sdmartin65

You're probably right on that raski. A minor inconsistent vacuum leak through the EVR might not be enough to lift the EGR pintle much, but enough to bump the idle. Explains the EGR code though. EGR is moving when it's not supposed to.

Now if the EGR in this instance was leaking, the code would be caused by the valve not moving the amount required while cruising.

Either way could cause the high idle.

Axios

That's the funny thing, there is no code set for anything EGR related.

raski

The condition probably is slight and not enough to set a code. As you stated, you noticed small vacuum present when it shouldn't be. If the valve opened more, the engine would die at idle.To veifiy if this is your problem, pull of the line to the EGR, plug it with a golf tee and go for a drive.

jereman

Thanks for starting this new thread. I am watching it closely because I have very similar symptoms at the moment. I just did a head gasket and am working out the last little kinks. I *feel* like I'm idling a little fast. I have no tach, so I'm going by ear. I have checked for vacuum leaks with propane. At idle I get a slight rpm increase with propane directed right into the holes on the back of the egr valve. I am pretty confident that it is not the big nut on the egr valve, the gaskets on the evp sensor, throttle body or anything else adjacent. I have tested the egr valve with a vacuum pump and it holds vacuum just fine. I believe my coffee can is leaking so it is out of the loop until a replacement comes.

I also *feel* like I'm running hotter than I used to. I am holding very steadily at the "N" of "normal", when the gauge used to only hit "N" when it was getting hot. I am willing to believe that cleaning the substantial amount of crud from the sensor on the block might have made a difference.

Anyone want to give advice on how to check rpms without an onboard tach and/or temperature, so I can have better data? I just bought an infrared thermometer at Harbor Freight today ($17.99) so I am hoping I can get good temp readings with that.

midwestbird

I didn't notice you had started this new thread and I responded to the first thread.

I think you're right. I can't see why you would see a leak out into the engine bay area. The EGR, as you know, intentionally leaks exhaust gas into the intake manifold, and intake manifold vacuum is what opens that valve to allow exhaust into the intake manifold at the right time, but why or how should intake air or exhaust ever be leaking into the engine bay? Doesn't seem right.
What makes you think that? As I mentioned in your other thread, when the engine is off, the Canister Purge Solenoid is not energized and is in a closed, non-flowing condition. The valve opens when the engine is running and is ready to accept fuel vapors. So when the engine is off and the canister purge valve closed, I wouldn't expect any fluid to pass through. Might your Canister Purge Solenoid be faulty?

I have my EGR blocked off. I do not plan to keep it that way permanently, but it is for now. I just cut a piece of aluminum flashing to the profile of the flange and slid it between the EGR valve and the upper intake manifold. Some time later, I heard a whistling sound from my EGR solenoid (it was disconnected from EGR valve, but not from intake manifold), so I capped the vacuum line off prior to the solenoid too. I can't hardly recall why I blocked off the EGR valve in the first place (maybe for "test" purposes, to eliminate a potential cause), but I think if I were you, I'd try just temporarily disconnecting the vacuum line to the EGR to see if anything changes (if the vacuum is disconnected, the EGR shouldn't ever open and, of course, your leak at the EGR should go away).

midwestbird

A manual transmission without a tach was such an offense to me, the first thing I did with my truck was replace the instrument cluster with a $20 JY one that had a tach. It's a pain to physically remove, but I took it from another 8th gen F-150 and the replacement one plugged in to the wiring harness just the same.