Running Hot

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QWKSLVR

QWKSLVR

Well-Known Member
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Location
Shediac N.B. Canada
Ever since I installed the 340 about six weeks ago I have had an overheating issue. A new thermostat ( 180 degree ) rad cap (16 lb) and the larger round top tank radiator were also installed. I have noticed that there is no pressure in the upper hose or rad after driving for 45 minutes. Temperature gauge stays about in the middle on the highway at 65 mph but as soon as I get in the city it keeps climbing. Last night after I got home from the cruise I could squeeze the hose easily and took off the cap with no release of air or water pressure. Tried it again tonight same thing. Anybody have any ideas ? Thanks Bobby
 
Are you running a shroud? Check and make sure your bottom rad hose isn't collapsing.
 
No shroud yet they are hard to find up here. Never checked the lower hose but it does have a spring in it so I doubt that it is collapsing. Thanks Bobby
 
QWKSLVR said:
No shroud yet they are hard to find up here. Never checked the lower hose but it does have a spring in it so I doubt that it is collapsing. Thanks Bobby
Click to expand...

I would have to guess a shroud would help. At lower speeds and at idle your probably not pulling enough air through the radiator.

Spring in the bottom hose, you should be good to go there.
 
I was one of those who thought a shroud wasn't a big deal. I have since changed my mind on that. It directs the air directly on the engine instead of spreading all over in the engine bay. A shroud works going down the road as well as sitting in the driveway!

I would recommend an external temperature gauge so that you can see exactly what temp you are at. In this type weather with high temperatures a engine temp of 210 degrees is normal in stop and go traffic. Especially if the engine is "built". I don't like that kind of temp and surely wouldn't want it to go over or stay that temp for a long period of time. Make sure the engine isn't running lean. How does it do going down the interstate? Does it run hot like loosing fluid out on the road?
 
mullinax95 said:
It directs the air directly on the engine instead of spreading all over in the engine bay. A shroud works going down the road as well as sitting in the driveway!
Click to expand...

That's not why a shroud works.
Just sayin,
It pulls the air better because the fan is surrounded, AND uses the entire core area to pull air through instead of just where the fan is.

Not trying to step on ya man, just the way it is.
 
Engine runs great, not running lean if anything a little rich, just a cooling issue. I understand a shroud would be a big help in cooling it but why isn't there any pressure in the system? Thanks for the replys. Bobby
 
TrailBeast said:
That's not why a shroud works.
Just sayin,
It pulls the air better because the fan is surrounded, AND uses the entire core area to pull air through instead of just where the fan is.

Not trying to step on ya man, just the way it is.
Click to expand...

Actually it's all of the above wouldn't say? I didn't want to get all technical. I've read what I stated online somewhere. I mean you really would have to be an idiot not to think the air isn't coming through the radiator core and blowing on the engine. lol
 
Have you chked for pressure when it's hot?
I didn't notice anywhere where you said you did.
Other than that, maybe a bad spring in the overflow return cap???
(That little disk in the center of the rubber)
Or the temp is nowhere near what you think it is.
 
QWKSLVR said:
Engine runs great, not running lean if anything a little rich, just a cooling issue. I understand a shroud would be a big help in cooling it but why isn't there any pressure in the system? Thanks for the replys. Bobby
Click to expand...

Huh no pressure! I looked right over that. Did you install a "fail safe thermostat"? I put one in and it stayed open on me! Just throwing something out there. Not sure if pressure would build with it stuck open. The way I noticed mine is I didn't have any heat and the temp gauge was low. (Dodge Ram)
 
mullinax95 said:
I mean you really would have to be an idiot not to think the air isn't coming through the radiator core and blowing on the engine. lol
Click to expand...

Oh no, it is coming through the rad and blowing on the engine.
Just makes next to zero difference.

After it goes through the core you could blow it at the ground and it wouldn't matter a bit.

That not and isn't thing you posted messed with me.
 
I would say you have a leak if no pressure when its hot,
 
Your upper hose should be pressurized when your up to temp. Sounds like you still have air in the system. Take the rad cap off,turn the heater on,and start the car. You thermostat should open around 180,in which you should see water flow. Let it idle for awhile,letting air out.I also like to squeeze the upper hose in and out during this process.
Eventually all the air will come out of the system.

Your water level should be just obove the top row of fins,before you start. Not all the way to the top of the rad.

Cooling tip of the Day:
Its summer time. Ditch the 50/50 percent antifreeze/water method.
Go to a 70/20 or even 80/10 water/antifreeze mix.

In the winter I use 50/50,so here is what I do in the summer.
Drain the radiator completely.
Add straight Distilled water with some Redline Water Wetter.Between the coolant in the block,you will have a nice mixture. You will be amazed at how much cooler your car runs like this. Mine went from 210 in the summer to 195. Nice !!
 
It seems as though your cooling system has more than one problem going on at the same time. The fact that it heats up with less air flow and cools down when it's on the highway shows there is an airflow problem through the radiator. The fact that there is no pressure in the system indicates the system is not tight. Your cap might be relieving the pressure. Use a coolant system pressure tester to make sure your system can hold 16 psi. Do you have a catch tank that is vented to atmosphere connected to the cap vent port? This could be where the pressure is bleeding to. Also to check your t'stat and to make sure it opens at 180, remove it, put it in a pot of water and heat it to 180. you should see it open if the water in the pot is shallow enough. I've seen brand new t'stats work incorrectly. Hope it helps.
 
I agree that something sounds strange. Why do you say it runs hot? Has it boiled over? Are you judging "hot" just by what the temperature gage indicates? If so, try a thermometer in the coolant after you stop.

I don't see how it can be hot and not build pressure in the hose unless you have a really big leak, and then you should see a lot of water or steam. Usually, with a pinhole leak, like in a heater hose, after you lose enough coolant the rest gets real hot and the cap blows.
 
I gotta call BS on some of this.
The radiator will fill it'self to the top even if you don't because of the return from the overflow tank will keep adding to it everytime it cools down.
And I doubt he's running warm and hasn't chked the coolant.
The rest is good.

Johnny Dart said:
Your upper hose should be pressurized when your up to temp. Sounds like you still have air in the system. Take the rad cap off,turn the heater on,and start the car. You thermostat should open around 180,in which you should see water flow. Let it idle for awhile,letting air out.I also like to squeeze the upper hose in and out during this process.
Eventually all the air will come out of the system.

Your water level should be just obove the top row of fins,before you start. Not all the way to the top of the rad.

Cooling tip of the Day:
Its summer time. Ditch the 50/50 percent antifreeze/water method.
Go to a 70/20 or even 80/10 water/antifreeze mix.

In the winter I use 50/50,so here is what I do in the summer.
Drain the radiator completely.
Add straight Distilled water with some Redline Water Wetter.Between the coolant in the block,you will have a nice mixture. You will be amazed at how much cooler your car runs like this. Mine went from 210 in the summer to 195. Nice !!
Click to expand...
 
TrailBeast said:
I gotta call BS on some of this.
The radiator will fill it'self to the top even if you don't because of the return from the overflow tank will keep adding to it everytime it cools down.
And I doubt he's running warm and hasn't chked the coolant.
The rest is good.
Click to expand...

Which part dont you agree with ?
Sounds as though you are talking about a "Closed Cooling System" with a recovery tank,which (I'm guessing) 9 out of 10 cars on this site "dont" have.Im assuming the OP does not have a CCS.
The proper way to fill a radiator without a CCS,is just above the top row of fins. The top portion of the radiator is for expansion.
 
There is no pressure in the system when it is hot. I used a Gates thermostat and rad cap that I suppose could be defective. There are no leaks.I say it runs hot because the gauge climbs above 3/4 mark and will over flow out the hose on the side of the neck. I am not using an over flow tank. I am going to borrow a laser thermal gun ( I think thats what you call it ) and check it to see exactly how hot it runs. Thanks to everyone. Bobby
 
Johnny Dart said:
Which part dont you agree with ?
Sounds as though you are talking about a "Closed Cooling System" with a recovery tank,which (I'm guessing) 9 out of 10 cars on this site "dont" have.Im assuming the OP does not have a CCS.
The proper way to fill a radiator without a CCS,is just above the top row of fins. The top portion of the radiator is for expansion.
Click to expand...

You are right about the closed system.
I was thinking recover system, which also makes my "recovery valve spring in the rad cap pointless.
Sorry, My bad.:D

I don't like leaving air gaps in the radiator because at higher RPM's it will aerate the coolant. (The waterpump WILL suck it down) But I guess thats just personal oppinion.
 
Have you chked the oil lately?
If you have zero coolant system pressure when it's getting hot something is definitely up.
That coolant is going somewhere.
Have you had to keep putting coolant in it all along also?
 
QWKSLVR said:
There is no pressure in the system when it is hot.
Click to expand...

if you have a completely closed air tight cooling system, you are definitely loosing pressure somewhere else as TB has said. there a number of other places it can loose pressure

TrailBeast said:
Have you chked the oil lately?
If you have zero coolant system pressure when it's getting hot something is definitely up.
That coolant is going somewhere.
Have you had to keep putting coolant in it all along also?
Click to expand...

also , is it puffing any white smoke , or is there a continual condensation in your exhaust pipes?
 
TrailBeast said:
You are right about the closed system.
I was thinking recover system, which also makes my "recovery valve spring in the rad cap pointless.
Sorry, My bad.:D

I don't like leaving air gaps in the radiator because at higher RPM's it will aerate the coolant. (The waterpump WILL suck it down) But I guess thats just personal oppinion.
Click to expand...

In a normal system,the top part of the radiator is called an expansion tank.
The purpose of the tank is to provide space for the Coolant to expand when it gets hot. If you fill the tank to the top of the neck,it will have nowhere to expand when it gets hot,except out the overflow hose and onto the ground.

Not trying to pick a fight,but the proper level of coolant is just above the top row of cooling fins. If you really want to get the absolute most coolant in your radiator,fill it to the top and let the coolant puke out the overflow hose onto the ground.
Keep driving the car,and eventually it will stop,and theres your level.
 
Or is there chocolate milkshake on the underside of your oil filler cap?

Or are we just chasing our tails around needing the shroud?

He did say it runs fine out on the open road, so how could he sustain any type of hiway speeds if it's leaking somewhere bad enough to overheat at low speeds?
WTH?

No system pressure and hi temps makes no sence at all.
 
Exactly.
That's why I like to let it purge what it does'nt need instead of possibly cutting it short from the start.

Somebody's in a fight? Who, where?:D



Johnny Dart said:
In a normal system,the top part of the radiator is called an expansion tank.
The purpose of the tank is to provide space for the Coolant to expand when it gets hot. If you fill the tank to the top of the neck,it will have nowhere to expand when it gets hot,except out the overflow hose and onto the ground.

Not trying to pick a fight,but the proper level of coolant is just above the top row of cooling fins. If you really want to get the absolute most coolant in your radiator,fill it to the top and let the coolant puke out the overflow hose onto the ground.
Keep driving the car,and eventually it will stop,and theres your level.
Click to expand...
 
Johnny Dart said:
In a normal system,the top part of the radiator is called an expansion tank.
The purpose of the tank is to provide space for the Coolant to expand when it gets hot. If you fill the tank to the top of the neck,it will have nowhere to expand when it gets hot,except out the overflow hose and onto the ground.

Not trying to pick a fight,but the proper level of coolant is just above the top row of cooling fins. If you really want to get the absolute most coolant in your radiator,fill it to the top and let the coolant puke out the overflow hose onto the ground.
Keep driving the car,and eventually it will stop,and theres your level.
Click to expand...

TrailBeast said:
Exactly.
That's why I like to let it purge what it does'nt need instead of possibly cutting it short from the start.

Somebody's in a fight? Who, where?:D
Click to expand...


XS3 ....i fill it to the top and let the system decide . it will stop puking when it is happy with coolant level. and just to add, even with the 100+ degree days we have had, i still run 80% water and 20% coolant because i have seen some nasty rusty engines that have ran straight water for long periods of time. i have a fan shroud, a 7 blade fan ,26" 2 core radiator 180* thermostat , my fan sits 1" away from the radiator , i can sit all day in traffic. when i shut my car off after running for an hour or two, my top hose is rock hard (lol) and nothing leaks, not even a hiss.
 
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