: car is dieing at idle. P048 current trouble code.



cadillaceldo93
12-17-10, 12:11 AM
my car has a current trouble code p048 which means "Exhaust Gas Recirculation (EGR) system Problem" my car is dieing when i idle. if i push my accelerater and give my car a constant flow of gas it will not die? so do i need to replace my EGR valve?

MrDobin
12-17-10, 11:50 AM
Someone with more experience on this may have more advice. But from my reading on here, if you have rodded out the egr lines then it may require replacing. You said it doesn't die if you press the gas. Guess being your idle may be off or you have a vacuum issue. If there was a back up the car would likely still stall out once it settled down to idle after your feet released the gas

cadillaceldo93
12-17-10, 05:58 PM
how can i test if the egr silanoid or the egr valve is bad. and thats the thing i can never take my foot off the gas or it die's so if im at a stop light i have to keep my foot on the gas and keep the rms at 1000. if i take my foot off the gas it dies.

cadillac_al
12-17-10, 09:02 PM
It sounds like a massive vacuum leak to me. If it was that bad you should be able to hear it while looking under the hood with an assistant keeping the car running. If you don't hear or see an obvious leak then it would be nice to check the vacuum. If it's very low it is probably a clogged catalytic converter. Check those EGR tubes first as was already mentioned. I think these cars have the old vacuum operated EGR valve that is usually pretty reliable.

I always thought the 93 Eldorados where Northstar engines; I dunno, close to transition time anyway.

cadillaceldo93
12-17-10, 10:38 PM
ive been trying to look up as much info about this trouble code as possible and it seems like when most people have this problem their check engine light also comes on. mine is not on. could this maybe help narrow down the solution? i cant find a leak anywhere? can i get a light tester and see if the egr solenoid is working?

HUF
12-18-10, 02:11 AM
1. Clean the bores and the backside of throttle blades with a carb cleaner.
2. Rod out those two EGR tubes under the blades (I am sure they are clogged).
3. Start the cold engine and press the diaphragm of the EGR valve with fingers. The engine SHOULD stall.
4. Pull off the vacuum line from the EGR valve, press it's diaphragm as far as you can and plug the vacuum input with finger. The diaphragm should NOT move .
Report the results of these four test.

You have had enough information to do some tests. We cannot do them for you.

cadillaceldo93
12-18-10, 07:16 PM
1. cleaned bored and blade.
2. cleaned out egr tubes in the TB. were not clogged not much residue in the tubes.
3. you cant press down the egr valve it doesnt move its bolted to the engine?

i took the hose off from the egr solenoid the input hose had a air going through it but no air was going through the output hose? will the engine stall if air is not going to the egr valve? and i took the negative of the battery to reset my codes
now the p048 trouble code is not appearing?

the recluse
12-18-10, 08:16 PM
3. you cant press down the egr valve it doesnt move its bolted to the engine?

:smack: Reach up UNDER the EGR valve. you will feel the diaphragm. Press it then and follow instructions.:pwn:


and i took the negative of the battery to reset my codes
now the p048 trouble code is not appearing?

It takes some 50 cycles before the motor throws a code, if you were having problems now, it'll probably pop up later.

HUF
12-18-10, 09:06 PM
I never mentioned EGR SOLENOID. I was talking about EGR valve.

cadillaceldo93
12-18-10, 09:21 PM
i pressed the diaphragm up. now my car is running worse when i take the vacuum hose off the EGR valve and plug the input and press the diaphragm it does go up it sounds like air is being pushed out.
now my car is dieing very quick i can barely start my car and get to the front of the car before it dies:banghead:

HUF
12-18-10, 10:37 PM
i pressed the diaphragm up. now my car is running worse when i take the vacuum hose off the EGR valve and plug the input and press the diaphragm it does go up it sounds like air is being pushed out.
now my car is dieing very quick i can barely start my car and get to the front of the car before it dies:banghead:
Oh boy.. can't you just follow these simple steps WITHOUT improvising? lol
3. Start the cold engine and press the diaphragm of the EGR valve with fingers. The engine SHOULD stall.
4. Pull off the vacuum line from the EGR valve, press it's diaphragm as far as you can and plug the vacuum input with finger. The diaphragm should NOT move

cadillaceldo93
12-18-10, 11:02 PM
what am i doing wrong i truly appreciate your help, i am not fluent with cars but have been trying to learn. as far as i knew i was following the steps. the diaphragm is the object in(under) the EGR that goes up in down correct? i was doing what you said and when i pushed the diaphragm up it would not die but it would drop rms like it was about to die then i took the hose of the input pushed the diaphragm up and put my finger on the input. when i am putting my finger on the input should the diaphragm be pushed up or be left down and try to push it up?

the recluse
12-18-10, 11:21 PM
...when i am putting my finger on the input should the diaphragm be pushed up or be left down and try to push it up?

:histeric: OK,OK, we'll work through this...

What he said was once you pull the line off of the EGR valve, push the diaphragm up and plug the vacuum port with your finger. RELEASE THE DIAPHRAGM BUT DON"T REMOVE YOUR FINGER FROM THE VACUUM PORT. The diaphragm should NOT move.

HUF
12-18-10, 11:22 PM
what am i doing wrong i truly appreciate your help, i am not fluent with cars but have been trying to learn. as far as i knew i was following the steps. the diaphragm is the object in(under) the EGR that goes up in down correct? i was doing what you said and when i pushed the diaphragm up it would not die but it would drop rms like it was about to die then i took the hose of the input pushed the diaphragm up and put my finger on the input. when i am putting my finger on the input should the diaphragm be pushed up or be left down and try to push it up?

The fact th engine was about to die when you pushed the diaphragm is good, that means the EGR passages are clean. Probably th eengine was warm, if it were cold it would rather stall.

The second test, engine not running, depressing the diaphragm and plugging the vacuum input with finger is supposed to test the integrity of the diaphragm. If it is good the diaphragm will stay pressed as long as you keep your finger firm. If it moves slowly back - the diaphragm is shot and you need a new EGR valve.

I would recommend to move with fingers the diaphragm up and down to free it up, drive for a few days and watch.

In the worst case scenario you may need a new EGR valve. Replacing one is a pain, GM did a good job to make it as difficult as possible.

As for two EGR tubes you cleaned, even if they were partially clogged, it might be just enough to set 048 code and SES light. Hope this helps. Do not forget to reconnect the vacuum line. Good luck!

HUF
12-18-10, 11:25 PM
The recluse,

Thank you for helping the guy out. You are better with words than I am! lol

cadillaceldo93
12-19-10, 12:42 AM
alright, engine is cold and i pushed the diaphragm up as far as i could and it did not die but did drop rms. with engine off i tried to push diaphragm up it is much harder to push up but i pushed it up as far as i could and then plugged the input with my finger and released and the diaphragm released . so now what do i need to do? it wasnt running as bad as it was when i posted last seems like the cold engine runs better. not for sure if this helps but i changed my spark plugs and spark plugs wires before this problem started happening could that have anything to do with this?

HUF
12-19-10, 01:06 AM
alright, engine is cold and i pushed the diaphragm up as far as i could and it did not die but did drop rms. with engine off i tried to push diaphragm up it is much harder to push up but i pushed it up as far as i could and then plugged the input with my finger and released and the diaphragm released . so now what do i need to do? it wasnt running as bad as it was when i posted last seems like the cold engine runs better. not for sure if this helps but i changed my spark plugs and spark plugs wires before this problem started happening could that have anything to do with this?
Well, if the diaphragm moved when the input was plugged with your finger - the EGR valve is shot.
If the cold engine did not stall, your EGR passages are not in great shape.

Rather closed when open EGR valve should cause less drivabilty issues than all time open EGR valve, so you probably can drive like that (fuel economy may drop, emission may be not good either, some spark knock at light throttle when engine is very hot may happen too).

Sure, you could mess up the plug wires, spark plugs , etc. Make sure (double check) the wires routed correctly to correct cylinders.

cadillaceldo93
12-19-10, 01:17 AM
ok so i guess ill buy a new egr valve but getting it on is probably something im not going to be able to do it looks extremely difficult and time consuming and yeah it did drop and it didnt drop slow it just came down i could not get it pushed up all the way with the car off it was very difficult to push the diaphragm up. and why would a bad egr valve cause these problems?

the recluse
12-19-10, 12:39 PM
and why would a bad egr valve cause these problems?

Ok, I'm going to give you the mechanics/mechanical description of how this system works. So here goes:

The Exhaust Gas Recirculation (EGR) system helps to reduce vehicle emissions by introducing a small amount of exhaust gas into the engine's intake manifold. Re-burning this used fuel reduces combustion chamber temperatures. EGR failures can be subtle and are usually progressive.

An EGR system starts at the exhaust valve or manifold, where a small channel redirects a certain amount of the spent gases toward the EGR valve. Then it will be opened by the engine computer (like the one in your car, it's opened by the computer controlled solenoid). Once the valve is open, a predetermined amount of exhaust flows into the intake manifold, and from there into the combustion chamber.

Essentially, there are only two types of failure: the engine receives either too much or too little exhaust gas. Failures are usually due to the EGR valve sticking open or shut, but can also be due to a leak in the system. The EGR valve can stick because it is not receiving the vacuum or electric signal to move, or because it is dirty and encrusted with carbon.

An inoperative or clogged EGR valve will result in a rough idle, poor fuel economy and possibly a loss of power. Loss of power is especially prevalent with valves that are stuck open, as this will permit hot exhaust gases to constantly enter the combustion chamber when they are not needed. These gases will displace the air and fuel that your engine needs, causing a loss of power.

So there you have a "Cliff Notes" of the basic EGR system. On your particular engine, there are rods under the butterfly's of the throttle body in the intake manifold. That is where the EGR feeds back the exhaust gases and these usually clog with carbon. It was suggested that you rod these out because in the cases where they are clogged, it renders the EGR system useless; causing the problems mentioned before.

The easiest way the remove the EGR is to remove the throttle body. If you don't want to go that route, a 13mm crows foot with a 4" to 6" extension and a telescoping magnetic bolt fetcher to set the bolt back into position is another option. Try and clean the passage ways the best you can with some picking, scraping, and carb cleaner before re-assembly.

HTH, and have fun.

cadillaceldo93
12-19-10, 01:07 PM
ok thanks for all the help i might take a shot at replacing it myself. but for now im off to work!

cadillaceldo93
01-18-11, 07:08 PM
i changed my EGR valve and my car is still dieing when i come to a stop or am idling?

the recluse
01-18-11, 08:05 PM
Did you ever check for a vacuum leak? You could have a problem with the EGR solenoid, as it is run, in part, by vacuum. Look for a vacuum leak.

cadillaceldo93
01-18-11, 08:48 PM
there is a possibility of a leak. all the hoses coming off the TB hard hard hoses so some broke getting the TB off but if replaced them with vacuum hoses but theirs a chance i dont have a good connection i guess.

the recluse
01-18-11, 10:38 PM
Take some carb cleaner and spray around all the vacuum connections. Spray around the base of the TB. Spray the TB itself (just not down the butterflies). Spray ALL the vacuum lines. IF the engine runs right or idles out fine (it will only be for a moment), you've found the vacuum leak; R&R the line.

You'll have vacuum lines going all the way up to the firewall (passenger side). These run the vacuum diaphragms under the dash for the A/C controls. On my car I had to replace about 12 feet total of line due to bad cracking and dry-rot. I've also had lines that were cracked that looked in tact. That's what the carb cleaner is for, seals up the crack just long enough.

Try it and report back.

cadillaceldo93
01-19-11, 12:46 AM
ok. i got a couple of questions. 1st how much would it cost to have a shop replace all the rubber vacuum hoses that come off the TB? 2nd what should my cars rpms be idling at? i think when i first changed my egr valve everything was ok then one of the vacuum hoses became disconnected while driving. then i tried fixing it and just didnt do a good job fixing the problem.

the recluse
01-19-11, 05:52 PM
$20 will buy all the vacuum lines in the car and should only take about an hour to do it. A shop could charge you $100+ for literally nothing.

Find the leak, if it exists, and fix it first. Run a zip tie around the base of the hose to hold it on if you have to.

brougham
01-22-11, 02:30 AM
:smack: Reach up UNDER the EGR valve. you will feel the diaphragm. Press it then and follow instructions.:pwn:



It takes some 50 cycles before the motor throws a code, if you were having problems now, it'll probably pop up later.

Problem codes come up the second the computer detects a problem. Once the problem isn't detected anymore it takes 50 or whatever number of cycles for the code to disappear or turn to a history code.

drewsdeville
01-22-11, 10:55 AM
Not necessarily. There are other requirements to meet besides the error itself, like recluse states, though there is no standard like 50 cycles. Depending on the error, there is a time, mileage, or ignition cycle requirement that has to be met with the error existing before it will set the code. This is to prevent a plethora of false postives. Your check engine light would constantly be going on and off if there were no "buffers" like this.

brougham
01-22-11, 04:28 PM
Not necessarily. There are other requirements to meet besides the error itself, like recluse states, though there is no standard like 50 cycles. Depending on the error, there is a time, mileage, or ignition cycle requirement that has to be met with the error existing before it will set the code. This is to prevent a plethora of false postives. Your check engine light would constantly be going on and off if there were no "buffers" like this.

That's what history codes are for and why a lot of problems don't make the check engine light come on. My point is that once the computer knows or determined there is a problem it's going to throw a code. It's not going to wait for 50 cycles to do it.

the recluse
01-22-11, 05:54 PM
That's what history codes are for and why a lot of problems don't make the check engine light come on. My point is that once the computer knows or determined there is a problem it's going to throw a code. It's not going to wait for 50 cycles to do it.

The number was just a number to make a point. He was thinking "clear the code, fix the problem". Some things, like ignition, will cycle 30 times to run circuit issues. The other thing you need to consider is that not every problem consistently causes a problem, i.e. your vacuum solenoid controlling the EGR faults (for whatever reason) and throws a code. You clear it. It doesn't throw again for a month. Same issue, different time.

So, yes, the engine might not wait "50" cycles to throw a particular code, but the PART might not fault EVERY time... :annoyed:

brougham
01-22-11, 08:16 PM
The number was just a number to make a point. He was thinking "clear the code, fix the problem". Some things, like ignition, will cycle 30 times to run circuit issues. The other thing you need to consider is that not every problem consistently causes a problem, i.e. your vacuum solenoid controlling the EGR faults (for whatever reason) and throws a code. You clear it. It doesn't throw again for a month. Same issue, different time.

So, yes, the engine might not wait "50" cycles to throw a particular code, but the PART might not fault EVERY time... :annoyed:

Some things won't cause codes like if the EGR solenoid isn't being monitored the computer won't know if it is working or not until something else causes an EGR code- IE a sensor picking up a wrong reading down the line somewhere.

Big question now- is there still a current code for the EGR or are there any other codes? If you've checked for vacuum leaks and there are no and it is still stalling it could be a completely unrelated issue. Maybe the idle is too low to keep it running. Even the new EGR valve could be defective. Are you sure all the wires are hooked up back there?

cadillaceldo93
01-22-11, 11:00 PM
im off tomorrow so im going to fix any vacuum problems. when my car is having this problem (dropping rms) my lights in the car dim when the rms drop is that normal for a vacuum leak?

the recluse
01-23-11, 10:12 AM
Not necessarily anything wrong. The surging and near stalling can run the alternator so low that the electrical system can "fade out", going from charging source to battery and back again when the rpm's rise and fall. Another issue it may be is a failing voltage regulator, but I wouldn't jump on that bandwagon until you fix the possible vacuum issues.

That said, when R&Ring vacuum lines remember to take ONE LINE AT A TIME. You don't want to mix up vacuum lines on these cars as some lines require more vacuum than others and have different starting points because of this. Replace lines with the same diameter line, don't make a small line "fit" because it's all you had left. :nono:

Other than that it should be cut and dry. Look for plastic angled line inserts that may be cracked also and replace those if need be. Most parts houses have replacement ones in a pack for about $3 or so.

cadillaceldo93
01-30-11, 01:19 AM
i fixed all my vacuum hoses today and now my car is not jumping rmps. it still dies at stops so i have to keep my foot on the gas and when im driving my car is hard to shift it revs up to about 4000 rpms before shifting it has not done this before. at idle by car stays around 600rpms

the recluse
01-30-11, 07:45 PM
You're probably looking at a MAP sensor. The MAP sensor won't definitely throw a code on your DIC, so running codes may not help. Run codes again anyway while I ponder....

the recluse
01-30-11, 07:54 PM
You're in luck, I found a closeout on Rockauto.com

Go to your car and look up Fuel/Air, look up MAP sensor, and find this closeout part for $20.79: AIRTEX / WELLS Part # 5S1151

For $20 it's worth the replacement and is looking to be, or at least part of, the problem.

EDIT: Before you go that route, check the vacuum line that leads to the MAP sensor. It should run off a hard line atop the motor. Sometimes, the rubber 90* or the straight vacuum lines crack and you can't see it. Check these first...

cadillaceldo93
01-30-11, 11:40 PM
can u give me more info on where the map senor will be. like near the beltside or sumtin like that. how and ive never been taught how to change my own oil. how many quarts do i need to do an oil change on my car and where is the oil pan at exactly?

drewsdeville
01-30-11, 11:51 PM
We really need a tutorial on how to use the onboard diagnostics here. You could , in real time, monitor MAP sensor operation right on the dashboard rather than spending $20 to find out...

cadillaceldo93
01-31-11, 12:26 AM
i just looked in my cadillac book. i know exactly where the map sensor is its right above the EGR valve. is there any possibility that i can just go to oriellys and have them test the sensor for me or is there an easy way i can test it?

cadillaceldo93
01-31-11, 01:15 AM
i just ran my trouble codes to see if anything new has came up. i have a PO22 trouble code. meaning open throttle position sensor.

cadillaceldo93
01-31-11, 01:20 PM
i have fixed the po22 trouble code turns out the sensor wasnt connected to the TB. seems to be running okay now. i guess ill find out throughout the day.

the recluse
01-31-11, 11:13 PM
We really need a tutorial on how to use the onboard diagnostics here. You could , in real time, monitor MAP sensor operation right on the dashboard rather than spending $20 to find out...

Good idea. I know I'd read it....

Of course, running codes again would've answered that suggestion before it was given....

cadillaceldo93
03-24-11, 05:46 PM
im still having problems with my car. it is still dieing when i come to a stop. i had a pulley break of my power steering pump and had a shop fix it. they said my problem with my car dieing is a bad fuel pressure regulator. is it possible this is the problem. is the regulator on the bottom of the car near the driver side door?

hcaddy95
03-25-11, 12:40 AM
umm take the vaccum hose of the fuel pressue regulator if theres any gas in the hose or its dripping out the nipple of the regulator then yes i would say its bad, do this with the car running and the FPR is on the top of the engine by the distributor, air cleaner etc.. it looks like one of these

http://img412.imageshack.us/img412/1691/01275579069198000000897.jpg

hcaddy95
03-25-11, 01:04 AM
down by the drivers side door??? and that is your fuel filter which i would replace because its cheap. how many miles are on this car? and what have you all done to it?

cadillac_al
03-25-11, 10:40 AM
Gee this threads getting old. I still don't see any mention of a vacuum reading even after it's been to a shop. Does the car have good power while it's running? I was thinking if it had low vacuum it might be a clogged catalytic. If the car still has good power it may not be. If the engine pulls 18 in of vacuum then everything is working normally. Did anyone try to adjust or replace the ISC? That's what actually controls the idle. The EGR code is puzzling since it seems to be working and it has now been replaced too. I have had a clogged cat cause an EGR code in the past.

cadillaceldo93
05-02-11, 02:09 AM
im posting again lol the problem seems to have subsided for now. the weather is warm now and i changed out a bad battery. idk if either one of those could mean anything.