Overheating Help
Overheating Help Trying to get some ideas from you guys and see if anyone has had similar issues. Its a forged ls2 with front mounted turbo. Running a radiator with the Meziere water pump. The pump works you can hear it kick on and running, but the car just doesn't stay cool. I think we got all the air out after switching the new pump, but not running a thermostat in the meziere pump now.
Has anyone had issues with the electric pump with no thermostat? Didn't think I would need it as more flow would have cooled better. Lemme know thoughts guys! Thanks
Has anyone had issues with the electric pump with no thermostat? Didn't think I would need it as more flow would have cooled better. Lemme know thoughts guys! Thanks
Thermo = restriction. Pressure plus a reasonable restriction =good. Pressure helps heat transfer from the engine to the fluid. Coolant that flows too fast has no time to pull heat. Put a thermo in.
No such thing as coolant moving too fast. Thermostats help an engine heat up, not cool down. Second, what's "doesn't stay cool"? Does it overheat (puke coolant out, out of control rising temps) or do the temps stabilize just higher than you'd like? Running hot during cruise is an air flow problem. Does the car have an overlfow tank? Did you fill it the first time you filled the system and let the system draw from it as it cooled? IMO that's the best way to eliminate air trapped in the system. Need more info on what's happening and when.
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Joined: Oct 2016
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From: PDX-OR-USA
Aside from all the other claims, one of the biggest benefits of running a wetting agent
is it helps transfer air out of the system into the radiator.
I've had several different versions of electric water pumps cavitate, and then they stop pumping,
in my experience,, you need a thermostat with a small bypass OR a variable speed pump drive.
They don't work as well with free flow. If you have the VFD pump drive, on most engines it
seems to help consistency to run a medium restriction disk in place of the stat. The placement of
the control stat for the pump in the system is critical to make them control the temperature well,
needs to be a spot that gets sort of a normalized temp, don't use ports on the head.
is it helps transfer air out of the system into the radiator.
I've had several different versions of electric water pumps cavitate, and then they stop pumping,
in my experience,, you need a thermostat with a small bypass OR a variable speed pump drive.
They don't work as well with free flow. If you have the VFD pump drive, on most engines it
seems to help consistency to run a medium restriction disk in place of the stat. The placement of
the control stat for the pump in the system is critical to make them control the temperature well,
needs to be a spot that gets sort of a normalized temp, don't use ports on the head.
This set up is almost identical with my car same radiator but my electric pump was the 35gpm and his is a 55gpm and also he still is running the heater hoses. I am thinking may be moving to fast but not 100% sure. Hoping the t stat helps as it’s a bit strange I’ll make an air damn.but my car never had one and it never got above 195 (water and water wetter mix)
here are both set ups
here are both set ups
His Set up LS2 Garrett 88mm Meziere 55gpm wp with heater hoses no stat Coolant water mix 205ish hot idle cruising will not go lower.....
My set up
dart 427 76mm
meziere wp 35gpm
water with water wetter mix no stat never got above 195idle or cruising, most of the time was in the 175-180ramge
no heater hoses on my set up
im thinking/hoping it's moving to fast as the set ups gave identical fans radiators and all around similar set ups I've done.
it was working decent with the stock pump idle around 210 cruise was about the same maybe around 200 but with the luck I had I guess we go at greedy.......I think we will try the stat first and go from there
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keep an eye on your timing. if it is to low idle or cruse it will create extra heat. I have raised the idle and low rpm timing on a car and dropped the coolant temps 15*
I have good luck with the idle timing in the 17 - 20 degrees and rise from there.
I have good luck with the idle timing in the 17 - 20 degrees and rise from there.
lol I just noticed that wasn’t in the top post. It got to almost 240 and we shut her down a few different times after trying to get all the air out. It’s definitely overheating......it wasn’t with the stock pump makes me believe it’s moving fast or we can’t get the damn air out. I have done all the tricks he will be trying a t stat today and crossing my fingers that works. If not I’ll go to trying a bigger wire direct key on power see if that helps. If it doesn’t the stock pump is going back on and we can come back to this next summer lol
definitely man I had it in the 14-15 range now is around 22-24 it’s on e85 also
We will see he’s trying a few things. Which build? The one below is the thread starters and I did some street tuning and she goes Lol we have barely touched the surface ran 3.9psi then added a little on top of the gate couldn’t get a full pull but it’s going to make some serious power for a full on street car. No cage right now so need to be “safe”
Zero reason an electric pump should cavitate. If you need to add additional restriction in the system to stop cavitation, your system needs attention to work it's best. Coolant passages offer more than enough restriction. Adding any additional restriction will lessen the efficiency. (thermo, washer, whatever) There is no such thing as coolant moving "to fast". Faster you can get it in and out of the heat exchanger the better it will cool, period.
In my experience 99% of the time it is air in the system or an inadequate fan/shroud combo.
Do you run a surge tank at the highest point? Is the radiator cap "open" and feeding the surge tank? If that i all done. jack the nose way up and burp it with a large funnel like so...
In my experience 99% of the time it is air in the system or an inadequate fan/shroud combo.
Do you run a surge tank at the highest point? Is the radiator cap "open" and feeding the surge tank? If that i all done. jack the nose way up and burp it with a large funnel like so...
Zero reason an electric pump should cavitate. If you need to add additional restriction in the system to stop cavitation, your system needs attention to work it's best. Coolant passages offer more than enough restriction. Adding any additional restriction will lessen the efficiency. (thermo, washer, whatever) There is no such thing as coolant moving "to fast". Faster you can get it in and out of the heat exchanger the better it will cool, period.
In my experience 99% of the time it is air in the system or an inadequate fan/shroud combo.
Do you run a surge tank at the highest point? Is the radiator cap "open" and feeding the surge tank? If that i all done. jack the nose way up and burp it with a large funnel like so...
https://youtu.be/Z-_BZ2wyH1U
In my experience 99% of the time it is air in the system or an inadequate fan/shroud combo.
Do you run a surge tank at the highest point? Is the radiator cap "open" and feeding the surge tank? If that i all done. jack the nose way up and burp it with a large funnel like so...
https://youtu.be/Z-_BZ2wyH1U
i agree reed there should be no reason I did my own car literally took 5 mins no jacking it up or any of the nonsense and it was always perfect. No surge tank on either. Both cars have the same fan and shroud which are very well designed my hood is a pin on his is bolt on. I removed the rubber strip on the cowl of the car in question. It’s really strange it’s having issues esp after the stock pump was doing a better job than this....I haven’t jacked up the front with the electric pump on the car because I didn’t think we would need to but I’ll gladly have him try that since we both think there is air in the system. Bled it by filling top port with the steam vent off filled till it came out then closed the port top hose and filled the radiator, ran the pump heated and cooled then repeated. Will jack the nose up and post the details. Thanks for the post! I never understood the moving to fast theory honestly but never had to think or care enough about it to visit it lol
TECH Junkie
Joined: Jul 2015
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Just to give you my experience, after I installed my motor, I had a similar issue as yours. It would overheat in my garage without even moving, to the point that I thought I somehow popped a gasket on the initial start up. I ended up letting the car run while continuously squeezing the top radiator hose while constantly adding water as it came out of the fill neck. Took about 30 minutes....literally. Finally got all the air out, and she cooled down. This is a fresh fire/build right? Not sure why GM didn't do the burp valve like they did on the LT cars.
TECH Fanatic
Joined: Jun 2014
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I couldn’t get the air out of mine till I ordered a lisle spill free funnel. I just ran it while squeezing the hoses till all the air was out. You can see it bubbling out of the funnel, and the coolant in the funnel keeps more air from entering. Some just take a while.
Just to give you my experience, after I installed my motor, I had a similar issue as yours. It would overheat in my garage without even moving, to the point that I thought I somehow popped a gasket on the initial start up. I ended up letting the car run while continuously squeezing the top radiator hose while constantly adding water as it came out of the fill neck. Took about 30 minutes....literally. Finally got all the air out, and she cooled down. This is a fresh fire/build right? Not sure why GM didn't do the burp valve like they did on the LT cars.
Is there an overflow bottle on the car? If so, fill it, let the car get hot, then shut the car off. The air will force its way past the radiator cap and draw in the coolant needed as the car cools down. Better yet, put it into a gallon jug of coolant. That way you’ll be sure it won’t suck the jug dry. If there’s air in the system, it’ll work. Believe me.
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Joined: Dec 2016
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I have seen this a bunch in circle track racing, people think moving water faster is better, but your right if it is to fast it will not cool, good call/