Rough idle, Rough under load
#1
06-24-2011, 08:43 PM
Join Date: May 2011
Location: LA (Lower Alabama)
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Rough idle, Rough under load
Let me start with the truck specs; 2001 F-150, 5.4 L, 196k miles.
I recently replaced the intake manifold (cracked plastic on the right side near crossover) since I reassembled, it has been running bad. I originally thought it was a misfire, and waited for a code to pop to focus my COP replacement but 200 miles later I have not had a code. I then thought it may have been a bad gasket on the replacement intake. It was a Dorman products replacement intake with embedded gaskets upper for throttle body and lower for intake/head.....
... so I took it to a garage and put a smoke machine on it and saw smoke coming out of the EGR valve. My question is, is the EGR valve suppose to be open or closed with the engine off? If it is suppose to be open would smoke coming out of it during this test be normal? And if it is suppose to be closed would it being stuck or otherwise messed up cause my problems, that I guess I should explain better.
The truck will run rough at idle and especially under load, ie. up a hill, passing etc it feels very similar to a misfire but like I said 200 mi. and no code. It seems to smooth out for no apparant reason occasionally for 10 or 15 seconds while driving or at idle but then go right back to running rough.
There also seemed to be a very small amount of smoke coming from the idle air control valve, but it was ver small. Also the EGR would still leak smoke if the vacum line on the top was removed.
Sorry this was so long I tried to get everything I thought was important. Thank you for any advice you could give.
I recently replaced the intake manifold (cracked plastic on the right side near crossover) since I reassembled, it has been running bad. I originally thought it was a misfire, and waited for a code to pop to focus my COP replacement but 200 miles later I have not had a code. I then thought it may have been a bad gasket on the replacement intake. It was a Dorman products replacement intake with embedded gaskets upper for throttle body and lower for intake/head.....
... so I took it to a garage and put a smoke machine on it and saw smoke coming out of the EGR valve. My question is, is the EGR valve suppose to be open or closed with the engine off? If it is suppose to be open would smoke coming out of it during this test be normal? And if it is suppose to be closed would it being stuck or otherwise messed up cause my problems, that I guess I should explain better.
The truck will run rough at idle and especially under load, ie. up a hill, passing etc it feels very similar to a misfire but like I said 200 mi. and no code. It seems to smooth out for no apparant reason occasionally for 10 or 15 seconds while driving or at idle but then go right back to running rough.
There also seemed to be a very small amount of smoke coming from the idle air control valve, but it was ver small. Also the EGR would still leak smoke if the vacum line on the top was removed.
Sorry this was so long I tried to get everything I thought was important. Thank you for any advice you could give.
#2
06-25-2011, 01:34 AM
Join Date: May 2011
Location: LA (Lower Alabama)
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I believe I have a small technical correction to my post above, I believe the piece that was leaking during the vacuum test is called the EVR solenoid. Whatever it is called it is locater on the right side of the engine coming off of the throttle body. It looks like a black saucer with a vacuum hose going in the top.