rickneworleansla

About five weeks ago I installed my Meziere HD EWP. The pump appears to run correctly. I can hear and feel it running as it should. I have no overheating problems during the week on short runs. The problem is.. about every week or two after a long 30 minute drive it starts to overheat. When I pull over and pop the hood all of the coolant is boiling out of the overflow tank and the reservoir by the firewall on the passenger side. The overflow tank fills completely up and starts to boil out. I let it sit and cool. I then add some water to the firewall reservoir while running the EWP and bleeding the air out. I start to drive and get about a mile down the road before it starts to overheat again. I pull over, fill it some more, and bleed. I then drive another mile and wait for it to overheat, then fill and bleed again. After three times doing this it seems fine and lasts at least another week or more before it does it again. This has been going on every week or so since the install. It only overheats after about a week of perfect operation when I take it on a longer drive.

I have a couple of theories on what it could be. I have to admit that I do not know the correct flow of coolant through the system so it has been hard to troubleshoot.

I thought that it could maybe be a bad thermostat. The thermostat is about 3 years old. It is a hypertech 160 deg. stat model 1008 for LT1's. I've read where some thermostats have a failsafe to prevent them from sticking open or closed. Does this hypertech have that feature? I pulled it out today on the side of the road when the car was still somewhat hot. It was partially opened and closed shut as I watched it cool in my hand. I don't think it is bad unless it is intermittently getting stuck.? I will test it further tonight on the stove. I left the thermostat completely out for now.

The other idea I had was that I could have the pump reversed. Especially since I don't know what way the coolant should flow. How can I test for this? I tried reversing the wires while on the side of the road. The water quickly started to flow out of the reservoir by the firewall. This didn't seem right so I put the wires back how they were. I'm thinking that the pump is not reversed now but I am not completely sure. How can I test further to be sure?

The other idea I had is that there is air in the system. Believe me I know how much of a bitch an LT1 can be to purge air out. This does not explain why every week or two all the coolant collects on one side of the car, in the two passenger side tanks. I thought EWP's were supposed to be easier to bleed anyway.

The only other possibility I can think of is that there is something somewhere in the system clogging it up. I thoroughly flushed the system when I installed the pump and clear water was coming out. I also have a newly installed Dewitt radiator that is not more than two years old.
I flushed the system extremely well also at the time of the radiator install.

I checked the fans both are running as they should. There are zero visible leaks anywhere in the system. Any other ideas of what the problem could be? Again this only occurs every week or so after a long 30 minute drive and when it overheats all of the coolant seems to be in the overflow tank and firewall reservoir boiling out.

Thanks

BrianCunningham

Let's cover the obvious 1st, what temp are you letting it get up to before you open the bleed screw?

How hot is it when you park it?

BlackC6LS3

How'd you wire it up? I know you said it was running but is it running a 100% of the time?

rickneworleansla

When I parked it, it was about 250-260 deg. I didn't immediately bleed it at the screw though. I first release the steam at the overflow after it stopped spitting coolant out. I thought the tank was going to bust. It is too the top every time this happens. I bled it at the screw first with the electric pump running and the engine off. This didn't seem to be doing too much though so I then sealed all caps up except the bleed screw and firewall reservoir and steam came out for a while while I filled the reservoir at the same time. Eventually only water came out the bleed screw and I topped off the reservoir and closed it off.

rickneworleansla

Yes, it's running 100% of the time. Key in the accessory position turns it on. It also runs with the enigne fully turned on. I can hear and feel it buzzing/working.




I can also feel a squishing bubbly weak air/water flow on both radiator hoses after this happens when all the water is in the overfill tank.

jonecap

What did you wire it to? I originally wired mine to the fan relays on the side of the radiator shroud. I learned the hard way that when only one fan was running, the pump was running, but when the car got hot enough to cut on the second fan, it actually cut power to the relay for the ewp and, of course, the pump cut off causing the car to overheat.

If that's your problem, wire your ewp to the other fan relay and it will work flawlessly.

grinditout

I suggest wiring it to the accessory wire under your console.
I would ask if your fans are coming on?
If so I would replace the radiator and thermostat, also pop the steam tube off and clean, reinstall with new gaskets and anti seize.
While at it bypass throttle body.
If you wired your pump up blue to power, black to ground then there should not be a problem with flow.

MK 82

The pump should have it's own relay.

BrianCunningham

Since the bleed is above the thermostat, you need the engine on and hot enough for the thermostat to be open.

rickneworleansla

Every time I check the pump with the accessories on or the engine on I can feel and hear the pump running. I was wondering though if it was running at the exact point that it was overheating. You may have a good point there. I guess I will have to jump out of the car immediately when it happens again and check the pump while everything is still running. It's hard to do because I have to constantly check the temps and catch it at the right time. If it's too hot I'll have no choice but to cut it off quick. Also when it's that hot it's hard to tell if it's running. The Meziere is pretty damn quiet and the boiling of the water is loud as hell at that point. I'm betting that at this point it may run for another week again with no problems. I'll have to get into my custom tune and see at what point my fans are kicking on and off. Here is a pic below of the wire I tapped into. I have it going to the cut-on terminal of the EWP relay. The EWP relay also has a ground going to the chassis and an always powered 12v wire going to one of my battery fuse box terminals. Is this the relay wire you had problems with that cut off with one of the fans?



Some more info... The fans are turning on. I watched today as they both were running. I have the thermostat removed at the moment. I may leave it out for a while to exclude that as the problem. I will also test it on the stove later. My TB has been bypassed for a few years now. See pic of the old water pump below that shows the bypass. I'm using a separate relay just for the EWP that has a constant 12v, chassis ground, and a remote cut-on wire that I tapped into the fan relay for.





Do you think it would behave as it was though from a little air in the system. It ran fine for a week or so at a time. Then on a longer 30 minute drive all the coolant would move to the tanks and it would boil over. I filled and bled several times. I bled it some more after it heated up tonight and very little air came out. I also have the thermostat removed now.

Thanks

I found a great article here. Along with the diagram of the coolant flow it's all making more sense now. It's hard to tell from the diagram the flow through the block, heater, reservoir. I'll have to go read the article again.

http://www.indipalass.com/ARCHIVE/Te...lingSystem.htm

MK 82

I don't think that running an LT1 without a thermostat is a good idea. It disrupts the normal coolant flow.

rklessdriver

I don't want to insult you, but it recently happen to someone I know (and he's an electronics tech). Are you sure the pump is not wired backwards?
Will

nogoodsam

double check...

rickneworleansla

I was only going to run without it for a few days just to eliminate that as the problem. I'll probably just test it out and throw it back in if it's functioning correctly.

No insult. I'm open to all suggestions. I'm a computer network guy and I've done some really dumb things too. To test it, I crossed the wires yesterday just to see and the coolant started pouring out the top of the firewall reservoir. I'm guessing this should not have happened if they were connected correctly. I know it's supposed to be blue to positive and black to chassis ground. The problem is.. this dumb *** relay I purchased does not have correctly colored wires. So I can't really be 100% positive. It came with instructions that show the numbered terminals and what they should be connected to which is what I used but the wire colors are not correct. The ground wire is not even black it's some other color.


Here's pics of the relay I used...





I decided not to use the gray circuit breaker pictured above.
I connected the #86 ignition terminal to the blue wire of the fan relay in the pics way above because it had power with the accessory position of the key and engine full on.
I connected #85 to a chassis ground.
I connected #30 to a 12V always on source by the battery fuse box.
I connected #87 to the blue wire of the EWP.
I grounded the black wire of the EWP to a chassis ground.

grinditout

move your switched + to the constant/battery to test.

rickneworleansla

?? Well, the pump runs when it is supposed to with the key in the accessory position and with the engine fully on. I can hear it and feel it. The problem is that the car just decides to eventually overheat one day after about a 30 minute drive. See original post at the top. It will run for a whole week and no overheating. I just can't tell if the pumps running at the actual moment when it does decide to overheat. For example, maybe that blue fan relay wire cuts off at some point for some reason like jonecap mentioned.? Does anyone know? If I hook #86 to a 12V instead of the blue wire it will just run constantly and drain the battery. I also have no way to test for sure if the pump is flowing in the correct direction. The only thing I know is that coolant started pouring out of the firewall reservoir when I reversed the wires. Is there some test while it's on the car to know for sure.

PDQUIK95

If water is ever being pushed out of the reservior head tank with the pump running,the pump is definetely running backwards.
Also check your cap to make sure it is maintaining proper pressure under normal operating temps with no leak back to the overflow tank before it starts overheating beyond the cap pressure lift point. If water is getting pushed out under normal temps and levels while driving, it will will obviously reach a low enough water level from discharging enough water and then the engine will overheat. Do you have an OEM cap on it and/or what is your cap pressure designation.
Rick

rickneworleansla

If thats true then at least I know the pump is running in the correct direction now.

hmm.. A couple of years ago I replaced a bad pressure cap with the only one that was available in the store at that time. I believe it was only 1psi above stock. I think it may be 17psi. Isn't stock 16psi for a 95? I will go ahead and replace it anyway since it's a cheap part. That could be another possibility for whats happening. Maybe it functions correctly for a while then on a longer run it gets a bit hotter and everything boils over into the over flow tank before the valve releases pressure? It's worked all these years but I never had the EWP on the car either. The overfill tank does have all the coolant pushed into it whenever it overheats and it starts to vent out of it's cap. Last time I also noticed some pressure coming out of the pressure release cap on the firewall reservoir but maybe the rating is too high.??

MK 82

Install THIS thermostat.

You don't need or want a 160 thermostat.

PDQUIK95

16 psi on 95. The system is designed to hold 16psi under normal operating conditions up to probably about 240 before the cap exceeds 16psi and would lift to allow water back to the overflow tank by way of the main rubber lip seal . If it is letting any fluid at all leak by before engine reachs abnormal temps, then the cap is bad. If cap is working properly under normal operating temps, water should only flow freely one way back into the engine thru the built in check valve in the cap as engine cools and water contracts causing a siphon affect on the overflow tank.
Rick