Repair And Fix it

A blow off valve is a device that allows recirculating air to exit the intake/exhaust system on a turbocharged vehicle. Without the blow off valve, air would be forced back into the turbochargers compression wheel when the drivers foot is taken off the accelerator, causing undue stress on the turbos components. This, in turn, slows turbo spool up time. Over time, this could cause the turbo to fail. Installing a blow off valve gives the air a place to go and relieves pressure from the turbos compression wheel during gear shifts (when the drivers foot is off the accelerator).

Instructions

1

Open the hood and disconnect the negative cable from the battery terminal. Disconnect the positive cable from the battery terminal.

2

Remove the battery.

3

Locate the factory recirculating valve. Use your shop manual if you need a visual description for the valve specific to your vehicle. This valve recirculates the intake air to the exhaust. This is the device we want to replace. There will be two hoses connected to vacuum lines. The top vacuum line is connected to the throttle body after the intake. This vacuum pressure is what makes the valve operate.

4

Use either a screwdriver or socket wrench (either should work) to remove the screw bolts on the hose clamps.

5

Slide the hose clamps out of the way and use the screwdriver to pry both the vacuum lines off.

6

Install the new blow off valve. Install the hoses the opposite way of removal.

7

Put the batter back in and reconnect the positive cable to the battery first, then the negative cable.

An exhaust valve allows cylinder head gasses to escape, Expensive engine work is often necessary when an exhaust valve breaks. Though repair is needed once this occurs, having information on what caused the valve breakage might be important.

Types

There are two types of breakage to which exhaust valves can fall victim. One type involves a breakage where the head and the stem connect. A break can also occur at the point of the stem where the keeper-grooves have been built in.

Head Breakage

Exhaust valves can experience this type of breakage because of stretching that occurs due to constant heat. Thermal shock negatively effects exhaust valves, because sudden drops in the engines temperature causes them to break.

Stem Breakage

Heavy wear in the keeper grooves will cause the stem to snap off an exhaust valve. Constant sideloading can cause stem breakage if the stem height has not been installed correctly.