Hot engine, 30min drive/how hot should 2 hoses be?

Danny_G

In regards to the car Sear Leon, 2007, Petrol Manual


Which of these statements is correct?

After driving for 30-40 minutes,
at 30-50mph in this cold weather: with the inside heater is set to full heat/maximum hot, with blower on full...


a) after 40 minutes, one hose should be boiling hot, and the 2nd hose should be warm (assuming the thermostat has opened) with the fans kicking in eventually?

b) Both hoses boiling hot, the same temperature.
(Thermostat opened), with the fans kicking in eventually?

c) one hose should be boiling hot, and the 2nd one cold, thermostat hasn't opened,
as the car engine gets cool by the blowing cool air, that it is driving through

d) another scenario, regarding the hoses?,
please state what would typically be expected to be 'felt' regarding the hoses ?, temperature, and engine fans ?

DoaM

https://forums.moneysavingexpert.com/discussion/5794298

This needed another thread because ............. ?

n217970

DoaM wrote: »

https://forums.moneysavingexpert.com/discussion/5794298

This needed another thread because ............. ?

because he clearly doesn't want to change his thermostat, maybe a different part will be faulty if he starts a new thread? I reckon it will be the indicator fluid.

roneik

replace thermostat.

Its a B.
Fan should not come on much in this weather if ever
The thermostat opens when the top of engine is warm enough to trigger the wax to melt in the thermostat and allow spring to lift. Then warm water circulates through entire engine and radiator.Thats why your rad and one hose is cold. Your thermostat is jammed shut

roneik

Its common sense that if one hose is cold, there is no flow equals thermostat closed preventing water to flow through second hose equals one cold hose equals jammed closed thermostat

System

Danny G, you're not going to get a different answer just because you've asked again.

Your thermostat is shagged, it needs changing. It is a part that costs less than a tenner and no more than an hour to replace if you're doing it yourself at the side of the road and a garage won't charge you more than an hour labour. The one on my MX5 is well buried and requires removal of some of the intake to get out but it only took me an hour. The one on my wife's car is at the top of the engine in clear view and takes no time to change.

By the time you've gone around the houses trying everything else you can to avoid changing a £5-£10 part held in by three bolts you'll possibly have knackered the engine and be looking at a few hundred quid for a new headgasket.

Danny_G

Another finding:

When the engine is cold, parked and idle,
Inside Heater on full max heat,
when the engine is started for about 30 minutes, both hoses get hot hot, and then after the fans kick in.

(so thermostat opens when engine is started in idle/non moving position)
and the front radiator gets hot,

but it is only when driving that one hose stays cold (with the inside heater on)




so the thermostat opens, both pipes get hot and front radiator gets hot, when starting in idle for long time.

Does that indicate that the thermostat does work?, but only when Driving stays shut?

[Deleted User]

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