↓ Advertise on Defender2 ↓

Home > Maintenance & Modifications > Mixing Coolants
Post Reply  Down to end
Page 1 of 1
Print this entire topic · 
Greyman110



Member Since: 29 Sep 2017
Location: London
Posts: 327
United Kingdom 
Mixing Coolants
Would mixing 4-5L of OAT coolant (108 boiling point) over time with factory coolant (137 boiling point) cause the coolant to boil and release through the cap?
Post #847248 31st Jul 2020 2:04pm
View user's profile Send private message View poster's gallery Reply with quote
sako243



Member Since: 08 Jul 2014
Location: Wales
Posts: 1237
Wales 1994 Defender 110 300 Tdi CSW Alpine White
You shouldn't mix different colours of coolant as they can react badly together and start eating things inside the engine (seals, aluminium etc).

So given they can chemically react together then as the temperature rises I can only imagine it'll get worse with temperature so possibly. Ed
82 Hotspur Sandringham 6x6
95 Defender 110 300Tdi
Post #847272 31st Jul 2020 3:45pm
View user's profile Send private message View poster's gallery Reply with quote
BuckBlu110



Member Since: 19 Apr 2014
Location: in the pub
Posts: 719
United Kingdom 1994 Defender 110 BMW M57 3.0 Diesel CSW Buckingham Blue
When mixed they can also form a gel when mixed which blocks the cooling system and causes overheating. I learned this the hard way after a not so helpful mechanic topped up my mothers old blue glycol filled disco with red oat.
Post #847306 31st Jul 2020 6:05pm
View user's profile Send private message View poster's gallery Reply with quote
Greyman110



Member Since: 29 Sep 2017
Location: London
Posts: 327
United Kingdom 
Think I'll be doing a flush Very Happy
Post #847314 31st Jul 2020 6:33pm
View user's profile Send private message View poster's gallery Reply with quote
Greyman110



Member Since: 29 Sep 2017
Location: London
Posts: 327
United Kingdom 
If I drain the coolant and flush with water, can I leave it empty until the new coolant arrives or should I not let the system completely dry out?

I obviously wouldn't be starting the car until it was filled up.
Post #847320 31st Jul 2020 6:50pm
View user's profile Send private message View poster's gallery Reply with quote
rallysteve



Member Since: 10 Feb 2014
Location: Cumbria
Posts: 2238
United Kingdom 2002 Defender 110 Td5 DCPU Keswick Green
If yours is a TDCi then surely it had OAT coolant in from new anyway?

Steve 02' 110 TD5 Double Cab Rebuild Thread
Post #847339 31st Jul 2020 7:47pm
View user's profile Send private message View poster's gallery Reply with quote
Greyman110



Member Since: 29 Sep 2017
Location: London
Posts: 327
United Kingdom 
It is a TDCi but the book mentions Texaco XLC.

I compared the boiling point of the OAT I recently topped up with and the recommended XLC or equivalent which seems to have a higher boiling point.

In the last two years since I've owned it I haven't done a coolant change so I don't know if its ever had anything added or changed previously.
Post #847359 31st Jul 2020 8:31pm
View user's profile Send private message View poster's gallery Reply with quote
Pacha



Member Since: 23 Feb 2020
Location: North Yorkshire
Posts: 772
United Kingdom 2008 Defender 90 Puma 2.4 HT Stornoway Grey
What colour is the stuff that is currently in the system? Rgds.

Chris
Post #847360 31st Jul 2020 8:35pm
View user's profile Send private message View poster's gallery Reply with quote
Greyman110



Member Since: 29 Sep 2017
Location: London
Posts: 327
United Kingdom 
It looks red to me.
Post #847366 31st Jul 2020 8:51pm
View user's profile Send private message View poster's gallery Post Reply
Post Reply  Back to top
Page 1 of 1
All times are GMT

Jump to  
<  Previous Topic | Next Topic >
Posting Rules
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum



Site Copyright © 2006-2025 Futuranet Ltd & Martin Lewis
DEFENDER2.NET RSS Feed - All Forums