high water temp at idle / low rpm ???

[ACII]

Hy all

i am still fighting with my cooling setup..... right now i have flushed my cooling system and put in the right cooling fluid.

I also checked the T-Stat (180 version) .....and modified it with a small metall piece to open a little bit earlier.

Today i made the first test ride...
it is pretty strange ...
at idle rpm the temp goes up pretty quick over 235 degrees....
But when i rise up the rpm to around 2000 rpm or even more (the car is still in parking) the temp goes down pretty quick to the 195 degress

During driving i do have the same effect...at high rpm the temp goes down.

What do u think is the prob ??? Does the T-Stat not open correctly ? Or maybe the water pump does not work at low rpm ?

Before i did the flush ...everything was ok. But at the flush i recognized some metall abrasion....so maybe the water pump is dying ???

Hope u can help once again

Thanks
Achim

[ls1nova71]

Sounds to me like you have air in the system.

[ACII]

i guess u are right....
cuz at the moment the gauge shows more than 230 degrees the lower radiator hose was still pretty cold.....
So maybe there is bigger air bubble on the engine side..

I got some informations about bleeding the system of the internet.
Also i will give it a try to sequeze the upper radiator hose..

Will check that tomorrow..

Thanks
Achim

Originally Posted by ls1nova71

Sounds to me like you have air in the system.

[Andy4639]

Here is what I had to do 6.0 ls.

Jack the truck up as far as you can safely. Take the small steam ports in the front of the motor loose and the top radiator hose off. Fill the motor up through the radiator hose until you see water coming out of the steam ports. Stop close them up good and then finish off the filling. Hook it back up and let it back down to the ground. Check the level and fill as you need to.

[ACII]

Hy all,

so here in Germany we do have a public day ...so i had time to check my cooling setup.. :-)

So i dropped the cooling fluid....and disassembled the T-state housing.
Back home in the kitchen i checked if the T-State is opening in the correct way.
It look likes everything is workin fine...as u can see on the attached pic

So back in the garage i put on the T-State again and filled up the system this way.

Loosening the steam ports (both side on the front of the engine). Filled in the fluid through the upper radiator hose til the fluid comes out of the port... after closing the ports i filled it up once the hose was full.
The rest filled up through the radiator cap opening.

After that i started the engine to get warm.....meanwhile i squezzed the upper radiator hose... (the radiator cap was still off)

After a few minutes .the fluid comes up quickly and overflowed. i stopped the engine and put on the radiator cap.


After a test drive ...i had to recognize that there is still the same problem.
During drivin with a higher rpm the temp goes down pretty quickly.
Idling in the parking position it goes up to 221 degrees.

I also checked the temp through the pcm.....to get a proper information.

I made a little video, after i switched off the engine.
U can hear the water rumbling inside the upper radiator hose.
--> pretty strange

here is the link to the video

https://sendvid.com/yi2y9s3s

I am using the original radiator of the chevy pickup (with a new radiator block, no alu).....maybe the radiator cap is not the right one ???
Also i sprayed the radiator tank ...so maybe the cap is not closing right anymore.

Hope u can give me some more advice

Regards Achim

[mongocanfly]

I'm having a hard time to get that video to play but when it did it sounded like ya still got air in it..also you might want to straighten out those kinked fuel lines...

[ACII]

Tomorrow i will try to get the air out with a funnel.

kind of these

https://www.youtube.com/watch?v=xYkKW0OyeUc

u r right the fuel lines have to be straighten ..but first i have to get my cooling setup clear :-)

i will try to upload the video at youtube,,,,

cu
achim

Originally Posted by mongocanfly

I'm having a hard time to get that video to play but when it did it sounded like ya still got air in it..also you might want to straighten out those kinked fuel lines...

[ACII]

so the video is now on "youtube"

https://www.youtube.com/watch?v=AcRT...ature=youtu.be


thx
achim

[Soyuz008]

Once you get the water flowing correctly, you still might have cooling problems. That radiator looks small for the engine you have. Also, do you have a cooling fan moving air through the radiator?

[mongocanfly]

Soyuz if I remember right his fan is in front of radiator...

[BR3W CITY]

Are you running a heater core? Its an easy place for air to be introduced into the system repeatedly. It sounds like your getting cavitation and/or your coolant is actively boiling.

Its possible air is being sucked back into the system, and no amount of bleeding will fix that if there is a leak spot.

Its also possible that there is a clog/restriction OR damage to the water pump impeller. Coolant flow should be quiet and fairly motionless, much like a garden hose. If you can't find another solution, I'd suggest popping the water pump back off and taking a look at the impeller vanes and its bearing.

Lastly, are you running a vent tank or an overflow? It sounds possible that there is more pressure than the system should have. Around 16lbs vented is what most radiator caps run, if you have way more pressure, the coolant will boil easier.

[ACII]

hy all,

just some more informations about my setup..

I do have the fan infront of the radiator..

i dont have any heater core or stuff like this.. ....as u can see on the attached pic, i have blocked the outlets of the water pump.

I do have a overflow tank....as u can see on the first pics.

Today i tried a bleeding with a homemade funnel out of a big bottle of coke :-)

During the engine got warm ..i could pump out some air by squeezing the upper radiato hose... i could see the air coming out at the funnel.

But at the moment the engine was really warm ...the water level in the funnel rised up and up and up...
It did not stop to rise so i switched of the engine.... after that i removed the funnel and closed the radiator with the cap.

Then i started the engine again.....after a few minutes i could hear the water/air rumbling inside the hose.

The lower radiator hose was still cold ....so i made a temperatur check with my laser pointer .. the result of this check u can see on the attached pic.


So the conclusion is that there should be still a big air bubble behind the t-state and the T-State does not open because its not getting warm enough.

What do u think ? Does it make sense to open the plugs at the water pump (for the heater core).
Or how can i bleed the ****ing air at this point ?? :-)

Thanks
Achim

[mongocanfly]

I don't know it for a fact because i never tried it but.... I was told not to block off the heater hoses fittings..they said its the only way the thermostat will see the moving hot water..they said if I was bypassing the heater core to use a hose loop on it ..

[ACII]

that makes even more sense compared to my conclusion ...according to the fact how the water pump is build and the T-State is located.

I just read some stuff on the internet ...u can find a lot treats for recommending blocking , but also for U - bending.

i will give it a try with the U Bend Hose.....makes definitly more sense for me.

Maybe i will install a plug valve within the U Bend ...so i can individually control the water flow :-)

Will keep u updated tomorrow....

Thx
Achim

Originally Posted by mongocanfly

I don't know it for a fact because i never tried it but.... I was told not to block off the heater hoses fittings..they said its the only way the thermostat will see the moving hot water..they said if I was bypassing the heater core to use a hose loop on it ..

[solidaxel]

If you have enough hose make it higher than the radiator cap and put your valve in the highest location for "bleeding"

[ACII]

Hy

The U-Bend hose is installed :-)

After the first test drive everything seems to be fine :-)

Thanks for ur help

regards
Achim

[mongocanfly]

Good to hear that fixed your problem...now drive the wheels off it..