Is EGR Valve the cause?

wow! this is a really old thread!

 

I have a 2004 volvo with an ISX450. I need to bypass the egr valve. Can anyone who has done this tell me how?

 

Check the other threads on the forum under EGR. There have been several discussions, both pro and con on doing this.

That being said, it is easy. There are two plugs on the ISX EGR. Unplug the lower one at the 6 o'clock position which unplugs towards the engine block. Tape over the plug to keep moisture out. Pure and simple.

Or, you could take a more dedicated approach. Remove the adaptor where the EGR enters the intake manifold. This would require taking the manifold off (4 bolts, one clamp and removal of tube to air compressor). Take off the EGR adaptor. It is a rather long tube which is curved into the manifold pipe. Take a chop saw to the adapter tube to cut it down to the level that the adapter bolts on. Then take a thick metal plate and bolt on between the adaptor and and the manifold pipe. Use something like Permatex hi-temp copper RTV to form a seal between the adaptor and the steel plate. This will effectively cut off all EGR gasses from entering the manifold and you could leave the EGR plugged in. It works. Just recently did this to my ISX. Took all of about 45 minutes.

The first method will give fault codes, and more than likely, a check engine light. There is a remote possibility of a derate of the motor, but that does not happen in most cases. The second method will avoid that. And, if you were to ever be inspected by the environment police, they would not be able to tell you had done anything unless they tore the manifold apart. That is so remote as to be a non issue.

A source for the pre-cut plate that would work for the gas block would be Performance Diesel www.pdidiesel.com since they make them for their Big Boss ISX intake manifolds. Or you could just get their manifold as well. That's your call.