cooling system issues

[pushkick]

i have a question how do you know if your water pump is working ? should there be a flow out of the thermostat housing breather if it is opened up? or the radiator bleeder when it is opened up? how long should a water pump last? any help is appreciated.
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i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper

[mikemtnbike]

If I squint hard, I can see the coolant moving through my bleeder ring. Or at least I think I remember that I can.
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1991 Vanagon GL 2.1 AT Westfauxlia. "Frankie" Totaled https://www.thesamba.com/vw/forum/viewtopic.php?t=764510&highlight=carnage
1995 Eurovan Camper "Marzivan"
2020 GTI SE manual

[Ahwahnee]

Water pump failures usually manifest themselves as noise or leakage. It would be fairly uncommon for the pump to simply not pump.

If, once the engine is warmed up, you have heat up front - that generally means that the water pump is working and the thermostat is not stuck open.

[AtlasShrugged]

WBX water pumps usually dont fail at the impeller. They fail by leaking or the bearings rattling around.

Describe what exactly your problem is..you think you have no water pump circulation because overheating?

Do your heaters front and back work? If so..coolant must be circulating.

[pushkick]

heaters front and back do not seem to work and when i felt the coolant pipes and hoses from radiator to pipes they were cold and i could squeeze them(this was after it had been running for 10 mins @ 1500 -2500 rpms). i changed the thermostat and put in a stock 87 deg C one which is new but i forgot to test in hot water before installing so i might have to pull it out and check. engine seems to run fine but gets hot if i drive it for awhile or i keep the rpms at 2500 for at least 10-15 mins. (it is cold outside here around 10-15 deg F during the daylight. so it takes awhile to heat up the engine especially when driving.

water pump was installed maybe 3-4 years ago. pump makes no noise but it may have made some a week or so ago and then quit. worked fine the day before but the next day over heated after about 4 miles of driving.
_________________
i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper

[Ahwahnee]

Are you very sure you did a thorough job of bleeding the system? I usually gauge success here as getting as much coolant back in that came out when work started.

[Wildthings]

Loosen the belt up and see if the pulley on the pump wiggles around at all. I agree with others that the impeller coming loose is very rare.

It would be almost normal for a brand new thermostat to fail.

If it is cold enough to freeze the coolant in the radiator, then overheating can occur very quickly.

With the pressure cap removed and the engine revved you should see a goodly flow of coolant through the pressure tank.

[pushkick]

thanks for all the input/advice! well the first time that i noticed this issue i am sure that the i had the system bled properly but after i replaced the thermostat it could have not been done . i dont see any flow in my expansion tank when engine is revved and nothing out of the bleeder on the top of the thermostat housing. when i first start the engine it seems if i remember correctly the expansion tank should show signs of pump moving coolant in the system and i dont see any lowering of level or inrush of coolant. if i pull the thermostat out and run the engine will that cause any problems or damage? i just want to see if the pump is doing its job.
_________________
i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper

[Wildthings]

[pushkick]

update: i changed the thermostat and bled the system via radiator bleeder and then let engine idle for around 10 mins and the temp gauge moved half way between the light and first line(cold) . i revved engine to 2500 rpm and then opened the bleeder and coolant began coming out. i checked front heater operation and it is now blowing warm air. so it looks like i had a bad thermostat and an air bubble in the system. next project the blinking coolant level sensor. then the idle control stabilizer. thanks for your comments they really helped in a really cold climate. really didnt want to pull the water pump in this weather outside. suppose to be below Zero F this next week so needed to make sure the coolant was at the correct concentration.
_________________
i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper

[pushkick]

i found this pic in another thread helped explain
system

https://www.thesamba.com/vw/forum/viewtopic.php?t=682404&highlight=water+pump+testing

_________________
i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper

[AZ Landshaper]

Open the bleeder and floor it for 10 seconds. Have fluid spraying all over kingdom come? If not then there's an issue. My heater was cold when I first installed it. (Didn't bleed anything). Punched it while holding the hoses to the front heater and felt warm water rush thru w/in 5 seconds. Prob less.
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85 Weekender w/ EJ22
Previously
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and a 67 bug.

[pushkick]

this is an interesting issue seem i have not fixed the problem. when it gets cold below 0 to 15 deg F the engine starts runs but heater dosent blow hot air even after 10 mins of running at idle and revving to 2000-3000 rpm intermittently . the engine temp gauge gets to around the middle of the led and the expansion tank starts releasing coolant to overflow tank and overflow tank fills and starts leaking through cap.

things i have done

test thermostat out of system (works ok tested in hot water and ir gauge)
installed a new 87 deg C thernostat
replaced temp sensor
bled radiator/system of air
made sure coolant has correct antifreeze amount ( specific gravity test)

has anyone had a problem with thermostat housing restricting thermostat movement when it is very cold outside?
_________________
i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper

[DanHoug]

what fan speed are you on when trying to get heat while stopped? "1" or "2" is the max, higher than that you pull more cool air than the heater core can warm up.

-dan

[Wildthings]

[pushkick]

[pushkick]

[Wildthings]

A compression leak will leave you with air in the system no matter how many time you bleed it. If you are getting leakage around the sensor then chance out the o-ring, they get hard with age and stiffen that much more with cold. You shouldn't be seeing any slush in the coolant, if you are then up the percentage of antifreeze. Also go with a motor oil at least as thin as a 5w30 or 5w40 oil. Going to a 0w30 or 0w40 would be okay as well.

[pushkick]

thanks for all the input i think i finally figured out what was going on. there was some air in system and the coolant was a little weak which caused the slushy coolant and caused the thermostat to stick. when i took the thermostat out and tested it worked fine. i added a little more antifreeze and ordered a new o ring for the temperature gauge sensor. seems to have fixed the issue.
_________________
i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper

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