Coolant Type

[nhaynes]

I'm about to change my engine coolant and have purcahsed 3 litres of concentrate Shell Radiator Fluid. The original Lotus coolant specification was Shellsafe Plus so I thought I might be ok with this Shell product. Unlike engine oil, it's really difficult to find a modern equivalent to Shellsafe Plus which in now obsolete. Whilst Organic Acid Technology (OAT) coolants probably offer superior longevity (up to 5 years compared with 2) I doubt they are compatible with copper and brass components and may not be compatible with some rubber compounds that may be present in the Elan cooling system. Shell Radiator Fluid does not contain any nitrates, amines and phosphates (NAP free), it contains Ethanediol and Bittering Agent. I've attached the specification sheet for a more detailed description of the formula. This suggests the main substances are: Ethane-1,2-diol (>75%), Sodium 2-ethylhexanoate (1-5%) and Disodium tetraborate pentrahydrate (0.1-1%).

My question to any techies or Chemists out there: Is the Shell Radiator Fluid I've purchased safe to use in place of Shellsafe Plus which was a Ethylene Glycol blend? As the bottle does not mention glycol I'm thinking maybe not. However, I've also discovered that Shell Radiator Fluid is the same formula as Glycoshell. The name is confusing as I thought Glycoshell was a glyco based product. The attached Glycoshell specification sheet states it is a monoethelene glycol substance and it is an OAT coolant!

Any advise would be greatly appreciated.

[nhaynes]

I changed my exisiting coolant to Shell Radiator Fluid back in May 2014 following the drain, fluch and fill instructions from WikiLEC. I actually flushed twice with de-ionised water as I wanted to be sure all the old coolant was out. I put 3 litres of Shell Radiator Fluid and approximately 4 litres of de-ionised water into the coolant system. I've done a couple of hundered miles now since the coolant exchange and on my Elan, the Shell Radiator Fluid performs very well with absolutely no side effects. Interestingly, the coolant temp gauge is now running slightly cooler leading me to think the new product is more thremally efficient. The problem I was fearing of silicon compounds emulsifying in the system has not occured but this may be due to my Elan never having coolant with silicates. I woud still strongly suggest to all, careful consideration of what coolant formula to use prior to a coolant exchange and if possible try and understand the history of what products have been used before.

[GeoffSmith]

Interestingly, the coolant temp gauge is now running slightly cooler leading me to think the new product is more thremally efficient.

Interesting thread (especially the 5 year life) but operating temperature is governed by the thermostat.

[nhaynes]

The thermostat opens the flow of coolant into the water to air heat exchanger; the radiator, therby allowing the engine coolant to be cooled by air. If the vehicle is stationary and airflow velocity is low then the radiator fans are switched on to allow the water to air heat exchanger to remain effective. When the engine is cold (and the coolant is cold) the thermostat is closed so the coolant temperature increases quickly due to the heat of engine combustion. The temperature sender and temperature gauge measure and show the coolant temperature (sometimes cylinder head metal temperaure is also measured to be used by the engine control unit. Therefore, the fact that the temperature gauge is showing a slightly cooler reading when nothing other than the coolant has been changed shows that the coolant is transferring heat from the water to air more efficiently.

[GeoffSmith]

The temperature oscillates between ~80°C and ~85°C due to the thermostat opening and closing. The gauge is a thermal device with a long time constant and only reads ¼ scale. I defy anyone to tell me what the temperature is from the OEM setup - most people (me included) can't tell that the thermostat is stuck open until they look at ElanScan. That's one reason why my gauge now reads half scale at normal operating temperature.

Show me an ElanScan run and I'll believe you....

[Ian T]

I like the explanation, but it is more likely that your thermostat is ''passing' slightly and therefore not holding the temperature up as well as before.

These have a jiggle valve in them to get rid of air locks, so it is hard to show as clearly, but if you start the cold engine and leave to idle until it gets to operating temperature, you should feel no warmth at all at the radiator hoses until suddenly the thermostat opens and then it will very quickly become hot on the radiator inlet pipe.

Ian.

[rip]

The stat keeps opening until thermal equilibrium is reached.

[Ian T]

The stat keeps opening until thermal equilibrium is reached.

Yes, I should have added that, thank you.

[Rusty Wishbone]

I bought some Halfords Advanced antifreeze a while back which it says gives 5 years protection and improved heat transfer properties and it is red. I am intending to use this in the Elan in the next couple of weeks.

It seems to me that the second most important property of an antifreeze (behind preventing freezing) is to inhibit corrosion. Improved heat transfer is good, but you would probably only see the benefit when it is really hot.

[Ian T]

I bought some Halfords Advanced antifreeze a while back which it says gives 5 years protection and improved heat transfer properties and it is red. I am intending to use this in the Elan in the next couple of weeks.

It sounds like it might be the new OAT stuff - be careful.

Ian.

[HJ2]

use the pink stuff only if there are no more brass parts on your car! (heatervalve or other coolant parts...)
I would go for green or blue

[rip]

Halfords 5 year stuff is OAT & may not inhibit corrosion on some copper/brass (the temp sensors are usually brass) which is why some of us would rather not use it.

Anti-freeze actually has poor cooling properties. Fresh water works much better but allows corrosion to build up, which is why a 50/50 mix is recommended.
Adding water wetter will allow coolant to work more effectively but this should only be necessary in an Elan in a very hot country.

[steve matthews]

Adding water wetter will allow coolant to work more effectively but this should only be necessary in an Elan in a very hot country.

I believe water wetter also helps inhibit corrosion.
For track days I use 25% green anti freeze 50/50 blend.
75% distilled water -w- 1 bottle water wetter.

Steve -w- no problems to report fluid changed 2 to 3 times a year.

[Rusty Wishbone]

It sounds like it might be the new OAT stuff - be careful.
Ian.

Reading the bottle, you are right. No mention on the bottle that it might not be suitable for some older cars, of course. I'll take it back.

Good advice from everyone again. Thank you .

[Rusty Wishbone]

It sounds like it might be the new OAT stuff - be careful.
Ian.

Reading the bottle, you are right. No mention on the bottle that it might not be suitable for some older cars, of course. I'll take it back.

Good advice from everyone again. Thank you .

[Rusty Wishbone]

:banghead:

I bought some Halfords Advanced antifreeze a while back which it says gives 5 years protection and improved heat transfer properties and it is red. I am intending to use this in the Elan in the next couple of weeks.

It sounds like it might be the new OAT stuff - be careful.

Ian.

[Fredjohn]

Edited 30/3/2015
Reposted under help!

Edit (Enright): I've consolidated today's posts in this thread to keep the same question and the various positive and negative answers all under the one heading (and added this note to the post so that it isn't the first thing that people see on what would have been the next page).

[Fredjohn]

There are plenty of posts on here saying don't use OAT antifreeze, but nothing to say specifically which to actually use. So my question is: what type?

Personal reason:

I am about to fit the Samco hoses I recently acquired. Checking in Halfords today they sell 2 different types of antifreeze: one is clearly labelled OAT, so I will not use it. The other is labelled as containing silicates, doesn't mention Ethylene glycol but comes up as the recommended one for my reg. no. Presumably this one is actually OK?

The Comma brand also have both types. The non OAT version G48 contains silicates and Ethylene glycol, so is presumably OK, but £4 more.
I will probably go for Halfords as I'm a skinflint (assuming it is OK). Both are sold in 2 litre containers which given the 6.25l capacity will (more or less) achieve the required 33/67 mix.

Await advice, many thanks.

PS originally posted this under Engine/Coolant Type but it slid down the rankings rather quickly! Could a mod please delete that post for me??

[dapinky]

John,

my advice (which is worth as much as it costs!) is to use 'old' type blue antifreeze.

I tend to buy whatever is cheapest on the day I need some - but stick to a 'known' brand, or an 'own brand' if buying from a known retailer.

As we don't get really severe winters here, the 'antifreeze' part of the coolant isn't that vital, but the 'corrosion inhibitor' part is of more importance to me - any Glycol mix will do the job, and fresh coolant of an unknown brand will still probably be better than old coolant of a great brand.

I tend to flush and change mine every 2 years at most, and often anually (depending on what else I'm doing at the time) - for the past few years it has needed a new radiator, new header tank, new thermostat etc, so has been changed at those times.

I (just my opinion) don't see the point in saving a fiver by re-using drained coolant, when new stuff gives better peace of mind.

[muley]

FWIW I've been using Comma Blue for years. With the odd work on cooling systems it get changed every couple of years. I use a 50/50 mix.



Jim