Disabling the EGR valve on gas motor -how has that affected the running of your motor

[Dan_69GTX]

Hey,



Don't know if this is the best place to post this... but...



What has your experiance been with disabling an EGR valve - how has doing that affected your engine? According to literature it could increase engine temps and increase pre-detonation.



The vacuum pod in mine is shot, so, what if I just leave it as is (vacuum port plugged).



Thanks!

Dan

 

[B.G. Smith]

Depending on what it is and the year model, some will put the "check engine light" on. As far as operation of the engine, I doubt you will be able to tell the difference. I don't see how it could cause extra engine heat or pre ign. as it only allows exhaust gas into the intake at cruise or decelleration conditions. Of course the clean air people won't be happy. bg

 

[rbattelle]

I have disabled the EGR valve on 2 vehicles: an '85 Bronco II and an '85 Cutlass. Both gave notably better performance without the EGR (more power).



It is absolutely true that EGR will decrease combustion chamber temperatures, and will reduce the tendency to knock. But in my opinion, on a gas engine with a moderate compression ratio (i. e. engine runs with a sufficient margin from it's knock-limited MEP) and no turbocharger, the positive aspects as far as cylinder temperature reduction aren't significant. Hence, the engine performs better when you're not cramming exhaust gas down it's throat. Also note that EGR tends to increase the carbon buildup on intake manifolds and valves.



As stated, if it's a modern engine the check engine light will come on. On my '94 Ranger, I didn't disable EGR specifically to prevent that situation.

 

[DKayser]

Think about this.

Would you like to get more nutrition from your food? First eat the food. second, take a dump on your plate. Third, eat what is on the plate. This is the theory of EGR. Sounds appealing, doesn`t it ? Don.

 

[Torque King Jay]

Re: Think about this.

First eat the food. second, take a dump on your plate. Third, eat what is on the plate. This is the theory of EGR. Sounds appealing, doesn`t it ?



:-laf :-laf :-laf :-laf :-laf

 

[Extreme1]

Originally posted by Dan_69GTX

According to literature it could increase engine temps and increase pre-detonation.

Yes it does. What the EGR system actually accomplishes is diluting the incoming lean mixture (which would ping and cause high combustion temps) with a non-combustable material, exhaust. It's cool enough by the time it gets to where it's going that it isn't a problem.



I used to think the same thing until I fixed the EGR on my Trans Am and it quit pinging.

 

[CFast]

When Detroit Diesel brought 2 of their new EGR engines to our shop 2 years ago I asked one of the engineers a question. "If I put a pipe up my butt and connect the other end to my nose will I run better?" He gave me a dirty look and walked away. He knew I was right. Well now here it is 2 years later and we're starting to see some of these wonderful POS. Their first EGR coolers are flawed, allowing the coolant into the ex gas and back into the engine. YOu lose coolant real fast this way. they're expecting a 100% failure rate. We pulled the head off of one last week with 130,000 miles. That's about 9 months on this truck. The intake valves were coverd with carbon junk. The cross hatching on the liner walls that is normally there even after 1 million miles, was almost gone. I hope to take my digital camera to work next time we pull the head off one of these so I can show you guys what a sad thing EGR is on a diesel. you can however save money with one of these and not buy an airfilter. Why put one on?

 

[mcoleman]

Dropping the EGR has always increased the performance on all of the late model stuff I have raced. The LT1 engines pick up quite a bit of ET when dropping that thing out of the intake completely. Leaving the EGR installed and not working is what caused your pinging. Make a plate and block the thing off.