Thanks to Johnny Chapman for contributing to this FAQ!
Bypass Valve Replacement proceedure The Heat Exchanger solenoid valve (coolant bypass valve) is located between the rear of engine and firewall.
|STEP 1||Relieve the coolant pressure form the overflow tank and be ready to catch any coolant that leaks out of the valve area.|
|STEP 2||Remove the turbo bypass control valve cover by prying it off with your hands.|
|STEP 3||Slide the red clip to the right to disconnect.|
|STEP 4||Picture of valve without the connector|
|STEP 5||There is a clip that holds the bracket in place after the nuts are removed.|
|STEP 6||Pop off the protective cover on the passenger side of the turbo bypass control valve area.. You can hold it out of the way with a bungy cord.|
|STEP 7||Now you can reach the coolant bypass valve. You will need to snip a tie strap that holds the valve to the firewall. You then disconnect the 3 coolant lines and vacuum lines. My old valve was sealed up with plastic epoxy until my new valve arrived.|
|STEP 8||Connect the new valve to all lines. Some dish soap may help them slide onto the new valve. Assemble in opposite order of removal. Put on a new tie strap so that it wont cut into the lines. Refill the coolant, run the heater and let it cool then recheck the coolant level.|
|STEP 9||Here is why it leaks. Coolant get sucked up into the valve (remember the vacuum line?) throughout the bottom of the valve, then leaks out through the two slots that connect top and bottom halves of the valve.|
Thanks to Paul Clarke for contributing to this FAQ!
If your engine temperature reads high, this part called the Bypass Cooling Valve is worth checking. I had this type of leak on the cooling system. Switch off your engine to protect you from the moving parts, then you have to reach up over the rear of the engine and between the firewall to locate it. Best wait till the engine is cool as the coolant can be dangerously hot if your engine has been running a couple of minutes of more. Let the engine cool and relieve the pressure by turning the coolant filling cap very slowly in an anti-clockwise direction. It might begin to bubble a bit, this is expected because of the vacum. As long as you have let your engine cool and youve switched of the ignition you should not be in any
You can by pass the Coolant Bypass Valve temporay by blocking the short top pipe on the left, I used an old spark plug in the hole with a jubilee clip. Connect the right hand hose to the longer hose on the bottom left with a piece of 20mm plastic or metal pipe and secured with jubilee clips, you can now top up your coolant resovoir on the left. Fill to between the
indication lines with just water for the time being and remember to leave room for expansion i your resovoir and replace with suiatable coolant fluid mixture in time. Everything including your heater will work until you get home or to garage.
When you replace the Coolant Bypass Valve remember to connect the two coolant pipes on your left in the right position. The short one that goes towards the firewall goes on the top connection and the longer coolant pipe which heads back toward the engine connects to the bottom position. On the right side you only have one coolant pipe so you cant go wrong there.
If your internal heating is not working after youve connected the new part, you have probably got the two coolant pipes on the left hand side connected upside down. I made this mistake and simply reconnect them in the way I described above. Happy motoring.