SES from EGR Question.

[RevingRed99FB]

Hi all,

I picked up my firebird about two weeks ago off of a used lot, it has 141,000 miles(yeah I know).

My first thoughts were to flush the engine,change the oil,change the fuel filter, and flush the lines...some very odd stuff came out :)

Now I plan on replacing plugs and wires as soon as possible(I've recently figured out the pain that will be involved) but was concerns me is my EGR Valve.

I popped a SES light and took it to the AZ to have it scanned, EGR out of range or something similair.

149.oo for a brand new one! So I have some options. First Think I should pull it off and clean it out real good including the connetors? or to replace it, should I hit up a junkyard or spring for the new one? Also, I've read about removing it completley but I need to search the board for more info.

How long would it be safe to run with it like this until I can replace the valve?

oh by the way, '99 Firebird 3.8. Something else about the car, I wasn't sure, but did all the v6 firebirds come dual tipped?

[BLLDOGG]

Re: SES from EGR Question.

what is the actual code. we can not help you with that otherwise.

not all came with dual tips. that is s Y87 option but some cars still came with it anyways

[RevingRed99FB]

Re: SES from EGR Question.

ah sheesh I really didn't see the code, just what the guy read out to me. EGR out of range is what I remember. I will have it checked again this asap

[kristen]

Re: SES from EGR Question.

imo if your going to change it, you should just get a brand new one. so you know that it will be fine for a while. there is also the option of blocking it off. i did that and i don't give out any codes. but the block off isn't really legal in some states

[nascar24jd]

Re: SES from EGR Question.

imo if your going to change it, you should just get a brand new one. so you know that it will be fine for a while. there is also the option of blocking it off. i did that and i don't give out any codes. but the block off isn't really legal in some states

Do you get any pinging with it removed? I have heard that removing it will cause detonation. Thanks...

Also, where did you get the block off plate?

Living in FL, we have no emmissions laws, so removing it will not be a problem.

[UDLOSE98]

Re: SES from EGR Question.

take a penny, nickle, whatever....

remove the bracket that holds the old EGR on to the upper intake
weld the penny in there
RTV
SOLID

[slow6]

Re: SES from EGR Question.

Do you get any pinging with it removed? I have heard that removing it will cause detonation. Thanks...

Also, where did you get the block off plate?

Living in FL, we have no emmissions laws, so removing it will not be a problem.

I'm not gonna say thats not possible.
It seems to me, removing the EGR would lower
hot air intake so you would have less chance of detonation/ KR
but IDK
I will have to do a controlled experiment on this

[CDNFB]

Re: SES from EGR Question.

Yeah, the EGR can cause an increase in intake charge temp, but knock doesn't develope because the introduction of the exhaust gasses is very effective in causing a lowering of the cylinder pressures, which by far negates the marginal temp increase effect.

[UDLOSE98]

Re: SES from EGR Question.

Yeah, the EGR can cause an increase in intake charge temp, but knock doesn't develope because the introduction of the exhaust gasses is very effective in causing a lowering of the cylinder pressures, which by far negates the marginal temp increase effect.

ive always had many questions about the EGR, im sure a search would turn up 1000000 results about nothing tho. So i see what you are saying, how it would lower clinder pressure because its basically acting as a wastegate for your exhuast system. However, wouldnt headers with larger primaries also act the same way. Or a larger diameter exhaust or free flowing cat?

[CDNFB]

Re: SES from EGR Question.

It doesn't work that way.

The exhaust gases that are introduced into the combustion chamber displaces some air/fuel volume that could have been in the cylinder, so the cylinder has less air/fuel. And because those gases won't burn, the net result at combustion is less bang, thus less pressure, thus lowered possiblility of knock.

[UDLOSE98]

Re: SES from EGR Question.

hmmm, i could undrestand that on a boosted car, but knock on a stock NA coulnt get too bad (2 degrees tops a wot) right?

[ReodDai]

Re: SES from EGR Question.

The knock won't be an issue, really. Its not going to be at any time where it would threaten your car. The only really opens for highway driving.

The purpose of the EGR is to keep a certain gas from being created while highway driving. This gas gets created when the temperatures in the combustion chamber get higher then a certain degree (I'm not going to bother looking up the gas or the temp). The EGR kicks on at this point adding already burnt exhaust gases back into the intake. These inert gases displace some of the fresh air/fuel that would have been coming in, causing a smaller explosion and less heat then if you would have filled the combustion chamber with fresh air/fuel. This keeps the temperatures low enough to keep these certain gases from being created. Also, supposedly it is to keep the car from "pinging" from high combustion chamber temps during highway driving. This won't effect the performance of your car and won't really damage it since the EGR closes during WOT.

With the EGR not opening properly you can experience some knock in highway driving due to the combustion chamber getting hotter then its suppose to. I've personally never registered any knock and my egr does not work.

To reiterate: EGR no working anyway during WOT.

[UDLOSE98]

Re: SES from EGR Question.

The knock won't be an issue, really. Its not going to be at any time where it would threaten your car. The only really opens for highway driving.

The purpose of the EGR is to keep a certain gas from being created while highway driving. This gas gets created when the temperatures in the combustion chamber get higher then a certain degree (I'm not going to bother looking up the gas or the temp). The EGR kicks on at this point adding already burnt exhaust gases back into the intake. These inert gases displace some of the fresh air/fuel that would have been coming in, causing a smaller explosion and less heat then if you would have filled the combustion chamber with fresh air/fuel. This keeps the temperatures low enough to keep these certain gases from being created. Also, supposedly it is to keep the car from "pinging" from high combustion chamber temps during highway driving. This won't effect the performance of your car and won't really damage it since the EGR closes during WOT.

With the EGR not opening properly you can experience some knock in highway driving due to the combustion chamber getting hotter then its suppose to. I've personally never registered any knock and my egr does not work.

To reiterate: EGR no working anyway during WOT.

interesting, thanks for the clear up

[ReodDai]

Re: SES from EGR Question.

Here I look up someone else saying basically the same thing that I just said:

EGR (Exhaust Gas Recirculation)This system was introduced in the early 1970s to all Chrysler Corporation cars, as well as most of those of other automakers. The EGR valve directs exhaust gas from the crossover passage into the intake manifold, and includes a temperature valve (CCEGR) on the radiator, sometimes with a delay timer and a vacuum amplifier. [Webmaster note: EGR is not normally on at idle. Early manuals on emissions control systems noted that EGR burned unused fuel, but this is not an issue in modern cars.] EGR reduces emissions and may increase gas mileage slightly; some vehicles shut off EGR during wide-open throttle in order to avoid having it interfere with power. EGR, when working, is a "good'un."

Bruce Clingerman added:

The purpose of EGR (Exhaust Gas Recirculation) is to reduce the NOx emissions. Air is mainly made of oxygen and nitrogen (O2 and N2). At temperatures above 1300°C (2372°F), these molecules split apart and rejoin with each other to make nitrogen oxides (like NO, NO2, etc...). The nitrogen oxides contribute to smog formation.

EGR puts a portion of the exhaust gas back into the intake manifold, so it mixes with the fuel and air. (Note that the exhaust adds to the fuel and air; it doesn’t replace any of it). The added mass in the cylinder is harder to heat up, so the combustion events have lower peak temperatures. The lower temperatures prevent the O2 and N2 from splitting and combining. Even though the exhaust is hot, about 600°C (or 1112°F), it's much cooler than the 1300°C required to make NOx.

In summary, the exhaust adds mass, increasing the heat capacitance of the mixture (i.e. making it harder to heat up the mixture in the cylinder). Peak temperatures are lower, reducing NOx formation, which ultimately reduces smog in the environment.

The reason EGR improves fuel economy is because it reduces the engine's pumping losses. For the cylinder to move down on the intake stroke, the piston is working against the intake manifold vacuum. Another way to say it is that the vacuum above the piston tries to prevent the piston from going down. EGR increases the mass in the intake; more mass means higher pressure, or less vacuum. Now the piston has less resistance during each intake stroke, which results in better gas mileage.

Edit: Read the last paragraph.... does that mean that by adding boost and removing the vacuum from the intake manifold your actually helping the piston go down ? ;)

[slow6]

Re: SES from EGR Question.

The exhaust gases that are introduced into the combustion chamber displaces some air/fuel volume that could have been in the cylinder, so the cylinder has less air/fuel. And because those gases won't burn, the net result at combustion is less bang, thus less pressure, thus lowered possiblility of knock.

CDNFB is kinda saying that the EGR lowers your overall combustion chamber size (ecotec haha, turning my 3.8 into a 3.4 lol)
Reodai is saying the egr help combat drag

The knock won't be an issue, really. Its not going to be at any time where it would threaten your car. The only really opens for highway driving.

It only opens during highway? I will have to check on that
BTW I've had knock 0rpms - 6000rpms (true, less of a threat at lower rpms)