Should I switch Coolants ?

**simonl8353** · 21st May 2010, 01:04 PM

In need a bit of the forum wisdom on this.

I want to add more coolant inhibitor as when the thermostat in my '99 D2 V8 was replace the cooling system was topped up with water only and I believe is now too diluted. (Doesnt look very green anymore)

I can either drain a little water out and top up with more Green Nulon that is currently there (and I have in my shed) or do a thorough flush and complete re-fill with the red Nulon OAT stuff.

Any advise on which one of these two options ?

Also. if I top up with green, can I just add about 2 ltrs of Nulon to the expansion tank in an undiluted concentrate ?

thnks

Simon

**cewilson** · 21st May 2010, 01:42 PM

I would flush and refill if it was my vehicle.

**Blknight.aus** · 21st May 2010, 01:45 PM

yep flush with fresh water, clean with the appropriate cleaner for the coolant you are about to put in. Then make up your new coolant with distilled or bottled water.

**PAT303** · 21st May 2010, 03:15 PM

^follow that advise. Pat

**simonl8353** · 21st May 2010, 06:54 PM

Ok thanks, so flush out the green, buy red OAT and add with (distilled or bottled) water in the approved mix 50/50 +/- 5%.

Can I also ask what the best (easiest) flush process is? just run tap water through the rad a couple of times for say 30 mins ea time while hot or do I put a garden hose in the top hose and back flush it through for 15 mins or so?

just to add, I had a new rad, and hoses when the head gaskets were replaced 12 months ago, all good, so I shouldn't expect any crud build up.

Thanks

**Blknight.aus** · 21st May 2010, 07:32 PM

Drain the coolant
remove all the hoses and flush out each part individually then reassemble the hoses
fill the system with the cleaner of choice (IAW its instructions) and run the vehicle up (again IAW the Cleaners instructions) till its got hot, let it cool and repeat the flush process.
using a hot air gun flow warm air through each component till its dry then put the system back together
Add your coolant of choice.

you wont keep it hot while you keep adding water to it.

**PAT303** · 21st May 2010, 07:56 PM

Mate if you've been running it with Nulon coolant stay with Nulon coolant,it's bad practise to switch. Pat

**simonl8353** · 21st May 2010, 09:07 PM

Originally Posted by PAT303

Mate if you've been running it with Nulon coolant stay with Nulon coolant,it's bad practise to switch. Pat

Pat, dont go confusing me now..

that's way too easy.

I have been well advised not to mix them but because Nulon can be both green or red, (with red having the OAT & I have a very diluted green Nulon currently in the V8) so you are saying stay with the green?

With the earlier reply's I was convinced to switch from my current green Nulon to the to the red Nulon. I'm assuming the red is generally speaking the better coolant and if I can swap over, I may as well.

I only want to do this once and I'll do a full flush if necessary.

I appreciate the advice.

**LOVEMYRANGIE** · 21st May 2010, 10:28 PM

Don't use red OAT unless handbook specifies it.
Red will eat out some rubber seals unless they are compatible with it.
It will also tend to remove any scale from gallery walls, then attack any corrosion underneath subsequently ending up in a blocked radiator.

Nulon do a non glycol in a concentrate, good stuff.

Cheers

Andrew

Sent from my iPhone using Tapatalk

**Blknight.aus** · 22nd May 2010, 04:40 AM

Originally Posted by simonl8353

Pat, dont go confusing me now..

that's way too easy.

I have been well advised not to mix them but because Nulon can be both green or red, (with red having the OAT & I have a very diluted green Nulon currently in the V8) so you are saying stay with the green?

With the earlier reply's I was convinced to switch from my current green Nulon to the to the red Nulon. I'm assuming the red is generally speaking the better coolant and if I can swap over, I may as well.

I only want to do this once and I'll do a full flush if necessary.

I appreciate the advice.

blending the different technologies of coolant (as opposed to colour, at the end of the day the colour is just a factory added dye) is almost always bad. Once you've correctly flushed and cleaned out your cooling system you can use almost any coolant you want BUT you have to make sure that the entire cooling system is capable of handling it.

I usually advise that you stay with the coolant technology as reccomended by the manufacturer so far as I know the V8's only come with Ethyl-Glycol mixes so thats what you should use and Ideally you use the same product from the same manufacturer at all times. Unfortunately for you this is going to mean yearly coolant changes and bi-annual cooling system clean outs.

Thread: Should I switch Coolants ?

Thread Tools

Should I switch Coolants ?

Should I switch Coolants ?

Bookmarks

Bookmarks

Posting Permissions