Jump to content


EGR Question

Recommended Posts


I tested my EGR by connecting the BPT valve and later the EGR valve directly to intake vacuum (my thermal vacuum valve isn't working) and the engine almost immediately died and the EGR valve made this strange whistling noise.  Any idea why this happens?  The engine was at operating temp in the video: https://www.youtube.com/watch?v=hTZni7rL87k

Link to comment
Share on other sites

Under certain circumstances, exhaust gas is intended to be ported into the intake stream to reduce some exhaust emissions (compounds of nitrogen). Now about those "certain circumstances"...

Those certain circumstances never include "at idle". At idle, the EGR system is disabled because it tends to make the idle unstable. And when you're not at idle, amount of vacuum applied to the EGR valve is modulated by the BPT valve so that the higher the engine load, the more exhaust will be recirculated.

I'm thinking that what you have done is applied 100% full open exhaust recirc under conditions where there should be zero. And the engine doesn't like that.

Here's a bunch of EGR and BPT theory in this thread:



  • Thanks 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.