My mother bought a radiator for her 1987 240DL and it's for an automatic, though I know this doesnt matter much as the oil cooling holes will just go unused

however, it has a good sized hole near the top right side.
It's a Nissens Radiator.

I believe the hole is for a sensor, but it's a good sized hole with no threading.

http://www.pelicanparts.com/euro/catalog/s..._WATrad_pg1.htm

appears to be a plug and bushing for it, but I want to be 100% sure.


Also, what's the best way to take the old radiator off? do I have to drain the block?

What's the best bleeding procedure once coolant is added again?

I know bleeding is a very annoying process on my '86 BMW.

I'm not sure what you mean by "bleeding procedure", never heard of that, but if you're changing the radiator, you should flush your engine thoroughly. I have an '85 DL, and it has the same sensor hole (large, top, passenger side), but when I replaced my radiator a couple of years ago, it had a plug and nothing else was required. The plug is for a temperature switch for the auxiliary cooling fan (which mine doesn't have, but plan to install.)

When I replaced my radiator, I also replaced the hoses (inexpensive insurance). When I read the warranty on the radiator, I also noticed (after working on cars for 2+ decades), that the warranty would be voided if I used any other water than distilled! I had never heard of that before, but knowing how aluminum oxidizes in water, it wasn't a great surprise. I would suspect, I will not have trouble with my cooling system for some time since my coolant is blended with distilled water. After I installed my new radiator, I re-filled, ran the engine, then drained (remove the lower hose) 3, maybe 4 times. I wanted to make sure all the old coolant was out, and make sure there was only distilled water in place. After my last drain, I refilled with 100% coolant, and based on my capacities, it put the solution at a 60-70% level. I've had no problems since.

To replace the radiator, remove the fan blade (four bolts which you will need a wrench to loosen). With a pan to catch the old coolant (poisonous to animals who will find it sweet tasting if it pools nearby), remove the lower drain hose. Remove the upper drain hose as well. There are two braces holding the top of the radiator, once removed (along with any other attachments - mine is auto and I had to remove the two trans lines), just lift the old one up then reverse for the install.

Check your capacities and if you decide to flush with distilled, buy an ample amount so you don't have to go to the store to finish the job. Any extra distilled is good to have on hand for your battery.

Good Luck!

Breadman

Fun problem:

the little rubber washer that fills the hole in the radiator tore when I installed it.

I got it all nice and wet first too.

I'm this close to handing it off to a shop.