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2011 GL 320 CDI, 2004 E320, 2000 C230, 2004 Toyota Sienna
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231 Posts
Discussion Starter #1
I replaced a new EGR valve but it will not open at 3000 rpm. The old one was cracked and sticking. When I apply suction to it, it opens. Does the engine have to reach operating temperature for valve to open at 3000 rpm? The old one was working but sticking. All vaccum pipes are fine.
 

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2013 E350 sedan, 2013 E350 cab, 1993 400E sold,1999 ML320
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2,436 Posts
If you put vacuum on it off the car and it worked either the tube is clogged and no vacuum is getting to it or the seal there is bad. If the old egr was crack maybe the fitting it was on has a crack also?
 

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2011 GL 320 CDI, 2004 E320, 2000 C230, 2004 Toyota Sienna
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231 Posts
Discussion Starter #3
If you put vacuum on it off the car and it worked either the tube is clogged and no vacuum is getting to it or the seal there is bad. If the old egr was crack maybe the fitting it was on has a crack also?
Thanks Macdorne. The old EGR was rusted and when reved at 3000 rpm, it would bend at the tropod ( mounting in the valve where the diaphram is) as
one side was cracked. With vaccum, the valve would pull in and bend.
So, I bought a brand new valve which works great when vaccum is applied manually and idle becomes irregular, which also means the valve is opening.
I have not touched any vaccum lines as the old one was working at 3000 rpm.
Now the new valve does not get vaccum at 3000 rpm thus will not open.
 

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2011 GL 320 CDI, 2004 E320, 2000 C230, 2004 Toyota Sienna
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231 Posts
Discussion Starter #4
Which seal are you refering to?
 

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2013 E350 sedan, 2013 E350 cab, 1993 400E sold,1999 ML320
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2,436 Posts
Should be a seal on the egr valve to where it mounts unless its threaded. Sounds like a vacuum leak, maybe its not enough. Check the rubber hoses for cracking and hardning and replace as needed.
 

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2011 GL 320 CDI, 2004 E320, 2000 C230, 2004 Toyota Sienna
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231 Posts
Discussion Starter #6
Should be a seal on the egr valve to where it mounts unless its threaded. Sounds like a vacuum leak, maybe its not enough. Check the rubber hoses for cracking and hardning and replace as needed.
The gasket between the EGR and the exhaust manifold does have a leak as I can hear exhaust noise. (seal where the egr is mounted to the exhaust manifold) But I thought that the vaccum is islolated from the exhaust and the valve should open even with a slight exhaust leak under the egr valve.
 

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'95 E300 DIESEL, '91 600SEL, '92 600SEL
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17,407 Posts
Not a viable option for anybody living in emissions controlled states/countries. Great idea though. Would have done it to my wagon if doing so would let me pass smog inspections, but it would fail the visual inspection instantly.
 

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2011 GL 320 CDI, 2004 E320, 2000 C230, 2004 Toyota Sienna
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231 Posts
Discussion Starter #9
Not a viable option for anybody living in emissions controlled states/countries. Great idea though. Would have done it to my wagon if doing so would let me pass smog inspections, but it would fail the visual inspection instantly.
Thanks Sbaert. My EGR works now. The engine has to reach 70 degrees before EGR valve will get vaccum to open. I thought blocking EGR would increase NOX and fail emission. I think mine failed for that reason.
 
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