Hello. My Mazda protegé 2000, gearshift, 1600 cc, 5 speed, LX at idle speed, intermitently and suddenly drops dows its rpm from aprox 700 down to 500 and then stabilizes back at 700 rpm. This event lasts maybe 1 or 2 seconds. While this was happenning I opened the front engine cover and realized that the noise come from the air intake filter box. The noise it makes while the RPMs drift is a sort of 'bloop bloop... sound'. I opened the air filter box and got a better approach. This bloop sound comes from the intake manifold I guess... Engine performance has not suffered any significant deviation. When driving (RPMs above 700) nothing is noticed.

Could somebody please give me a light, hint, idea, recommendation on how to troubleshoot and perhaps fix this problem?

Regards. Vick.

 

definately sure 100% its the EGR valve...there is a recall for the 2002 and up...I have a 2001 it happened to me 2 weeks ago. I tried changing the spark plugs but I really had to go with the EGR costed me about 400$ CDN (200$ for the valve and 1.6 hours of work)...I got the code P0300

 

Are you running your A/C compressor? That'll do it every time.

 

Thanks for the answers. Originally, this 'bloop - bloop' sound used to come only while running iddle/still and when either I hit the clutch or turn the wheels left or right or turn On/Off the A/C. Now, it appears at any time and as I said before, RPMs go from 700 down to 500 and up again. Question: where is this EGR valve located? how does it look like?

 

Here is a 1.6L with header installed--you can see the EGR piping and connector just to the right.
It's the thin copper tube.
Note that some '99-'00 1.6L engines do not have an EGR. Do you have a California car? If you don't you may not have one.


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my car does the same thing and i am not worried about it. i doubt its that big of a deal, just the car trying to idle as low as possible