Lifter Question

The Gas and Diesel Engines - VQ40De, VK56DE, YD25DDTi, V9X, Transmission, Transfer Case, Oil, Differentials, Axles, Exhaust...

Moderator: volvite

Twospeed
Posts: 41
Joined: Wed Jul 30, 2014 1:43 pm
Location: San Marcos, CA

Lifter Question

Postby Twospeed » Mon Oct 15, 2018 5:54 pm

I can't find any information about the lifters on an 06 Pathfinder. Are they hydraulic or solid?


User avatar
smj999smj
Site Admin
Posts: 6054
Joined: Sun Jan 22, 2012 11:13 pm
Location: Prospect, VA

Postby smj999smj » Mon Oct 15, 2018 8:33 pm

They are solid "bucket tappets."

Twospeed
Posts: 41
Joined: Wed Jul 30, 2014 1:43 pm
Location: San Marcos, CA

Postby Twospeed » Tue Oct 16, 2018 10:28 pm

I'm getting noise that sounds like a dry lifter. It's been going on since I've owned the PF. It had 40K miles when I bought it. The noise has always been pretty loud when it's cold out and I used to never hear it when it was warm out. If I let the engine warm up for a few minutes when the weather was cold, then I wouldn't have any problems with it. Now it's got 175K miles on it and the noise doesn't stop whether it's warm or cold outside. It's a light noise after the engine has warmed up but it's still noticeable. Now I've heard about a Variable Induction Air Control System (VIAS) Power Valve Actuator but the noise I have is continuous throughout the RPM range but it does get louder with higher RPMs. The injectors have been replaced as well as coils with OEM parts. The noise didn't change. Should I start looking at the lifters? The oil has always been changed on time with Mobile 1 5-30 and a Mobile 1 filter. I take really good care of the PF. Any suggestions will be greatly appreciated.

Twospeed
Posts: 41
Joined: Wed Jul 30, 2014 1:43 pm
Location: San Marcos, CA

Lifter replacement

Postby Twospeed » Tue Jan 29, 2019 5:55 pm

Has anyone had to replace lifters on the 4.0? Is removing the CAM required or can they be replaced without removing the CAM, front engine cover, etc. etc.? The lifters are making a lot of racket and I have a long trip coming up soon so I don't want to have to worry about them, or listen to them, for several days.

User avatar
underworld1001
Posts: 328
Joined: Sun Nov 27, 2016 9:05 pm
Location: Austin, TX

Postby underworld1001 » Tue Jan 29, 2019 9:34 pm

Not sure if this applies here, but hanging around "tuner" shops when I was younger, some of the guys thought their Hondas has lifter issues when it was their fuel injectors that were just loud. Factory injectors mind you.

Not sure with Nissan. I hear a clicking with mine, but never had any issues in the 40k that I've had it regarding the engine. So, I just keep on, keepin' on. :D

Twospeed
Posts: 41
Joined: Wed Jul 30, 2014 1:43 pm
Location: San Marcos, CA

Postby Twospeed » Tue Jan 29, 2019 10:10 pm

I changed injectors on it just recently. Maybe two years ago with around 6000 miles on them now. The noise was already there. That was the reason I changed them. Did plugs and coils too.

User avatar
smj999smj
Site Admin
Posts: 6054
Joined: Sun Jan 22, 2012 11:13 pm
Location: Prospect, VA

Postby smj999smj » Tue Jan 29, 2019 10:15 pm

They are solid, bucket tappets. Unlike earlier VQ engines, they do not have replaceable shims, so the proper sized bucket tappet has to be determined by checking each one's valve clearance and figuring out what size tapped will be needed to get the clearance in spec. It is a very time consuming job and does require removal of the camshafts, which in turn requires removing the front cover assembly and timing chains. I won't say they never fall out of adjustment, but it's not uncommon. If you here a lot of noise, you may want to make sure the oil pressure is not too low, which can occur if the gallery plate gasket blows out on the rear timing cover. Another thing that can sound like a lifter tap is an exhaust leak at or near the exhaust manifold. There have been cases of cracks developing near the flanges on the VQ40DE manifolds.


Return to “R51 Engine, Driveline and Powertrain”