Overheated Stupidity

[MarkW]

Who runs that clueless club around here? I need in, in the worst way.

So, pulled the water pump, looks good, metal impeller & all. So back in.

Installed new thermostat with trick 1/16" hole right on the arrow.

Crankup to bleed. While looking about for leaks etc after a bit of bleeding, I happen to caress the radiator, hummmm, hot at the top, very cool at the bottom, over on the lower right by the hose. And yes, I had poured a goodly amount of water down through the thing & it seemed to run ok when I had everything apart. Still not much heat from the heater either.

Y'all think it's new radiator time?

TIA

[Jay 535i]

My unexpert opinion is that you've created an air lock or some other blockage in the system.

[Rus]

Feel the heater hoses to check if they are all hot. If not you need to crank the heater on full and compress the heater hoses repeatedly while the engine is running. This worked pretty well on my 535i when the heater core had air in it. Just my $.02

[Jay 535i]

Feel the heater hoses to check if they are all hot. If not you need to crank the heater on full and compress the heater hoses repeatedly while the engine is running. This worked pretty well on my 535i when the heater core had air in it. Just my $.02

Or perhaps just bleed the system as per the Bentley manual?

Just throwin' ideas out there until someone smarter comes along... :)

[uscharalph]

Who runs that clueless club around here? I need in, in the worst way.

So, pulled the water pump, looks good, metal impeller & all. So back in.

Installed new thermostat with trick 1/16" hole right on the arrow.

Crankup to bleed. While looking about for leaks etc after a bit of bleeding, I happen to caress the radiator, hummmm, hot at the top, very cool at the bottom, over on the lower right by the hose. And yes, I had poured a goodly amount of water down through the thing & it seemed to run ok when I had everything apart. Still not much heat from the heater either.

Y'all think it's new radiator time?

TIA
The 2 simple things that can cause overheating are (1) if the return back to the overflow is blocked and (2) you need a new radiator cap. Other than those is if the cooling system is not bled properly.

[uscharalph]

The 2 simple things that can cause overheating are (1) if the return back to the overflow is blocked and (2) you need a new radiator cap. Other than those is if the cooling system is not bled properly.
If those don't help maybe it is new radiator time.

[MarkW]

Thanks guys, I'm still stayin' with the bleeding and working that.

This half hot radiator is what has me puzzeled.

[MarkW]

The 2 simple things that can cause overheating are (1) if the return back to the overflow is blocked and (2) you need a new radiator cap. Other than those is if the cooling system is not bled properly.

Well, I can see the return pissing into the expansion tank so I don't think it's that. I have not replaced the radiator cap, I will do that as soon as I can get by the dealers again & give him back his plastic pump.

[Kalevera]

Unless the urge to throw money at the car is calling, it would be wise to do a little more investigation.

Unless the radiator itself is leaking, don't mind the temperature differential -- it's supposed to be there. Pay attention to the upper and lower radiator hoses, which will dictate flow.

If the car is overheating, the upper radiator hose is hot, and the lower radiator hose is cold, there's a flow problem. If that metal impeller was still attached to the shaft (saw an M62 pump that had its impeller separated at the shaft last week, but was only apparent when messing with it -- oh, and the scars from the dislocated impeller nicking the block) when it went back in the car, I'd be looking at the thermostat and confirming that it was correctly installed.

Other circumstances -- how long and under what conditions the car overheated -- would help. Aluminum cylinder heads and blocks do break.


best, whit

[MarkW]

Unless the urge to throw money at the car is calling, it would be wise to do a little more investigation.

Unless the radiator itself is leaking, don't mind the temperature differential -- it's supposed to be there. Pay attention to the upper and lower radiator hoses, which will dictate flow.

If the car is overheating, the upper radiator hose is hot, and the lower radiator hose is cold, there's a flow problem. If that metal impeller was still attached to the shaft (saw an M62 pump that had its impeller separated at the shaft last week, but was only apparent when messing with it -- oh, and the scars from the dislocated impeller nicking the block) when it went back in the car, I'd be looking at the thermostat and confirming that it was correctly installed.

Other circumstances -- how long and under what conditions the car overheated -- would help. Aluminum cylinder heads and blocks do break.


best, whit

Whit - Thanks so much. I put a new 88 degree thermostat in, correctly oriented, with the 1/16" hole drilled @ the top, in the arrow. I saw nothing wrong with the pump I took out.

I drove a bit tonight, 15 minutes stop&go, sat for 2 hrs, 5 mins, sat for 30 minutes & 5 minutes. Bled each time, no air. Gauge still at excately 1/2, but, no heat in heater. BUT, now, after this, lower hose & radiator warm,? I ran about a week with occasional reading up to 3/4, with one half way between 3/4 & red, but never red. The wife said she saw it @ red once & promtely shut it down & walked home(great wife, it is her car though). That is what promted the investigation. I see no evidence of any water/oil intermixing. During that period of rising temp, I would note the gauge jumping around, 1/2 to 3/4 back a bit, down under 1/2, back up to 3/4. I chalked that up to a thermostat going out.

What has me so puzzeled/worried is this lack of warmth from the heater. This is something that has just manifest itself. Could the radiator core have collapsed during those heat cycles? Even if they never got into the red? I've put 140,000 miles on the car since acquiring it & this is the first weirdness I've had to deal with. The radiator has a BMW sticker on it, though it looks very good, even after all these miles. I always figured it was put in right before I bought it.

Oh yeah, ain't got no throwin money, that's why I'm tryin this myself, and why the cars got 206,000 miles.

Thanks again for the help.

[632 Regal]

just a follow up, you are bleeding it with the heat on full & hot? also at idle if the aux pump isnt working you may need to raise the rpm's as you bleed it to get the air pocket out of the heater core.

[MarkW]

just a follow up, you are bleeding it with the heat on full & hot? also at idle if the aux pump isnt working you may need to raise the rpm's as you bleed it to get the air pocket out of the heater core.

Thanx Jeff, yeah. I am. Maybe I just gotta do it more.

Global Warming getting to the big guy?

[wingman]

Don't discount a faulty thermostat. Even brand new ones can be jiggered.