BMW 325i Radiator, Water Pump, Thermostat, and Thermostat housing change

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1995 325i Radiator, Water Pump, Thermostat, and Thermostat Housing Change

At 67K while driving home I suddenly smelled coolant. I started to watch the temp gauge and about

1 mile the needle started to move. I got about 1 more mile before the temp needle moved to a point

I felt uncomfortable. I pulled off the highway and into a parking lot about 1 mile from my house and

had to call a tow truck. Upon inspection, the top radiator neck had cracked and was venting fluid.

Since my wife drives the car, and she was on a business trip, I had to find a replacement radiator fast.

I found a Baer the same day and picked it up.

Long story short, I replaced the radiator, and realized very quickly the car was still on a path to

overheating. Now I was really confused until I found out that BMW made a water pump with a

plastic impellor!!! Here is how I changed the radiator, water pump, thermostat and thermostat

housing.

All the parts cost me about $500 which were dealer prices except the radiator. You can probably

get them cheaper from a discount dealer.

For reference, the dealer wanted to charge me $1200 not including the radiator cost I think they

wanted another $450 for the radiator.

-Shawn

Here are some of the parts I needed to buy.	You can get the part numbers off of these shots if you need.	More part numbers.	Even more part numbers.
Here is what the new water pump looks like. It is made of some kind of composite material. It is like metal, but not. Maybe a ceramic?	Here is another shot.	And yet another.	This is a above view of where the water pump and thermostat housing are located.
First thing to do is remove the radiator. To do this, you will need to first pull the plastic cover.	The back shield on the radiator is held in by some push pins. I broke mine trying to get them out. You may want to order some new ones.	Here is a shot of the new thermostat. I am told the new ones have a slightly higher temp. I think the real reason they changed them is to make the temp need line up exactly with the center line! But since you are in there, might as well change it.	This is the new gasket for the thermostat housing.
In order to do this right, you are going to need to drain the fluid. This is a coolant drain plug in the block.	It is located on the passenger side. A little bit difficult to get to. But once you locate it, it is not too bad.	Here is a picture of the shield removed. the radiator is held in by the back ratchet type clamps. You will need to stick a screw driver in there to free them. I broke one and had to buy a replacement.	If you car is an automatic like mine, then you will have a tranny cooler you must disconnect. To get to it, you will need to remove a plastic shield. The shield is held in by 4 screws on each side. This picture shows the screws holding the tranny cooler.

This is another shot of the tranny cooler location, but it got whited out by the flash.	Here are two of the tranny basket shield screw holes.	In order the get the water pump out you need to remove the fan. In order to do this I made an aluminum holder.	The holder goes between the fan and secures to the water pump. This allows you to remove the fan. (I don't remember if the fan bolt is held in with a reverse thread?)
This picture is actually difficult to distinguish, but important. It shows the plate in place to remove the fan.	Here are the two different water pumps.	You can see the crack in the plastic.	This crack caused it the shaft to spin and the blades not to.
Here is the opening on the block where the water pump goes. It is under the thermostat housing.	I also removed the thermostat housing to replace the thermostat while I was in there.	Here is the difference between the two thermostats.	Another view of the difference in the thermostats. You can also see the radiator clip I had to buy because I broke one.
Here is the new thermostat housing. My old one didn't show any signs of wear, but might as well replace it since it is also plastic. I inspected my radiator hoses and they looked good so I didn't replace them. Depending on their condition you may want to replace these while you are at it.	Here is the opening with the thermostat housing removed. I was very impressed with the BMW coolant. There was no corrosion in the water line. I was so impressed I used BMW coolant on my GSX race motor.	This is the show the direction the thermostat fits in place	Starting to put things back together. Here is the housing put back on. Next will be the radiator hoses an then the water pump.

Forgot to mention the belt. Make sure you remember how the belt is routed!!!

Here is how I recompressed the belt tensioner. I then locked it in with a screw driver.

This picture shows the route of the belt in case you forgot. It also shows the water pump pulley on. You will notice I didn't put all the screws in yet. I need to put my holder in place.

Here is the holder back in place. This is so I can put the fan back on. Now is a good time to put the radiator hoses back on. Next is the fan. Once you get the fan on, tighten the 4 bolts on the water pump pulley. The rest is just like the way it came off.