Possible New Thermostat

[dokalj]

Hi all,

I hope everyone is well.

I recently travelled 45 miles in the evening the other day and the temeperature outside was reading 5. I noticed that through the whole trip my temperature guage went from 40 to 70 tops.

The vehicle is a 2003 ML270 CDI

Could this be a possible fault with the thermostat or am I just jumping ahead too quickly?

Or does the car not get so hot on the motorway?

What is the usual operating temperature? 80?

Thanks

dokalj

 

[Sp!ke]

Yep, sounds like the thermostat has gone. As very temporary assistance you could part block your radiator with some cardboard or something but you want to do it pretty soon as its not good for the engine to be running at such low temperatures.

 

[renault12ts]

The usual temp will be about 85. With a working stat, this temp will be the same (maybe varying by about 1 degree C) in winter or summer, in town or on motorway.

 

[dokalj]

Cheers, how much would one cost? Is it easy to fit?

What could happen if I don't fit one soon? Lastly would I notice any improvement?

Thanks again.

dokalj

 

[Sp!ke]

Not sure where it is on your car but its usually upper front of the engine bay with fat rubber hoses leading to it.

MB price for the thermostat is about £15 usually including the little rubber seal.

Takes about 20 minutes to change one if you just top up the fluids after but its probably worth doing a coolant flush at the same time so 30 minutes or so.

Fuel consumption should improve somewhat once the engine is running at the right temp.

 

[jaymanek]

Dont rush, CDI's run quite cool and in this cold weather they will run even cooler. I would wait and see what happens as the weather warms up a little.

 

[renault12ts]

Dont rush, CDI's run quite cool and in this cold weather they will run even cooler. I would wait and see what happens as the weather warms up a little.

Agreed J, but even in the sub zero temps of recent times, it gets to temp in about 10 miles. The OP had done 45 miles in +5 temp..

 

[dokalj]

Cheers, so should the temperature get up to around 85 if you are driving more than 45 miles in this current climate? On the weekend I did around 15 miles and the temperature only went as a high as 60.

As stated it was +5 degrees outside.

 

[dokalj]

With the coolant flush is it just out with the old in with the new? Or do you put a cleaner in there first?

 

[renault12ts]

Cheers, so should the temperature get up to around 85 if you are driving more than 45 miles in this current climate? On the weekend I did around 15 miles and the temperature only went as a high as 60.

As stated it was +5 degrees outside.

It should get up to 85 well within 15 miles. I presume that's 15 miles out of town? My car gets to temp in 10 miles or so in sub zero temps, I'd expect yours to do the same.

 

[dokalj]

Well just near town, there is a national speed section that I drive through.

 

[renault12ts]

What I mean you were not stuck in traffic? Its your stat...guaranteed.

 

[dokalj]

I was not stuck in traffic at all. Would my performance improve?

 

[renault12ts]

I was not stuck in traffic at all. Would my performance improve?

I experienced much improved MPG figures. I suppose performance would also improve. But, it is primarily for the sake of the engine. Just as you don't want to run your car too hot, you also don't want to run it too cool.

 

[dokalj]

Cheers.

What usually causes the thermostat to fail? Is there a typical life expectancy?

dokalj

 

[tagnut]

Mine went recently and I also have a 2003. I can't find any record in the service history of it having been replaced previously so suspect this is the first one to go.

 

[dokalj]

Cheers tagnut!

Where would I look on the EPC to locate the thermostat?

 

[tagnut]

No idea - I just got it fixed by a local indy

 

[dokalj]

No worries - Do you remember how much he charged for it roughly?

 

[tagnut]

Total price is £118 including labour. Getting the car back later today so will find out price for stat then.