Higher oil pressure. Oil? Filter? Jeep 4.0

[RegDunlop]

In late march acquired a new to me jeep 4.0

Put in castrol gtx HM 10-30, 5qts and 1 qt castrol gtx 10-40 with orange fram 16 filter.

After oil change i noticed lifter tick on startup until warm, as it was still cold here in nyc

Also the oil pressure gauge was just below the middle



Yesterday i put in a 16 mobil 1 filter and 5qts PHM and 1 quat formula shell 10-40

Still getting the tick on startup

Now the oil pressure gauge is slightly above the middle , and it is very warm in nyc now.



I did notice the PHM seemed very thick when pouring.

What would cause the higher oil pressure? Thicker oil or the different filter?

As far as i know the history of the jeep is conventional 5-30 and generic filters ( they actually had a 3600 on there).

Is the higher oil pressure a concern?

 

[nwjones18]

Why would you be worried that the oil pressure gauge is showing 'slightly above middle'? I think you may be worrying a little much about your new toy. Drive on and enjoy it.

 

[HemiHawk]

My jeep 4.0 will start above the middle (40) but after driving settles just below, maybe 35. Mine has 190k on it.

I found that the Motorcraft FL1A filter quieted down the motor, and seemed to make it start better (just my experience). I use Mobil 1 HM 10-30 and top up with cheap pro-line oil if it gets a little low.

 

[thescreensavers]

The Gauge cluster/oil pressure sender is notoriously incorrect.

You went with a 40wt oil so your oil pressure will be higher than a 30wt oil that's normal.

If its within spec don't loose sleep over it, if you care to see what your oil pressure is buy a gauge. Mine read 11psi at hot idle but I've verified its actually ~25psi

Also Service manual lists

Not less than 13 psi at HOT idle
Between 37-75 psi over 1600 rpms

 

[gomes512]

That gauge isn't even good for answering the question "Do I have pressure?" reliably. They fail pretty often, and as mentioned above are inaccurate.

But to answer your question, no the higher pressure isn't a concern. 40 weight is fine in the 4.0.

Are you sure your tick isn't coming from a hairline crack on the exhaust manifold? This was extremely common on the 4.0s stock manifolds. The crack expands as the exhaust manifold gets hot and seals itself enough to make the tick go away.

The 4.0 will run 30 or 40 weight equally fine, but I'd say that running 10-40 in winter is just a waste of fuel. There was some guy on a Jeep forum that averaged a bunch of UOA's for 4.0s running 30 and 40 weight oil, nothing statistically significant between metal numbers.

 

[RegDunlop]

I was not wooried about it.

I never stated i was worried

The oil weights are the same from change to change, jst different brands

I was just wondering why one would be higher than the other

O guess i did nt state any of it clearly enough

Thanks

 

[Chewie]

I'm not familiar with the Jeep forum, but if I had to guess I'd say there would have been nothing statistically significant between the fuel consumption numbers either between 10W-30 and 10W-40.

 

[Sunnyinhollister]

I may have missed it but what year is the Jeep? Some have gauges some have idiot lights.

 

[JeepWJ19]

I have a 4.0 WJ and have been battling cold start lifter tick for two years. I have always ran Pennzoil HighMileage and a Fram TG16 filter. Upon recently I have been using the FL1A and the Napa Gold 1515 (currently in it) and they seem to be just as good.

Don't worry about the oil pressure. Mine on startup is near 60psi (per the gauge). For my jeep it seems it likes a thicker oil like PHM but likes a 5w rather than 10w. It really shows in the winter. Yours may be different. KCJeep has noted PYB has been about the best for keeping his 4.0 quiet with a filter that has a silicon ADBV.

Since mine *seems* to like thicker oil but a 5w rating I've been toying with the idea of going with Rotella T6 5w40 as I think it has a higher HT/HS vs PHM 5w30. Still on the fence about it. My tick used to be really bad and loud until I found my #6 spark plug had two cracks in the insulator. After replacing plugs the ticking has not been as bad. If it quiets when warm then you have nothing to be worried about.

It's a typical sign of lifter bleed down and truly the real fix is replacing the lifters IMO.

 

[jmb3675]

I had unusual pressure readings after an oil change with my 4.0 Jeep, but it turned out to be a faulty pressure gauge. It seemed like it was working fine and I was convinced it was, but a few weeks after changing the oil it failed completely. I put in a new gauge and the readings were more in line with what everyone told me they should be. I changed to Havoline conventional 5w-30 on my last oil change with a Mobil-1 filter. The Lifter tick is a lot quieter and I only notice it if it sits for more than a few days.

I have a Mobil-1 filter on my F-150 and it quiets the start up rattle on that as well, but not as quite good as the Napa Gold I had on it before. With the Napa filter it could sit twice as long before hearing the rattle. I plan to use a Wix/Napa Gold on the Jeep next time I change the oil along with more Havoline conventional %w-30.

 

[Sunnyinhollister]

I see ~60psig on start up running 10W40. One the oil warms up it is about 45-50psig @2200RPM. Mine is a 1998

 

[Nick1994]

Jeep 4.0s are noisy.

Run some 10w30 and keep on driving!

 

[HemiHawk]

I will add as others have said the gauge is touchy. I had what I assume was an original sensor, and I broke it getting the oil filter off one time. the sensor is right above the filter (at least on my 1998).

 

[Gene K]

I haven't looked at the numbers for those oils but if you went from a 3.0 HTHS oil to a 4.3 HTHS like the difference between some GF5 30 Grades to some 40 grades it could definitely effect pressure.

 

[RegDunlop]

Just to be clear i did not go from a 30 to a 40.


I never stated that.

I think the higher pressure was cause by the mobil 1 filter.

Either that or the pennz hm has much thicker viscsity until warm when compared to castr hm.

It leaked a lot yesterday from around the filter.

Not sure if the higher oil pressure caused the o rings on the filter mount to give up the ghost or what.

Gonna wait a few days and see if the leak stops

I should have never used a pennzoil product , absolute [censored].

 

[JeepWJ19]

Hahahaha And what exactly is the reason of concern about Pennzoil or PHM? Quit blaming Pennzoil for your junky stuff

 

[BrocLuno]

Originally Posted By: RegDunlop
I was not wooried about it.

I never stated i was worried

The oil weights are the same from change to change, just different brands

I was just wondering why one would be higher than the other

O guess i did not state any of it clearly enough

Thanks


the oil weights are not the same. They are both in range so they can claim to be those numbers. But the individual formula for each tests the spread allowed by the range ... The Pennz is thicker...