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Average coolant Temperature

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bigoldboy

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Hi guys , I don't very often get answers on this site but I'll try again with a single question . Whilst changing the water pump on my R4s I ordered a Digital coolant temperature guage with a sensor that screwed into the new pump so what should the usual driving temperature be .
Thank you
 
From a search on this forum:- ‘running temp’
“fan switch cuts in at 85 c but that is reading on radiator it self
thermostat on engine opens at 83 or 88 depending on make and cross reference used
so it may sit at 90 c b4 fan kicks in
guess 80 c normal driving would be nice
ps factory red light comes on at 115 c at which point carrying on melts the pistons etc.”
 
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Thank you . My car doesn't have an electric fan and like wise no thermostat. 1972 852cc R4s FASA
 
If 80-90 is a good average running temp, over 115 melts pistons would say anywhere under 100 is an OK average running temp, ( taking climate and driving conditions into account),problem with digital guage readouts is your looking at numbers, which having fitted digital temp gauges your looking at degrees all the time, up one or 5 one minuite down 2up 7 and so on , analoge universal gauges that are sold universal for most Renaults as an after market add on tend to start at 0 and go up to 120, there is only a worry when it gets into red, which is usually quite close if not before to the 115 degrees too hot quoted as these analog gauges are for fitment to most Renault car models irrespective of it being a Ventoux or cleon/sierra engine with or without an electric fan. So a good way of seeing what your digital meter should read is to look at the face of an analogue gauge Medium to start of red the numbers you be looking for on your digital one.
 
That makes things much clearer thank you so much . I wonder if you could answer this . I'm trying to solve my overheating problem which occurs if I drive at 80kph for more than 10 mins . I have done most logical tests and checks but I still don't have any pressure build up in the expansion tank that I believe is supposed to happen and I don't have any obvious water leaks and now I'm thinking it could be the expansion tank which is allowing pressure to leak out . Do you know what the correct BAR the cap should be rated at .
Thanks again .
 
There should certainly be pressure build-up in the expansion tank. I don't know what the correct pressure valve should be for your engine. But is the rubber seal in good condition?
Presumably the radiator is getting hot?
 
This thread covers all bases in detail:-

Overheating

Hi, I am new to the forum. I recently bought a R4 1982 TL in France, its in general good order. I had a 20 km testdrive in 30c + tempretures and the engine ran very well, smooth and responsive. The next day when I collected the car and drove 50kms across country in very hot conditions and the...
www.renault4.co.uk
 
Thanks jjhad . This is a 50 year old car so you could be thinking the right way as far as seals being no longer good . I'm going to make an addaptor for the radiator expansion tube and one for the expansion tank so that I can put some pressure in with a foot pump then maybe I will find out where the pressure is leaking . One member suggested 0.7 BAR is the pressure for the expansion tank cap but he wasn't completely sure .
Thank you for helping
 
bigoldboy said:
Thank you . My car doesn't have an electric fan and like wise no thermostat. 1972 852cc R4s FASA
Click to expand...
I don't think the car will ever perform properly without a thermostat. The French RTA manual says that the thermostat on the 813-02 engine opens at 82°C.
- I don't know if you've already done it, but it's worth taking the radiator out and reverse flushing it.
- Overheating can be caused by bad engine timing.
- As others have suggested, there might be an airlock - you have to bleed the system carefully (with the heater tap 'on').
 
Thanks for that . Head , heater matrix , radiator and all hoses thoroughly flushed plus here in Southern Spain there really is no need for a thermostat. Cheers
 
bigoldboy said:
Thanks for that . Head , heater matrix , radiator and all hoses thoroughly flushed plus here in Southern Spain there really is no need for a thermostat. Cheers
Click to expand...
But the thermostat is there to help the engine operate at the correct temperature - you'll get better mpg and cleaner plugs with one. And a working heater is a must when your car overheats on the road or in traffic...
 
If you still don't have pressure building up then something is wrong. If you're not losing coolant then it must be an air leak. The expansion bottle would seem to me to be the most likely culprit. I'd start with the cap and its seal.
 
Interestingly, @DaveP's problem of overheating was caused because the lack of thermostat caused too much vacuum effect on the bottom hose, causing it to collapse at higher temperatures and higher revs/speed.
So, that's another reason to keep the thermostat in.
 
bigoldboy said:
Hi guys , I don't very often get answers on this site but I'll try again with a single question . Whilst changing the water pump on my R4s I ordered a Digital coolant temperature guage with a sensor that screwed into the new pump so what should the usual driving temperature be .
Thank you
Click to expand...
Hi. seeing you have just fitted a digital temp gauge perhaps someone might have a suggestion to the problem I am having I have just fitted a digital/analogue combination one when switching ignition on all appears OK when starting up the gauge goes haywire
going full circle and back again (fast) kill the engine and gauge returns to normal car is a 4GTL If I pick up the 12v + directly from the battery all appears OK. Have tried disconnecting the alternator incase of sending a spike but still does it Anyone with any
bright ideas. Gerald post here or text on 07737703217
 
Hi . I bought an electronic gauge for 12 euros and it seems to work fine it shows coolant temperature and voltage . Screwed the sensor into the new water pump and ran the two wires to the dash board and then the other two wires connected red to a switched live at ignition and the black to earth . It really seems to work well .
I connected a bicycle pump that has a pressure gauge on it to the expansion pipe from the radiator and pumped till it read about 12 PSI and it showed where I had small water leaks from joints in pipes so they are now corrected . Then I connected the pump to the expansion pipe on the expansion tank with water in it and there it showed air escaping at about 5 PSI . All leaks cured and a new 0.7 bar pressure cap fitted and just waiting till I have time to test drive my baby .

Betty coolant and voltage gauge.jpg Betty coolant sensor in pump.jpg
 
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