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Thermostat VS thermo fans VS explosion

Posted: Fri Dec 30, 2011 5:54 pm
by A112H
I am after some advice.
The hardtop is getting warm, I say warm as it has never got over 3/4 on the gauge and that was at traffic lights, but I think that is enough for concern.
I have the new alloy rad (to disperse heat more efficiantly), the new water pump, new hoses and I have a nice big electric fan. Now I know the reason this is happening (fan always on and no thermostat) but not sure on the be all and end all cure.
At the moment the fan is hard wired, until payday the 15th (13th as 15th is Sunday :) ) I can't afford the switch.
Question 1, whats the best switch, the one that slips into your top hose or the one that reads from the rad?
Question 2, what is the optimal running temp for an Asstron?
Question 3, how should I set up the fan / thermostat readings? ie; theromostat at 85c and fan at 75c?

As always any help is appreciated.

Re: Thermostat VS thermo fans VS explosion

Posted: Fri Dec 30, 2011 9:04 pm
by gaz914
1. Stick a thermostat in it - just a standard 80 degree one.
2. If it only gets hot while at lights, then the fan just isn't moving enough air through the radiator.
It may not be the fan, it may be too far away from the core, it may need a shroud, it may need another fan.
3. Fan should come on at about 90 C and off at about 80-85 C.

cheers
Gaz

Re: Thermostat VS thermo fans VS explosion

Posted: Fri Dec 30, 2011 11:33 pm
by geezer101
Time to try out one of those new high flow thermostats. Does the twin Dell's manifold have provisions for sender units to be fitted in the thermostat housing base? The fan sender under the thermostat would be about the optimal point for triggering the fan as the hottest location prior to entering the radiator. A sender in the radiator is the better late than never option. Out of curiousity, is the heater hooked up through the manifold - or hooked up at all? I can't see any heater hoses or recirculation hoses anywhere...

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 8:50 am
by A112H
Thermostat it is, might look at the high flow, not sure yet.
Yes there are two outlets on the manifold, one is currently plugged and the other has the temp sender in it.
No heater connected.

Another member has suggested a external temp control switch, which seems like a very good option.

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 9:57 am
by davetrees
There are a few schools of thought re where the fan switch should go ..... there is a lot to be said for putting it in the BOTTOM radiator hose, because that's going to measure the temp of the water going INTO the motor. Overall, it probably doesn't make a massive amount of difference where you put it ... the water temp differential between manifold & top hose will be minimal.

Question - what temp is it actually reaching ... is your temp gauge marked in degrees ? Where the needle sits on a stock gauge doesn't really mean much. Just put an adjustable switch in it - the Davies Craig ones are as good as anything - and set it so the fan comes on at the appropriate temp (by the gauge ..... the marks on the switch may not be accurate).

Remember that getting maximum flow through the radiator isn't always a good thing .... if the water flows through too fast then it doesn't have time to dissipate the heat properly (similar to having no thermostat fitted).

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 10:16 am
by A112H
I just have the stock gauge at the moment, so I have no idea what degrees 3/4 is but I assume it is warm as most cars sit on or under half.
I also have a Sigma temp sensor in it as I couldn't get a new one for a Galant. Are they the same? Could this be the issue and not the actual temp?
Either way I still need to fit a thermostat and get the fan working correctly.
I think just fitting the thermostat will fix this issue as the water is flowing constantly and wont be sitting in the radiator long enough for the air flow or fan to have any real effect.

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 10:30 am
by astronturbo77
Are you using the galant saturn temp sender in the astron manifold? Using a astron sender will more than likely give you a incorrect gauge reading.

Also ive found in the past that running no thermostat in a astron actually makes em cook ,try puttimg a thermostat in and see how it goes, possibly even drilling a few holes in it aswell.

The thermostat regulates the opperating temp, as long as the re st of the cooling system can keep up. Probjrun it around 90deg. Sorry about spelling on my smart phone

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 10:36 am
by A112H
Funny how they call them smart phones, lol

I am running an Astron sender, can't seem to find a Saturn sender anywhere :( I need a speedo cable today so might do the wrecking yard rounds and see if I can find a Saturn somewhere.
Could I use one from a FWD Colt or would it need to be Galant to be accurate?

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 11:00 am
by GB_BB4C
Just bought a new sender for my Saturn motor in the Yellow Galant. Cost me $22ish for the new sender. Thought mine was running a bit low (temp wise) then one day it just went all over the place. Now its replaced it reads about half.
If ya want me to get ya one, let me know.

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 12:05 pm
by A112H
Yeah grab one, for sure. I will fix you up on the 14th :thumpsup:

So I just went to UPI and scored a speedo cable and as new thermostat fron a GJ Scorpion for $17, lol

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 12:35 pm
by davetrees
According to the Tridon online catalogue, the senders for all the Galants & Sigmas are the same .... Part No. TT5017. You should be able to get one through any auto parts shop.

A new one is probably a cheap option, if only to eliminate that as a cause. The gauge itself may be faulty of course .... remember it's 30+ years old !

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 12:46 pm
by A112H
The one I have is new, I will check the part number if I still have the packet.

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 1:20 pm
by astronturbo77
Def need the galant sender. They only run 1/4 on the gauge hot

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 1:49 pm
by davetrees
I assume the replacement radiator is at least the same capacity as the original one ?

Bottom line though, you don't know if it is actually running hot or not .... put a thermostat in it for starters, & then hook it up to a proper temp gauge - it's the only way you will be able to tell.

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 3:34 pm
by A112H
Yeah the new rad is 1/4 bigger area and is 3 core, also it is alloy so should disipate heat better.
So I have chucked a thermostat in there and when for a drive. When I got back the gauge was almost at 3/4. I carefully (with a thick towel) released the rad cap to depressurise, then removed it totally, inserted the sensor from an aftermarket gauge I had around at it reported 87c.
The sensor on the aftermarket gauge is too long to fit in the manifold unfortunately so can't be used.
This is good news however, for some reason I am still a little sceptical about driving it on such a hot day. Guess I am used to new car reliability, lol

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 4:26 pm
by 81pw
I did this today. Brought a 14 inch radaitor electric fan. And a Davies Craig thermo switch which is adjustable from 60-100 deg. Cost 50 bucks from repco. I had to order one in took about a week to get.Comes with easy wiring instructions. I put my thermo probe in top radiator hose. Also make sure u know if your fan is pushing or pulling air. Mine was already set up for pushing through the radiator so I mounted it in the front. If u want to mount it behind so it pulls air just take the blade off turn it around then reverse the polarity. Oh yea buy a aftermarket Temp gauge. Cos without a thermostat your temp shouldn't be going over 60.running that low means More wear on the engine, poor fuel economy Blar blar blar. Hoped that helped

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 6:14 pm
by A112H
Cool, cheers for the info.

Just did a 70k round trip to 84GKSIG's and back and what I found was as soon as my gauge reported 3/4 temp it just as soon dropped down to between 3/4 and half. So having the thermostat in is definately working, a rough guess would be that it is running between 80 and 90 degrees.
Once I get the fan set up all will be well. :thumpsup:
Now I have the mechanicals sorted out I can finish the interior, for which I have some old school Smiths gauges, oil pressure, volts and coolant temp.

Re: Thermostat VS thermo fans VS explosion

Posted: Sat Dec 31, 2011 7:54 pm
by davetrees
81pw wrote:Cos without a thermostat your temp shouldn't be going over 60.
Most engines will run hotter without a thermostat than with one ... simply because the thermostat (even when open) provides a necessary restriction to the flow rate, so the water actually spends long enough in the radiator to exchange heat with the atmosphere.

Re: Thermostat VS thermo fans VS explosion

Posted: Sun Jan 01, 2012 10:52 am
by tubby
temp sensors arent all the same I had issues with the panno running at what it read was just over 3/4 swapped to my original sensor and it was running correct temp the whole time.
Image
two senders obvious difference

Re: Thermostat VS thermo fans VS explosion

Posted: Sun Jan 01, 2012 5:26 pm
by 81pw
Never seen a car run hotter without one. Anythings possible I suppose

Re: Thermostat VS thermo fans VS explosion

Posted: Mon Jan 09, 2012 8:19 pm
by amgis_obrut
81pw wrote:Never seen a car run hotter without one. Anythings possible I suppose
any cleveland will run hot without the correct thermostat

Re: Thermostat VS thermo fans VS explosion

Posted: Mon Jan 09, 2012 8:45 pm
by A112H
Yeah, I don't think I have ever seen a car run cooler without a thermostat

Re: Thermostat VS thermo fans VS explosion

Posted: Mon Jan 09, 2012 9:02 pm
by dvsfin
I was having overheating problems with my galant when I was driving on highways the temp would climb up to the H on the temp guage and start pissing steam out of the overflow, it ran warm in slow traffic but not hot. I replaced the radiator with a slightly bigger one my dad has had lying around for maybe 20 years lol. Cleaned it up, filled it with just plain water and put on a shroud which I think I got from Vaughn. No thermo fan, just a viscous drive engine fan. And now even after quite a spirited drive (flogging the shite out of it) you can touch the bottom of the radiator and it's still quite cool, the temp guage doesn't even reach the lower line which I think is suppose to be running temp. Also I am running a standard thermostat. It's also 4G54 and it has a blown head gasket (thanks to the overheating problems) and is leaking compression into the water and it's still running the astron coolant sensor I am pretty sure. I hope you find this info helpful. Because I thought my temp problems could have been heaps of other things, but when I found the radiator and checked that it didn't leak I just gave it a go and put it in and it has fixed all heating issues.

/end life story lol

Re: Thermostat VS thermo fans VS explosion

Posted: Mon Jan 09, 2012 9:15 pm
by woops
There is always another simple option of using a thermo fan switch and wire in a simple relay for it. A fair bit cheaper and simpler then the davies craig one but just not adjustable. Although you don't normally need a thermo fan running anywhere below about 70 degrees at the absolute lowest. And that's even with taking the water temp from the outlet of the radiator. Otherwise your fan would never turn off during normal driving.

Just take a look at the tridon catalogue for switches and look for a suitable temp range, prob lower is better in the mid 70's for the radiator outlet temp to assume a 10 to 15 degree drop across the radiator, find a usable size sensor and then just wire it in using a relay for the fan. Take into account the electrical terminal type and just google the sender to see how cheap it typically is.

http://www.tridon.com.au/Products/Produ ... 483&P=2014

I would personally make a hose adapter which holds the sensor and you put it inline with the lower radiator hose. Something like this concept but with a piece of stainless tube and a say 22mm nut welded to the side for the sender.

Image

Also a shroud will help significantly with getting the fan to work effectively, otherwise the fan will pull air from the easiest location which isn't through the raditor but just circulate air around the engine bay.

Re: Thermostat VS thermo fans VS explosion

Posted: Mon Jan 09, 2012 9:26 pm
by A112H
Thats a great idea. I have used the joiners on my top and bottom hoses. Think I might get the thread tomorrow and work out which one I need.

Re: Thermostat VS thermo fans VS explosion

Posted: Tue Jan 10, 2012 6:28 am
by davetrees
A tip with thermo fans (whether on an adjustable or "fixed' temp switch) ....... make sure you wire in an "over-ride" switch as well.

That way you can fire up the fan even if the thermo switch fails (and they do, occasionally).

I have just used a 3 position ON-OFF-ON switch on the dash - one position is "auto" (ie. through the thermo switch) and the other is "over-ride" which bypasses the thermo switch and puts power direct to the relay. Cheap insurance !

I took the power for mine from an "Accessories" feed in the loom. That way I can have the fan running at controls (eg. to get rid of heat soak) without having the engine running or ignition on.

Re: Thermostat VS thermo fans VS explosion

Posted: Tue Jan 10, 2012 10:36 am
by amgis_obrut
mount temp sensors/switches as close as possible to the thermostat

Re: Thermostat VS thermo fans VS explosion

Posted: Tue Jan 10, 2012 12:49 pm
by A112H
Before or after?
I have a joiner with a plug in it before the thermostat and the manifold has a plug in it next to the temp sender.

Re: Thermostat VS thermo fans VS explosion

Posted: Tue Jan 10, 2012 4:24 pm
by davetrees
amgis_obrut wrote:mount temp sensors/switches as close as possible to the thermostat
Why ? (serious question ....)

In the short distance between the thermostat and the inlet to the radiator - on most cars anyway - I can't see that the water temp would change much ?