Mk3 Cavalier Owners Club | Vauxhall Cavalier Dot Com

So, while I'm saving to get the head gasket replaced, the Rembrandt is being a tad thirsty and draining the coolant at a slow and steady rate. I'm topping it up as and when required, but as winter nears, I'm going to have to start thinking about antifreeze as well, and whilst browsing the generic pap market that is Halfords, I came across two different types... One with some kind of organic additives, and one without. The usual flippy chart they have for choosing which kind you need for your wagon has a glaring omission in the form of the Mighty Cav, so I was hesitant to choose something that I wasn't sure would be an issue or not.

I'm asking this mainly because if these newer types of AF are starting to appear, which one is best for our old machines, or does it make the slightest bit of difference?

I use the same red long life anti-freeze that I use in the Vectra-C.

It is my train of thought that hopefully newer fluids are at least as good, if not better than the limited range available 25 years ago.

There are many varieties avalable including waterless anti-freeze fluid.

I would maintain your mix and levels with the cheapest ethylene glycol mix you can find until the head gasket is sorted.

You do not want the block to crack due to frozen fluid.

After that, I would use better quality anti freeze if that is available.

The cheapest, eh? I figured that would be the case, I was just more concerned about the newer stuff for when it's fixed. The weird stuff I saw in Halfords was OAT AF, which is something I was wondering about. Not sure if it's meant for newer cars with better gaskets and seals or what, but I thought I'd ask in case anyone knew if it was safe to use in our old engines.

I say the cheapest for now, because I'm tight, and wouldn't want to throw expensive coolant into an engine that is peeing out fluid at a noticeable rate.

The Haynes manual simply says -
"Ethylene glycol based antifreeze".

I will have a look what TIS has to say later...

If it is anything like engine oil, then Vauxhall tend to use one product to cover all of their model ranges.
So it is likely that they use one anti-freeze type (long life pinky red) for all model ranges.

I don't think Vauxhall engine gaskets are anywhere near as delicate as the early 80's VW engines. They are VERY specific as to chemical compositions.

I've had OAT in my C20NE cav for two years now.. The 20NE in the GTE has been fine on it for 6 years.

Can anyone offer me any informed guidance re choice of antifreeze for my H-reg 1991 SRi - as on offer on Amazon or possibly eBay? I am not sure I have much faith in their filtering systems. What I think I want is the orange concentrate (1 L - 5 L) though you get the impression that Prestone clear will mix with just about anything. Are they all the same but with different labels? Some seem to be beamed more at industrial applications.

The thing to do, is look at your Haynes / Porter / Halfords or even your owners' manual.
It should state the specification there.

I have used virtually every variety under the sun.
Including Prestone Clear. By virtue that it is sold by Costco implies that it is for trade purposes, and therefore a "generic" grade to cover a broad spectrum of vehicles.

I tend to use the Orange fluid because any leaks are clearly visible and therefore easily found and rectified.
It is also the stuff that my local dealer and my preferred garage always used at annual service.
It is often labelled "long life", so should be good for several years' use.

The blue stuff -again it is, what it is.
Usually mass produced "generic" supermarket fodder.

The importance is good checks, and fluid changes, ensuring a good mix ratio for the time of year.

Interim further ponderings:
I have just purchased a new A/F tester (Draper) because the previous one was giving dodgy readings, and ordered some "orange" (officially "red") concentrate. Years ago someone advised me to go for orange for a 1991 Mk 3 Cavalier SRi and I have done that ever since.
Checking today I see that the indicated protection is more than adequate.
Question: The car is sorned at present so gets very little use, just the occasional engine warm up. The existing A/F must have been there for some years. Is there any logic in changing the mixture now just "for the sake of it" if what is there seems to be doing its job? Bearing mind that I would have to use a siphon rather than have access to a ramp in order to drain the system fully. Also: You can get distilled water for batteries. I have never used this for coolant. Would using distilled water now be pointless?
[Just to confuse the issue I am using Prestone Clear Ready Mix for the 1995 LSi ]

I prefer to use ready-mixed for both coolant and screen wash. At least you know that they are the correct concentration and therefore should fulfil the manufacturers' packaging blurb.

The battery chemistry is a lot more important to be free of contaminants.
The coolant and screen wash are not.
Assuming the obvious theory that you are using typical tap water rather than water from a muddy puddle.

The Prestone Ready-Mix floats one disc at the top indicating protection down to - 7°C.
I'm guessing that the mix does not "degrade" over time (very little mileage) and that the additive provides a certain amount of corrosion protection as long as it is active to the tune of one disc, regardless of what water ("Northumbrian Water") is used.

For most of the UK, -7°C would be adequate.
The coldest I have had it in the Manchester area is -4.5°C...
But that does not give you much margin.
I would prefer stronger, to say -20°C just to be on the safe side.
BUT...
If the fluid has worked in the '95 car, then it should be fine in the older car.

As with anything, I would use fluid that should meet the needs of your particular situation.
Regardless of where your "corporation pop" is from.

As for degradation... showing my age, in the old days, it was recommended to change the fluid every couple of years... I think long life gives upto 5 years of protection.

So yes, I am sure the fluid does degrade over time.
And yes - there are anti- corrosion / inhibitors in the fluid to help to protect your engine from pitting and corrosion which would otherwise lead to porous alloy heads etc.

Been using the yellow prestone stuff for the cavy, but using dex-cool with omega, as the omegas must use that.

Most cars dont get their coolant changed unless something fails, waterpump, radiator, etc. Though the risk of rusty water these days is low given it's all alloy on modern cars, most cavaliers will be an iron block.

For old vauxhalls, use the red stuff, drain and fill it every 5 years. For filling I do half a litre of each until I get within a litre of capacity, then top in quarter litres so that it's near 50/50 mix.

-7°C is borderline for scotland, even with global warming

Regarding Halfords look up tables for spares, anti-freeze, engine oil etc and the absence of the Cavalier from these. I've found that these tables do still include the Calibra, which of course has exactly the same mechanicals as the Cavalier. Halfords sell two types of antifreeze - the blue silicate stuff and the orangy-pink OAT stuff. For the Calibras Halfords recommend the blue silicate stuff, presumably because this is what they would have come filled with from the factory.
I know that you can't use this silicate stuff in modern cars, but I don't know for sure that it's OK to use the OAT stuff in older cars. Up to now I've taken the cautious approach of only using the silicate stuff in my Cav and accepting that it's not long life so needs replacing every 2 years or so.

I've always used Bluecol and changed if after a couple of years, I would rather use the (red) one but was of the understanding it was corrosive to brass parts?
The only brass parts I can think of is the heater?

Alan

Is it brass? I thought it was silver in colour, so more likely alu alloy

Hmm - the pipework of the heater matrix.
That is the only copper/ brass part that I can remember from my old mk2 Cavalier days.
At least the stubs that come through the firewall where the hoses run to the plastic coolant distribution pipe at the rear of the cylinder head.

Maybe just another calibra thing, but it looked silver to me

vexorg wrote: ↑Thu Jan 13, 2022 9:33 am Is it brass? I thought it was silver in colour, so more likely alu alloy

When I had the heater matrix out it was the original harrison one, and I thought it was either copper or brass. I had a replacement one just in case and it was alloy. I just reused the original as there was nothing wrong with it and would probably outlive the alloy replacement!

I looked into the waterless antifreeze that never needs changing, can't remember the name of it but it was about £45/50 for 5 litres the only downside (beside cost) was that all previous coolant had to be removed.
From experience I know there is a certain amount left in the block unless the water pump is released.

Alan

There's a guys on youtube that makes the case for waterless coolant being very bad for engines. Basically along the lines of, if something has gone wrong to the point where the water boils over, then you want to know about. With waterless coolant, you wouldn't know other than hopeing you see the temp gauge. Steam from the bonnet is more noticable.