Bob: ro284's - FD Temp guage and Thermoswitch mod. [Archive]

Glenn Butcher

22nd April 2006, 10:39 AM

<html><head><meta http-equiv=Content-Type content="text/html; charset=windows-1252"><link rel=Edit-Time-Data href="./Temp-guage-and-Thermoswitch_files/editdata.mso"><title>Temp guage and Thermoswitch, my best mod</title><style></style></head><body bgcolor="#FFFFFF" class="Normal" lang=EN-AU><div class=Section1> From Bob: ro284 Temp guage and Thermoswitch, my best mod. My best mod. for me anyway! I know some owners like to keep their cars standard, but I think for the sake of the engine and reliability an aftermarket water temp gauge is a must. I decided on a cheapie gauge from TIM, I got a triple speaker pod, (beautifully made) I put the boost gauge on the right and the Temp gauge in the middle, on the left I will put a clock, I promised a Non member (soon to join!) who has limited access to a computer at the mo, how I would install this with pic’s, I expect most members have access to Robinets site, so will have seen pic’s like these before, They are self explanatory, Out with the old,
 <img width=480 height=360 src="/general/r0284/Temp-guage-and-Thermoswitch_files/image002.jpg" v:shapes="_x0000_s1026">
 
 Remove I.C etc. Disconnect the hose from the stat housing and move to the right to stop getting  swarf in it. cover it up with rags. I fitted new belts at this stage.
 <img width=480 height=360 src="/general/r0284/Temp-guage-and-Thermoswitch_files/image004.jpg" v:shapes="_x0000_s1027"> 
 X marks the spot! This is very thick housing, ideal for tapping, And I think the best position for the sensor, 
 <img width=480 height=360 src="/general/r0284/Temp-guage-and-Thermoswitch_files/image006.jpg" v:shapes="_x0000_s1028">
 

 
<img width=480 height=360 src="/general/r0284/Temp-guage-and-Thermoswitch_files/image008.jpg" v:shapes="_x0000_s1029">

The TIM gauge needs a drill size of 14 ½ mill but best drill 5 then 8 then 11 mill pilot first, slowly. The Tap size is  5/8 U.N.F. (for sale used once £7-50 inc p&p ,) Wind the tap in slowly with lubricant on, half in, quarter back, after every 4 turns take the tap out and clean it, stop cutting when you have about 15 % of the tap threads  left outside the hole. ( makes for a good tight fit, )
 <img width=479 height=360 src="/general/r0284/Temp-guage-and-Thermoswitch_files/image010.jpg" v:shapes="_x0000_s1032">

With a hose blast out the swarf, especially off the belts, collect the swarf with rags under the stat housing!
 <img width=479 height=360 src="/general/r0284/Temp-guage-and-Thermoswitch_files/image012.jpg" v:shapes="_x0000_s1033">
 
  Use PTFE tape on the sender unit and screw in to place 
 <img width=480 height=360 src="/general/r0284/Temp-guage-and-Thermoswitch_files/image014.jpg" v:shapes="_x0000_s1034">
 
 I used a dremmel to cut a hole through the bulkhead 1 inch down from the lip just to the right of the brake servo, to take sensor wire, Boost gauge pipe, and some other wires I needed to the gauge pod, this hole comes into the cabin just above the clutch mounting bracket, using a thick grommet.and with the hole here the sensor capiliary is long enough!
 <img width=480 height=360 src="/general/r0284/Temp-guage-and-Thermoswitch_files/image016.jpg" v:shapes="_x0000_s1035">
 
  If you use this gauge the sensor earths to the engine and the instrument light will short and blow a fuse, so the bulb holder has to be changed for a 2 wire plastic one, I connected mine to the dimmer switch circuit at the ash tray light wires, Replace Air filter etc and top up water, I like this type of air filter as it’s a cold air feed and does not rob the I.C of any of it’s air supply. 
<img width=480 height=360 src="/general/r0284/Temp-guage-and-Thermoswitch_files/image018.jpg" v:shapes="_x0000_s1036">
 
 I hope this helps someone, all at your own risk, if you feel confident enough to do it. I have to say that I am very pleased I installed the gauge as it probably saved my engine, I noticed that running round town it would settle at about 85c rising to 90c in traffic, that was in winter! and I was surprised how sensitive the guage is, but it’s warmer weather now and I thought I would leave the car ticking over for a while to see when the fans came on, but they didn’t! at all. So I checked the circuit from relay to the Thermoswitch, ( no continuity !) and at the same time fitted a lower temperature Thermoswitch, the standard one that came out is 108 deg, which is flipping hot, I fitted a 90 deg one, (stamped on the side, you could also use a 95 deg one ) it is the one with the black single wire connector, the way I got at it was to remove the alternator, it’s tricky but possible, this is what is under the alternator, crossover pipe, and a small bore water pipe, (best replaced at the same time,) from Mazda,
 <img width=480 height=381 src="/general/r0284/Temp-guage-and-Thermoswitch_files/image020.jpg" v:shapes="_x0000_s1037">
 
 Well I did that bit, and started the car and after a drive let it idle, still the fans did not come on, so I bypassed the original wire from the Thermoswitch straight to where the old wire ( since found to be broken down somewhere!) connected to relay no 3, that did the trick, and I am very pleased with the result. On tick overin traffic the temp gauge rises to 100 deg, then the fans come on and cool it to 95 deg, very quickly, and it will do that all day, it seems to me that the Thermoswitch overrides the ECU, and controls the fans, There is no heat soak problem cooking all the pipes and wires, ( rising to only 105 deg, when switched off ) as the engine never gets too hot in the first place, so I won’t bother with the fan switch mod, of course I realise Mazda designed it to get very hot, I guess for emissions reasons, but I would add that I am paranoid about overheating my rotary. Because the standard gauge won’t tell you! And this mod suits me fine, hope it may help someone in some way, I don’t have to keep switching the air con on now. If I thought it necessary my next mod to eliminate heat soak if it was a problem,  would be to wire a relay controlling an electric water pump (with ignition and engine off ) from my turbo timer. If nothing else from this thread, it may be worth checking your fans do in fact come on! Any advice/comments please add. Bob  </div></body></html>

Bobfish

4th May 2006, 10:17 AM

Good write up, to be fair though you could just remove the t-stat/coolant filler neck. Thats what i did - much easier than removing IC etc. Its only 3 bolts!

ro284

4th May 2006, 03:41 PM

you could just remove the t-stat/coolant filler neck. Thats what i did - much easier than removing IC etc. Its only 3 bolts!
Very true Bob, but then you have to clamp it, drill it, and tap it, without slipping or distorting it! or snapping a bolt. then fit a new gasket, but also i replaced my belts at the same time,and took alternator off to get at the Thermoswitch. and it's easy to remove IC. & clear the leaves out,
Having done this a few weeks ago, i'm well pleased with the result, i no longer have to worry about the engine getting too hot, as the fans are automatic. when they come on you can watch the guage go down very quickly, about 1 min down to 95c from 100c by which time hopefully the traffic jam has cleared!
cheers Bob

tinker-27

8th June 2006, 07:44 PM

hi do you know what make the air intake is or where might have one simalar cheers craig

ro284

8th June 2006, 08:17 PM

Hi Craig, i was lucky to find that one, from another member on here, i wanted that one as it is a cold air feed, Quiet, and does not share/rob the cooling air supply duct to the IC, which a standard air can do. (Apparently Mazda spent millions on developing the shared air supply to find that hot air can be sucked back through the IC and damage the engine! as mentioned on Rob Robinetts site) i believe Mazda increased the size of the intake duct on the later models because of this, i tried Apexi twins which were ok, but got fed up with mooing noise from the air pump, I much prefer this setup, i think i have only seen a very similar kit of this type advertised once before i think from Gary at Rotaryart, but it was far superior quality, and i think Carbon fibre, it might be called Gruppe type M! but not really sure about that, mines GRP, best give Gary a shout, i'm sure he could help or advise,
cheers Bob
(i will try and find a pic of the filter (one big one)

ro284

8th June 2006, 08:28 PM

As i understand it fitting aftermarket filters is a good thing as they don't rob the IC but they do need a cold air supply as they suck hot air from the engine bay, but the air pump moos! hope this helps,
Single filter pic,
Bob

tinker-27

8th June 2006, 08:34 PM

im not bothered about the MOOING noise as its a V8 6.3 litre so the noise is not a problem i would like more cold air for the motor will try rotaryart unless anyone has a second hand one ,i might be able to copy it in carbon fibre (or could borrow one) ?

ro284

15th April 2007, 10:39 AM

Any help Jim?
Bob

ro284

16th June 2009, 04:24 PM

Resurrected for James.:3gears-lh

gear1275

16th June 2009, 10:27 PM

thankyou matey, if anybody needs help with fans, thermoswitches, relays, anything really, speak to him. he knows all!! cheers bob