Hi guys.
As you know I switched to Evans waterless coolant a few months ago. I fitted an engine guard coolant monitor to keep an eye on both banks and today is the first time I have been out so some advice on the observed temperatures please. A bank driving at the normal 50-60mph temperature reading between 81-86c B bank however seems to be running cooler at around 74-78c. Driving through town 20-30 mph temps up to around 90c quickly dropping to the previous temperatures when back on the open road. Heat sink when I got home and parked in the garage topped out at around 105c then slowly dropping. Engine guard temperature pickups are bolted to the rear of each bank water rail and the heat soak temperatures are the same as I get with my IR temp gun so accurate. Dashboard temp gauge sits just under the N during normal driving. Forgot to mention 82c stats fitted. Thoughts on all this appreciated especially the difference between the banks as I have read the B bank is the one which normally runs a bit hotter.
Rob.

 

First, what were the ambient conditions? 36ºC ? 18ºC?

I don't see anything alarming. But you might have a bit more work ahead of you.

Is 90ºC as hot as it gets? It doesn't keep going up-up-up?

In mild conditions the system should be able to stay at or very close to thermo temp even in city driving. On hot days it will likely creep a bit higher which, IMO, is nothing to worry about so long as is doesn't keep climbing right out of sight.

The A-B bank difference is more than I would've expected. I don't recall there being that much difference in mine although it's been years since I checked. And I would expect both banks to be at least 82ºC since you have 82º stats


Are you confident that the system has good flow? Radiator clean? No air pockets? If so the engine doesn't really care if the coolant is 80º or 90º or 100º. There isn't a specific doomsday temperature. What's more likely to cause a problem is lack of flow. You can being running a comfy 82ºC all day long and still cause engine damage....dropped valves, specifically...if there isn't good flow to all parts of the engine, especially the heads. Unfortunately we can't see inside the engine. All we can do is take the usual precautions.

Cheers
DD

 

Hi Doug.
Forgot to add the ambient temperature it was around 18c today. Temperature doesn’t continue to climb and soon drops back when out on the open road. I’m fairly confident of the flow around the engine this as far as I’m aware has never been an issue with this car and certainly not in my ownership. I did expect it to run a bit hotter with the Evans that’s why I fitted the 82c stats. I have a set of 88c stats in the garage so could soon change back. I am confident the system is correctly bled with no air in the system and the expansion system is working perfectly siphoning back coolant as the engine cools. I have added a sight glass in the hose so can see this in action. I’m actually quite happy with the temps I’m getting apart from the difference between the banks with the A bank running a bit warmer than the B bank when I have read it’s normally the other way round.
Rob.

 

R obbo
Temps are fine, but in say ambient 30 might be different. I would test the B bank thermostat, as that is the likliest casue of the difference.

 

Hi Greg.
Thanks for your response. Stats are new but I suppose it may have failed in the open position. Genuine Jaguar from DM and tested before I installed them. I also thought the temps were good. Do you think going back to the 88c stats would be a good idea?
Rob.

 

I would just verify that the two open at the same temp in a saucepan of water; but mark them carefully when you remove them! Then, anyway, refit them swapping the sides and remeasure.
Is the rad all good/new?

 

IMO, it's a toss-up. Obviously your minimum operating temp will be higher with the 88s, and there's nothing wrong with that. The 88s were standard issue on the USA cars and perhaps others, presumably for emissions reasons.

And, again IMO, there's no particular advantage to running the 82s.

The engine doesn't really care one way or the other.

Cheers
DD

 

I'm in a bit of a quandry. I've long advocated that V12 owners worry a bit too much about coolant temperature. And there's nothing at all wrong with the 90º that you've mentioned, especially since the system is working well enough to hold that temp and go no higher.

But......

In 18º ambient, which is very mild, I really don't think you should see any increase when you're in city driving conditions. That it comes right down on the open road suggests that there's an air flow problem, perhaps a weak fan clutch?

What you're describing in 18º conditions is what I would expect in 36º conditions. So, without sounding alarm bells, I think there's room for improvement in your case.

Cheers
DD

 

Hi Doug.
Thanks for your reply. Fan clutch is new and working well with a new black fan. I can hear this cutting in as needed. To be honest I went out a few weeks ago when it was a lot warmer around 30c this was before I had the engine guard fitted so couldn’t monitor the bank temperatures. However the instrument temp gauge was reading the same as it did yesterday ie just under the N which to me indicates that all is well in higher ambient temperatures. The auxiliary electric fan cuts in and out as needed which is a lot less now the new fan clutch is fitted.
Rob.