Someone explain EGR and PCV to me.....i know i'm dumb

[AWeb80]

I know what they each stand for.

 

EGR

 

I know it recirculates exaust gasses, but why.

Does it help with gas mileage....and does it take away from the power the engine makes?

 

If I disconnect it, what will happen?

 

 

 

PCV

 

I know it lets blow-by out of the crankcase and allows the preasures to escape....but, does it do anything else?

 

If I disconnect it, what will happen?

 

 

 

 

Thanks.

[pitzel]

I know what they each stand for.

 

EGR

 

I know it recirculates exaust gasses, but why.

Does it help with gas mileage....and does it take away from the power the engine makes?

 

If I disconnect it, what will happen?

 

PCV

I know it lets blow-by out of the crankcase and allows the preasures to escape....but, does it do anything else?

If I disconnect it, what will happen?

Thanks.

 

EGR = lowers the temperature of combustion in order to reduce the formation of NOx during parts of the engine operating cycle.

 

PCV = allows hydrocarbon-rich gases to be recycled back into the combustion system, where they can be dealt with in a more environmentally friendly manner.

 

Both systems are essential for optimal operation of your engine, including optimal fuel efficiency. Disabling either will not improve your mileage, and will decrease overall reliability and increase emmissions. Suctioning blowby out of your crankcase, for instance, improves ring seal and keeps oil cleaner.

[ShockTherapy]

I know what they each stand for.

 

EGR

 

I know it recirculates exaust gasses, but why.

Does it help with gas mileage....and does it take away from the power the engine makes?

 

If I disconnect it, what will happen?

 

PCV

I know it lets blow-by out of the crankcase and allows the preasures to escape....but, does it do anything else?

If I disconnect it, what will happen?

Thanks.

 

EGR = lowers the temperature of combustion in order to reduce the formation of NOx during parts of the engine operating cycle.

 

PCV = allows hydrocarbon-rich gases to be recycled back into the combustion system, where they can be dealt with in a more environmentally friendly manner.

 

Both systems are essential for optimal operation of your engine, including optimal fuel efficiency. Disabling either will not improve your mileage, and will decrease overall reliability and increase emmissions. Suctioning blowby out of your crankcase, for instance, improves ring seal and keeps oil cleaner.

 

what that guy said, however, as for them hurting your car's drivability, that's a long story, and both can be removed, with the proper setup/comuter, honestly what it comes down to is: if you don't know what it is, don't mess with it.

[cutlsp]

i'm going to remove my egr valve once my truck is 24 years old and make it have dual exhaust with an h pipe

[GnatGoSplat]

Since EGR also lowers combustion temps, it can also allow more spark advance without preignition. In theory, that sounds like it could help performance, although in real life I think it reduces emissions more than anything.

 

PCV is strictly for emissions. It just reburns crankcase vapors. There will be no performance degradation from disabling it. I don't believe there will be any performance improvement either though.

[Miko K]

 

PCV is strictly for emissions. It just reburns crankcase vapors. There will be no performance degradation from disabling it. I don't believe there will be any performance improvement either though.

 

There is a slight improvement in the cleanliness of you TB and IM-sometimes oil gets pass the PCV valve and "lubricates" everything from the valve cover to the intake valves Or, at WOT when you got a lot of blowby, the PCV is closed and oil goes out the other hose (on the rear valve cover) and into the intake hose, around the air filter. Such a mess...

[DaveFromColorado]

the PVC system was orignially created as a strictly crancase vacuum setup, to help seal the rings better (as they do when they are pulled into vacuum). opening the other side and allowing the system to vent back for reburn was an afterthought that was found to increase oil life, engine life, and emissions.

 

as for the EGR system, not only is it used to cool combustion temps, on newer engines, it's also used to replace a certian ammount of air into the cylinders, reducing the ammount of fuel needed and saving you more in fuel milage - this was slightly expiremented with on many fuel injected cars, as you'll notice your EGR only opens at part throtle, cruising speeds.

 

--Dave.

 

--Dave.