6.0 overheats at idle
I would be willing to bet you still have a air pocket in there a very common on first fire up jack up the front of the car up so the radiator cap is the highest point of the car and while the car is running and the thermostat opens,cap off the radiator and use a shop vacuum and cup your hand around the neck and the vac.controling the amount of vacuum with your hand suck the access air out of the system NOT the coolant and you will be golden.
I will crack the front two coolant crossover plugs while the car is running to get the air out. I had this exact issue, and it got all the air out the system and the car stopped overheating.
This was after I did head gaskets on the car.
This was after I did head gaskets on the car.
Before you built this engine did the old combo run cool or normal? What on the cooling system changed? If nothing then that means the engine is creating more heat... why would it? Ive seen clearances too tight do this... but that would be evident in the oil (sparkly). Before putting any money into the cooling system if it worked fine before I would add a little more fuel and adjust the timing. Timing could also make it run hot at idle and cruise.
Make sure you dident flip the headgaskets. I had heads and cam 04 corvette built by the owner that ran hot at idle. I have a force filler/bleeder. One thing that tip me off was the steam vent in the back of the head was dry. I pulled the heads and bam the head gasket where backwards. These where gm mls also.
If you are running a factory water pump and thermostat , and you plug the heater hose connections instead of looping them, you are creating this problem.
look close at the thermostat location in the water pump , it cannot 'see' hot coolant with the heater hoses blocked until the engine is already too hot. This causes it to overheat. The thermostat needs the looped flow from the heater hoses to 'see' engine heat, in order for it to open
look close at the thermostat location in the water pump , it cannot 'see' hot coolant with the heater hoses blocked until the engine is already too hot. This causes it to overheat. The thermostat needs the looped flow from the heater hoses to 'see' engine heat, in order for it to open
If you don't have the heater hoses looped that will cause it. One thing no one mention is Harmonic balancer! I have a under drive balancer25% on my engine, and it cause the water pump to turn to slow at idle, water is not moving much at idle. Once I give it gas temp drops right away! I just don't let it idle much, and if I get stopped for a while I just rev it to 1800, until I get rolling!
The stock thermostat bypasses when closed. I have two stock ones. One has 4 .100" holes for bypass, the other has steps where it meets the housing in the back to allow bypass.
Might have a look at your thermostat setup. Sounds funky with the modified housing you are using???
I just plugged my heater hose outlets. Today. As a safety measure, I drilled an additional hole in the WP housing for more bypass.
Would be very interesting to see what the heater valve actually looks like. If the hoses really must be looped, that valve must create a loop when the heater is off.
It's an interesting deal, others have reported no issues with the outlets blocked off. I guess I'll find out in about 3 months....when my car runs.
Ron
Might have a look at your thermostat setup. Sounds funky with the modified housing you are using???
I just plugged my heater hose outlets. Today. As a safety measure, I drilled an additional hole in the WP housing for more bypass.
Would be very interesting to see what the heater valve actually looks like. If the hoses really must be looped, that valve must create a loop when the heater is off.
It's an interesting deal, others have reported no issues with the outlets blocked off. I guess I'll find out in about 3 months....when my car runs.
Ron
I would be willing to bet you still have a air pocket in there a very common on first fire up jack up the front of the car up so the radiator cap is the highest point of the car and while the car is running and the thermostat opens,cap off the radiator and use a shop vacuum and cup your hand around the neck and the vac.controling the amount of vacuum with your hand suck the access air out of the system NOT the coolant and you will be golden.
Before you built this engine did the old combo run cool or normal? What on the cooling system changed? If nothing then that means the engine is creating more heat... why would it? Ive seen clearances too tight do this... but that would be evident in the oil (sparkly). Before putting any money into the cooling system if it worked fine before I would add a little more fuel and adjust the timing. Timing could also make it run hot at idle and cruise.
I was finally able to tear it apart and snap a few pics.
modified CSR housing
bypass end of 160* mr gasket stat
stat sitting flushing in CSR housing
approx. 1/4" compression of bypass valve into WP housing
stat view through CSR housing inlet
plugged heater ports
steam vent fitting into WP outlet
I've also modified the pump as RonSSNova posted and will give this a try. I have everything put back together but haven't had time to test it again. Hopefully this weekend i'll have some feedback.
modified CSR housing
bypass end of 160* mr gasket stat
stat sitting flushing in CSR housing
approx. 1/4" compression of bypass valve into WP housing
stat view through CSR housing inlet
plugged heater ports
steam vent fitting into WP outlet
I've also modified the pump as RonSSNova posted and will give this a try. I have everything put back together but haven't had time to test it again. Hopefully this weekend i'll have some feedback.
I know you have it back together. One thing I notice from the pics is the height the therm sticks out of the WP housing. Mine is more like 1/8". Would have been interesting to compare that therm height with the stock one.
Let us know how it works.
Let us know how it works.
One thing i didn't see asked is if your radiator cap the highest point in the system?
Also food for thought; With the cap off water will boil at 212 at atmospheric pressure, add 20 pounds to that with the cap on and it will boil at 258 or so.
Also food for thought; With the cap off water will boil at 212 at atmospheric pressure, add 20 pounds to that with the cap on and it will boil at 258 or so.
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Verdad Gallardo Well guys I have some good news. I have the car all back together and took a for a drive earlier today. With the mod done to the WP as RonSSNova suggested, newly burped coolant system, and only 1 pusher fan (mounting hardware zip tie things broke and couldn't mount the other one up), the motor ran around 205 while cruising and maxxed at 225 when sitting at a light but pretty sure the other fan would have helped here.
i'll get the other fan mounted up and see how it helps. I feel a lot better about it now and have a better place to start for when I can start driving it around more regularly.
Thanks for everyone's help and suggestions
i'll get the other fan mounted up and see how it helps. I feel a lot better about it now and have a better place to start for when I can start driving it around more regularly.
Thanks for everyone's help and suggestions
Hey, good news. Huge improvement from where you were.
Which temp sensor are you reading?
What was the air temp outside?
As far as it running at thermostat temp. It will only do that if the entire cooling system can support it. Radiator size and airflow.
The vette guys have this argument all the time. Blah blah blah...:-). They will also argue that anything other than the stock 197 deg unit will ruin the engine.
I do think that mr gasket thermo fits odd. The 160 I bought is from SLP and fit like the stocker.
It will be awhile before mine runs. The radiator I have cooled the rat motor almost too well.
Ron
Which temp sensor are you reading?
What was the air temp outside?
As far as it running at thermostat temp. It will only do that if the entire cooling system can support it. Radiator size and airflow.
The vette guys have this argument all the time. Blah blah blah...:-). They will also argue that anything other than the stock 197 deg unit will ruin the engine.
I do think that mr gasket thermo fits odd. The 160 I bought is from SLP and fit like the stocker.
It will be awhile before mine runs. The radiator I have cooled the rat motor almost too well.
Ron
Hey, good news. Huge improvement from where you were.
Which temp sensor are you reading?
What was the air temp outside?
As far as it running at thermostat temp. It will only do that if the entire cooling system can support it. Radiator size and airflow.
The vette guys have this argument all the time. Blah blah blah...:-). They will also argue that anything other than the stock 197 deg unit will ruin the engine.
I do think that mr gasket thermo fits odd. The 160 I bought is from SLP and fit like the stocker.
It will be awhile before mine runs. The radiator I have cooled the rat motor almost too well.
Ron
Which temp sensor are you reading?
What was the air temp outside?
As far as it running at thermostat temp. It will only do that if the entire cooling system can support it. Radiator size and airflow.
The vette guys have this argument all the time. Blah blah blah...:-). They will also argue that anything other than the stock 197 deg unit will ruin the engine.
I do think that mr gasket thermo fits odd. The 160 I bought is from SLP and fit like the stocker.
It will be awhile before mine runs. The radiator I have cooled the rat motor almost too well.
Ron
i'm reading the temp sensor in the driver's head.
It was a nice day out when I drove, I don't recall exactly but I think it was in the mid 60's.
Yeah, it basically acts like the looped heater ports to allow for additional flow.
