Rough idle and engine surge after replacing valve cover gasket

BILLY29

MEMBER
2004 NISSAN XTERRA
3.3L
6 CYL
2WD
AUTOMATIC
180,000 MILES

I had to change the valve cover gasket on the drivers side. To do that you have to take off the upper intake plenum. I replaced that gasket as well. Everything was put back as it was. I now have a rough idle and engine surge. Could it be the EGR valve? I sprayed starter fluid around the intake and idle did not change. So the gasket is good. All vacuum hose were put back in the right place.

Friday, October 19th, 2018 AT 1:57 PM

5 Replies

JACOBANDNICKOLAS

MECHANIC
110,068 POSTS

Hi and thanks for using 2CarPros. Com.

Most often, a rough idle is caused by a vacuum leak, but you checked that. Just make sure none of the hoses split or fell off while things were going back together. As far as the EGR, if there was not an issue prior to the gasket replacement, it should be fine.

Next, confirm that all the air intake tube components and hoses are properly attached and not leaking.

Recheck to make sure none of the plug wires are arcing or if one of the spark plugs is partially disconnected.

Let me know what you find.

Joe

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Saturday, October 20th, 2018 AT 4:45 PM

BILLY29

MEMBER
3 POSTS

Hey Joe, thanks for the response!
Okay, this is what I found. I forgot to put a gasket on the EGR plus the PCV valve hose was rough. I put a seal on the EGR and bought a new PCV valve and hose. It is running fine now. Should I reset the computer so it will learn the idle again?

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Sunday, October 21st, 2018 AT 1:36 AM

JACOBANDNICKOLAS

MECHANIC
110,068 POSTS

Great! That will do it. I had a feeling it was vacuum related. As far as the relearn, it will do it on its own. If you delete the codes, it should not make any difference.

If the idle issue does not change, let me know. It may take a few miles to relearn itself.

Take care and good job.

Joe

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Sunday, October 21st, 2018 AT 5:47 PM

BILLY29