[06XterraSE24]

I have a 2006 Xterra 4WD with 121,000 miles. Recently, when the vehicle is at operating temp, my oil pressure gauge moves around like this

but my gauge jumps around a little bit more. It seems to get worse when the outside temps are 90°F or higher. We’ve cleaned the original oil sender with another OE sender and nothing changed. We checked the oil pressure with a mechanical gauge and it seemed okay. I do notice a little noise coming from the engine when the gauge begins moving around. It’s not like a metal on metal sound but like an engine that is slightly getting bogged down. Is this the beginning of oil gallery gasket problems? Somebody else on here started having fluctuating oil pressure after getting the timing chain done. I had mine done a couple days before I noticed the oil pressure gauge moving around. I’m aware the 05 and 06 have a live gauge but the way my gauge acts is different. The gauge jumps around when at idle but shows good oil pressure when driving.

 

[careyj]

Really hope someone has a good response, pretty much what I’m dealing with.

 

[mtnbound]

easiest thing might be to just swap in a new sensor and see if it fixes it. they are very easy to replace.

it is interesting that several people report this after timing chain work, i wonder if its possible for a gasket to be damaged during the job?

 

[06XterraSE24]

easiest thing might be to just swap in a new sensor and see if it fixes it. they are very easy to replace.

it is interesting that several people report this after timing chain work, i wonder if its possible for a gasket to be damaged during the job?

Swapped the sensor. Both sensors were OE. Tried manual oil gauge and it read oil pressure that was okay.

 

[mtnbound]

Swapped the sensor. Both sensors were OE. Tried manual oil gauge and it read oil pressure that was okay.

which is odd if the mech guage was showing good( im assuming you mean stable pressure) that would indicate that there is no actual oil pressure problem, just the guage not reading it correctly

 

[06XterraSE24]

which is odd if the mech guage was showing good( im assuming you mean stable pressure) that would indicate that there is no actual oil pressure problem, just the guage not reading it correctly

What’s weird is when the gauge on my gauge cluster begins to dip, you can hear the engine make a different sound. It’s like it’s getting bogged down slightly.

 

[mtnbound]

What’s weird is when the gauge on my gauge cluster begins to dip, you can hear the engine make a different sound. It’s like it’s getting bogged down slightly.

its not the AC kicking on/ off is it?

 

[06XterraSE24]

its not the AC kicking on/ off is it?

It happenes both with the AC on and off. Most of the times I notice the gauge bouncing around is with the AC off.

 

[mtnbound]

It happenes both with the AC on and off. Most of the times I notice the gauge bouncing around is with the AC off.

well im all outta suggestions!

 

[Tlrtucker]

It happenes both with the AC on and off. Most of the times I notice the gauge bouncing around is with the AC off.

Check your battery and battery cables. Can't tell you how many times I've experienced, or heard stories, about gauges doing the dance when either a battery is on the way out, or one of the cables is corroded. You have to physically inspect the cables, not just look at them. They corrode from the inside out and can look fine, but be completely corroded inside.

 

[06XterraSE24]

Check your battery and battery cables. Can't tell you how many times I've experienced, or heard stories, about gauges doing the dance when either a battery is on the way out, or one of the cables is corroded. You have to physically inspect the cables, not just look at them. They corrode from the inside out and can look fine, but be completely corroded inside.

I’ll inspect the cables. Battery was replaced last year but out of the vehicle for about 8 days when the timing chain was done.

 

[Brian086]

You have cause and effect reversed.

The bogging engine is causing the oil pressure to dip. When the idle drops to about 500rpm the oil pressure gauge will pick up the dip in pressure.

It's also possible to see the same fluctuation when the oil is extremely hot at normal 600-650 idle (like, just towed 4,500lb up a mountain kinda hot)

You're oiling system is almost certainly fine. You need to figure out why it's idling poorly.

 

[Lowcountry idn]

From your video - wth it bouncing around like that - up and down - it looks a lot more like an electrical problem. Battery cables, ground, not sure if the cluster goes through the IPDM, or what. If it were actually bad oil pressure at lower RPM it would drop and stay there until RPM picked up for a bit - ie it would be smooth up and down, not jittery.

 

[Xtra99]

It would be interesting to view scan tool data for RPM and oil pressure at operating temp and at cold start up. The oil pressure gauge seems to fluctuate at the low end of its range at idle (625 rpm), but goes to the middle of the gauge at higher RPMs (1,500 and above?) and stays in the middle even as RPM rises.

This makes me think the oil pressure gauge is "sort of live" in that it fluctuates at lower pressures, but stays in the middle of the gauge regardless of higher rpm and higher oil pressures. In other words, if the scan tool data shows rpm and actual oil pressure numbers correlate well, then ignore the oil pressure gauge. That "live gauge" may only be partly alive...more of a nuisance gauge.

Also...the timing chain job could have involved a vacuum line not being properly reconnected leading to a small vacuum leak and the rough running at idle. The small vacuum leak isn't significant at higher rpms.

Prior to the timing chain work, did the oil pressure gauge always remain in the middle of its range?

 

[Brian086]

Early X's have a real live oil pressure gauge.

Nissan VQ engines have oil pressure regulators. Pressure will basically never go higher than 'normal'

It's rough on Z cars. Sustained track duty has a nasty habit of overheating the oil because the pump is pushing more oil than the engine needs. The excess just gets discharged right back to to the pan and the constant churn puts a lot of heat in.

Only time I've ever seen mine raise up is on startups in negative temperatures. And it only takes about 10 seconds for it to heat the oil enough to fall down.

 

[Xtra99]

Early X's have a real live oil pressure gauge.

Nissan VQ engines have oil pressure regulators. Pressure will basically never go higher than 'normal'

It's rough on Z cars. Sustained track duty has a nasty habit of overheating the oil because the pump is pushing more oil than the engine needs. The excess just gets discharged right back to to the pan and the constant churn puts a lot of heat in.

Only time I've ever seen mine raise up is on startups in negative temperatures. And it only takes about 10 seconds for it to heat the oil enough to fall down.

Interesting. I didn't realize there was an oil pressure was regulator (part 15241-43U0A) on this engine. Learned something today.

For reference purposes, oil system chart and expected oil pump discharge pressures:

 

[06XterraSE24]

You have cause and effect reversed.

The bogging engine is causing the oil pressure to dip. When the idle drops to about 500rpm the oil pressure gauge will pick up the dip in pressure.

It's also possible to see the same fluctuation when the oil is extremely hot at normal 600-650 idle (like, just towed 4,500lb up a mountain kinda hot)

You're oiling system is almost certainly fine. You need to figure out why it's idling poorly.

The RPMs don’t move. They stay steady at 600rpm when idling. The engine make noise like you’re starting off in 2nd gear but RPMs are still at 600.

 

[careyj]

It would be interesting to view scan tool data for RPM and oil pressure at operating temp and at cold start up. The oil pressure gauge seems to fluctuate at the low end of its range at idle (625 rpm), but goes to the middle of the gauge at higher RPMs (1,500 and above?) and stays in the middle even as RPM rises.

This makes me think the oil pressure gauge is "sort of live" in that it fluctuates at lower pressures, but stays in the middle of the gauge regardless of higher rpm and higher oil pressures. In other words, if the scan tool data shows rpm and actual oil pressure numbers correlate well, then ignore the oil pressure gauge. That "live gauge" may only be partly alive...more of a nuisance gauge.

Also...the timing chain job could have involved a vacuum line not being properly reconnected leading to a small vacuum leak and the rough running at idle. The small vacuum leak isn't significant at higher rpms.

Prior to the timing chain work, did the oil pressure gauge always remain in the middle of its range?

Are there any specific vacuum lines that come to mind?

 

[careyj]

Swapped the sensor. Both sensors were OE. Tried manual oil gauge and it read oil pressure that was okay.

Do you remember what the gauge was actually reading? I know when it's advanced stage pressure can drop to like 2 psi. I'm trying to gauge how long I have.

 

[06XterraSE24]

Do you remember what the gauge was actually reading? I know when it's advanced stage pressure can drop to like 2 psi. I'm trying to gauge how long I have.

PSI at idle should be 14. It was reading 14 most of the time then dropping to just under 13nthen back up to 14.