406oc.co.uk

Hi All,
Been tinkering (under the premis of long term maintainence...) which included a fuel filter change (bottled it when the housing top would not come off - is the metal surround supposed to come off? It is covered in rust and ideally needs replacing), air filter (easy) and thermostat/coolant. Car takes an age to warm, often cools when heat turned on and at the moment generally sits at a little to the left of 90 degrees. I have never witnessed the fan come on but perhaps with the extreme cold at the moment, perhaps there is no need.
Thermostat change was a doddle. Coolant change in haynes said you need a header tank arrangement which I did not bother with. I could not however find the bleed valve at the rear of the engine block. (Bleed valves on top of rad, thermo housing, heater matrix outlet pipe and this missing one somewhere at back of engine - buried under the turbo somewhere?)
Other obervations are the top hose being soft until up to temp(thermostat opened) and also top and bottom rad hoses are hot - would this suggest the rad is kaput or the fan should have kicked in by then?
Anyhow, as usual, my tinkering may have unleashed further woes...
Kind regards,
Ed

There isn't a block bleed valve.

Top and bottom hoses along with the radiator being hot suggests all is well.

Radiator fan will only come on with the temperature higher than normal, you would have to sit there and rev the car until the fan comes on.

Thanks for that. I was fearing that top hose and bottom hose hot suggested the rad was not cooling properly...i.e bottom hose should be cooler...

What is the haynes manual on about then? Did a run to Heathrow today and car was fine but still does not get to 90 degrees...

EDWARD757 wrote:Thanks for that. I was fearing that top hose and bottom hose hot suggested the rad was not cooling properly...i.e bottom hose should be cooler...

What is the haynes manual on about then? Did a run to Heathrow today and car was fine but still does not get to 90 degrees...

No idea what Haynes are on about, I've never seen or heard of a block bleed valve on this engine.

As for the thermostat, what temperature of stat was it?

You may possibly have got an 82 degree one that is more for summer running, you maybe need an 88 or 90 degree one depending on what is available for your engine.

Check the part number or the box it came in for the temperature rating.

Of course it may just be the outside temperature cooling the system more than would be normal with the air temperature higher.

Old and new thermostat are both 83 degrees. My old 405 used to have a wavering coolant temp but never went up to 90, even on a hot day. All the German cars I have ever driven, warm up to 90, and stay there, regardless of workload or outside temp...

EDWARD757 wrote:Old and new thermostat are both 83 degrees. My old 405 used to have a wavering coolant temp but never went up to 90, even on a hot day. All the German cars I have ever driven, warm up to 90, and stay there, regardless of workload or outside temp...

If you want a higher running temperature fit the higher temperature thermostat (88 or 90).