Cooling System Question

Hey guys first time poster here, so have so mercy . I was at roadfly.org but decided it was time for a change. This site setup rocks my socks.

I have a question on the 528i cooling system. I wanted to replace the thermostat + its housing/ and the water pump. The car has about 85k miles right now and I have the 6th sense that it needs to be changed ASAP. Do you know where I can get an upgraded aluminium thermostat housing and water pump with a metal impeller and any sites that will be helpful during the install?


Thanks Guys,

Matt

Originally Posted by E39_boy

Hey guys first time poster here, so have so mercy . I was at roadfly.org but decided it was time for a change. This site setup rocks my socks.

I have a question on the 528i cooling system. I wanted to replace the thermostat + its housing/ and the water pump. The car has about 85k miles right now and I have the 6th sense that it needs to be changed ASAP. Do you know where I can get an upgraded aluminium thermostat housing and water pump with a metal impeller and any sites that will be helpful during the install?


Thanks Guys,

Matt

Matt, keep me informed on how you get on....read on....

This morning while driving into work, about 5-10 mins into my drive, I noticed the temp gauge rise slowly up past the half way mark and into the red zone on the gauge. The red light came on, so I backed off from the traffic on the verge of pulling in & switching off the engine. Just as I had to accelerate, the gauge came out of the red zone, settled back in the centre and didn’t budge for the rest of my journey. Needless to say it gave me a few more grey hairs.

When I got to work, I let it cool down and checked it later. I’m not too familiar with the cooling system of this car, but noticed 2 fans. One on the engine side of the radiator and one on the outside. Both will spin freely with the car off. Starting up the car, the internal one operates immediately. I let the car sit for 10-15 mins to let it heat up and as the gauge got to the centre point, I drove off. About 5 mins into the drive again the gauge started rising up again, but only went ¾ way up and came back into the middle and settled for the rest of the journey. My speed at this time was about 40-50 whereas this morning, when it went into the red, I was stuck behind a truck for the first 5-10 mins at 20-25mph. I also had the car on for 10 mins to warm it up before I got in.

When I got home I let the car idle and watched the temp gauge. It went as far as the ¾ mark and sat there but the 2nd fan never came on. I’m told this is a viscous fan, whatever that is.

When it comes to troubleshooting water cooling problems from my experience, it’s really a chicken or the egg scenario. It could be the thermostat, or the water pump or the fan switching, really depends on what you go for first.

Can anybody explain to me the method of operation of the dual fan system and what to expect in the sequence of operation? I’m guessing the reason for the dual fan is due to the big engine block and the need for extra cooling, but I’m not sure.

Any suggestions or experience from anybody who may have seen this before?

It’s a 1997 E39 (523i) 97k miles

Thanks.

Tom

Check to make sure you have enough coolant, also you could have some air in your coolant system. You would need to bleed it out correctly. Here is the water pump replacement diy --- > www.understeer.com >tech icon on the left > water pump replacement diy. Also: http://www.bimmerfest.com/forums/showthread.php?t=47093



Matt

spot on e39 boy. I checked coolant level last weekend and it needed a litre. ok since.