Jaguar Forums - Jaguar Enthusiasts Forum - Lower temperature fan switch on AJ16

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- - Lower temperature fan switch on AJ16 (https://www.jaguarforums.com/forum/xjs-x27-32/lower-temperature-fan-switch-aj16-219624/)

Quote:

Originally Posted by Doug (Post 2095304)

Actually it makes good sense for an auxiliary fan. Maybe a bit high, but if the fan works effectively, it isn't an unreasonable temperature.

Somebody figured that 220º was the point where A) the cooling system needed some help and B) post-shut down temps might begin to be an issue.

If you're running less than 220º (which you probably are) and shut down, the fan will come on at 220º to keep things in a more comfortable range.

If you're running 190-200ºF while driving, well, that's a perfectly normal-safe range. If you shut down at that temp it's unlikely the spike will reach anything dangerous. You shouldn't need the aux fan.

If you're consistently running more than 190-200 while driving then a lower-temp fan switch makes particularly good sense, as the cooling system obviously needs a bit of help.

But I fully understand the desire to build-in some buffer zone to a cooling system.

This is of interest to me, though, because I'd like my aux fan to come on less often. In my case it operates needlessly. The sources for various switches is helpful !

Cheers
DD

I guess similar predicaments. My car can probably handle getting hotter, but for me in Texas, the problem is the AC. In order for the XJS to keep me ice cold in 98degree plus weather, the car needs to run left of the N. I have overcharged, undercharged, modified and tried it all, but what really helps this car’s AC perform is how cool the car is. If the car passes 215/220, the A/C suffers, and it suffers greatly. On the E type (!) I don’t have this issue, nor do I have it in the X type. I I am not sure if it’s due to the cars aesthetic design or what, but airflow is a problem.

Quote:

Originally Posted by Doug (Post 2095277)

Recently, either here or on J-L, a fellow did a lot of temperature graphing and concluded that the best after-cooling occurred by re-starting the car after a few minutes to circulate new (hotter) coolant into the radiator.
DD

Indeed. I've read the same thing. Which is why I wonder how cooling the rad alone works so well. But having insta-cold aircon would, indeed, be well worth it.
I run 88-degree thermostats, and decided to stick heat-sensitive labels over my engine to see just how hot it got. They have funny gradations, but immediately after shutdown the hottest parts (water rails) were showing between 93 to 99 degrees, then after leaving it to cool on its own, bonnet shut, they showed between 99 to 104 degrees. The A Bank seemed to be slightly hotter. The rad hoses were 88 degrees. Inside the vee didn't even register.
https://cimg4.ibsrv.net/gimg/www.jag...9ec48bd84e.jpg
A Bank water rail, front, after a run.

https://cimg3.ibsrv.net/gimg/www.jag...0207d0d609.jpg
A Bank water rail, front, after heat soak.

https://cimg4.ibsrv.net/gimg/www.jag...bc1ca9833f.jpg
B Bank water rail, after heat soak.

Hi Spike, just saw this now.

I live in Southern California, but until two years ago lived in Colorado (where the summers are brutally hot). I drove the car a lot over this last weekend and, because I am now thinking about it, I noticed that fan does stay on for a really long time, though I didn't time it. But no flat battery problems. Until recently I was having some other cooling system related problems, but after this weekend I am sure that the aux fan and its switch are working fine. Incidentally I first installed this version of fan switch back in 2012. And it ain't broke, so...

Quote:

Originally Posted by Mike Beda (Post 2096000)

Thanks for sharing as much information about the switch and how it is performing in your car. It’s very helpful since we both have the same model.

I do think that Doug is right in that we are using the auxiliary fan circuit as a supplemental “main” fan. Car will always go past 180, hence the fan will always be on and will always stay on to cool the coolant back to 170.

I was going to test the 6010.88 I got, but your feedback is just convincing me to leave the 6010.82 in and just let the aux circuit do what it’s doing.