running hot problem

[alex_cristocea]

I have a cooling problem with my 87 951.First I must say that I don't have the original cooling fan relay but I have 2 smaller ones which does approx the same job.
When I'm running on highway temperature indicator stays right at the second white mark most of the time.When I hit the traffic things gets a little hotter.Indicator gage nearly hits the upper white mark before fan comes on.I changed the temperature switch, I removed the thermostat and in traffic it's still running hot.Yesterday I had the same problem and when I came back home I pulled on a gas station, improvised a wire strap and I've put the cooling fans on full power mode.With fans turned on at max speed and with no thermostat the water indicator gage stays straight on the second White mark.Some times when I stay more then 5 minutes at the stop lights and water temp indicator gage almost hits the last white mark if rev few times to 3-3.5k rpm fans take off.
Now I had speak with other local owners of 951-s (witch have original cooling fans relay and thermostat) and they say it's normal and they have same temperatures in traffic even in winter, and the say their cooling fans starts when water temp gage reaches the last white line.
Since the car runs more cool with the fans turned on I don't think it;s a scored water pump.or it may be ca clogged radiator.I don't know what to think.Maybe someone could help me. Thanks

[soxnail]

It should only go to the first small white mark( not the first fat one) at cruise. At idle on traffic lights it should go up a little, one to two needle widths then the fan cuts on it drops to just at or above the first small white mark. If this is not happening then you need to check your cooling system.Start with a flush and refill and go from there.
Sox

[bscpanther]

alex,
just me but I don' feel smart enough to be substituting relays and trust they'll work the same way the originals did. In my experience if it won't go in the red, then it's more minor things like a flush, air in the system if it's been recently tampered with, or a relay that doesn't work properly.
Good Luck

[alex_cristocea]

first I would like to thank you for your imputs.
second I relay hava this issue with the relays.at first step it's starts only one fan in slow speed and at secont step it starts both fans but just one runing in full speed.Now from what i've searched today i;ve seen that the original relay has 4 relays inside.Tomorow I'll try to bulid one witch does the same things as the original.here is a schematic witch isn't completed but i'll finish tomorow.

[soxnail]

With fans on full and no thermostat the temp should not be at the spot shown on the pic. Imho. If not there is a lack of cooling ability.
Sox


Edit Sorry it should be at the spot..