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Blow off valve 1.5DCi Diesel?

Posted: Mon Jan 22, 2018 5:34 pm
by Jamietomlin
Hello,

I'm wanting to fit a blow off valve go my Megane but I'm not quite sure on how to fit it or where it goes.

Could anyone assist me? I've uploaded pictures to Dropbox go show people my engine bay..

https://www.dropbox.com/s/ixs038gh7v2wx ... 9.jpg?dl=0

https://www.dropbox.com/s/gbndbx4zfsg6r38/20180122_171536.jpg?dl=0

Re: Blow off valve 1.5DCi Diesel?

Posted: Mon Jan 22, 2018 7:43 pm
by Oliver
A blow off valve makes in a diesel no sense, because the throttle has not the same function like in a gasoline engine. In a diesel it is not responsible to adjust the engine´s load (here it´s only the injected fuel mass). The purpose of the throttle valve in a diesel is for adjusting the exhaust gas recirculation rate (create an certain underpressure) and for safety reasons.
If you release the pedal in a diesel this does not automatically mean that the throttle will be closed. So there is no reason to blow off the impounded boost pressure, because there is nothing impounded.

Re: Blow off valve 1.5DCi Diesel?

Posted: Mon Jan 22, 2018 9:56 pm
by Jamietomlin
Oliver wrote:A blow off valve makes in a diesel no sense, because the throttle has not the same function like in a gasoline engine. In a diesel it is not responsible to adjust the engine´s load (here it´s only the injected fuel mass). The purpose of the throttle valve in a diesel is for adjusting the exhaust gas recirculation rate (create an certain underpressure) and for safety reasons.
If you release the pedal in a diesel this does not automatically mean that the throttle will be closed. So there is no reason to blow off the impounded boost pressure, because there is nothing impounded.



Right... thank you for the quick reply! Makes a lot of sense now.