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Supercharger coolant system question

newv

Seasoned Member
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Jul 16, 2014
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Had a question on the supercharger coolant system. A few months back I took my V into the dealer for a coolant drain and replace since I didn't know when or if this was done by the previous owner. Talked with the (one!) XLR tech, gave him distilled water to use, and asked both before and after about draining and filling the charge cooling system. I even chalk marked the bolt on the filling plate at the top of the charger to make sure they actually opened it up. The chalk mark was rubbed off, but I never checked the level there afterwards. Decided to check this weekend as part of general upkeep, and found it empty up top. I added 22oz of coolant there. This generated a few questions:

1) What is the capacity of the charge cooling system - could not find that anywhere in the service manual - they only seemed to list the entire coolant system?
2) What is the connection between the regular cooling system and the charge cooling system? In reading the threads here it seemed as though there were different opinions on that. I believe the charge cooler has it's own pump, and drain port, and it obviously has it's own fill port - all this suggests they are separate. However, the single capacity listed in the manual, and the gurgling I thought I heard down low in the radiator when I filled the charger's port suggest there may be a connection.
3) If they are connected is it possible that I wasn't really low on coolant up top, and that coolant would be drawn in from the reserve tank into the charge cooling system when the charger/engine heats up?
4) If they are separate, then it would appear the shop drained but didn't fill the charge cooler system, would this generate a code somewhere? If I have been driving gently is there any chance of damage to the charger?
 
.. a few questions:

1) What is the capacity of the charge cooling system - could not find that anywhere in the service manual - they only seemed to list the entire coolant system?
2) What is the connection between the regular cooling system and the charge cooling system? In reading the threads here it seemed as though there were different opinions on that. I believe the charge cooler has it's own pump, and drain port, and it obviously has it's own fill port - all this suggests they are separate. However, the single capacity listed in the manual, and the gurgling I thought I heard down low in the radiator when I filled the charger's port suggest there may be a connection.
3) If they are connected is it possible that I wasn't really low on coolant up top, and that coolant would be drawn in from the reserve tank into the charge cooling system when the charger/engine heats up?
4) If they are separate, then it would appear the shop drained but didn't fill the charge cooler system, would this generate a code somewhere? If I have been driving gently is there any chance of damage to the charger?

Wow, lots to discuss here. Let me preface my reply by stating my charge coolant system hasn't been stock for a number of years so my replies are based on memory. First the charge coolant system is a closed system, i.e., there is no connection of it to the engine coolant system. I know this because I use water wetter in in the charge system and regular 50/50 antifreeze in my engine - they never mix.

I never investigated the total amount of coolant in the charge system; its not much, just what is in the SC and the lines to&from the pump and intercooler. When I was experimenting with charge cooling options, I tried several larger intercoolers to increase the capacity and cooling, but after no significant advantages in any I decided to add a high flo pump and an external tank to the system to increase my cooling efficiency. When that wasn't enough "for my application", I added the Super Chiller and Venom cooler which has served me well for the last few years.

I don't think there's a low coolant sensor for either coolant system. Temperature is your warning indicator. For the engine the coolant temp gauge and warning lights are on the dash. For the charge cooling system, above a certain temperature, the ECM will start pulling timing (A LOT!!); above a critical temp threshold, the ECM will throw a code (I don't remember which one at this time).

Believe me, if you haven't felt a significant loss of power, there's very little likelihood of your damaging the supercharger by driving it "gently" and no codes (what is gently, I know not of this type of driving ;) ). Three years ago, I had my SC coolant temp up to 270* a few times on the dyno, currently spinning it up to 22psi boost, and its still running strong.
 
GizmoQ,
Thanks much for the info! And the laugh - since I read about some of your modifications while searching for my answer I can see you haven't driven yours gently in a looong time. Mine has been running fine and nowhere near 270 degrees so I feel much better. I'll check codes and doublecheck for a leak but looks like I just need to chat with the service guys about attention to detail, and of course check up on them a little sooner next time.
 

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