Running warm, almost hot

levirolla

New Member
May 2, 2008
127
0
0
Winston-Salem
Well driving down the highway and I see my temp guage start to hover around the middle. So I got to the store and see that my upper radiator hose is bulging with pressure. I put a new hose on and the temp was normal for a while then started to hover up again. There is no sign of BHG, not loosing coolent, no milky oil, no burning of nothing, no power loss, no smell. Ever since i got the car when I didn't let it warm up sometimes the temp would go up to the middle then drop to normal. To me i'm convinced its the thermostat not opening up.
Any advice on what else could cause this is appreciated.
 

TurboStreetCar

Formerly Nosechunks
Feb 25, 2006
2,777
6
38
Long Island, Ny
Middle of the gauge is most likely normal, i have a separate gauge so i never really payed attention to stock.

Hows your radiator cap? Check level of overflow cold and hot, any hoses collapse when cold?
 

SupraMario

I think it was the google
Mar 30, 2005
3,467
6
38
38
The Farm
nosechunks;1417832 said:
Middle of the gauge is most likely normal, i have a separate gauge so i never really payed attention to stock.

Hows your radiator cap? Check level of overflow cold and hot, any hoses collapse when cold?

The stock gauge is pretty accurate, and he has said the damn hose is bulging...AKA something is stopping the flow.
 

TurboStreetCar

Formerly Nosechunks
Feb 25, 2006
2,777
6
38
Long Island, Ny
I would HIGHLY doubt the water pump could create pressure in the cooling system, if that were true when the engine was cold (thermostat closed) it would bulge hoses.

Problem is pressure, caused by either a bad radiator cap, or if the thermostat is sticking and the coolant is beginning to boil. Though if the thermostat was sticking causing the coolant to boil the radiator cap should release the pressure to the overflow keeping the cooling system to the proper pressure.

As per TSRM radiator cap relief is 8.5 psi.
 

toyotanos

What will we break today?
Staff member
Super Moderator
Nov 29, 2008
2,841
2
38
Coon Rapids, MN
Chunks is right, the water pump can't "create" pressure in the cooling system, it merely makes a pressure differential that moves the water through the coolant passegeways.

Skim's got the right idea- t-stat&gasket, rad cap, then see where you're at then. Might as well flush the cooling system out while you're at it, too.
 

TurboStreetCar

Formerly Nosechunks
Feb 25, 2006
2,777
6
38
Long Island, Ny
SupraMario;1417840 said:
The stock gauge is pretty accurate, and he has said the damn hose is bulging...AKA something is stopping the flow.

SupraMario;1417873 said:
Who said anything about the water pump in here?

You said "Something is stopping the flow", Does the water pump not create "flow" in the cooling system?

Would that not mean that you are suggesting that the hose is bulging due to pressure build up because the thermostat is stopping the flow that is created by the water pump?

I figured that was what you were implying because you mentioned replacing the thermostat, then mentioned something stopping flow.

Maybe im lost as this is what i thought you were saying.
 

SupraMario

I think it was the google
Mar 30, 2005
3,467
6
38
38
The Farm
nosechunks;1417879 said:
You said "Something is stopping the flow", Does the water pump not create "flow" in the cooling system?

Would that not mean that you are suggesting that the hose is bulging due to pressure build up because the thermostat is stopping the flow that is created by the water pump?

I figured that was what you were implying because you mentioned replacing the thermostat, then mentioned something stopping flow.

Maybe im lost as this is what i thought you were saying.

Negatory. LOL, The cooling system does flow, but not enough to create a bulge, like you were saying. I was refering to the pressure build up from the water basically boiling from the T-stat not opening and allowing the system to work properly by flowing, heat rises, so I'm assuming the steam at this point has no where to go so its taking the easiest way out, which should be the over flow, but if the hose is bulging then something is blocking pretty much every exit. Then again his words for "bulge" could be just normal hose pressure, and its just the cap or t-stat like stated before.

I should have been more specific.
 

TurboStreetCar

Formerly Nosechunks
Feb 25, 2006
2,777
6
38
Long Island, Ny
SupraMario;1417886 said:
Negatory. LOL, The cooling system does flow, but not enough to create a bulge, like you were saying. I was refering to the pressure build up from the water basically boiling from the T-stat not opening and allowing the system to work properly by flowing, heat rises, so I'm assuming the steam at this point has no where to go so its taking the easiest way out, which should be the over flow, but if the hose is bulging then something is blocking pretty much every exit. Then again his words for "bulge" could be just normal hose pressure, and its just the cap or t-stat like stated before.

I should have been more specific.

No worries, IIRC the stock gauge doesn't have temperature on it, only a "H" and "L", or something to that effect depending on Pre or Post 89. I would imagine the middle of the gauge is normal operating temperature, if thats the case, i really only see the issue of the bulging hose, witch would be improper pressure regulation of the radiator cap. Though like you said the bulging could be normal swell.

Of course this is assuming the middle of the gauge is normal operating temperature, as i said i have a separate gauge for that so i never payed attention to my stocker while driving.
 

levirolla

New Member
May 2, 2008
127
0
0
Winston-Salem
ok. I took the radiator cap off and put in back on and let it run until it the heat started to rise up and shut it off. FINALLY it shot coolent out the overflow tank and I could clearly here the pressure going through the cap and shut. I think it could be the cap. BEFORE I TOOK THE CAP OFF IT WAS NOT OVERFLOWING, JUST BUILDING PRESSURE ON THE UPPER HOSE AND IT AS IF IT WAS ABOUT TO POP. After this episode I drove it about an hour last night and it did fine. Drove it this morning and the temp rose a bit then was fine. I'm going to get a new cap and thermostat and see what happens
 

SupraMario

I think it was the google
Mar 30, 2005
3,467
6
38
38
The Farm
levirolla;1418029 said:
ok. I took the radiator cap off and put in back on and let it run until it the heat started to rise up and shut it off. FINALLY it shot coolent out the overflow tank and I could clearly here the pressure going through the cap and shut. I think it could be the cap. BEFORE I TOOK THE CAP OFF IT WAS NOT OVERFLOWING, JUST BUILDING PRESSURE ON THE UPPER HOSE AND IT AS IF IT WAS ABOUT TO POP. After this episode I drove it about an hour last night and it did fine. Drove it this morning and the temp rose a bit then was fine. I'm going to get a new cap and thermostat and see what happens

Better safe than sorry, replace the cap and T-stat before you drive it again.

Also Make sure the over flow has coolant in it. The system is designed to use that to remove air. I've never seen my temp gauge hit half way, always was like a little bit lower than half and when the t-stat opened it would drop down even more.