Coolant Leak

1982-1993 :180E, 190E, 190E 2.3, 190E 2.6, 190D 2.2, 190D 2.5, 190D 2.5 T
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Model you own: w201

Coolant Leak

Post by Blade » Fri 12 Jun, 2015 8:56 pm

Hi All,

I'm new here to the forum and have recently purchased a 1992 180e White, I have just done a radiator flush and replaced the coolant. After I got the engine upto running temperature I opened the hood to check for any leaks, there was a fine mist spraying out, after closer inspection it seems that coolant is leaking from somewhere onto to fan belt and thus the fine mist spraying up. I checked the bottom radiator hose and could not a hole in it. Any ideas as to where this leak is coming from?
Any suggestions would be greatly appreciated.

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Tony From West Oz
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Model you own: w202
Location: Bedfordale WA

Re: Coolant Leak

Post by Tony From West Oz » Fri 12 Jun, 2015 10:42 pm

Welcome to the Forum.
I hope you will get as much from it as I have.

Regarding your coolant leak, there are a number of possibilities:
One of the radiator hoses has a pinhole leak;
Hose clamps may not be tight enough (unlikely in this case)
Radiator has leak;
Water pump has leak;
Thermostat housing has a leak (alloy corrodes and can cause pinholes in castings);
Other hoses in area have leak;
Other ????

Members who have experience on this particular model may be able to elaborate further.
The best you can do is to look for the leak yourself, or go to a radiator shop and have them check out the issue. They can pressurise the system by connecting an air pump to the radiator cap.

Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (SOLD)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
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Mercedes Demigod
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Joined: Sat 12 May, 2007 2:21 pm
Model you own: w204
Location: Melbourne

Re: Coolant Leak

Post by Ivanerrol » Fri 12 Jun, 2015 11:02 pm

Unfortunately radiators from that era had a common problem of breaking off at the location where the top hose connects to the radiator.
The radiators are partly made from plastic. To keep this plastic in good shape and not let it go brittle it's essential
to use the proper MB spec radiator coolant.
here's some images

Your radiator maybe on the way out. There is no fix for this - you need to buy a new radiator if this is your issue.
W211 - E240
W204 - C280
W202 - C200, C180, C180
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
W111 220s (Indonesia) 4 speed manual column shift
W123 230
W116 450SEL
W140 420SEL
W210 E240, E240
W209 CLK 240
W201 190e 2.6 (ex U.K.)

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Joined: Mon 13 Apr, 2015 6:10 pm
Model you own: w201

Re: Coolant Leak

Post by Blade » Sat 13 Jun, 2015 8:32 pm

Thanks for the information much appreciated, will try again tomorrow to locate the leak. The radiator is good, thermostat housing is good, will check water pump and bottom radiator hose.

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