Cooling issues!

[peugeot206cc]

Hi again...

So after a few months of messing around with this I thought i'd post seeing as i'm just throwing hours into the car to cure the last issue it had before it overheated previously and it was rebuilt and cleaned up.

Work done:

- New head gasket
- Head skimmed
- New radiator
- All sensors replaced
- New coolant
- New expansion tank
- New oil
- New sparks
- New battery
- New slave cylinder
- New brake fluid
- New gearbox oil
- New water pump
- New cam belt
- New tensioner
- New AUX belt
- New fan
- New fan switch
- New stat

Now dispite all of this the car still was getting hot, so after some googling I managed to find a thread which highlighted some issues around the relay's and wiring here.

After stripping the front end down again and revealing the relays, sure enough they had corroded and one wire was fully corroded off of its terminal.

After buying two new relays and repairing the wiring I hooked it up to PP2000 and ran the hi and low fan tests and the fan responded successfully to both tests.

After starting the car up and running it up to temperature the car still went over 90 to about 97/98 according to PP2000 and the hi fan kicked in. Leaving the car to see what happened the temperature fell to just below 90 and then the same behaviour repeated itself again and again. This is with the car idle and not moving.

After checking for air leaks and checking the wiring again to make sure the tests ran in PP2000 weren't a fluke, the tests checked out again and I ran the car up to temperature again and the same beahaviour repeats itself.

All sensors are reading correctly and everything seems to be working.

I'm now at a loss as to what this could be, the BSI has been restarted properly and i've also renewed the earth from the chassis to the gearbox and to the battery negative as reading another article highlighted the earth may have been corroded giving dodgey readings on the dash cluster.

With all of this done, I can't think of any further things I can do as i've really exhausted every angle possible, it can now only be wiring (somewhere) or ECU related and neither of these I would know where to start.

Any suggestions?

[Capncol]

That temp is fine.

[IanL]

Indeed - remember that the system is pressurised as it heats up; the water will not be able to boil at 100 deg, so there is no problem even if it were to reach that temperature. Normally, the designer tries to maintain the temperature between 90 and 100 - it helps increase efficiency.

[johnbrander]

I agree totally. Mine runs between 90 and up to 110 and then the fan kicks in and temp comes down and so on...
Not a problem that I too can see

[peugeot206cc]

Thanks for the reassurance guys, every car I've ever owned the gauge never climbs over 90 degrees unless there is an issue.

So this is perfectly normal and nothing to worry about and I should now use the car?

[Capncol]

Yep

[Slo]

I have a 2 litre too and it barely ever goes over halfway does your low fan speed work properly under its own steam rather than the diagnostic check?

[peugeot206cc]

I don't think it does, works fine on the pp2000 test but it seems rather hot at 97 degrees until any fan kicks in. In my experience the slow fan kicks in around 92 and hi fan around the hotter 98+ mark.

I'm not sure what to think as I'm not sure when each speed should operate on the pug, or how to test if this is really happening.

[Powellct]

From memory, casting my mind back [hmmph cough] years to engine tech lectures, water boils at 110C ish at 5psi above sea level pressure (ergo ~20psi total)