2002 2.2 auto engine cooling

[veralum]

Firstly the car runs great after I rebuilt the cylinder head during the summer, I changed the thermostat as well and there are no leaks, but the gauge hardly rises unless I have been driving for ages then it sits nicely in the middle. Is it just the sender being tired and sending inaccurate info? Or could it be the wrong thermostat as the one I fitted was the same as was in there but wrong according to euro car parts ( different fittings) I have ordered both temperature sensors and plan to change them when I get a chance, do you think it will make a difference? Would be nice is the needle went up to the middle and stayed there

[Doctor Gollum]

If the needle/gauge worked before, then that suggests a faulty thermostat.

It happens and it wouldn't be the first time that cheap shyte from the likes of Eurocrapparts didn't work as advertised.

Wahler would be a reasonable choice or AC Delco (Cadillac Catera 3.0 amongst other GM models) presuming Peugeot can no longer be arsed to offer any parts for the Omega.

[Andy H]

If the needle/gauge worked before, then that suggests a faulty thermostat.

It happens and it wouldn't be the first time that cheap shyte from the likes of Eurocrapparts didn't work as advertised.

Wahler would be a reasonable choice or AC Delco (Cadillac Catera 3.0 amongst other GM models) presuming Peugeot can no longer be arsed to offer any parts for the Omega.

I think Verulam has a 4 pot, not a V6

[cam.in.head]

if the thermostat has failed 'open' .or the new one is faulty and letting coolant through you will tell by feeling the top hose. this should remain cold until the engine is up to temp. if it gets warm soon after starting then its letting coolant through.this is the main failure mode of most thermostats and the new one could either be badly made,warped or the centre spindle not located on the top holder by faulty manufacture or damage in transit ?

[Doctor Gollum]

If the needle/gauge worked before, then that suggests a faulty thermostat.

It happens and it wouldn't be the first time that cheap shyte from the likes of Eurocrapparts didn't work as advertised.

Wahler would be a reasonable choice or AC Delco (Cadillac Catera 3.0 amongst other GM models) presuming Peugeot can no longer be arsed to offer any parts for the Omega.

I think Verulam has a 4 pot, not a V6

There's enough cars using the four pot to get a reasonable choice 

[Doctor Gollum]

If the needle/gauge worked before, then that suggests a faulty thermostat.

It happens and it wouldn't be the first time that cheap shyte from the likes of Eurocrapparts didn't work as advertised.

Wahler would be a reasonable choice or AC Delco (Cadillac Catera 3.0 amongst other GM models) presuming Peugeot can no longer be arsed to offer any parts for the Omega.

I think Verulam has a 4 pot, not a V6

There's enough cars using the four pot to get a reasonable choice 

https://www.ebay.com/itm/134133350483
Starter for 10...

[veralum]

Well I went out and had a play, I let it idle for ten mins, heater got hot and the thin small hose warmed quickly, top hose started to warm after about 8 mins but not only half the temp of the thin hose,  temp needle not moved at all, I'm leaning towards it being a temp sender problem, if that doesn't work I will change the thermostat for one not from euro car parts.

[Doctor Gollum]

The process you described above is meaning less.  The heater will have heat as long as the engine is running. The gauge may not move much, especially if you watch it whilst driving as the radiator and fans will keep the temperature down...

Do this vvv, and report back.

Start the car from cold, and hold the top hose as it idles.

You'll feel one of two things:

1. The hose warms slowly to the point where it becomes a bit toasty.

2. The hose warms slightly as the ambient temperature in the engine bay rises, then suddenly gets hot when the thermostat opens.

[Enceladus]

The target is for the thermostat to remain closed until it starts to open at 92°C. 107°C should be fully open. Sounds like yours is possibly stuck open.

Which thermostat from EuroCarParts did you fit? ECP part number or link?

One of the other members fitted a Circoli part from ECP to a 2.0L. Live data suggests that this thermostat opened at 76°C. So way off, the engine was never properly up to temperature unless maybe driven hard.

[veralum]

A pleasant update, fitted a new QH thermostat 92degrees, current one (vernet) was 82! Car runs much warmer and happier! Gauge goes to 80 much faster , should needle point to 80 or the middle which would be 90?

[Doctor Gollum]

90 given the 92° thermostat.

[veralum]

I have ordered the two senders , so will change them

[cam.in.head]

you can sometimes find that the guage is not 100% accurate and a better check may be with live data from a obd reader. that would confirm thermostat better.
and then by trying a couple of different senders (thebrass spade headed one )you may get a different (better) guage reading .

[veralum]

Well it's been over a week and the 92degree stat seems to have done the trick, car a bit perkier and mpg seems to have improved slightly, I changed both temp sensors which was fun and gauge seems to move more. Thanks for the help