Those using Evans Waterless coolant

[Grim Reaper]

Have you noticed the temperature reading going up and down a lot more?

In a 4 mile journey through town yesterday I had everything from 89 to 105 on the dash.

Wonder if the 'better' heat transfer of the evans is doing its thing when at idle and there's not much movement in the coolant.

[Stationary M25 Traveller]

or your temperature sender is on the way out ??

[Jonathan Kay]

I'm not aware of any evidence* for better heat transfer in most car engines in most conditions.

 

The solution has lower thermal capacity than water or commonly-used water-based solutions so it's possible that in limiting situations you would see greater variations in temperature.

 

But SM25T's suggestions and other faults are probably more likely.

 

Jonathan

 

* But I'd love to see some.

 

Edited by - Jonathan Kay on 3 May 2014 08:39:52

[Grim Reaper]

Think it may have been something else, on the way down to Stoneleigh I had a low oil pressure moment, and it seems that when I turn the heater fan on, the oil pressure goes down and the oil temp goes up suddenly?? As an additional twist, my speedo is reading erratically as well.

Bad connection to the dash (Stack)? Earth or supply?

[Stationary M25 Traveller]

Almost certainly an earth problem .... probably on earth stud on wiper motor bracket.

[Grim Reaper]

Cleaned that up, no difference.

Have noted that same fuse feeds instruments and heater.

Voltage reading on stack changes dramatically with heater fan turn on but not with headlights or radiator fan but multimeter on battery terminals doesn't change.

[Jonathan Kay]

I think that suggests you've got a high resistance on the feed side to that circuit: could be before, in, or after the fuse. But it has to be upstream of where those circuits divide.

 

I don't know your layout. What can you disconnect, inspect, clean and reconnect?

 

Can you get a meter on the fuse or somewhere in the circuit nearby and see if the voltage there behaves like the battery or like the Stack voltmeter? That should help you localise the lesion.

 

If nothing is easily accessible you can make a blade fuse which includes breakout leads: take a broken fuse, attach two leads and fit a new fuse holder and fuse at the accessible end of the leads.

 

Jonathan

 

Edited by - Jonathan Kay on 4 May 2014 23:01:43

[Grim Reaper]

Been down at Stoneleigh this weekend so not got much access to testers and tools. now home, will take the dash out and check it over along with the wiring and senders.

A strange fault, only noticed it because it's the first run out since the rebuild and since I'm using running in oil for the first 500 miles or so I've noticed the oil pressure was a little erratic since it's so thin.

Now I know it's not a problem I'll be less worried about it.