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1990 300E new EGR valve

3K views 8 replies 4 participants last post by  frobi 
#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.
 
#3 ·
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.
 
#6 ·
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.
 
#8 ·
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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