[W204] Whaler thermostat doesn't fit + cooling issue

[Operations]

Like i said in my "which waterpump" topic, i am having a weird issue with my 2007 C350.

Car has got 186000 kilometers on it. Belt and rolls (including the one that tights the belt, sorry don't know what the correct name is) have been replaced. Radiator doesn't have a leak, car doesn't leak any cooling fluid at all. Fluid has been replaced with new G13.

First i will also explain in this topic what the original problem is, which made us decide to change the thermostat and water pump.

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When the car is at normal temperature
(after 30 min highway) and i reach a street or a traffic light, the fan goes up to a 140% . According to my simple icarsoft device this is done at the request of the engine (so NOT the AC).

We have also checked the car with Xentry, and what happens is the cooling fluid reaches 110 / 112 degrees. We couldnt really find a reason why, except that according to my mechanic friend the thermostat opens quit late. So he/we figured it probably is the thermostat, which isn't 100%. So any other thoughts are of course more than welcome.

So we will replace this and because we are working on the car at that moment (and i also have to drive for a hour to get there so we often combine things), we will also replace the waterpump. Which technically could also be (a part of) the problem. Correct me if i am wrong, i am a computer nerd not a car nerd.
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So at this moment the SKF waterpump is running fine, only for a day or so but it fits fine and we didn't came across any problems.

Replacing the Wahler thermostat with a new Wahler thermostat is a whole different story... The thermostat fits fine but the hole for the hose is too wide. And because of this the hose leaks fluid. Let me explain:

When we plug the hose in the hole of the old thermastat, you have to apply a bit of force. When it's in, it's in so to speak. When we put the hose in the hole of the new thermostat, it has room to move and it goes in without hardly applying any pressure.

Because i needed the car we put the old one back for now. I forgot to measure both the holes to "proof" my point, but the difference is easily noticeable.

This seems weird to me, the original part is also a Wahler. I didn't order an OEM part, which i will do now... I ordered an aftermarket Wahler at Autodoc.com. Based on my license plate, and they only sell one Wahler thermostat for my car. So it is not like i ordered a wrong one. Autodoc is a german supplier/website.

FYI my engine code ends at 056

But looking at the original one this one looks exactly the same, Mercedes did remove the Wahler part number

So i don't really get why the new Wahler thermostat is different. Like i said i will and should have ordered the OEM one (which will most likely be the same as i have bought already, had to imagine that MB would change the hole size... right?...), but this feels strange to me.

TLDR; fan is at 140% because cool fluid get 110 degrees, why? Appearently a thermostat Wahler is not always the same?

Any ideas about my problem? And any thoughts on the thermostat issue? I apologize for the long story but i wanted to share as much info as possible...

 

[sonic]

I am not an expert on these matters but there was another similar post regarding the fitting of a non MB thermostat. That person was having similar problems with temperature. My advice is fit an original MB one.

 

[onefortheroad]

Anything to do with waterworks or electronics , .my advice , pay once and buy from a mb dealer.

 

[Operations]

Anything to do with waterworks or electronics , .my advice , pay once and buy from a mb dealer.

So you also wouldn't have bought the waterpump aftermarket? (SKF)

The aftermarket one was almost 3 times cheaper than the OEM. Something like 110 euro vs 295 euro.

I don't really mind to spend a bit more on OEM parts, but this was quit a difference.

Plus i often just figure out which brand an OEM part is and then buy the aftermarket one if it is way cheaper. But appearently you cannot assume that an OEM Wahler and a aftermarket Wahler thermostat are the same... which i find strange...

The aftermarket transport/logistics is also way better than the MB one. MB doesn't have a webshop, you have to order by phone (which always means several minutes on hold). And i also have to pick the parts up 35 minutes from here, the MB dealer in my city doesn't have a warehouse/storage to hold / sell parts (anymore).

I realise i am complaining a bit and of course there are bigger problems in the world, but the way MB does these things sounds like 1995 to me rather than 2021....

Will stick to OEM parts as much as possible from now on....

 

[Mr Greedy]

Another way you can check the part Autodoc recommend is go on to 7zap, put in your VIN and look for the Mercedes part number for the thermostat. This will be specific to your chassis.

Or, if you have the Mercedes part number on the thermostat you removed, then you should be able to check these Mercedes part numbers match.


Then, just type in the Mercedes part number into the search box on Autodoc and see what comes up. Is it the same part as you have ordered?


If I am unsure of part number (i recently had this with an aircon compressor I wanted), email/call the part manufacture with the Mercedes part number and see what they recommend. Alternatively, they (Wahler in this case) might have a good online aftermarket catalogue you can use to double check e.g. ZF have a good one for checking Sachs, bilstein, Lemforder and TRW parts numbers amongst other brands (ZF are the parent company)

 

[onefortheroad]

Skf will of probably made the waterpump. I should of said don't buy aftermarket thermostats ...

If you know who makes for mb , its half the battle.

 

[Mr Greedy]

So you also wouldn't have bought the waterpump aftermarket? (SKF)

The aftermarket one was almost 3 times cheaper than the OEM. Something like 110 euro vs 295 euro.

I'm going to change all my serpentine belt and pulleys and tensioner when the weather improves using a serpentine belt kit. I am intending to use SKF who make and supply great components at a fraction of the price of Merc, including water pumps. I would have no problem recommending SKF for this sort of stuff, just like Bosch parts for electronics.

The best SKF prices are usually by ordering direct off the SKF website. It's amazing the price, even over other OEM brands. When I speak to garages and ask why they are charging so much for parts and mention they can get it direct from SKF in 48hrs much cheaper, they have no idea, but I guess exchange is more of an issue if wrong. Less of a problem for the DIY mechanic.

 

[Mr Greedy]

But appearently you cannot assume that an OEM Wahler and a aftermarket Wahler thermostat are the same... which i find strange...

This does seem odd.
Having done the checks I suggest above for 7zap and Autodoc etc, can you update us on the results please?

I was going to buy a Wahler stat for the very reason you did. It is THE ORIGINAL manufacturer for the stat. Once you have the Mercedes part number confirmed, it's definitely worth a call to Wahler, because they are still making the stat for Merc; just how do we get our hands on the correct one via aftermarket (if we can).

 

[Operations]

Another way you can check the part Autodoc recommend is go on to 7zap, put in your VIN and look for the Mercedes part number for the thermostat. This will be specific to your chassis.

Or, if you have the Mercedes part number on the thermostat you removed, then you should be able to check these Mercedes part numbers match.


Then, just type in the Mercedes part number into the search box on Autodoc and see what comes up. Is it the same part as you have ordered?

Yes that is what i/we did. That is why it makes no sense to me. It is/should be the correct part....

 

[onefortheroad]

Yes that is what i/we did. That is why it makes no sense to me. It is/should be the correct part....

Mercedes part numbers change , the epc at 7zap is old now , parts could of changed since 7zap epc was released.

 

[Operations]

Mercedes part numbers change , the epc at 7zap is old now , parts could of changed since 7zap epc was released.

I checked the number with Xentry. And checked this number on the Autodoc website. Like i said i am quit sure this is the "correct" part.

 

[Mr Greedy]

Yes that is what i/we did. That is why it makes no sense to me. It is/should be the correct part....

So when you called/emailed Wahler with the Benz number, the Wahler you bought and explained the sizing problem vs. what you must be able to buy direct from Mercedes in the correct sizing, what did they say?

 

[mattkh]

Please whenever you can, put up pictures of the old stat and one of the new one.
When you changed the coolant, did you remove all the air in the hoses.
Do Mercedes recommend G13 as a coolant..?

 

[Operations]

So when you called/emailed Wahler with the Benz number, the Wahler you bought and explained the sizing problem vs. what you must be able to buy direct from Mercedes in the correct sizing, what did they say?

I apologize if i a gave you the idea that i called Wahler.

What i did was check the original part number and checked with Autodoc if this is the correct part number which is compatible with the Wahler thermostat which they sell for my car.

Since i am not a mechanic i always try to double check stuff like this. I never just order based on license plate (for example).

Since we noticed the problem (yesterday) i have explained this to Autodoc, still waiting for an answer.

I could send Wahler an email, but warranty wise in The Netherlands you always have to go to the seller and not to the manufacturer.(aan if seller is not cooperating or bankrupt then of course you can go to the manufacturer)

But i will send them an email just to hear their thoughts on this issue.

 

[Operations]

Please whenever you can, put up pictures of the old stat and one of the new one.
When you changed the coolant, did you remove all the air in the hoses.
Do Mercedes recommend G13 as a coolant..?

I am told that MB recommended G11 back in the day, but since it is an older car there was no G13 back than.

G13 is compatible with G11. So a more recent non official recommendation is G13.

Again i am not a mechanic, so if you are sure this is not the case please just tell me

Yes we removed all the air. I forgot to take a picture of the old one, which is back in the car now. I know this is a bit dumb.... i should have taken a picture.