My SES light keeps comming on after about 5 min above 55 mph, and up until now i thought it was because of an exhaust leak i have where the manifolds connect to the cylinder head. but upon reading around here it seems it may be because of a faulty EGR valve, now im new to this, so dont laugh. What is an EGR valve and does anyone else think it could be this? thanks for the input.

-chuck 305 tbi lo3

 

What codes have you gotten. And when you get the ses light does the car seem to bog down a little?

 

It does sound a lot like an egr valve, mine did the same thing, ran ok, but occasionally popped a SES light on the freeway after it kicked into cruise mode.

An EGR valve recycles burnt exhaust fumes into your intake. The reason it does this is to add this unburnable gases to the combustion process. Since it can't burn, it controls the the burn rate and temperature of the mixture. Basically cooling down the piston chamber and the process, thereby reducing emissions.

An EGR not only sends the exhaust gasses in, it regulates how much goes in.

The computer in your car is setup to adjust the fuel mixture with the EGR working. So there's actually a few states of the EGR not working.

#1 The valve is stuck open. Too much exhaust means too much unburnable gas in the intake. That means your car won't idle well, and stumble on take off, until the car reaches a decent RPM, and the fuel and air is increased to the point at which it can keep up with the added exhaust, and so it will run decent at WOT, and hard acceleration.

#1 Stuck shut. When it's stuck shut, the gases used to control the combustion temperature are not availible, this means the temperature inside the combustion chamber is hotter than usual. A hotter chamber than usual results in overheating, detonaition, and that un godly pinging sound which will eventualy burn up your pistons.

When stuck shut you usually will not notice a rough idle, as the EGR is usualy closed at idle. You will however notice a slight increase in engine temp, and a pinging under light acceleration, usually like when you hit the gas in overdrive, right before it kicks down to third. You usually dont hear it under hard acceleration because the motor is louder than the ping.

3) sticky valve. A sticky valve will sometimes display both symptoms. A rough idle as your coming down from full throttle. AS you reach idle, the EGR valve is trying to shut if it is slow to close, It dumps that exhaust into the intake at idle, the car will idle rough, and have a hard time taking off. Unless you sit for a minute, then the EGR has time to close, and the idle straightens out.

When you go to take off, the EGR will open slowly and not allow enough in to cool the chamber, so you will ping on take off, and then it will go away as the EGR slowly opens.

My problem was a sticky EGR, I had a ping so I asssumed it was not getting enough fuel, I gave it more fuel, adnd the ping went away. Then I fixed the EGR and my power did not return I found out that after I fixed the EGR I was running way rich to cover the ping the EGR was causing. That, and I had a SES light after I was on the freeway for more than 5 minutes at a cruise it would pop SES.

Jump pins A&B on your aldl connector, read the codes, let us know what you find. I bet one of them is the infamous 32 for the EGR

This is by no means a text book I coulda missed a lo of stuff. Anyone who sees anything wrong with this let me know, so's I ken fix it Aside from the 10000 typos.

 

yea, this definitly sounds like my problem. First of all, no, the car doesnt seem to bog down at all, but then how much more can an unmodified lo3 really bog down ? And now you're going to realize just how much of a noob i am. This "Jump pins A&B on your aldl connector" means next to nothing to me, how do i check codes or jump pins and stuff like that?

thanks for explaining this lykan, it already makes infinatly more sence then it did before.

 

This post here, thanks to Vader shows where your aldl connector is, and how to read your SES messages, let us know what you come up with eh?

 

Do i have to run the car until the SES light comes on and then check the SES light? Because right now i do the hairpin/wire thing and the light blinks once right off the bat and then doesent blink again at all. Well ill try running the car on the expressway and then checking for a code and let you know what i get.

 

yea that worked, i needed to run from pin 5 to pin 6, not pin 6 to pin 12 another thing i was doing wrong. but yep, just like you guys said, error 32, egr. anyway, is this something i can pull apart clean and stick back in? or do i need to pick up a new one. Are junk yards a good idea or should i go brand new? BTW, is the egr valve this black circular thing above the passenger side valve cover w/ about 3 rubber hoses comming out of it? thanks again, you guys are awsome.
-chuck

 

I don't know where the link went, but looks like you found how to pull codes anyhow.

A lot of people routinely take out their EGR"s and clean them. I didn't want to mess with it I just bought a new one.

 

"BTW, is the egr valve this black circular thing above the passenger side valve cover w/ about 3 rubber hoses comming out of it?"

do you just dissassemble it and clean it w/ carb cleaner like you would a carb?

money is really tight, you'd be surprised how hard $40 is to come by.

Some buddys of mine told me i should just take it off and bypass it? is this a good idea or no.

 

I have a picture of the EGR somewhere ill dig it up. There it is.

It is definately possible to vclean the EGR. Pull it out and see if cleaning will do the trick for you. I understand the $$ being hard to come by, I have three kids, and a wife I like them all to look good so a lot of my mod money goes to $$hopping. Heh.

Perhaps somone will chime in here and let you know how to clean the EGR. I know a lot of them get really crudded up and it's obvious.

Running without and EGR is not a good idea unless you can burn a custom chip for it. As i explained you will have higher combustion temps, and and that will lead to pinging/detonation. No good for your motor.

Unless your big into internal mods, it is best to have a good working hooked up EGR

**edit** the thing with three hoses should be the EGR solenoid, the one your looking for is round and metal with one hose.

 

thanks, ill let you know how the cleaning job goes, ill do it tomorrow on my half day since i got the wrong aircleaner from the parts store and wont be able to put that on! (damn thing didnt say it was a drop base on the box, so now i have to return it and buy from summit).

 

Be ware that exhaust gasses roll through that thing, so if your car is hot wear gloves, or let it cool down.

I didnt know.. fryed my ****