Picked up a very good condition Nissen's radiator from a Mercedes shop i know. will test the 'new' used radiator tomorrow and update what happens. I will also clean the condenser although i looked today, and you can see right through it.....

hopefully this will solve the problem and i will not have to change the pump...if it does not work...the pump has to go

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1993 300E, 2.8 M104 .....

I think I might have found the problem. it seems that the aftermarket unit design is causing this issue, exactly as i expected.....

Aftermarket on left, the new (old) Nissens on the right







The fins on the nissens are much finer (and it has more), therefor the surface area exposed to air is bigger....

I will have to test it more tomorrow as i have not finished burping the system. hopefully this took care of the problem....

I will update again ....

Thanks,

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1993 300E, 2.8 M104 .....

do you have the under body plastic engine cover? if you don't have that on, try putting it back on. i've noticed that my car will start to creep up in temps when it's off. it was designed to make the car more aerodynamic, but also to increase the flow of air through the radiator at speed. it does however help a little in stop and go traffic to have it off.

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Allen Kroliczek
Oak Grove Autosport | Oak Grove Autosport
01 G500, 82 300TD, quite a few more.....

I just took another look under the hood of my puny 2.6 and I definitely have the radiator with the denser rows.
http://img.photobucket.com/albums/v242/tjts2/Green%20Mercedes/a17.jpg?t=1275615087
This very well could be the source of your problem. Weird way to cut corners.

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CENSORED due to not family friendly words

That is what i am thinking, i changed this out in January, but i guess the higher temps in Florida these days (and the AC usage) exposed the problem....these cars do not like cheap parts i guess, every cheap part i used came back to bite me....from now on, i'd rather get used Mercedes parts than new cheap parts.....

hopefully i will not need to redo the pump again, we'll see....

bsmuwk: no under-body shield on mine.....

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1993 300E, 2.8 M104 .....

if you want quick answer just take the thermostat out and put the car back together, fill it with water, don't even bother with antifreeze and drive it...you'll find out that way real quick.....there are very few issues that will cause an engine to overheat as long as the engine starts and runs OK

This is very true and something to try however I suspect the water pump is bad. Most water pumps are constructed with the impeller as a press fit onto the shaft. I used to manage a large Auto Center and have seen new but defective pumps where the impeller wheel spins on the shaft so as the pulley spins, the impellar slips on the shaft and hence poor circulation. Probably not an issue when the ambient temps are low but critical when the temps are high. Unfortunately, the only way to know is to pull the pump.

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2001 E320
1991 350SD 265,000 - SOLD
2000 VW Beetle 1.8Turbo - restored
1997 E320 - SOLD
1988 190E - SOLD
1969 Mustang - SOLD

that is what i am afraid of, but this was an easier way of testing for me...total time was an hour, and $35 for the used radiator.....

pump is under warranty, so if this does not fix it, pump will be replaced...although that will be an awefull and time consuming job that i don't look forward to....

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1993 300E, 2.8 M104 .....

Would Behr be considered a good brand for radiators? I know Nissens is OE...Anybody used Behr?

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

My OE radiator was a Behr.

I replaced it with another Behr.

If that Nissens radiator is O.K. put it in the car and see how it goes. If the problem goes away then you now know to save some pennies for a new OE unit.

Unfortunately even if the older Nissen's unit works O.K. you don't know how long it will before the plastic top neck breaks off.

Changing out a radiator is a whole lot easier than changing out a water pump.

If you cooling was ok under less load it is unlikely that the pump is bad.

You can test the water pump.
- Pull the fuel pump relay, start the engine.
- If it does not run anymore, remove the thermostat.
- Disconnect the hose from the water pump to the
radiator (at the radiator).
- Put in as much water as possible.
- When to turn the ignition key water should pour out of
the hose.

Dot his only when the engine is cold, and with fresh water.
If you can temporary use some longer hoses it will be easier. Still be prepared to get wet.

Rob

Hey Latief, this note does not really address the context of your current situation, but I think it is true that GRAF water pumps are better in circulating water. I think a forum thread(s) address this.
My C280 had the OEM water pump replaced some time ago and it always runs a bit hotter afterward. But it's still not so significant that it alarmed the mechanic.
Don't know the manufacturer but it was not Graf or OEM.

My 300SE had a pump replaced with a 'LASO' brand. It works fine and kept the temp same as with former OEM.

Regarding your tranny, try using some tranny cleaner. Read the forums. There is one product that many have used.
Run the stuff for a while and then change the fluid.
It could just be a gummy valve in the valve body.
My 300D just went through this. Weakness and finally slipping.
Just was a sticky valve.

BTW only use OEM Mercedes radiator fluid when you get to the point of committing the refill.

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1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
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1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

weather was cooler today, but no overheating with the new radiator, and holding pressure just fine...

will update tomorrow...hopefully this cures the problem!!!!

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1993 300E, 2.8 M104 .....

It was the radiator, car has not overheated for the last three days.....

Thanks guys for the feedback and help!!!! I will update if anything changes...


Latief

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1993 300E, 2.8 M104 .....

Awesome

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http://i193.photobucket.com/albums/z...-RESIZED-1.jpg
1991 300E - 212K and rising fast...