Changed gaskets and the car ran fine. Unfortunately, the valve cover started leaking again and it turned out I incorrectly torqued the valve bolts. Finally had a chance to redo it and no leak but now my idle is lumpy. Already checked that all hoses and connections are installed correctly.

Car drives fine but once I stop the idle fluctuates around 500 rpm and sounds like its going to cut out.

Really trying to finish this project and move on. Help troubleshooting would be appreciated.

Thanks!

 

sounds like you missed a vacuum line...check everything over again. Make sure everything is sealed and tight too

 

This.

 

Maybe a vaccum hose is not attached or it's cracked. Check the plenium area again for hoses that are cracked or that are leaking or the plenium gasket are not properly installed and it's cracked.

 

Prolly need to regasket the UIM again. Did u use a lil RTV? Jus a thin amount so that the goop will add to the gasket seal. Also did u clean the old gasket off entirely?

 

I did not add RTV to UIM and the hose connecting the front valve cover to the rear one is cracked at the edges that I zip-tied.

Also, noticed there's a hissing sound from the left side of the engine area, so I'll check everything again.

Thanks!

 

you dont need to use RTV I never do and mine is fine.

check your brake boost and make sure you tightened the rear UIM bolts accordingly if the hissing is coming from the left hand side

 

Why would he need to put rtv on the intake manifold? The uim gasket is solid and reusable. Have you removed the uim on a maxima before??

To the op, like the others said just check for a vacuum leak. I just did this repair yesterday to fix a rear valve cover leak. My car ran rough when I first restarted it because I sprayed a ton of carb cleaner in the manifold to clean it out.

Make sure the 2 bolts that go on the egr tube are tight. And.. god forbid, but make sure you don't have any vacuum hoses that you may have stretched too much and now have cracks.

 

I appreciate all the quick replies.

It turned out to be the UIM gasket. I had replaced the oem (160k on it, about time) with Pep Boys one. Might be why I had a prob. Anyways, tore it down and used alil RTV and it's back to normal.

BTW, torque spec is 13-16 ft. lbs. and would squeeze the new rubber gasket too much. Torque to 10 seemed to work better. Wish I still had the oem to compare.

Thanks again!

 

Lesson learned: Use gaskets, not RTV unless specified in the manual

 

some ppl use rtv for everything

 

Not sure what you mean, but I did change the valve cover and UIM gaskets. For some reason the new UIM gasket was leaking and someone on the board suggested using alil RTV. Worked like a charm.

My conclusion is that the aftermarket gasket may be of lesser quality than oem.

The manual did not suggest RTV for the UIM, but I'm glad it worked. Was just a hassle to go back in there again.

Thanks everyone!

 

Hey can you be more descriptive on the problem? I just recently changed the gasket and now i think am experiencing the same issue. when the car is in D around 550 rmp the RPM would dip to like 450-500 and go back up real quick. It does not happen all the time and when it does it happens for only about 5-10 seconds then stops if i give it alittle gas

 

That's exactly what was happening to me except most of the time. Turns out I was getting an air leak around the new aftermarket UIM rubber gasket I installed. (Make sure to torque in 4,1,2,3 order.)

Solution was to use some RTV. However, the new UIM gasket rubber is pretty soft and I've heard that the OEM one is either harder or even reusable. Unfortunately, I threw mine away so I can't compare.

You should also check all vacuum hoses especially the 4 under the thottle body. Luckily, you didn't miss the coolant line behind the UIM. That's what I did. It's a PITA to go back.

I hope this helps. It's a straight DYI, but there's a ton of little steps.