chaindrive

I purchased my first MB, a 1979 450SEL/4.5 liter...got beauty through an estate sale...benn working on it for 2weeks now and just the usual stuff, brakes, exhaust, lube, etc...

Today I noticed antifreeze dripping from block on drivers side...It is coming from a machined hole towards the back of block...the best way I can describe it is that it looks like a "weep" hole for a water pump. The hole is aproximately 3/8 in diameter with no threads and looks deep enough to go towards the crank as if it were an inspection hole for rear bearing seal.

The coolant only begins to come out when car is sufficiently warmed to open thermostat.

Does anyone know what this could possibley be about ? I have spent the better part of the day talking to tech people at parts stores on the web and I have stumped everyone including self proclaimed veterans 30+ years in the business

I could take a pic and post it if it would be useful.

hoplessly stumped in Ohio...best regards..."chain drive"

mbtech208

Call up a dealer and talk to one of the old farts that knows those cars inside and out. It's a little out of my range of knowledge.

RJC

Can your find the workshop manual for that year/model car from MB? Probably would be a great investment sice you like to do your own stuff.

chaindrive

Only MB would design saftey in every aspect of their engineering process...I figured it out and it's very small problem. Here's the answer if anyone cares to know or has heard of a similiar problem.

On the front of the intake is an aux. air valve with pellet on the bottom that sits in the systems coolant and thus operates the plunger to control airflow during warmup. The gasket was leaking coolant down into the intake section of engine as it was being blown back to rear of block by the primary fan and then it found its way down to a drain hole in the block which happens to exit on the drivers side about 3 inches from oil pan and 1 inch from the end of the block....it's that simple.

The saftey feature/aspect being addressed would be, at least I assume to be, for leaks of this nature, including fuel leaks which under the right set of circumstances could occur with CIS mechanical fuel injection systems of this vintage.

Thanks for your input...

Chaindrive

chaindrive

I was told by a tech guy today that the MB engineers have developed a computer CD set that would make Chilton's read like "Dick and Jane". It's a bit pricey at $135 and only available directly from MB/Daimler-Chrysler? Just thought you might want to know............