Citroen XM Forum

Its a matter of personal choice. I ran a bx td on about 80% mix which I beleve alowed the original head gasket to last longer then avereage. She went from 121k to 175k without a change. Ive done it will all now and never needed to do a change. The hdi xantia was the same and she seen almost 300k without a coolant issue.

Well anything to help things last longer. That's quite impressive results Paul...will do that next coolant change.

Corrosion resistance is presumably greater with higher concentrations of good quality antifreeze/coolant. Have always assumed that there is no objection to running on a 100% mix, since most coolant manuacturers recommend this for severe low temperatures. The important thing is to do any dilution with distilled/demineralised water, to prevent scaling and clogging.

Dilution reduces the cost, sure, but the savings over time are minimal, let alone the possible increase in risks. I now use Citroen's own Pro Mix (1135 305 ready-mix, and good to -35C), which is made in Spain for Peugeot Citroen. Previously used Citroen Dynagel, same spec.

Probably best to avoid long-life OAT (organic acid technology) forumations, and NEVER mix these with standard types. In fact, never mix coolant makes or brews, even if the colour (which means nothing) is the same - always drain and totally replace. Sorry if I am repeating this standard advice.

I think that many of the historic problems with radiator, matrix and gasket failure (and maybe water pumps too) which plagued the last three decades may have been down to coolant neglect, all too easy to do, especially for DIYers. Many of the properties of good quality coolant were overlooked, including corrosion inhibition, mixed-metal protection, anti-fungal, pump-seal lubrication and small leak stopper. Most folk did, and still do, call the stuff Antifreeze, which is only part of its job, and not an excuse for forgetting it just because you live in the tropics!

The best methd is to use waterless coolant, this will not pressurise the coolant system making life easier on your hoses etc and will last forever so long as you dont spill it, will completely stop any corrosion taking place at all, ive seen it in use and it is the dogs whatsits and the bees thingies all rolled into one, the downside however is the cost, the system must be filled and flushed with prep fluid first to remove the water and then filled with the coolant itself and at about £10/ltr your looking at about £200 for an XM!

D

I have heard about this waterless coolant Dean. It's impressive as you can reuse it I believe. Expensive, but if it's a long lasting solution, and works... great. Food for thought.

I used deionised water in my last coolant change Chris.

If it's the Evans Waterless Coolant you're referring to, it seems it's not all it claims to be.
It does contain water (see MSDS sheet).
Its heat absorption/transfer properties appear to be inferior to a traditional glycol-water mix.
Its formulation is very close to a normal glycol preparation.

Details here, as well as on numerous other sites:
http://www.daihatsu-drivers.uk/node/17499

Good profit margin, though, with some slick marketing effort.

Ive seen the arguement but if it contained so much water it would pressurise the system and it does not, at all.
It will be better for seals and hoses but i am currently running 100% veg acid new world 5 year antifreeze and that still pressurised the system, not sure of the risk of flashing to steam with sudden pressure loss though.
The waterless stuff should stop kettling in the engine while the coolant system would be coming up to temperature and pressure.

100% glycol use is not recomended either due to its inferior heat transfer properties but to be honest my coolant temp remains the same as it always did with a 50/50 mix so whether the engine requires the level of heat transfer supplied by raw water or not is maybe up for debate, if the coolant system is maybe running very close tolerances it could be an issue?

D

I too doubt it will be the diff causing the noise, much more likely is the driveshaft joints or bearing.

White Exec wrote:If it's the Evans Waterless Coolant you're referring to, it seems it's not all it claims to be.
It does contain water (see MSDS sheet).
Its heat absorption/transfer properties appear to be inferior to a traditional glycol-water mix.
Its formulation is very close to a normal glycol preparation.

Details here, as well as on numerous other sites:
http://www.daihatsu-drivers.uk/node/17499

Good profit margin, though, with some slick marketing effort.

It was the Evans one I was thinking about too. Interesting.....

Now at 270000 miles I've done a few more jobs. I discovered that the bearing noise I was experiencing was caused by the intermediate bearing on the long driveshaft. When I removed it I found that the bearing race was cracked in half! It was a lot quieter running with another driveshaft...

Other matters other than changing the oil I've had to contend with have been a couple of tyres, new discs and pads after the incorrect discs fitted led to mearly loosing a pad and a new pair of strut repair hoses. Yesterday I finally got a chance to investigate the cooling leak into the footwell and I found the leak appeared to be from the pipes for the matrix rather than the matrix itself. The pipe to matrix fixing screw however was not tight so I've nipped it up and will monitor. I also cleaned up some areas of surface rust to the front subframe, sills and tow bar and gave it a coat of Aldi metalcare paint. Future jobs likely to be wishbone bushes (a pull to the right has developed along with a certain vagueness) and also investigating a low speed jerkiness/intractability assumming this isn't a temporary development due to some bad biodiesel. I'm also going to change the LHM again.