Is my electric fan setting correct?

[UKPhilTR7]

I think have my electric fan coming on too soon and going off too early. It comes on at half way and then off at 1/4. I think it should be coming on at 3/4 and going off at 1/2.

What point do you have yours coming on and is mine on too early?

Coming on:


Going Off:

[Hasbeen]

Phil, the gauge doesn't tell you all that much really, the engine temperature of different cars could vary by 10 degrees C when their individual gauges read half.

Having said that, I would be starting to panic before the gauge got to 3/4 in my current 7.

When it's pump impeller was slipping the temperature at the thermostat, taken with a UV external thermometer was at just about 100C. when the gauge read 3/4. I really would not like to see it that high again.

I suggest you buy a UV thermometer, they are only about $20 at Supercheap, & take some actual temperatures. You will then know what is really going on in your car.

Hasbeen

Sorry, must have been off with the fairies, I meant an inferred thermometer.

H

[Sautie]

Hi Phil,
I assume that you are a 7 and not an 8. However read my strange temperature tale because even though it was on my 8 there could be some interesting problems solved.
Presumably we have common ambient temperatures that are much higher than the UK.
Certainly an additional modern temperature gauge is a blessing and the fan warning light that I installed is a wonderful thing to put me at ease.

[jclay (RIP 2018)]

I was having trouble with the wind screen wiper and found out about cleaning the grounding lug at the battery. Everything started working better.

Two days later, I got a huge surprise! My fan come on. Scared me to death! It had never come on before. The fan starts when the gauge reaches 1/2 and goes off a little above 1/4. Sound normal.

Clay

[url="http://www.jclay.me/"]My Triumph Site[/url], [url="http://www.triumphtechnical.me"]Technical Stuff[/url], [url="https://docs.google.com/folder/d/0B8MWEvqOpX3udEF4SmFQUW9RS09hbU5uNW5Wd0xrUQ/edit"]My Public Folder[/url],

[FI Spyder]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Hasbeen</i>


Sorry, must have been off with the fairies, I meant an inferred thermometer.
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

When I read that I knew that everything is upside down in Australia but I didn't think that applied to wave lengths as well. Good to know all is well in the world.[:o)]



- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[jeffremj]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by UKPhilTR7</i>

I think have my electric fan coming on too soon and going off too early. It comes on at half way and then off at 1/4. I think it should be coming on at 3/4 and going off at 1/2.

What point do you have yours coming on and is mine on too early?
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">I had a temp sensor fitted into the radiator. It switches the fans on at 88 deg C. On the temp gauge it reads just under 3/4 when the fans kick in. They take it down to around 1/2.

[saabfast]

I worked on the basis that with the standard viscous fan most 7's seem to run at just over the 1/4 mark (in the UK at least). When I fitted an electric fan I set it to cut in just under 1/2 and it cuts out at just over 1/4 (OK, you can only set the cut in but that's how it seems to work). Of course, maybe in Oz 1/4 = 3/4 being as its working upside down.

Alan
Saab 9-5 2.3t Vector Auto Estate
'81 TR7 DHC

[Hasbeen]

Incidentally Phil, with a new mildly uprated engine, about 120 BHP, a new stock radiator, new stock water pump, & a new stock viscous fan, & with a modern air conditioning system grafted into the old stuff, my 7 runs usually at just under 1/4 on the gauge.

On the very hottest days, which can hit 40 C here, I have not seen the thing get a full needle thickness above 1/4. The thing is then reading 89 C at the hose fitting on the thermostat housing, & a little bit less beside the temperature sender.

Makes me feel safe about head warping.

The overflow redrawing system I fitted, off one of the Toyota Cressidas is keeping the water in the engine a couple of inches higher in the header tank than previously, & it really does help. There is now never any air in that top hose, & I have not had to add water since fitting the thing about 18 months ago.

Hasbeen

[dursleyman]

Hasbeen, got any pictures of your overflow/redrawing system. Sounds like an interesting idea.

Russ

1981 TR7 Sprint DHC
Dursley
UK

http://tr7russ.blogspot.co.uk/

[Hasbeen]

Sorry Russ, I don't even have a camera.

My son will be home for some months in about 10 days. I'll try to remember to get him to take some.

Hasbeen

[FI Spyder]

It seems the original stock set up keeps the temperature rock steady. I think the temperature gauges from car to car can be quite different and any comparison should be taken with a grain of salt. With mine the needle at running temp is somewhere between 1/4 and 1/2. Summer temps are usually between 70 F (21C) to 80 F (27C) with occasionally going to 86 F (30C). In those rare hot days driving in stop and go traffic (not easy to find here on the Island) the needle might move a needle width. With the electric fans on the Integra and Tercel the needle will move more similar that described in posts above. It seems that the clutch fan is superior to the electric at keeping temps on an even keel and whether modern engines can better handle it or whether it makes no difference I don't know. I have thought of adding an addition "catch" bottle like Hasbeen has done as I have some new "used toner" catch bottles from copiers that would work and it just seems like a good idea to catch any excess coolant rather than have it dribble on the lower suspension when it exits the bottom of the overflow hose. If I find the time to fiddle this summer I might do it.


- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[Hasbeen]

No photo Russ, but a simple description.

I removed the black flap that blanks off the gap between the radiator & the body on the header tank side.

I duplicated the flap in a bit of body metal. Pinched the overflow bottle, & the bracket that holds it from one of our old Toyota Cressidas, & fitted the bracket to my new metal flap. The 80s Cressida bottle is the perfect size & shape for this space.

I now fitted my new metal flap, using the same gear that had held the waxy one, fitted the bottle & hoses, overflow hose to bottle, & bottle overflow hose out through inner guard, & added coolant. It has worked perfectly ever since.

There is one trap. Be careful you connect the overflow bottle hoses correctly. Get it wrong, & you will pump water out each time you start your engine.

I had one Cressida's radiator recored. The shop fitted the hoses to the overflow bottle the wrong way round. It was losing water, & tending to over heat for a couple of weeks, before I found what they had done.

Hasbeen

[UKPhilTR7]

Thanks for that guys, from what I can work out, it seems to be correct and if it went to 3/4 before the fan kicked in, that would be a bit of a worry. Oh yes Hasbeen, that is on my birthday present list. It was on the Christmas present list too, but the socks and bottle of whisky beat it to the top I am planning a trip to supercheap this weekend so hopefully it will be in the tool box. When I was in the UK I was going to get one from Halford's but the guy said that they do not sell them any more, which I thought was a little strange.

I will be ordering a new coolant sensor to fit as the one in has not been changed since I have had the car, for the last ten years. So now would be a good time to try and get the gauge to tell the (truth or as close as it can).

From what I can make out the normal running temperate on the gauge is 1/4, when the viscus is on it. So as long as it is running between the range which it currently is, that seems to be both correct and safe. I will confirm this though when I get the digital gaget though when I have it.

[Hasbeen]

One more thing I forgot to mention, you have to fit a rebreathing radiator cap to the header tank. I picked one up at the local Repco, parts store.

Don't forget, ours should be a 14Lb cap.

Phil it really doesn't matter what your gauge says, as long as you know what it means at the engine.

Hasbeen

[FI Spyder]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Hasbeen</i>


Don't forget, ours should be a 14Lb cap.
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">


My replacement cap only lasted a few years as the centre post rusted away (you just can't get quality parts these days). I tried to get a rad cap locally but the only caps they had in stock were 15 lb. caps. or was it 15 lbs and all they had was 16 lbs. Seems that's what the new cars use as they run hotter than the old cars

- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT