EGR Valve?

Tiny
JAKEBARN
  • MEMBER
  • 1996 FORD BRONCO
  • V8
  • 4WD
  • AUTOMATIC
  • 176,000 MILES
I had my check engine light come on. At Autozone they diagnosed it as low flow throught the EGR system. I was wondering what is the best way to address this problem. I con't really afford to have a professional mechanic diagnose and fix the issue.
Monday, December 31st, 2007 AT 6:17 PM

41 Replies

Tiny
INDYUKE
  • MECHANIC
  • 416 POSTS
If I understand correctly, the code(s) say that there was a small amount of flow through the EGR system? The computer cannot read the actual flow of exhaust through the EGR system into the intake, but it can measure how far the EGR valve opens at any given time using an EGR position sensor. Your flow may be fine. But the EGR valve isn't opening up very far.
That could be a problem with the EGR valve itself such as a punctured diaphragm, or a problem with the vacuum solenoid (or wiring) that modulates the amount of vacuum to the valve, or a comprimised vacuum line.
Check the valve first by observing it while revving the engine. It should move. If it doesn't move, put a vacuum pump to it. It should open at about 8Hg. Seeing when it opens with a pump should tell you the condition of the diaphragm. Check all the vacuum hoses relating to the EGR system, as well as the operation of the solenoid and the wiring for that as well. Taking the valve off and cleaning all the carbon out of there is a good idea as well. I hope this helps.
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Tuesday, January 1st, 2008 AT 12:50 AM
Tiny
BUBBA BRONCO
  • MEMBER
  • 2 POSTS
  • 1995 FORD BRONCO
  • V8
  • 4WD
  • AUTOMATIC
  • 17,000 MILES
I recently replaced my entire exhaust system from factory to true dual high performance and after it was all said and done I have a ticking noise barely noticable at idle but loud as could be at normal driving speed. Could this be a bad EGR valve I had a mechanic smoke it for exhaust leaks and it had none. I have really bad rough idle and a weird ding or bong noise noticable when I slow down to stop at a light or stop sign. I also have a weird smell that burns my nose when I floorboard it, it the smell is very strong that burns my nose like an acid could this be normal due to break-in or something else. (Bronco's have a rear power window, when its down I smell it) Thanks.
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Friday, July 17th, 2020 AT 12:03 PM (Merged)
Tiny
2CARPRO JACK
  • MECHANIC
  • 11,533 POSTS
The smell could be the oil used to keep the exaust pipes from rusting when in shipping and storage, it may burn off after a few days, otherwise it could be the cat if so equipped. If you want to see if it has an exhaust leak, use rags and wedge them into the tailpipes, start the engine, the added backpressure will make any leaks loud enough to find
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Friday, July 17th, 2020 AT 12:03 PM (Merged)
Tiny
MACH77
  • MEMBER
  • 2 POSTS
  • 1993 FORD BRONCO
  • V8
  • 4WD
  • MANUAL
  • 165,000 MILES
The check engine light is on and the shop told me the code showed the EGR valve sticking. I would like to know if it would hurt the engine if I can make it stay in the closed position? We don't have IM testing here so that is not an issue. If the valve is always closed would it mess with the computer and make the engine run too rich or too lean?

Thanks.
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Friday, July 17th, 2020 AT 12:03 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
If the EGR valve is not opening it will cause the engine to detonate/ping like a bunch of marbles being thrown into an empty tin can-during acceleration
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Friday, July 17th, 2020 AT 12:04 PM (Merged)
Tiny
MACH77
  • MEMBER
  • 2 POSTS
Well that is not the case in my rig. We disconnected the EGR valve and plugged the vacuum line. The EGR valve is closed. The rig runs great, has lots of power, and does not ping under any circumstance, even when lugged down and mashing the throttle to the floor. Of course the check engine light is on, but that is it.
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Friday, July 17th, 2020 AT 12:04 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
I've overlooked the CEL -get it scanned for code/s might pop up with the code causing the problem-could be the DPFE sensor
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Friday, July 17th, 2020 AT 12:04 PM (Merged)
Tiny
NUB
  • MEMBER
  • 3 POSTS
  • 1992 FORD BRONCO
  • V8
  • 4WD
  • AUTOMATIC
  • 155,000 MILES
One more time, guys.

The tube that leads from the cat. Converter to the egr. Dont really know what it is. Is it really necessary? It has a hole in it and it looks like it will be a real ***** to replace!
This is a 1992 5.8 bronco by the way.
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Friday, July 17th, 2020 AT 12:04 PM (Merged)
Tiny
LEGITIMATE007
  • MECHANIC
  • 5,121 POSTS
Its part of the emissions setup. So if there is a hole in it, it might cause a check engine light also if it is caked up with carbon, that will cause another code, both will make you fail emissions, it should run from the egr valve (underneath it, then down to the cat.
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Friday, July 17th, 2020 AT 12:04 PM (Merged)
Tiny
KINGOFC1UBS
  • MEMBER
  • 2 POSTS
  • 1990 FORD BRONCO
Engine Performance problem
1990 Ford Bronco V8 Four Wheel Drive Automatic 92XXX miles

Alright guys. For the last month or so, my Bronco has been having performance issues. I'm not geting the power I should have, idling is all over the place whether I'm in gear or in park, and I'm puffing black smoke when the engine runs over 2500rpm.
I have replaced plugs, wires, the distributor cap and motor, the upstream O2 sensor, the egr valve, and I have tried to adjust timing. All these fixes have helped, but the problem persists. I'm thinking the problem is the fuel injector, or maybe the bypass valve back to the fuel tank, but I'm not a mechanic, so I really have no idea. What do you think?
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Friday, July 17th, 2020 AT 12:04 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
HAs the check engine light come on? Also, the black smoke indicates a rich air fuel mixture. So, there could be a problem with the injector. (If I remember correctly, 1990 has throttle body injection). If it has multi port injection, let me know.
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Friday, July 17th, 2020 AT 12:04 PM (Merged)
Tiny
RSISCO
  • MEMBER
  • 1 POST
  • 1990 FORD BRONCO
  • V8
  • 4WD
  • AUTOMATIC
  • 25,000 MILES
I have been fighting this problem for about a year. The motor was replaced 25 thousand miles ago. When it was replaced we put an after market intake from edelbrock, and a BBK throttle body. It misses really bad and the idle fluctuates, but only when it warms up. I noticed it after I wrapped one of my headers to protect the starter. I have replaced everything on the ignition system except the distributor cause that was also replaced with the new motor. I have checked all the fuel injectors and they are fine. The egr valve sensor is new but not the valve itself. The exhaust is cut off right after the first cadalitic convertor. The only codes being showed are the tps sensor(wich is also new) and egr flow not sufficiant, also the o2 sensor. Ive been told by a few mechanics that the computer might be bad. If u have any idea please let me know
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Friday, July 17th, 2020 AT 12:04 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Have you checked the EGR for carbon build up? Can you describe what the engine is doing?
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Friday, July 17th, 2020 AT 12:04 PM (Merged)
Tiny
BIGCHIEF31TM
  • MEMBER
  • 6 POSTS
  • 1996 FORD BRONCO
I have replaced the EGR valve, oxygen sensors, IAC valve, and the EGR sensor. My truck still idles rough, unless I remove the vacuum line off the top of the EGR valse then is runs like a champ. Where do I look now?
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Friday, July 17th, 2020 AT 12:05 PM (Merged)
Tiny
BIGCHIEF31TM
  • MEMBER
  • 6 POSTS
ALRIGHT HERE IS THE LESSONED LEARNED. IF YOU GET CODES STATING EGR FLOW INSUFICIENT OR EXCESSIVE. START WITH THIS PART FIRST. UNFORTANELTY IT WAS MY LAST. EVEN THOUGH AFTER 140K MILES THEY WERE IN NEED OF REPLACING ANYWAY. THE FORD DEALERSHIP TOLD ME IT IS CALLED AN EGR "CHECK VALVE". A LITTLE BLACK CANISTER THAT LOOKS LIKE A PRESCRIPTION BOTTLE FOR MEDICINE. IT IS LOCATED TOWARDS THE BACK FIREWALL DRIVERSIDE. THE VACUUM HOSE COMES OF THE TOP OF THE EGR VALVE TO THIS. IT NEVER CAME UP WITH A SPECIFIC CODE FOR THIS JUST (BANK1 +2 RUNNING LEAN AND WHAT I MENTIONED UP TOP.) THANKS FOR THE HELP, AND I HOPE I HELP SOMEONE ELSE THAT COMES TO THIS SITUATION
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Friday, July 17th, 2020 AT 12:05 PM (Merged)
Tiny
BIGCHIEF31TM
  • MEMBER
  • 6 POSTS
ALSO THIS PART I FORGOT TO MENTION IS ONLY 40 BUCKS, COMPARED TO ALL THE OTHER I REPLACED THAT TOTALLED ALMOST 200. YOU PROBABLY HAVE TO BUY IT AT FORD, AUTOZONE HAD NOTHING ON IT
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Friday, July 17th, 2020 AT 12:05 PM (Merged)
Tiny
RJOHNSN
  • MEMBER
  • 22 POSTS
  • 1989 FORD BRONCO
  • V8
  • 4WD
  • AUTOMATIC
  • 120,000 MILES
I got my truck smogged today and the NOX was off the charts high. The tech told me that my hot combustion chamber was responsible for this. I had my cat changed and he said it was something in my egr system. I was wondering how I could diagnose and repair this. Hopefully just cleaning the egr valve?
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Friday, July 17th, 2020 AT 12:05 PM (Merged)
Tiny
DAVE'S BIG BACKYARD!
  • MECHANIC
  • 262 POSTS
You can check the valve with a vac pump and see if it holds vac. The thing you realy want to check is the vac line going to it and make sure it dont have vac at idle.
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Friday, July 17th, 2020 AT 12:05 PM (Merged)
Tiny
RJOHNSN
  • MEMBER
  • 22 POSTS
Could a problem with this system lead to rough idle. Cause the care will idle rough then regular sometimes
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Friday, July 17th, 2020 AT 12:05 PM (Merged)
Tiny
DAVE'S BIG BACKYARD!
  • MECHANIC
  • 262 POSTS
Yes if it has vac at idle it will make it run very rough. But that sounds like a sticking egr valve, but make sure it dont have vac at idle.
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Friday, July 17th, 2020 AT 12:05 PM (Merged)

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