Thermostat change, yes or no?

[Eric1066]

hi all,
So I'm thinking of doing a coolant flush in my SL 350, I have been watching videos on YouTube about it and it seems straightforward enough, but, one guy has a video on YouTube where he changed the thermostat, during the coolant flush. His reasoning behind it was the fact that the car was getting old now, that he did not know the service history of the vehicle, but for a 15 year old car, it was unlikely that the thermostat had ever been changed, So, doing a coolant flush was the best opportunity to get this done now.

Bear in mind that the car was showing no symptoms of there being anything wrong with the thermostat.

What do you guys think, if it ain't broke don't fix it or is this the perfect opportunity to throw in what is a relatively cheap new part?

Thanks!

 

[MancMike]

You only lose a glug of coolant when changing the thermostat, so unless the engine is taking a long time to get up to temperature, I would just change the coolant.

Changing things for the sake of it can lead to other things that you disturb starting to go wrong.

 

[Deleted member 131833]

Yes, I would change t stat, minimal cost and satisfaction of knowing it is OK.

I had a problem with one Merc, took out t stat and checked it opening at figure stamped on it, re installed and still heater not working ok, in the end I binned the stat fitted new despite it opening at specified temp and lo heater worked ok.

 

[moog999]

Minimal cost?

£125 for my 350cdi.

Is it much cheaper on yours then?

 

[OneForTheRoad]

Cheap part you say ? Keep at it lol.

 

[zipdip]

Keep the old stat you never know you could snap a bolt taking it out,and then you would kick yourself for changing something that was still working

 

[flowrider]

Minimal cost?

£125 for my 350cdi.

Is it much cheaper on yours then?

A thermostat is a £25 - £30 part surely? Looking on Google it is anyway.

 

[Deleted member 131833]

You are having a laugh 125 for a stat, is it gold plated? 25 sounds right even from stealer

 

[Eric1066]

Thanks for all the replies.

It seems cheap for the SL then. I'm not sure if that's because the r230 sl350 doesn't have the sensor, but these all include the housing and the seal. Ranging from £8, averaging around the £16 and the apparent 'Mahle' OEM is £24 (Please let me know if this 'Mahle' is indeed the OEM. I have found some in thr £30+ mark too.

 

[moog999]

I can absolutely assure you a stat on a 350 cdi is that price....it comes with the housing and an electrical plug so has some sort of sensor in it too.

You can't get one from ecp/gsf...

 

[MancMike]

You are having a laugh 125 for a stat, is it gold plated? 25 sounds right even from stealer

No, I was quoted 90 plus vat from Merc. £25 is for a cheap one from euro car parts.

 

[Deleted member 131833]

Oops apologies! Posted without knowledge of particular car, what on Earth are MB thinking about making a part so expensive?

 

[flowrider]

No, I was quoted 90 plus vat from Merc. £25 is for a cheap one from euro car parts.

Could be the same part!

 

[Oldlae]

I had a thermostat replaced on my S204 and the part was about £50 from the local MB dealer.
It came with the temp sensor in the housing.
Tony

 

[moog999]

ECP and GSF dont sell a thermostat for my car. You can buy just the stay itself from some obscure site i can't remember now but it means prizing the old one out of the housing. When I changed it the other day I couldn't really see an easy way of doing that.

As a comparison the stats on a BMW 3.0d are about the same price, and also have a habit of failing after 70odd thousand miles.

 

[Yugguy]

Genuine MB stat for my 646 engine was just over 50 quid off fleabay. It has the temp sensor in the housing.

Pretty much every car I've ever had has needed the stat changing around 70k, or over 8 years old. VX, Ford, VW, doesn't seem to matter about the maker. Feels almost like a consumable part.

 

[moog999]

Yup.

Friday's I work in a health centre 22miles up the mway. Prior to changing the temp gauge would get up to about 90 then fluctuate up and down between about 75-90 the whole drive. Today, with the new stat, it was rock solid at 90 all the way. And I got an extra 5mpg!!

 

[moog999]

Oh and I kept the old stat and housing, if anyone wants to try prise the old stat out and fit a new one I give you good price.

You can actually buy just the stat bit for about 25 quid.

 

[vabenzi]

I'd say change it out at the same time, you wouldn't want to find out its bust during winter and then have to change it out. You're already getting your hands dirty - why not..two birds one stone.. You can buy it cheap from MB - I bought mine for £30 inclusive of VAT

 

[exvolvoman]

...if it ain't broke, don't fix it
The number of times I've regretted not doing that...