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Another member with the handle wstaab reported the dealer Discovered there was air in the intercooler system Chevy dealer vacuum filled it with the GM vacuum fill system and the noise went away. Pump was cavitating and shutting down due to the air in the system. Resulting in poor performance . He complained of a water gurgling sound in the car.
Here is a pic down inside the passenger front fenderwell of the tank with 2 big bubbles up top. are these bubbles significant - Would this cause a problem and the pump to cavitate, the pump shutting down resulting in poor performance. https://www.corvetteforum.com/g/picture/9508836
There has to be an air bubble at the top of the reservoir so the coolant has a place to expand into as it heats up. I just got my car back after the dealer mechanic used the latest release bleed tool recommended by GM to bleed the system on it.
Here are pictures of what the reservoir looks like on mine with the coolant level brought all the way to the top of the intercooler plumbing at the top of the engine so there are no air gaps in the plumbing into the bricks.
Bill
Last edited by Bill Dearborn; 04-09-2018 at 05:41 PM.
Thanks. My tank looks like it’s about a quarter low. Seeing your tank with the dealer process to fill it.
is this done at the radiator fill or somewhere else specific to the supercharger system.
There is a port right in front of the S/C at the top of the engine near the driver's side. The port is in a horizontal line that feeds coolant to the bricks. The port cap is spring loaded and if you turn it slightly you can remove it. There shouldn't be any air visible in that horizontal line. That is the most critical place as air there gets fed into the intercooler bricks and doesn't cool the intake charge as well as fluid does.
There is a port right in front of the S/C at the top of the engine near the driver's side. The port is in a horizontal line that feeds coolant to the bricks. The port cap is spring loaded and if you turn it slightly you can remove it. There shouldn't be any air visible in that horizontal line. That is the most critical place as air there gets fed into the intercooler bricks and doesn't cool the intake charge as well as fluid does.
Bill
You can just take the cap off and pour what 50/50 mix antifreeze it will take in there and repeat. I had to on my recent blower swap!
I guess it uses dexcool / pink stuff like the radiator.
Yes, and the factory fill for the supercharger intercooler system is 60% water & 40% antifreeze. I would premix some with distilled water so the fill is consistent regardless of the amount used.
Last edited by C7/Z06 Man; 04-09-2018 at 09:08 PM.
There has to be an air bubble at the top of the reservoir so the coolant has a place to expand into as it heats up. I just got my car back after the dealer mechanic used the latest release bleed tool recommended by GM to bleed the system on it.
Here are pictures of what the reservoir looks like on mine with the coolant level brought all the way to the top of the intercooler plumbing at the top of the engine so there are no air gaps in the plumbing into the bricks.
Bill
I was at the dealership today getting the state inspection completed on my Tahoe. The mechanic came out to talk to me about the Corvette. He did the S/C bleed last Friday and I took the pictures of the reservoir yesterday. He showed me the pictures he had taken of the reservoir where there was absolutely no air at the top of the reservoir and we compared his pictures to the ones I took yesterday. He followed the GM procedure exactly and used the new tool they recommend and had all of the air out of the reservoir and out of the lines at the top of the engine. The question is where did the air in the reservoir come from three days and about 30 miles later???? He said there are no visible signs of leaks in the system and he can pull the recommended vacuum on it. We decided to see how it runs at my next track event and then consider how to proceed.
I took the spring clipped on cap off this morning and was able to poor in about 4 ounces of a 50/50 dexcool distill water mix in. I am driving the car today and will stick my iPhone inside the fender and take a snap shot of the tank. And see if the bubbles are smaller. I’ll keep driving and adding a little bit of dexcool at a time.
It is a peculiar set up. I think this is what recall gm claimed caused the some of the performance issues on the 2015 Randy Pobst tested and he came away calling the car a z05 and a half.
while not the same , it reminds me of the same thought process the engineers had on the vacuum operated secondaries of the c4 lt5 with that pump motor and all the vacuum lines and associated problems with a little subsystem operating a critical part of the car’s performance
Hey Bill your air pocket pic of the coolant tank is how mine looked when new. I took it back to the dealer at the time thinking the air pocket was to large so they redid it and when it was all over the air pocket was still the same.
I took the spring clipped on cap off this morning and was able to poor in about 4 ounces of a 50/50 dexcool distill water mix in. I am driving the car today and will stick my iPhone inside the fender and take a snap shot of the tank. And see if the bubbles are smaller. I’ll keep driving and adding a little bit of dexcool at a time.
It is a peculiar set up. I think this is what recall gm claimed caused the some of the performance issues on the 2015 Randy Pobst tested and he came away calling the car a z05 and a half.
while not the same , it reminds me of the same thought process the engineers had on the vacuum operated secondaries of the c4 lt5 with that pump motor and all the vacuum lines and associated problems with a little subsystem operating a critical part of the car’s performance
Don't add 50/50. GM doesn't use 50/50. The C7 uses 60/40 with water being the 60.
Not sure how you would get rid of the bubble on the top? I've been filling mine and now it seem full and everything works good. Was trying to read data today. But the bubble is still there!
its extremely important to rid the system of any air, as this reduces the quality of water the pump can handle, before it goes into shut down mode.
We have been offering our tank only to local customers with good success. It removes the stock tank, loops the intercooler, with the cooling lines re-engineered, where we feed the pump with head pressure from the tank.
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its extremely important to rid the system of any air, as this reduces the quality of water the pump can handle, before it goes into shut down mode.
We have been offering our tank only to local customers with good success. It removes the stock tank, loops the intercooler, with the cooling lines re-engineered, where we feed the pump with head pressure from the tank.
In the c7z when the pump cavitates and shuts down does this flip something in the ecm that kills the power
there have been a few times when I stand on the gas and the car feels like a 1980’s v6 camaro.
Other times it runs pretty good and it feels like it’s almost as fast as my 100percent stock c6z was.
In the c7z when the pump cavitates and shuts down does this flip something in the ecm that kills the power
there have been a few times when I stand on the gas and the car feels like a 1980’s v6 camaro.
Other times it runs pretty good and it feels like it’s almost as fast as my 100percent stock c6z was.
Absolutely! Ign timing is retarded to the point where if the intake air temp sensor on the supercharger gets above 230*, the throttle simply closes.
Keep in mind, the pump restarts after 180 seconds.
Cant you just take the cap off the top line by the S/C cover and fill it up until the level of the coolant stabilizes. While the motor is running with the cap off it will prime and bleed itself correct? Like a radiator system? The fill, tank and lines are above the pump correct? I'm not understanding the vacuum tool thing. I'm new so please educate me.
Not sure I understand the vacuum tool completely either but I think it does a couple of things. First, because the bubble at the reservoir is at atmospheric pressure with the plumbing going into the reservoir at a level below the air bubble the only way to reduce the bubble is to pull a vacuum on the system so the bubble air expands and pushes down to the point it hits the plumbing and then it goes up through the plumbing to the top of the system. Theoretically, pulling a certain amount of vacuum for a time should bring the remaining air level in the reservoir to a proper point that it acts like an expansion chamber as the liquid heats up. It should also remove air from other parts of the system so the system can be filled to the top with no air gaps at the top.
My opinion is the reservoir should be the highest point in the system just like your cooling system reservoir is at the highest point in the cooling system but that probably won't work since it would be higher than the hood line.
One thing they could do is add a cylinder to the top of the reservoir that would capture air as fluid flowed through the reservoir and then bleed air out the cylinder until the air level was above the level of the main reservoir.
Residential and Commercial Hot Water heating systems with reservoirs some times 15 or more feet below the top of the system have similar types of solutions since air doesn't conduct heat as well as water and they have to get all of the air out of the system to have it work properly and still have expansion capacity to handle expansion of the water as it heats. They have air bleed valves that automatically bleed air based on a float in the valve body. When air enters the body the float drops and air is bled out to the atmosphere. Here is an example: https://www.supplyhouse.com/Bell-Gos...waAiTtEALw_wcB
I used this type of valve on my home heating system in NY State. The only problems I had were due to hard water deposits messing up its operation requiring replacement every now and then.
had the car in for street alignment, check fluids in diff/transmission. And look at bubbles in intercooler.
The corvette specialist bill at elco agreeed the pic I posted doesn’t look right. He says he will be draining the system and then he creates a vacuum within the system that will draw the coolant in to completely fill without air pockets. Seems similar to how an a/c system is evacuated.
I would imagine the factory does a quick fill and sends them out the door. — hence Many owners get a z05 and a half when they get there car.
04-09-2018, 05:24 PM
Bubbles in intercooler tank
