on image link for approvals.

Thank you for all your replies.
I've had a read through GoMog....very informative, thanks.
Gonna run the car and check for leaks again, then with the cap off to see where coolant level rises too in tank.

When running engine with the pressure cap off don't let it start boiling or you will have a hell of a mess to clean up. Yes, there should be coolant up to the marker in the expansion tank when engine has cooled. Just a small amount of air in the system can adversely effect performance so always wise to have a good burp, the other watch point when replacing the engine thermostat is to make sure the air hole is at the 12 o'clock position.

Lovely year for Plus 8s! Your observations indicate insufficient coolant

Essentially, all otherwise being in good health, let the coolant find its own level. Your engine is set up so that it cants mildly rearwards
which takes some understanding of the consequences which I will not bother this forum with.

However, one of those consequences is that it is hard to get rid of air in the cooling system. Easier after 1994 when Bill Beck altered
the Plus 8 chassis design.

1. Check if your 15psi pressure cap is on the expansion tank. I prefer that as it eliminates a lot of the risk in dealing with coolant level
adjustments when the engine is hot. This is the way LR/Rover planned it but nothing is certain after 34 years of usage. Also, use a
safety radiator cap..cheap insurance and the possible cause of your issue.
https://bbclassics.co.uk/products/p...ety-release-lever?variant=44138658431278

2. Remove the blocking cap from the rad Fill to the top and then shake your Morgan. Watch the bubbles and keep filling until none
appear when shaking. Replace the blocking cap on the rad. Now fill at the expansion tank. However, this one time, you should overfill
to discover what level it should be at cold. Fill the that tank to 2/3s. Over the next few days, your car will overflow (on the ground via
the overflow hose) as it gets rid of any air that remains in the system (if any) and finds its correct level. There after, you will know what
level you need in the expansion tank.

WHICH COOLANT? Very important. There are many different coolants for many different engine blocks. The wrong coolant was one of
the primary reasons our engines was given up in the US and sold overseas to become a British icon. But coolant technology is now
in an era of great change. I wrote it up on gomog. I have adapted though I have found it prudent to always be just behind cutting edge.
(wryly)

You can use the original manufacturer recommended coolant called Land Rover Summer Coolant, if you can find it. I used that 25 years
ago. I see that Land Rover came up with much more up-to-date stuff using OAT technology.
https://www.jgs4x4.co.uk/extended-life-anti-freeze-coolant-1-litre/It is extended life, so you won't be bothered with it much. If you are
switching coolants, might as well flush your engine. Different coolants do not mix well, (very dangerous) and flushing every 2-3 years is
wise. If you are using an OAT coolant, just reuse it after flushing. If you want another 2 degrees cooler, add a bottle of Water Wetter.
https://www.amazon.co.uk/Red-Line-80204-Water-Wetter/dp/B000CPI5ZK

I use GM Long Life (also OAT) with Water Wetter. No LR dealer for 100 miles. My big bad V8 on very hot days runs at 90C.

Good luck

Lorne

P.S. Avoid waterless coolants