Stupid question about the EGR System

[deaz]

Hey, in the middle of changing my ECTS today, and figured I'd ask a little question while I sit here and wait for the engine to cool off...

Recently cleaned my EGR valve, which I would have to say is the worst case of carbon buildup I've ever seen...

Anyway, I was wondering, where exactly do the two ports on engine side head to? I'm mainly asking this because I figure if my egr valve was that gunked up, and by looking inside the port it is also gunked up, then obviously, there must be even MORE buildup inside there...

Wondering if I removed the exhaust manifold, would I be able to get access to those areas? Or would more be required?

Any info or insights as to what else should maybe be de-carbonized would be great too! Thanks!

Information:

92 SL2, DOHC, 182k miles(ish)
MMO soak done(Actually done with seafoam, and also some in the oil, with great results... I only lose between 1/4 to sometimes 1/2 quart of oil per 3k miles)
Throttle body cleaned, not intake yet tho, which really needs to be done... I had about a good 1/8 buildup of carbon gunk all over the t-body... so I really want to get that cleaned up to give it some better airflow

Therm replaced, engine warms to proper temp now, which is also why I'm getting ready to replace the ects.


Getting around 28 MPG as of last month(mixture of city+highway, with a city only of 29)... going to check it again at next fillup after I do these changes and reset the pcm.

Thanks in advance!

[deaz]

Sweet... Just got done the ects, and reset the computer... and now, its just sooo sweet... the car doesn't constantly have to keep switching the fan on and off to lower the temp... its staying pretty constant... still smells rich though... so now I just have to figure out why... or maybe its just still burning off all that excess fuel.....

However I did notice one thing... when I was removing the old ects and putting in the new one, my face was down pretty low so I could see what I was doing. My face was where the air intake was removed for access and I picked up a distinct smell of gas. Now, I thought that the vapor canister was on the other side of the bay, which would account for it, that is if the car was running rich and the canister was flooded with fluid. So, anything else it could be, or is that where the vapor canister usually sits?

[saturnspeed_12]

you could have a small gasket leak making the smell come out under the hood.

here is where the canister is located.......


notice the left side of the picture on frame rail in front of tire. thats it there. oh and the smell of unburned gas is most likely everything built up in the exhaust. catalytic converter might be bad now or all of the exhaust.

and if your curious, that picture is from my car as it stands now. tearing it down after that accident and figuring if i want to rebuild it or strip it.

[deaz]

Okay, well... I don't think the cat is bad, since I'm not throwing any codes. There are usually two o2 sensors, correct? one before and one after the cat I thought. And where that canister is located is around where my head was... in between the battery and the engine, so, maybe that needs to be replaced... Would be nice if I could just empty it out and refill it with some fish filter charcoal, lol... But I doubt that would do any good... Also of note was that the old ects was brass also, however it was heavilly corroded. I noticed some nasty fluid while I was doing my original coolant flush, and it is perfectly fine color now. So, I know that the ects wasn't working properly, but now its working just a bit better. How about as far as all the buildup goes in the intake/exhaust manifolds... Would you suggest I pull them off and clean them all out? I'm off for the next several days, so I need SOMETHING to do... I work graveyard, so it'll be a fun project to do during the wee hours of the morning and the wee hours of the evening, lol...
I KNOW the car is still running rich, I'm just not sure why. I wish there was someway for me to just make it run leaner for a little while and help clean out some of the buildup naturally, but I know that won't happen... I'll check all the vaccum lines once the engine cools off (Just got off from work) and check the vapor canister while I'm at it... Thanks for your advice and the picture!

[PlayStation3]

i forget where i heard this from but i think it was hear that saturns run rich with out any reason

[saturnspeed_12]

your car is obd 1 so it has 1 oxygen sensor before the cat. and if a car has been running rich for a while it will clog a cat up bad. now to clean up the intake manifold you can try pouring seafoam through the pcv and let the engine suck it in but go slowly or it will die. but that wont get rid of everything so its best to remove it and starting fluid does a pretty good job at cleaning it away, but the most effective that most guys do is pour gas into it and all over the build up spots, then set it on fire.

now about it still running rich, what kind of gas mileage are you getting? and did you replace the connector on the ects too because they can corrode up inside and into the wires and you will never know which will cause problems.

oh and about saturns running rich, they will if not in tune. they do have a rich period under full throttle (LIKE ALL CARS!) which is done to protect the engine for damage. my car never ran rich because it was perfectly in tune. it ran rich for a few seconds under full throttle but then leaned back out once it got under control. my car also didnt burn oil, i did things right so it treated me right.

[deaz]

Originally Posted by saturnspeed_12

your car is obd 1 so it has 1 oxygen sensor before the cat. and if a car has been running rich for a while it will clog a cat up bad. now to clean up the intake manifold you can try pouring seafoam through the pcv and let the engine suck it in but go slowly or it will die. but that wont get rid of everything so its best to remove it and starting fluid does a pretty good job at cleaning it away, but the most effective that most guys do is pour gas into it and all over the build up spots, then set it on fire.

Whoops, guess I'm just used to my honda, lol. Used to having two sensors... I would probe the wires to make sure I'm getting the right voltages, but if I wasn't my check engine light should be on...

Well, I figured if I was going to remove it I was going to soak it in that purple power stuff. It did wonders on my egr valve, rinsed it off, and after that, only a little was left to be removed... However, my egr passages on the engine itself are pretty carboned up... and I doubt pouring gas on them and then setting it on fire would be the best idea when its inside the engine... Thats also part of the reason I was wondering about the egr passages... whether they were on the intake side, or exhaust side, so I could get to them easier to clean... Unless I have to take off the valve cover... Which is something I'm planning on doing this weekend anyway, since I want to see what type of condition the engine is in. Well, the top half anyway, lol... And yes, it HAS been running rich ever since I got the car (back in dec/jan I believe).
My cat doesn't seem to be clogged however, since I still have some really nice and good performance... And I really don't have any difficulty running the car at all... Nothing that would indicate a blocked cat... Unless you might have some suggestions as to how to test it... Would stuffing a rug into the exhaust pipe, and it pushing it out be a good experiment? But then again, I have a slight hole in my muffler anyway, which I'm going to be fixing today... Damn rust, lol.

now about it still running rich, what kind of gas mileage are you getting? and did you replace the connector on the ects too because they can corrode up inside and into the wires and you will never know which will cause problems.

Thats the crazy part.. I'm getting 27-29 mpg... (its been going down about 1 mpg per 3k miles I guess... not really sure, since I just recently did my two fillups last night and got my 27 reading... However, about two months ago, it was at 29...
Now, I know what they say, if it ain't broke(or not too broke), don't fix it. But I love tinkering and fixing things that are slightly wrong.
And no, I didn't replace the connector... The old ects I had pulled out was also a brass one, but was heavilly corroded. It looked like a saturn dealership job, because the connector, for being what, 14 years old? looked in really good shape... No corrosion around the connectors at all... I could always probe them to make sure the voltages are being sent correctly, and that would tell me if the connector is bad or not. The new one I had bought from Advance. They now also have the brass tipped ones, just so everyone knows, otherwise I would've went to saturn.
I stopped by Autozone today, and asked a guy if he knew of any good way to clean carbon out of a intake... he suggested the seafoam spray...
He suggested the following:
1. With engine running, spray it into pcv/brake booster lines)
2. With engine off, yet hot, open throttle plate, and soak the mo-fo, let sit for a while, and then start it up, and then finish off with a second treatment (with engine running) to break up anything else.

So I figured, It can't hurt that much, not much different that reg seafoam, as far as I'm concerned... also, the new gaskets themselves aren't all that expensive...

I'm also thinking about investing in a parts cleaner... they had a nice one on sale at Advance... I think it was a 20 or 30 gal w/ everything included for 69.95, reduced from I think around 110.00. Still sounds a bit high, but not too bad for a retail store, lol.


Sorry for the delayed response... for some reason, the forum didn't email me when someone posted here...


Thanks saturnspeed for all your help... (In the past, and into the future )

[deaz]

Oh, almost forgot. I pulled my sparkplugs the other day. I only have about, I'd say 3k miles on them. They were COMPLETELY covered with carbon. I put them in after I did my MMO/Seafoam treatment originally for the piston rings. I just picked up new ones today.

The electrode and the area around the porceline thing were completely covered... Now I know that that could be a major contributor to the running rich problem, but why would it still be running rich even after I replaced them the first time? The amount of the fuel smell has not changed slightly since the day I put them in. I noticed a performance boost when I installed the new ones, but thats about it.

[deaz]

You know what I just thought of....

The oxygen sensor helps control how rich/lean the mixture is correct?
Now, if the engine has been running rich for a while, it's probably all gunked up.
Now, if it was operating properly, it shouldn't throw a code right? Now, what if its operating properly, but throwing the wrong values towards the pcm. The car has a good amount of miles on it. I should probably replace it and that might help solve some of the fuel problems, wouldn't you think?
I mean, considering how much carbon buildup is in the exhaust piping and such, the oxygen sensor has to be really really bad. Shame you can't just clean them and pop them back in.. *sigh*

I guess I'll pick up one next week with my paycheck, unless someone can give me some better ideas...

[saturnspeed_12]

well yeah, i would replace that oxygen sensor. if you know how to wire, then get a universal bosch one which is like $18. of course with that sensor wiring it in is easy.

also i wouldnt get a ects from any parts stores even if they are brass. ive ran 3 or more within a week from advance and auto and a couple times it ran fine till warm, then it went to crap. then a other ive had the car run a few days, then go rich. id trust the dealer part. and a drop of 2mpg isnt anything to be concerned about. if it drops 2mpg every month for like 4 months or more, then there might be a problem. i use to range from 35-42mpg, but have had times down to 32 or a bit lower because of the driving habits or lack there of, .

oh and about the fire thing, i thought you said a way to clean the intake manifold. i havent done it that way, ive used starting fluid, but some saturn guys have actually threw crap all over it and set it on fire which proved very good.

[deaz]

Well, the guy at advance wouldn't sell me a universal...

What exactly should I ask for? Just an OBD-I universal oxygen sensor?

Also, got the valve cover off... Damn that was a hard job... whoever had it off last put WAYYY too much sealant. It had actually run over a bit onto the inside and outsides of the cover...

Anyway, was looking at the cams... Now I wish I had bought a micrometer while I was out, cause the lobes are scorched majorly. Some have a burnt look to them, while others look blueish in hue. The later, I believe is due to oil starvation correct?

Now, heres another part... replaced those plugs not more than 2, well, 3 days ago now, and they are fully set with carbon again... The oil is already majorly old looking (running around for only the past 2 weeks)
And looking down into the spark plug holes, only shows the same major carbon buildup on the heads, when after I did the last treatment, they looked as tho they were brand new...

Oh, and the oxygen sensor WAS completely COVERED in carbon, to the point that I doubt anything was getting inside it... I'm surprised the pcm never threw a code.

[saturnspeed_12]

ah i cant remember when they switched the oxygen sensor bungs, because i know older ones had a smaller bung while the newer had a larger and mine is larger so i was able to get the universal sensor.

now that discoloration on the cam lobes probably means they were starved of oil. and it sounds like the piston rings are carboned REAL BAD, which could is probably letting fuel get into the oil and decreasing oil life. does the oil smell a bit like gas? and for some reason, it sounds like your still running extremely rich.

[deaz]

Yep, still running really really rich... and not sure about the oil smelling like gas... I'll check it out next time I do the oil change... Sigh, damn I miss my honda, lol

[deaz]

Well, right now I'm in the middle of fixing my timing. Stupid me ended up taking off the cam gears without making sure I was at tdc. Before you ask why I took the cam gears off in the first place, it was because I was planning on doing some extra work to the engine, and realized the sun was going down, and didn't have time to finish. And when I attempted to start the car, the valves were chattering like a mo-fo, and I couldn't keep the car running... so, right now, I'm hoping that the valves aren't messed up. But, if they are, at least it's only the intake side ones I'll have to replace.

Now, I'm not sure if I should, but I'll ask all of your opinions right now... Since I'm going to be pulling off the timing belt and all that. Would you guys/gals suggest that I pull the cam gears off again, and then soak the lifters? I don't know exactly how bad they are, or if they are bad at all. But just wanted some suggestions as to anything I could do to help with my current "rich"-ness problem. Also, I guess I should either get some more mmo, or perhaps some of that gm tec? Don't know how much that stuff runs, but since the car is going to be down for another few days, just trying to think of some things I could do while waiting for the rain to stop.


Also, any and all suggestions about ANYTHING that I can do while this engine is apart would be greatly appreciated.


Thanks!

Mike

PS. Could an overly advanced/retarded timing be causing the majority of my problems? Because whoever did the last timing chain replacment(It looks almost brand new, teeth are in great shape and all that) messed up a lot of torque-specs and also didn't properly seal a bunch of areas...

Time to pull out the haynes and start looking up some stuff I guess right? lol

[deaz]

sigh... Was just reading about a guy over at saturnfans.com that had the same sorta problem that I had...

Turns out his was a bent valve... sigh... Well, I'll know for sure once I do a compression check on all of the cyl's once I'm sure the timing belt is good... and god I hope its not more than 2(or 4) valves that need to be replaced.