Too hot

[Azazello]

It is very hot here in Italy, 35°C in the shade, too much for working in garage or in the garden...
I noticed that my car i quite too hot, reaching 100°C uphill, with high rpm...
The engine is running well, not water consuming, just drinks a bit of oil (half a liter after 4000 km) but I am used to that from when I bought the car...
On tuesday I washed the water system, flushing it with water and bicarbonate and then with water, filling it again with antifreeze and distilled water.
I did not fit the thermostat.
Now, without thermostat, the temp is quite normal, between 80 and 90°C, a little bit more when I go uphill or at high speed.
Could be, as I was told, a radiator problem?
I found a "Frigair" radiator for 65 euros, I do not think it's worth to try to repair mine...
Could be a water-pump fault?
What I have to look for to understand a little bit more?

 

[JohninColombia]

Sounds like you have the problem we do here in Colombia.
Crap builds up in it and your problem appears.
Here they take the top of the radiator off and use a long brush to flush everything out. Just flushing does not do the trick. Then they resolder the top back on.
Works great!

 

[angel]

Where is the temperature gauge sender located? If it's at the rear of the head, it's quite normal to read 100 or higher. At the same time, coolant temperature on the thermostat could well be 15 degrees lower so no need to worry.
Also, automotive temperature gauges are no laboratory instruments, they can have a deviation of 10 deg. Celsius, plus or minus.
I would start worrying if temperature didn't drop even after downhill driving, or rising even after the fan had cut in.

 

[Azazello]

Where is the temperature gauge sender located?

On the water pump; my mechanic made a threaded hole for the sender.

Also, automotive temperature gauges are no laboratory instruments, they can have a deviation of 10 deg. Celsius, plus or minus.

Sure, but I have this gauge from this winter, and although the climate is quite different now I refer to my past readings...

I would start worrying if temperature didn't drop even after downhill driving, or rising even after the fan had cut in.

The temp drops downhill, but, when the engine is running at high rpm or uphill, temp still grows with the fan working.
The funny think is that usually temp grows when the car is standing, cause no air goes trough the radiator, and drops running, when the radiator is well vented.
Now, my temp grows when the car is going and decreases when I stop it...
Can it be only due to the very hot weather we have this days?

This, with friend's and yours advices, let me think of a choking system...

 

[angel]

Now, my temp grows when the car is going and decreases when I stop it...
Can it be only due to the very hot weather we have this days?

It could be so, but could also be because of incorrectly adjusted ignition timing, a blocked radiator (either from the inside or the outside) or, less common, a faulty water pump seal that sucks air.

 

[DaveP]

Mine was similar (but worse) and has been cured by a replacement water pump, the spindle had come a little loose and the car overheated at speed, as diagnosed by Angel.

 

[Azazello]

I bought the radiator, I am waiting for the courier to deliver it.
I hope it will cure this symptoms...
If not, I think it's worth to put an eye on the water pump... is there any method to see if it is working properly?

 

[Azazello]

I changed radiator and fan switch yesterday. Filled with coolant and a 75°C thermostat, today I had a ride.
Still reading hot (about 210°F) uphills at high revs, once at home I left the car running still for a while to see what happens... the fan switches on and off periodically, as it should be, but the thermometer gives always high temperatures, about 200°F.
So we have two possibilities:
1. the problem is the thermometer and I am worried for nothing;
2. there is a big difference of temp between the radiator and the water pump.

I hope the first is the right one, but I wonder how should I do to understand it...

 

[malcolm]

On ordinary Renault 4s the fan switch should operate at about 93°C. Though the switch for the fan is at the bottom of the radiator so the top is probably 5 degrees warmer.

We don't understand °F in the UK - it must be some Italian thing. :smile: 210 of your Fahrenheit would be 99°C - about right for idle when the fan is cutting in and out. It's a pressurised cooling system so should be OK to at least 105°C at the water pump.

For normal running the coolant should be about halfway on the gauge (a little cooler than idle). When going up hill at high speed in Italian temperatures it will be hotter. Your gauge seems OK so slow down a bit on the hills when it starts looking hot!

 

[Azazello]

I am telling the °F temp because my gauge is a °F one (it was cheaper!), I was wrong thinking in England you were more used than me to that (Which country still uses °F?). In Italy we use only °C, I know of °F just from my physics lessons and from Ray Bradbury.
So now turns out I am worried about nothing? I thought that changing from 83°C thermostat to the 75°C one would be sufficient to correct our like-hell summer climate...
If you are right now I have a good spare rad.
But at idle it is quite more than halfway on the gauge, and I am not running as mad...
I will run a bit keeping an eye on what happens.
One more question: what should be the right working temp for our cleon engines (and is it the same for 956 and 1108 ones)?

 

[malcolm]

Don't know the temperature engines should run - my MG has a gauge that goes from low to high with no markings between.

Idle is about 60% on the gauge. Normal running 50%. Going up hill in the summer maybe 70%. Traffic is the problem in the MG and sometimes I have to turn the heater on to help cool the engine. The danger line is about 80% on my gauge.

 

[Azazello]

The red line in my gauge is around 210°F, 98°C according to google, and I have never fully reached yet (always some degree under). But it is a universal gauge, so I do not know if these values are right even for ours r4...
But, given your data, I think that the situation is not so hard as I was thinking. Though the temp is, in uphill situation, a little further tha 70%...

 

[angel]

98 degrees Celsius is not too hot. Keep in mind that in a pressurized cooling system, coolant will not boil until around 115 deg., and the factory "too late" lamp is set to come on at 112 degrees.

 

[Azazello]

Thanks, you are reassuring me... yesterday i had a trip to Viterbo, 40 km to go and another 40 back home, uphills and downhills...
The gauge indicator was right about halfway at average speed and never more than 90°C.
With the new rad it goes down faster. And it seems to me that with the 75°C thermostat the situation was better and cooler than without thermostat at all...