Got a code P0400.

Took my EGR valve off. The valve portion had a coating of carbon.

The plunger moves in and out easily by hand. You can feel some air come out of the vacuum port.

If I try sucking or blowing in the vacuum port air seems to flow through it. I kind of think the diaphram has a leak. I would think that if it was good, I would not be able to draw any air through it. Is this a good enough test or should I buy a vacuum pump?

So what do you guys think? Is my EGR valve toast? I will buy a new one if it is. I am not interested in removing my EGR system at this time.



A seperate note for those of you going to work on your EGR valve for the first time. Go out and buy a set of 12 point stub wrenches if you don't have any. They make this job a piece of cake. Got mine at Walmart for $15.

 

You need to get a vacuum pump to accurately test it.Buy one and see if it holds a vacuum.Or just go buy a new valve.

 

If you can draw on the vacuum connection with your lungs and it does not suck in the diaphragm or hold vacuum, then the diaphragm is toast.

 

Also, be advised that I had an EGR code set, and took it off, tested and cleaned it well [removed seat, etc] of carbon... put it back on, and it still set a code [it was VERY intermittent tho]
I just got a new one from Cromer for about 40 bux.. been OK since then[last yr sometime...]
Point I make is: they can APPEAR and 'test' OK, but still 'fail'..

 

Do you guys know that on a 96 or 97 camaro , caprice, or impala 5.7 v8 GM will replace FREE your egr valve within 10 years or 100,000 miles if it fails. It seems that the egrs were failing due to corrosion of the internal diaphragm plate. Didn't GM send you a letter? I have mine that I would gladly scan for you if I knew how. Ask the dealership they should know about it.There is even a number you can call about getting reimbursed if you paid for it already. The number is 1-800-833-2438 its the Chevrolet Customer Assistance Center.
Good luck
Dan

 

Thanks for the help. The code only seemed to come on when I first started driving on the highway in sixth gear. I evently just left it like that until I finally took it apart. I am trying to get the car in top shape for the spring. Not much else to do in March.

I will first try to see if I can get a free one. I was able to get my air pump replaced for free at a local dealership so maybe I can get a new EGR valve as well. I not sure what they will say if they are not doing the work on the car.

I am the third onwer of the car so I don't get notices from GM about it. I have seen a recall number on the EGR valves for 96's, anybody have the number handy?