Cooling system issues

[Mike Self]

4 hours ago, Healey3000 said:

Since the thermostat is new,

I've had 'em bad when they were new out of the box...

 

And...since you've had a thermostat out recently, you know it has two valves internally that open in tandem.  When cold, coolant is routed past the radiator but (IIRC) through the heater core to allow for cabin heat to occur sooner.  Removing the heater core from the system may well upset that dual thermostat's operation...as the system was designed to have a heater (no heater delete for tropical countries to my knowledge).

 

That cold lower hose--after the car has reached operating temperature--is either a defective thermostat or water pump.

 

mike  

[Preyupy]

The reason to NOT bypass the heater by just simply routing the water from the back of the head to the water pump inlet (which is what happens when you just connect the hoses) is you are just circulating the water in the engine and not through the radiator. If your heater leaks,  plug the hoses until you repair the HC.

 

The water pump bearings could be in perfect working order but the housing and/or impeller could be corroded badly enough that it does not flow water very well at lower engine speeds. If you have not replaced the pump in the last 10 years I sure would at least remove it and inspect the impeller and housing.

 

I know now this might sound stupid or insulting but you do have the thermostat installed correctly? I have seen a couple installed up-side-down over the years ( the hoses don’t fit very well and they had to work very hard at getting installed that way) 

[grizzlebar]

The reason to NOT bypass the heater by just simply routing the water from the back of the head to the water pump inlet (which is what happens when you just connect the hoses) is you are just circulating the water in the engine and not through the radiator. If your heater leaks,  plug the hoses until you repair the HC.
 
The water pump bearings could be in perfect working order but the housing and/or impeller could be corroded badly enough that it does not flow water very well at lower engine speeds. If you have not replaced the pump in the last 10 years I sure would at least remove it and inspect the impeller and housing.
 
I know now this might sound stupid or insulting but you do have the thermostat installed correctly? I have seen a couple installed up-side-down over the years ( the hoses don’t fit very well and they had to work very hard at getting installed that way) 

Any chance you have a picture showing “correct?”

The angled part is on top for mine

[7502]

Here's a pic of mine from yesterday before I pulled the radiator.

 

 

[grizzlebar]

Yep, that matches mine

[TobyB]

Quote

Started it up but the temp continues to rise past 210 and the lower radiator hose is cold.

 

Then you don't have a radiator problem.  Full stop.  Unless it's plugged solid, but your garden hose flush disproves that.

 

Does the thermostat housing get hot?  If it does, bad thermostat OR gauge.

If it does NOT, it's a circulation problem.

 

I've no experience with SpeedSlut products, but I too would confirm temps, as you're planning.  A simple IR

temp gun will do it.  You will get different readings off of the metal parts vs. the black rubber,

so don't get too worried about 10 or 15 degree differences- you're looking for gross differentials.

 

I second Mike- about 30% of 'new' thermostats malfunction in some way.

 

While I haven't seen this on 2002's specifically, I've seen impellers come loose on the shaft.  Or come apart-

yes, even the metal E46 one from Graf...

 

The heater pump bypass isn't the best way, BUT if your lower hose isn't even getting warm,

that's not your whole problem.  I bypass the heater core, but add a restrictor in line.

That makes it easier to bleed the system, but blocks most of the flow.

 

 

Good luck- you'll figure it out.

 

t

who left a blue towel in a carburetor, once.

[grizzlebar]

[grizzlebar]

Just too a secondary reading of the top of the radiator - 160

[golf02]

Are these temps using an IR sensor (gun) or a thermocouple? IR guns have issues with reflective surfaces (emissivity). If the temps are correct then your thermostat is around 100c what temp TSTAT did you install. I would be suspicious of the thermostat being kaput.

[grizzlebar]

Just too a secondary reading of the top of the radiator - 160

[grizzlebar]

Are these temps using an IR sensor (gun) or a thermocouple? IR guns have issues with reflective surfaces (emissivity). If the temps are correct then your thermostat is around 100c what temp TSTAT did you install. I would be suspicious of the thermostat being kaput.

IR gun. Once it cools down I’m gonna pull the thermostat to test it on the stove.

[grizzlebar]

Everything’s apart. Have the thermostat on the stove now heating up.

Here’s the water pump

[grizzlebar]

Thermostat checks out, somewhere between 180 and 190 it opened up.

[golf02]

I’ve seen worse water pumps what is the clearance between impeller and body? Manual says 0.031 to 0.047 inch.

[grizzlebar]

I’ve seen worse water pumps what is the clearance between impeller and body? Manual says 0.031 to 0.047 inch.

Not sure, I’ll grab my feelers when I get home and see. I ended up ordering a new one anyways