Strange Water Temperature

[BIG_MVS]

Right guys wondering what this is:

When driving my car the water temp slowly rises up all the way to 90 degrees, then it falls down to 60-70 degrees as if the thermostat opens

It then seems to run normally and does not go over the 90 unless sat in traffic then the rad fan kicks in.

My old gta turbo just gradually rised in temp and sat at about 80 degrees (without hitting 90 then this sudden fall in temp) from cold without touching the 90 unless again sat in traffic etc.

Could it be a stuck thermostat, dodgy water pump, or I have heard that a blockage around the turbo can cause cooling probs?

I have flushed the coolant and that seems to have helped sligtly but hasn't sorted it. There are no leaks and the system has been bled. Just strange it does it from cold and once it hits 90 degrees everything is OK.

Anyone any thoughts?

First sounds normal to me .That's what mine does .
Engine warms up then thermostat opens letting the cold water in the rest of the system circulate .Temp gauge sensor is on the water pump so will see a lot of cold water for a few minutes innit .
I would say you had a dodgey senso or bad flow on the last one .

[BIG_MVS]

First sounds normal to me .That's what mine does .

Quick out of the traps as usual Lee

Just seems strange to me, I agree with the concept, engine cools itself for a while gets hotter and hotter then a thermostat opens and it's then cooled via the rad.

I need 3 eyes with a GTA though, one on the road, one on the non functioning speedo and one on the temp guage

Who else has a GTA that runs like this? Lee did it do this even after your rebuild?

Yep .
I'll see if it does it again after this next build

Mine pretty much behaves like this, too, although I reckon when it falls back, it's probably a bit more than 60/70C. Today, the needle was pretty much straight up (which is a bit under the 90 line) while I was on the motorways and rose to 90 when I was in traffic.
Earlier this year, I flushed out the coolant when I replaced the radiator and its hoses and the cooling is much better than it was before. I reckon it could be something to do with it being a bit chilly at the moment, too. In the summer, I didn't notice this - it pretty much went to 90 - whereas over the last few days I've noticed something like you describe.

Jon

sounds fine to me. as lee says, your old car had the problem, not your new one.

Yes, sounds normal to me too. Mine starts cold, gets up to temperature, then the thermostat opens and the temperature drops back down, then rises back up to normal and sits around 80 all day. Unless I spend a long time sat in traffic. Then I think it'll climb to about 90 and the rad fan kicks in.

[BIG_MVS]

Yes, sounds normal to me too. Mine starts cold, gets up to temperature, then the thermostat opens and the temperature drops back down, then rises back up to normal and sits around 80 all day. Unless I spend a long time sat in traffic. Then I think it'll climb to about 90 and the rad fan kicks in.

Oh good just thought I had issues

It did go slightly above the 90 degrees yesterday before the sudden drop in temp, is there a different thermostat which opens sooner that anyone has tried? I have owned other Renaults in the past where the stat should open at 88 ish degrees and swapped it for one that opens at 82 or similar, would this be a good or bad idea?

if you really want to do some work for the sake of it, then take you radiator out and have it re-cored. could be full of crap in there.

maybe the old one had no 'stat