Potential cooling problems - 450SE

[Styria]

As already referred to in another thread, my 450SE 'Goldie" has been off the road for a number of years now. It's aleays been an ready and immediate starter, but I did discover a slight water leak from somewhere 'deep down' that I could not really trace accurately. So, I decided to remove shroud and coupling, top and bottom radiator hoses, the overflow container, but I left the rediator untouched.

Whilst groping around in that area, I got rid of the seized smog pump and gave the whole front of the engine a really good degrease - quite remarkable just how much gunk I was able to get rid of. Oh, BTW, I also removed the Alternator and respective brackets. Anyway, I refitted all the components I had removed, and filled the system with water and started the car. Normally, once an engine reaches operating temperature, the running engine will just suck all water into its eternals, but that didn't happen in this instance. After putting in not a real lot of water, it just stayed in the overflow tank, the temperature remained at normal, and the top radiator tank got hot after a while, but the bottom tank remained cool or cold. I am looking for advice as I am not really sure what causes this phenomenon. Could the radiator be blocked, or is the thermostat stuck in the closed position ? I simply don't know what to make of it. Regards Styria

 

[Styria]

This is the first time that I have had the opportunity to again have a very close look at the M117 engine, and the various components located at the front of engine. When compared with my 6.9, I don't particularly like what I see. Water and Hydraulic Pumps are buried 'down below', in other words an area that I would want to avoid, and the thermostat housing also takes a bit of coming to grips with. Also, the spark plugs on the driver's side prefer to remain in position, although I am lucky enough to have the right tools to get them out, particularly Nos. 3 and 4. The other side's okay. Just my observations. Regards Styria

 

[BenzBoy]

It's an easy task to take the radiator right out and have it professionally cleaned - that would be a must do when re-commissioning a car.
Regards,
Benz-Boy

 

[AAB]

Styria,

As you observed, there is not much fun getting at the water pump of a 450.
( a lot easier than the rotten Aircond compressor job,..ie only a 4 G & T job !!)

I just did mine, water leak that I could not find, & eventually decided that it was the pump.

To get it out, remove fan, ( barked knuckles ), remove distributor,..( be sure to mark the timing point on the front pulley because you have to turn the shaft backwards to access the lowest 2 studs ), remove alternator ( I did not but regretted it later ), to get at the lower hose clamp.

You have to loosen the fan/steering pump belt, no fun in itself, to get the fan off.

My pump was knackered, & it is amazing how silent the engine is with a new water pump !!

Regards,

Alex




The studs were 13 mm, & a 1/4 inch set of sockets is perfect for getting into the tough spots.

 

[BenzBoy]

Sounds like the right time to renew the water pump and flush the radiator anyway - no time like the present to avoid issues later down the track. When I did the timing chain on mine I also did the water pump as a precaution rather than because it showed symptoms - but it is so much easier to do it now.
Regards,
Benz-Boy

 

[TJ 450]

This seems an interesting topic.

Seeing as the upper tank of the radiator is getting warm, I would suspect that the thermostat is at least not closed, and that the radiator is probably partially blocked.

Also, you raise some very interesting points regarding the front of the M117/M116 engines. They are all similar in this regard, and compared to the M-100 engines, they are certainly a little quirky, and very different. There is also a greater chance of oil leakage than that of the M-100s, due to the full-size removable timing cover.

Removal of the harmonic balancer is however, a walk-in-the-park affair.

The thermostat housing as a bit of a pain to get at, but it has the benefit of being part of the water pump and thus not prone to breakage from heavy handedness.

I would also start with a recore/rodding of the radiator, and perhaps a replacement water pump and thermostat.

Tim

 

[WGB]

Both my 450 and 6.9 ran a little hot for a week or two when I changed the coolant which settled suddenly with a distinct drop in coolant level when they were ready with no subsequent top up of coolant necessary after the first drop.

I have no doubt your radiator should be rodded but I still think both motors have a little problem with trapped air for a while after the coolant changes.

Bill

 

[Styria]

I realize that there is every chance that I will be involved in further maintenance and replacement tasks. I sort of tend to go easy until the car tells me more explicitly what is wrong with it. I must confess to not being keen on replacing the water pump on account of the expense, AND work involved. Part of my problem also relates to the fact that right now I am somewhat reluctant to road test the car - there are still too many open ends that require rectification.

An extended road test would soon show up any cooling deficiencies, particularly if the thermostat fails to open which can result in water really boiling and spilling its contents out of the overflow tank. This, of course (a really hot engine) can lead to other problems such as splitting hoses, destroying the seal in the water pump etc. etc. - situations to avoid. Best for me to do whould be to tie some of the 'open ends' and get Goldie to stretch her legs in everyday traffic - close to home and help. Regards Styria