upper hose hot, lower hose cold [Archive] - Chevelle Tech

: upper hose hot, lower hose cold


curley8788
Feb 5th, 08, 6:12 PM
my upper radiator hose gets hot and is pressurized once my thermostat opens. the drivers side of the radiator is also warm/hot. when i feel the lower radiator hose, it is cold but its somewhat pressurized. the passenger side of the radiator is cold too.

i am thinking it is clogged? i dont know how, because it was working fine a few days ago. now all of the sudden my engine heats up to 215 degrees and i have a 180 thermostat. i dont like that at all.

any thoughts? i am planning on flushing the radiator to see what happens.

curley8788
Feb 5th, 08, 6:18 PM
oh and my heater hoses are hot and the heater works fine too.

furball8994
Feb 5th, 08, 6:24 PM
So you are saying that the inlet side of your Radiator is hot and the outlet side of your Radiator is cold. Isn't that the way its supposed to work? :D


On a more serious note. Remove your Rad. cap. Run your engine until the stat opens and see if you have good cross flow.

Did you change anything in your cooling system. You may have an air pocket.

Where is your temp. gauge mounted? If its in the head, It will read hotter than in the intake.

novaderrik
Feb 5th, 08, 8:28 PM
215 aint nothing- as long as you have a good pressure cap, it won't boil over until about 230.
thats assuming, of course, that your gauge is accurate. if it doesn't boil over and run like crap, won't worry about it.

curley8788
Feb 5th, 08, 9:28 PM
yeah the gauge is in the intake manifold. also, i did have to take off the power steering pump and i have custom brackets so the bolts go into the water pump. it caused it to leak like crazy so i refilled it after i was done...

i will burp the system tonight and let you know if i see the coolant moving...

it normally runs at 185-190... i dont get it.

curley8788
Feb 6th, 08, 3:36 PM
bump

curley8788
Feb 6th, 08, 5:31 PM
when i squeeze the lower radiator hose, the coolant rises. like i said though, no heat from the lower hose though. i get heat on the drivers side of the radiator and it gets colder as i go down and towards the passenger's side... i realize that that is what's supposed to happen, but im running 30 degrees above normal now...

any help is greatly appreciated... i will continue to search for people with similar problems.

onovakind67
Feb 6th, 08, 8:51 PM
Sounds like you have a low flow problem. In order to cool the engine the radiator must achieve a certain average temperature in order to dissipate the heat. If you slow the flow so the outlet temperature drops, the inlet temperature will have to be raised to maintain the same heat rejection.

curley8788
Feb 6th, 08, 10:12 PM
Sounds like you have a low flow problem. In order to cool the engine the radiator must achieve a certain average temperature in order to dissipate the heat. If you slow the flow so the outlet temperature drops, the inlet temperature will have to be raised to maintain the same heat rejection.

so what the heck am i supposed to do? i really doubt that because everything was working perfect, and then i replaced my loose belts with tighter ones and now it has this problem. im going to run it with no thermostat and see what i get... i will keep you all updated...

aukai
Feb 6th, 08, 11:32 PM
I had a cooling problem once and it drove me crazy it turned out to be the stamped steel impeller sheared off of the shaft it cooled by thermal circulation till I found it.

curley8788
Feb 6th, 08, 11:56 PM
guess what? it was just a thermostat stuck in the half way open position! im going to buy a new one tomorrow...

aukai
Feb 7th, 08, 1:39 AM
On the road again:thumbsup:

curley8788
Feb 7th, 08, 8:10 PM
update:

put a new stant thermostat in. refilled and burped the coolant... took the car out for a drive and it was overheating even worse... 230-235 degrees after driving for a few blocks. so i hurried home and shut it down. now the upper radiator hose feels cold!:mad:

tomorrow im going to run without a thermostat and see what happens. what a pain it the a** this is turning out to be!:(

Chevl_Steve
Feb 7th, 08, 8:29 PM
Take the thermostat back out, put it in a pan of water on the stove. Put in a thermometer and watch as the heat goes up. Verify the temp it opens.

Some guys drill a small hole in the thermostat to help burp air bubbles. I'm not sure if that works or not.

Did the timing change recently? You said something about tighter belts?

What kind of fan are you using on the radiator?

curley8788
Feb 7th, 08, 8:38 PM
Take the thermostat back out, put it in a pan of water on the stove. Put in a thermometer and watch as the heat goes up. Verify the temp it opens.

Some guys drill a small hole in the thermostat to help burp air bubbles. I'm not sure if that works or not.

Did the timing change recently? You said something about tighter belts?

What kind of fan are you using on the radiator?

yeah i test pretty much every thermostat i get sooner or later...this new one is going to be tested tomorrow.

drilling the little hole is unnecessary, so im not going to do that.

actually the timing did not change, i just set it weeks ago.

yes i did change my power steering belt and my alternator belt because they were WAYYY too loose.

i am using a 17 or 18 inch flex fan inside of the stock radiator shroud. it cooled fine a week or so ago... i think it may be clogged with some leaf bits or something because when i took the "old" thermostat out, it had pieces of leaves stuck in it.

running the car with no thermostat will ultimately tell me what's going on...

onovakind67
Feb 7th, 08, 9:54 PM
Did you put the new thermostat in correctly?

curley8788
Feb 7th, 08, 10:20 PM
Did you put the new thermostat in correctly?

lol i think that statement is beginning to insult my intelligence, nova. ;)

but to answer your question: yes.

Philip
Feb 7th, 08, 11:06 PM
Try a Robertshaw type thermostat, it is also marketed by Mr. Gasket.

http://i80.photobucket.com/albums/j199/64elcamino/thermostat1.jpg

http://i80.photobucket.com/albums/j199/64elcamino/thermostat2.jpg

http://i80.photobucket.com/albums/j199/64elcamino/thermostat3.jpg

curley8788
Feb 7th, 08, 11:21 PM
actually i had that same type thermostat for my first 2... my new one is the standard stant 180... ill figure it out tomorrow.

onovakind67
Feb 8th, 08, 8:54 AM
lol i think that statement is beginning to insult my intelligence, nova. ;)

but to answer your question: yes.


Your refusal to drill a small hole in the thermostat may be exacerbating your problems by inhibiting the flow of hot water towards the thermostat and allowing it to sense the engine heat in a timely fashion. There was a thread recently with a problem like this:

http://www.chevelles.com/forums/showthread.php?t=210274

curley8788
Feb 8th, 08, 2:36 PM
Your refusal to drill a small hole in the thermostat may be exacerbating your problems by inhibiting the flow of hot water towards the thermostat and allowing it to sense the engine heat in a timely fashion. There was a thread recently with a problem like this:

http://www.chevelles.com/forums/showthread.php?t=210274

hmm... i think that drilling a hole in the thermostat is undermining its purpose.:confused:

i will read the thread you suggested...

curley8788
Feb 8th, 08, 3:36 PM
I DONT GET IT! i ran the car with no thermostat, and it is fine. no blockages. i then put the thermostat in water and boiled it. the thermostat is working fine! once i put the thermostat in the car, it overheats again.

i am clueless. i was going to buy ANOTHER thermostat, but this will be my fourth one!!!!!!!:mad:

furball8994
Feb 8th, 08, 3:48 PM
Mike. Sounds like your having a flow issue. With the stat out, Your getting enough flow to keep it cool.
You stated that you found "leaves" in your old stat? They could me clogging your radiator.

Is your Rad a cross flow? (inlet on one side, outlet on the other) If so, Try this little trick. Remove your lower Rad hose. Stick a hose in the top and see if it fills faster than it runs out.

curley8788
Feb 8th, 08, 4:26 PM
Mike. Sounds like your having a flow issue. With the stat out, Your getting enough flow to keep it cool.
You stated that you found "leaves" in your old stat? They could me clogging your radiator.

Is your Rad a cross flow? (inlet on one side, outlet on the other) If so, Try this little trick. Remove your lower Rad hose. Stick a hose in the top and see if it fills faster than it runs out.

its the stock radiator that came in the car. my car was an AC car too. working on it now...

Rags66
Feb 8th, 08, 4:52 PM
I may have misse this in other posts but, what Psi. cap are you running?

curley8788
Feb 8th, 08, 4:57 PM
I may have misse this in other posts but, what Psi. cap are you running?

no you didnt miss it actually u are the first to ask. i am running a brand new 16 psi cap.

onovakind67
Feb 8th, 08, 5:11 PM
hmm... i think that drilling a hole in the thermostat is undermining its purpose.:confused:

i will read the thread you suggested...

Think about this: How does your thermostat get hot water to it to signal it to open?
If it is closed tight and no water is flowing by it, it will depend on radiant heat to warm it up and this could take several minutes. When guys are cognizant of an overheating problem, they don't wait several minutes for this to happen. If you drill a couple of small holes in the thermostat to promote a small flow around it, you will have hot water out to your thermostat much sooner than if there is no flow. This will cause the thermostat to open sooner and your engine won't get as hot.
The small flow of water around the thermostat will not undermine the purpose of the thermostat. Anytime you run your engine you will need coolant flow, so a thermostat that closes tight is actually less desirable than one that does not.
Before you go out and buy your next thermostat, drill a couple of small holes in the one you have and give it a try.