Water pump

[mauro12]

Hello guys, I want to replace my water pump and thermostat. Is it better to buy the water pump original from mb dealer or from sls shop or others and so non oem?
Do you know what can be the price for a water pump (250sl) from mercedes dealer ?
Thank you .

[Pawel66]

Mauro, for 113043 I see in the EPC water pump is not available, PN A 110 200 02 20.

Thermostat, you would have to check or someone maybe can help, I see:

A 130 200 02 15 - just the thermostat on the drawing for $270 (roughly), and also

A 110 200 05 15 - a set, 87 degree, thermostat and gasket for $40 roughly, which is closer to where you would expect it to be.

[mauro12]

Is not available anymore? Seems strange.
About the thermostat I think could be better to have the 79degrees instead of 87, what do you think?

[WRe]

Hi,
there are a lot of OEM parts for engine cooling available, e.g. here https://dbdepot.de/Engine-Cooling_10 because these parts are used for several models. The 79° thermostat is the right one.
...WRe

[ja17]

Lots of water pumps and thermostats available and inexpensive. Just look around the Web or use some of our listed suppliers. You should be able to get OEM quality at way  less than 100.00. If you cannot find one in a Mercedes box try a good German manufacturer.

[450sl]

If memory serves me well, there are 2 versions. Short nose and long nose model...

[mbzse]

Re: replacing your water pump, some wise words from M-B workshop owner Stu Ritter here:
Pump dimensions are critical
"Be very weary againsty use of aftermarket non-MB water pumps. Overheating may result, we have fixed many by replacing what seemed to be a operating water pump, that was non-MB, with a M-B rebuilt pump. The clearances between the impeller and the pump housing on most of the aftermarket pumps is excessive and the pumps cavitate.. It's amazing how much difference a few mm can make in this instance. Check your water pump to make sure that the part number is cast into the pump together with a M-B star"        /Stu

The nominal dimensions of the impeller are given in the BBB and the Book of Tables. See sketch below. Note the tight tolerance of measure a:  0.4 mm(!)

See both pump models on photo here:

[ja17]

If price is not your primary concern, and you want to talk to a real person who really knows these cars and parts, try Jeff at Star Quality in Monkton MD. He is very reachable by phone and will answer your questions. He will sell you Genuine Mercedes Factory New or good quality aftermarket as you request. He is a full time parts guy and owns and drives a Pagoda. This is not an advertisement, he's just the best and most accessible parts guy I know.

[ja17]

I often wondered why the "weep hole" on water pump housings was never directly pointing down or at the bottom of the casting. I ran across this information today from one manufacturer "A small amount of coolant leaking from the weep hole is normal. Small drips are OK. Longer streams or continuous leaking may indicate a problem. OE manufacturers developed the weep chamber as a way to hide the small drips so pumps are not prematurely determined to be failing. Those drips will remain in the chamber and evaporate as the engine heats up."

[450sl]

I think it's because of the seal being of the labyrint type that a smal amount of leakage during static status is inevitable.
dynamic it seals fully.

[mauro12]

For what I've just read it seems that original mb water pump is not longer available. My concern was between a febi pump or maybe GK PUMP (these are the brands that there are on sale)and a mb pump ( probably NLA) I don't have yet any trouble with the pump, but my thermostat needs to changed because it stays always opened, so for this reason I thought was the right time to replace the pump, belts and coolant. Have you ever bought a pump from sis shop or mbclassic.de or other European sources?

[ja17]

Well when Mercedes lets us run out of critical items like head gaskets and water pumps for our cars we're forced to try other brands. I see on line, Gates brand new water pump, precision made,  tested, with the impeller precision balanced, built to OEM specs and a lifetime guarantee for $19.95 plus shipping!  I bought a new front wheel hub from the dealer for my Mercedes  E430 a while back. It came from the factory with bearings made in Japan. I replaced the original spark plugs in my Mercedes SLK AMG which I bought new. The factory original plugs which I removed from the engine, from the factory had a big Mercedes "Star" on one side and "NGK" on the other side (also made in Japan). I bought some Bosch plugs the other day and they had "made in Russia" stamped on them.

[450sl]

That leaves us to buy from the bigger companies like febi bilstein  etc.
They also sell parts from exotic countries, but we then have to rely on their quality-department.
I this is what. MB more or less does.

[mauro12]

I will go to my mercedes local dealer and ask if they have availability. But I don’t think is worth to spend 200€ or even more for a pump that has only a Mercedes sticker on it.
Probably febi or gk or other brands produces spare part for mercedes with half of the half price.

[MikeSimon]

Bear in mind, that Mercedes never made the water pump. They bought it from a supplier. For many parts Bilstein, for example, was an OEM supplier. Once the original OE contract expired, the supplier was free to sell to the aftermarket. This is true for a lot of parts where people are looking for "original" Mercedes Benz. The only difference is, the supplier is not allowed to use the Mercedes Benz trademark, i.e.: the "Star"

[mauro12]

Thanks for the information, last question is about the water thermostat . Which brand and temperature is the best for our cars? I found that behr is considered and oem supplier, are there any better thermostats? . There are 79degrees Celsius or 87, which one is the best solution to avoid overheating?

[ja17]

Make sure your radiator is in good condition, have it tested. Never remove the thermostat completely. It is a double acting valve which opens one passage and closes another. I see new original Behr thermostats on-line and inexpensive.

[mauro12]

These old thermostat tend to remain always open and let too much coolant pass on the radiator. As a result the car never gets to operating temp.
I have never had any overheating problem, but recently I have noticed that the car during cold weather  tends to take a lot of time to get hot. For sure my thermostat is stuck open.
I heard  that the long pump is better than the short one.
Are they interchangeable?
My 250sl has the short one , but is it possible to put the long pump for higher cooling efficiency?

[450sl]

The long pump has a bit more distance between its bearings
so theoretical a bit longer bearing life.
check if you have the extra intermediate bushing. If so you can
Use the long pump without the bushing.

[mauro12]

I thought the long pump was only for 280sl and short pump only for 230 and 250

[ja17]

Yes, and you'll need a set of four short fan bolts if you switch to the long pump. The long pump is easier to install also since you are not dealing with the long bolts and spacer.

[Minerva]

If you have a viscous fan you'll need the short pump, I found out the hard way...

[ja17]

Not necessarily, some engines used a large spacer and the short pump with the viscous fan. With these you simply delete the spacer and use the long pump and short bolts.

[jond907]

I've recently just bought a water pump for a 1971 280SL from MB here in San Diego and it was cheap. List price 42.50 plus a 7.75 core charge

[UJJ]

I just bought a new thermostat from the Classic Center (Tom Hanson).
79 Degrees - P/N: 100-200-07-15 and the price was $22.00 - with discount only $18.00
Tom always gives me a discount either because I am a member of the MBCA or because I am a member of this Forum.
Don't know about the water pump.
Urban