Overheating in my daily driver.
make sure your mix is 50/50 or close to that first.
Start without radiator cap on, wait for the stat to open and fill to normal.
I wouldn't have used that truck tank..just a normal overflow would've worked. That and the hose is on the wrong spot, should be on the upper one. Cap the lower one.
Start without radiator cap on, wait for the stat to open and fill to normal.
I wouldn't have used that truck tank..just a normal overflow would've worked. That and the hose is on the wrong spot, should be on the upper one. Cap the lower one.
TECH Regular
Joined: Jan 2010
Posts: 497
Likes: 4
What condition is the stock LS1 radiator in? Why not upgrade to a dual row radiator. They are like 150 from summit. im running a griffin and in 115 deg heat with ac on full blast in traffic up a hill, my car still has not gotten above 210deg. Normal temp 180 with ac on.
I agree with the merv, get rid of the surge tank and just hook the two Radiator hoses up to the radiator. I saw where you were on another site and said you have two radiator caps, one on the radiator and one on the surge tank. I could see where that couls cause issues, although I've never tried it personally. When you say its overheating, is it actually boiling over? What temperature are you getting to?
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Brett Foote Get rid of the surge tank completely and put a normal vented overflow in there. Then hook the line up for it in the correct spot.
Properly burp the system and have the correct mix, and you will be fine. If something is wrong that is when you will see it.
Properly burp the system and have the correct mix, and you will be fine. If something is wrong that is when you will see it.
By passed the tank and purged the system again. Still over heats.... The faster I go over 60 mph increases temps to 240 and up. Used scan tool to to verify. Driving slow speeds it does not seem to overheat as fast.
Did you have the heads off of it when you did the swap? I had a similar issue when I had to replace my lifters, wasn't paying attention and put the passenger side head gasket in backwards.
Try pulling one of the steam line vents as you fill the system. That is a better way of getting all the air out than trying to fill it through the top radiator hose. Also jack up the front end of the car as you fill it. Try to get the radiator cap to be the highest point.
If that is good, then there are probably a dozen or so things not related to the coolant that could be causing it to over heat. The fan is what cools the car when it is not moving. What type of fan do you have and is it well shrouded?
When you are moving, the fan shouldn't need to run. Can the air make it past the fan when it is off, or does the shroud block air flow? Make sure the air has an unobstructed path through (not around) the radiator. Some cars need a chin pan under the back of the radiator to prevent turbulence and smooth air flow through the radiator.
How old is the radiator? Maybe you need to take it in and have it flushed by a radiator shop.
Another thing I have read about multiple times is the lower radiator hose collapsing shut when the engine is reving a bit. Is there a spring inside the water pump intake hose to keep it from being sucked shut by the water pump?
If that is good, then there are probably a dozen or so things not related to the coolant that could be causing it to over heat. The fan is what cools the car when it is not moving. What type of fan do you have and is it well shrouded?
When you are moving, the fan shouldn't need to run. Can the air make it past the fan when it is off, or does the shroud block air flow? Make sure the air has an unobstructed path through (not around) the radiator. Some cars need a chin pan under the back of the radiator to prevent turbulence and smooth air flow through the radiator.
How old is the radiator? Maybe you need to take it in and have it flushed by a radiator shop.
Another thing I have read about multiple times is the lower radiator hose collapsing shut when the engine is reving a bit. Is there a spring inside the water pump intake hose to keep it from being sucked shut by the water pump?
Any chance the radiator is plugged up? Was it a new radiator at the time of the swap, or just something you had or used? I wouldn't be at all surprised if the radiator was gummed up with years old dex-cool funk. With it taking 25-30 minutes to reach critical temperature, it just doesn't sound to me like a blown headgasket. Usually things would go south quicker than that. Especially if the radiator itself was cool to the touch where the fans were pulling from. A CO test would quickly tell. Basically they put some special die in the coolant system and it comes in contact with Carbon monoxide ( a byproduct of combustion), it means you have a leaking head gasket. Napa would probably have the kit.
One problem is that you can't get the air out because the motor is higher than radiator. You stated that when you take off upper hose it will leak coolant. They make a tool to fill radiators and burp them. It is a bowl or funnel style tool that goes on radiator cap that should put it higher than the motor. It cost about $30 dollars. More expensive would be a vacuum bleeder that will definately get it done but more dinero. It is odd that it overheats faster at highway speeds when it is less load on motor. I agree with merv about coolant. After all that said though, go buy a smoke detector which will test for blown headgasket. You are chasing all these theories but you should just buy the combustion detector and work backwards from there. Rule out the worst case scenario.
Back in the old old days I had a 63 Valiant Convertible with the slanted six and the push button automatic. (I wonder how many people remember that.) It would constantly over heat. I checked the fluid levels, burp the system, found no leaks, no nothing. Caulked it up to just a car that overheated a lot. Drove the car 75K miles that way. Then an old mechanic of way back, said to replace the water pump. I said it wasn’t leaking around the seal, I took out the thermostat, argued with him and all that stuff. The old man said replace the pump and he walked away. Well eventually I did and low and behold I found the impeller was spinning freely on the water pump shaft. I got an additional 100K miles on that slant 6. Just my 2 Cents.
Teching In
Joined: Jun 2012
Posts: 42
Likes: 0
From: Nebraska
I had this problem on my 2000 5.3 as there was a huge air pocket in the intake manifold.
I took a funnel and taped a rubber hose to the end of it. Popped off the rubber piece that runs from the steam tube to the throttle body and poured coolant into the steam tube. I think I used an entire gallon. Just keep letting it gargle and burp itself..pouring more and more water in. You could literally sit there for an hour like I did.
After that I went out and drove it and it rarely gets over 190* unless its hot out!
I took a funnel and taped a rubber hose to the end of it. Popped off the rubber piece that runs from the steam tube to the throttle body and poured coolant into the steam tube. I think I used an entire gallon. Just keep letting it gargle and burp itself..pouring more and more water in. You could literally sit there for an hour like I did.
After that I went out and drove it and it rarely gets over 190* unless its hot out!
I had this problem on my 2000 5.3 as there was a huge air pocket in the intake manifold.
I took a funnel and taped a rubber hose to the end of it. Popped off the rubber piece that runs from the steam tube to the throttle body and poured coolant into the steam tube. I think I used an entire gallon. Just keep letting it gargle and burp itself..pouring more and more water in. You could literally sit there for an hour like I did.
After that I went out and drove it and it rarely gets over 190* unless its hot out!
I took a funnel and taped a rubber hose to the end of it. Popped off the rubber piece that runs from the steam tube to the throttle body and poured coolant into the steam tube. I think I used an entire gallon. Just keep letting it gargle and burp itself..pouring more and more water in. You could literally sit there for an hour like I did.
After that I went out and drove it and it rarely gets over 190* unless its hot out!
Pulling a steam tube cap helps drain the radiator in like half a minute.