2.3-16 front heater hose..

190E 2.3-16, 190E 2.5-16, 190E Evolution 1 & 2 models
16v specific information.
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2.3-16 front heater hose..

Post by AMG » Sat 08 May, 2010 5:46 pm

Here's something you don't get to see every day.

Hermann, the 2.3-16 originally had a temperature gauge that fluctuated just a little too much for my liking. When I acquired the car a few weeks ago, I decided to quickly check the cooling system. a good close look at the hoses and associated wiring to confirm there wasn't an issue with the sender wires and the electromagnetic clutch, revealed that the clutch wasn't engaging correctly on temp.

Quick call to MB Spares and I had new senders (decided to replace all of them) the next day. Flushed the system out and replaced the senders, cleaned the fan and shroud - (which looks as new now) and new genuine coolant (Lots of it.. I run it a little over spec, for an added safety margin).

refilled, bled and tested the system, ran the temp right up to temp and the clutch engaged. perfect. No problems.

Drove to work for 3 days in the car (about 400km total) and then on day 4, steam starts coming out of the gaps between the bonnet and front guard, whilst idling along in traffic.

Temp gauge is showing UNDER 80 degrees.

Pulled over, popped the bonnet and looked around. a little bit of coolant near the header tank discharge... So I thought it might be the radiator cap.

Ordered a cap from MB Spares late that afternoon (was running late with other work stuff) and it arrives the next day before I get in to work. (couldn't believe it - thats a proper overnight service!)

Fit new Cap. add more coolant. run up to temp. nothing leaking, nothing blown. go for a drive. all OK.

Next morning, driving to work, the SAME thing in the SAME place. idling in traffic on the princes hwy. Pull over. Header tank is almost empty. coolant is boiling.

Fearing I'd cooked the engine, I started to think maybe I'd done a head gasket. Unlke some engines, the cosworth head, when it does go, leaks coolant into the exhaust system. So I check everything as best I can, and it looks OK.

walked into the auto parts store, bought 10 l of Zerex G05, filled the coolant up again, drove to work and everything is fine once more.....

before going home, I decided to pop the bonnet and poke around to see if there was evidence of a head gasket or a leak. Because the Zerex has plenty of fluoroscein dye in it, I was able to see clearly some droplets low on the engine. I started thinking of welch plugs and horror stories, but could see no evidence from where the droplets originated.

Drove Home OK.

All this time, the temp gauge is looking perfectly within spec, so I am not worried, as the fan is working correctly also.

Last night on my way home I decided to give the car a bootful. I rung it's neck all the way home, and the temp didn't move one iota. I parked in the driveway and let it idle down to see if the needle would move. it crept up to 80 degrees and everything is fine. stopped the engine, pulled the bonnet up, and thanks to the 2x500W spotlights out the front, I could see steam eminating from around the front near the water pump.

I started to look really closely, but there was nothing to see... a few dried spots of coolant on the header pipe and tappet cover.

this morning I decided to have a really close look at the spot where I thought the water was coming from. the engine was stone cold, and there were trace droplets of coolant on the alternator and bottom hose, where it meets the water pump.

I felt around and my fingers got wet, next to the hose clamp. Drained the coolant, and removed fan, and the hose. nothing. Looked at the heater hose.... it's all OK. Pull the hose anyway, and this is what I found....
The hose clamp was completely obscuring the split in the hose. the last drive obviously had increased the split around past the clamp a little, and as i removed it, the hose tore a little more along the split.

completely obscured. There was no way you could have seen it, and the condition of the hose itself is no indicator that it required replacement. I had some 3/4 heater hose laying around and cut a length to replace the dodgy heater hose.

As a consequence of this discovery, I am replacing a number of hoses this week. part of the joy of a newly purchased vehicle. :lol:
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1987 560SL 4sp. auto Signalrot "Stella"
1987 190E 2.3-16 5sp. man. Blauschwarz "Hermann"
1992 300CE-24 6sp. man. Perlblau / Iceblau "Gretel"
1992 Range Rover Classic 4sp auto Ardennes Green "Oswald"
2012 E63 AMG Speedshift MCT Diamantweiß "Klaus"
1986 560SEL Anthracitgrau "Schultz" - In Mercedes Heaven
1987 190E 2.6 4sp. auto Signalrot "Sabine" - which now resides/owns Andrew M's Garage
1972 350SLC Astralsilber "Lurch" - now in the loving care of Craig B
1989 2.5-16 Blauschwarz 4sp. auto (parted) formerly owned by Derek/Hasan.
2012 Renault Sport Megane RS265 Trophy 8:08 6 sp. man. Liquid Yellow "Jean Rédélé"

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Re: 2.3-16 front heater hose..

Post by kaiser » Sat 08 May, 2010 5:55 pm

Glad to hear Hermann has not suffered any terminal problem Joe. Too few cossies in Oz as it is! I had an oil cooler line do that once, right under the clamp.

I have been through the worry over a possible blown head gasket too...It's not fun.

Nice process of deduction......In the immortal words of Mr Holmes - when you have eliminated the impossible, whatever remains, however improbable, must be the truth.
1971 300 SEL 6.3 - #5417 - "Merlin" (LPG)
1990 300E - "Silver Arrow"
1982 230E - "Charlie"
1987 300E - "Indy" - Taken from us before his time...
1973 280E - "Angus" - Gone too
1966 250SE - "Bessie" - Long Gone

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Re: 2.3-16 front heater hose..

Post by dan_189 » Sat 05 Jun, 2010 6:59 pm

Same thing happened to mine, same hose too

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