getting hot....no cabin heat, bad waterpump?

[jakeb]

Today when making a short trip I look down and my temp gauge is nearing the red. But my heat is dead cold. I start heading for home, only a couple blocks away and the gauge starts to drop and I have cabin heat again. Another block away, no cabin heat and the gauge starts creeping back up.

Get home...check the fluid level, looks good.
Let the car sit for an hour or so and go for a short drive....car starts to get hot, above half and I have no cabin heat.

The m50 has about 130k on it. Around 3-4k since the swap to my e30.

I did replace the water pump and thermostat when I did the swap.

From the symptoms it seems like the water pump is bad, ie no water circulating.

I have the pump I pulled out of the car so I can put that back in without all that much trouble. Can I get the pump out the the rad in the car? I am running a m42 radiator.

TIA

[1990m3]

sounds like you have an air bubble in your system or a bad thermostat. I don't think a bad waterpump is going to keep hot air from coming to your cabin necessarily. I think a bad waterpump will overheat your motor

[jakeb]

Hmmmm. It could be the themostat I guess. It is almost overheating. I thought no heat because there is no circulation.

[jakeb]

another update....

I went to the garage and started it to see if I could see any movement in the expansion tank. I let it run for a few minutes and then reved it to 3-4k and there was zero movement of the coolant. Not even a ripple. I would think that would be something, even with the thermostat open or closed.

The engine also sounded....different. Hard to explain, almost like something else was spinning.

Anything else i should test before I drain the coolant and pull the pump off? Not that pulling it even will take very long.

[318isbmw]

another update....

I went to the garage and started it to see if I could see any movement in the expansion tank. I let it run for a few minutes and then reved it to 3-4k and there was zero movement of the coolant. Not even a ripple. I would think that would be something, even with the thermostat open or closed.

The engine also sounded....different. Hard to explain, almost like something else was spinning.

Anything else i should test before I drain the coolant and pull the pump off? Not that pulling it even will take very long.

Sounds like pump. Be sure while your at it to do new thermostat. Right there and can't go wrong.

[jakeb]

its fixed....

It was an all day experience but it is good now.

Pulled the water pump....seemed fine. The impeller was not loose or anything. And for the record this was a new (4months ago) geba metal impeller water pump from BMA. So I decide to still put the one I took out of the car back in. Thought I would replace the thermostat as well. Even tho that is brand new too. That turns into me stripping out the first bit on one of the holes for the thermostat housing. I was able to use a little longer bolt and grab some thread further in and everything seems good.

So then I get it all filled up, drive around some. With the bleed screw open. Engine gets hot.... Boiling over pretty much. Took an hour+ to get home, go a little bit, shut down and sit for awhile. Go another mile and sit.
All the time I still have no in cabin heat, and it is 20 degrees outside now. Mind you the wife is with me...she isn't all that happy about being cold.

So I get home...let it cool down for a half an hour, get more coolant. Jack the front of the car in the air and let the engine run for a while at 3k rpm. All the while I am adding coolant here and there. After a bit of this I finally have in cabin heat and the temp on the gauge is below half. Whew looks like everything is finally ok.


Take it for a shake down drive and it is better than when it was before all this started happening. The temp stays between 1/4 and 1/2 on the gauge. Also a side note...before I would loose in cabin heat when at idle (sitting at lights, etc) now the heat is great all the time.

So...it sounds like it was a band water pump from the time I put it in. Bummer I stripped out part of that bolt hole but it shouls be fine as it is.

During the shake down drive I did some nice 1-2-3 to 7k rpm runs. Man this car is fun. Shifting into 2nd and break the rears loose to the point of hopping.... I am sure the salt on the roads and snow tires don't help in the traction area.

wow that was long.... a good ending to a pita problem, time for a beer.

So a brand new water pump.....junk from new.

[318isbmw]

its fixed....

It was an all day experience but it is good now.

Pulled the water pump....seemed fine. The impeller was not loose or anything. And for the record this was a new (4months ago) geba metal impeller water pump from BMA. So I decide to still put the one I took out of the car back in. Thought I would replace the thermostat as well. Even tho that is brand new too. That turns into me stripping out the first bit on one of the holes for the thermostat housing. I was able to use a little longer bolt and grab some thread further in and everything seems good.

So then I get it all filled up, drive around some. With the bleed screw open. Engine gets hot.... Boiling over pretty much. Took an hour+ to get home, go a little bit, shut down and sit for awhile. Go another mile and sit.
All the time I still have no in cabin heat, and it is 20 degrees outside now. Mind you the wife is with me...she isn't all that happy about being cold.

So I get home...let it cool down for a half an hour, get more coolant. Jack the front of the car in the air and let the engine run for a while at 3k rpm. All the while I am adding coolant here and there. After a bit of this I finally have in cabin heat and the temp on the gauge is below half. Whew looks like everything is finally ok.


Take it for a shake down drive and it is better than when it was before all this started happening. The temp stays between 1/4 and 1/2 on the gauge. Also a side note...before I would loose in cabin heat when at idle (sitting at lights, etc) now the heat is great all the time.

So...it sounds like it was a band water pump from the time I put it in. Bummer I stripped out part of that bolt hole but it shouls be fine as it is.

During the shake down drive I did some nice 1-2-3 to 7k rpm runs. Man this car is fun. Shifting into 2nd and break the rears loose to the point of hopping.... I am sure the salt on the roads and snow tires don't help in the traction area.

wow that was long.... a good ending to a pita problem, time for a beer.

So a brand new water pump.....junk from new.

Hate it when its not a good bleed. Had to do the same thing on mine. Pain in the butt.