EGR Valve Question

Have a 1997 Ford TB 4.6. Bought this car new, has only 36,000 miles on it. Question is: This is the 4th time I've had to replace the EGR valve. Anyone have any ideas why this is happening?

Thanks in advance for any input or comments.

Reply to
Brian Arnett
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Thanks in advance for any input or comments.

Reply to
Swanny

Swanny Thanks for the info. Car read a P0402 trouble code. Ford replaced the EGR valve. Display monitor DPFE read 2.3 volts hot idle/Koer exesive EGR flow/ pin point replace EGR valve clear codes retest OK now Pass drive, Postest DPFE read .99 volts hot idle. (Taken from Ford readout).

In the past the DPFE sensor has been replaced, and the EGR replaced twice. Fuel injector service has been performed, so no carbon buildup to blame.

Will see how it performs this time. Again, thanks.

Reply to
Brian Arnett

Brian Arnett opined in news:ulRJc.264317$Gx4.80866@bgtnsc04- news.ops.worldnet.att.net:

Assuming carbon gumming of valve...try changing your brand of gas, and driving habits.

Higher rpm's, longer drive after warmup.

Reply to
Backyard Mechanic

Funny you should mention brand of gas, have always been "brand loyal" using Shell gasoline, recently used BP Amoco. Will rule brand(s) of gas out. Although this is a low mileage vehicle, most of miles are interstate miles, so will rule out second suggestion. Maybe should start challenging local tuner cars at red lights?? Thanks for advice, but still at a loss.... Glad Ford has 12/12 guarantee......

Reply to
Brian Arnett

In my experiance it is the DPFE that fails almost ALWAYS on that year. The older ones would build up carbon and block the passage. Does your car warm up proberly I wonder? It shouldnt take more than a few minutes to reach normal temp....

Reply to
Scott M

Humor me please.... What is the DPFE?

Reply to
F.H.

Differential Pressure Feedback EGR sensor. It is a solid-state sensor that measures the pressure difference between two ports on the pipe that exhaust gas flows through when the EGR valve is opened. In the middle of the pipe, between the two pressure sampling ports, there is an orifice that generates a small amount of pressure drop. The flow of exhaust gas in this pipe is proportional to the pressure drop, which allows the engine management computer to calculate the actual amount of exhaust gas flowing when the EGR valve is opened.

If the DPFE is defective, or if the pressure sampling ports or the hoses attached to them are clogged with deposits, the computer will think there is less or more EGR flow than there actually is, which can cause problems.

Reply to
Mark Olson

Thanks. I have the same vehicle and I was curious.

Reply to
F.H.

egr systems are carburation legacy devices! when the throttle plate (valve) closes with your foot off the accelerator intake vac goes hi and subsequently the mixture rich and unburned hc hi. opening egr valve dilutes rich intake mixture and thus reducing unburnt hc. you know the egr system is working when you coast off the freeway and the engine stumbles or dies when you subsequently step on the accelerator. with cumputerized sfi there should be no reason for egr systems except that CARB likes them, manfacturers get by making you pay for them, and dealers get to sell you stuff and charge you $$$ to put the mil out! the amount of nox the egr system reduces is about zero. i've been getting a pi407 code for quite sometime on my 95 TB 4.6L. i just reset it with my obd2 codereader. maybe one of these times i'll try and clean the egr passage in the intake manifold. over the last 30+ yrs i've plugged vac lines to egr valves, blocked off valves and cleaned a few. i replaced one before i found out they were cleanable. who stuck us with this neusence CARB? the lord? the devil? obviousely i don't do this for a living -- i would not be complaining! the Charles O Probst' book on ford fuel injection is the best i've read on gasoline burning engines in years.

Reply to
lowell75

I have looked over some of the other replies to your problem. One question I have is; has anyone cleaned the EGR port in the intake? They have a tendency to foul and restrict or outright plug the EGR gas flow. Mine has plugged to the point that I could completely remove the EGR valve with no effect on performance or idle. It can and many time does give a code for improper DPFE readings. I have had the same problem with my CV. It is a bit of an oil burner and the problem will go away for 25-30K miles after a good cleanig and always shows up as a DPFE problem. Your low mileage indicates it may not always be operating at high enough temps to keep itself clean even though many of the miles are highway miles.

Reply to
lugnut

================= Dude, you need to read up on EGRs. All of your statements about them are dead wrong.

Reply to
Scott M

Your mileage is very low for the vehicle year. Do you make a lot of short trips? Or does the vehicle just not get a lot of use? Either way you're a candidate for getting a lot of sludge buildup due to the motor not getting good and warm when you drive. Condensation is your biggest enemy, and the only way to keep it down is to drive the car a decent distance at least once every 2 weeks or so in order to get it good and warm, and give it time to burn off the condensate. Another problem may be oil change intervals. Frequent short trips is severe duty, not light, and you should change the oil more often. Cutting the crud buildup will keep your EGR (and the rest of the motor!!!) cleaner and will make it last longer. I generally change the EGR valve every 2 years, but that's at the 25,000-30,000 mile time. They still rattle when I replace them.

Reply to
max-income

From all indications, it appears that you are in fact referring to the *PCV* valve.

Not the same thing...

Reply to
Neil Nelson

LOL, Relief, I thought it was just me having senioritus.

Reply to
F.H.

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