Increased Oil Pressure with Synthetic?

[12glocks]

To date I have basically run my Titan V8 (VK56DE) through 4 3K OCI's using Castrol 10W-30 SL. Now before BITOG I would only use factory filters and would never consider Penzoil.

However, I changed to PP 5w30 with a Wix filter (which saved some money over Mobil 1 and a OEM filter). My sump is supposed to hold 6.5 quarts with a filter change but it has always held 7 for me. I do let my oil drain for over 1/2 hour when changing it.

Anyway, after I changed my oil I drove about 12 miles or so into town to take my wife out. We ate (~ 40 minutes) and while on the return trip I happen to accelerate briskly on an on ramp. I noticed my oil pressure jump up to 3 bars, which would be much higher than normal. My first thought was that the oil had cooled more than I thought, because I always try to take it easy until things are up to temp. I drove another 5 miles or so and accelerated briskly again. Same thing.

So I thought I had over filled it. Nope, checked it like 5 times on a level surface in my garage over the last 12 hours. Then I thought maybe there was a filter issue.

I took it out today and after 20 miles of driving I tached it up. The oil pressure went up to 3 of 4 bars. So maybe I worried about nothing. It's just the change that caught my eye.

Sorry about the "long way around the barn" on this, but could someone explain why I am getting more oil pressure from a 5w30 Synthetic than a 10W-30 dino?

Maybe it's the way that synthetics poor that make me think they are thinner. I know they change into a 30W after heating up. Also, yes I am a noob at this. I have pretty much got the hang of the wear metals in the UOA's but the whole shearing and viscosity issue is over my head at the moment.

Thanks in advance.

 

[il_signore97]

I don't know the specs on those two oils off hand, but if you were to look up the kinematic viscosity at 212 F and compare them, you'd be able to tell for sure if one is thicker than the other at operating temps.

From the way you're describing the issue, I would think that the PP 5W30 that you put in is thicker at operating temps than the GTX 10W30. If that is indeed the case, then as long as your oil pressure does not hit "max" (so as to open the oil pressure relief valve), then you're okay.

 

[Highroller]

This topic is similar to mine too (look at my topic that i started in the oil filter section on this site). I have an 06 nissan titan. My oil pressure would be the same with using different weights of 2 syn oils: 5w30 mobil 1 and 0w-30 GC. I believe it's the oil filters that is making the difference in elevated pressure. When i switched my pureone to a wix, i notice a higher pressure reading during startup and driving. With the Wix, when i take it up to about 30 mph in the morning, the needle starts to get higher near the H mark than when i was using the Pureone's. With the pureone's the needle didnt go that higher up going about 30 mph. I didnt know this was normal until i did some research around some nissan titan forums. It seems like many titan owners are asking the same question with their oil pressure gauges. Here's a reply that i got when i asked them about the oil pressure issue:

"Well without getting into this too technically, the main reason you see different pressures is because the Titan uses a "real time" oil pressure gauge. Which means the gauge reads exactly what the pressure is at that exact time. Almost all other manufactures oil pressure gauge just reflect an average pressure. And you will see variations based on oil, filter and ambient temps."

I dont think the oil did anything when i switched to a thicker weight 0w-30 GC. It was when switching to the wix filter that caught my attention. Hope this helps if any.

I must note that during the past winter here in Texs, i was using mobil 1 5w30 and pureone and i did notice a very slight higher pressure reading on the gauge upon startup. So ambient temps. may play a role too.

 

[sootyoil]

quote:

---

Originally posted by 12glocks:
To date I have basically run my Titan V8 (VK56DE) through 4 3K OCI's using Castrol 10W-30 SL. Now before BITOG I would only use factory filters and would never consider Penzoil.

However, I changed to PP 5w30 with a Wix filter (which saved some money over Mobil 1 and a OEM filter). My sump is supposed to hold 6.5 quarts with a filter change but it has always held 7 for me. I do let my oil drain for over 1/2 hour when changing it.

Anyway, after I changed my oil I drove about 12 miles or so into town to take my wife out. We ate (~ 40 minutes) and while on the return trip I happen to accelerate briskly on an on ramp. I noticed my oil pressure jump up to 3 bars, which would be much higher than normal. My first thought was that the oil had cooled more than I thought, because I always try to take it easy until things are up to temp. I drove another 5 miles or so and accelerated briskly again. Same thing.

So I thought I had over filled it. Nope, checked it like 5 times on a level surface in my garage over the last 12 hours. Then I thought maybe there was a filter issue.

I took it out today and after 20 miles of driving I tached it up. The oil pressure went up to 3 of 4 bars. So maybe I worried about nothing. It's just the change that caught my eye.

Sorry about the "long way around the barn" on this, but could someone explain why I am getting more oil pressure from a 5w30 Synthetic than a 10W-30 dino?

Maybe it's the way that synthetics poor that make me think they are thinner. I know they change into a 30W after heating up. Also, yes I am a noob at this. I have pretty much got the hang of the wear metals in the UOA's but the whole shearing and viscosity issue is over my head at the moment.

Thanks in advance.

---

first time I heard more pressure from syn oil change, I have learned that oil filter manifolds are all different and do change volume rates/pressure between brands, hole sizes location design all change physical properties of lubricant flow.
with that said I just finished a call from a friend who used Amsoil in his 05 honda and was curious why the drop in pressure at idle and startup, I had to tell him synthetic oils have low temp fluidity much lower than dino and natrually requier less pressure to flow, and the brand filter he has flows more oil in less time than what he had originally.
he did say under acceleration pressure was normal.

 

[Curious Kid]

Here's a theory for you Highroller - Let's assume for a minute that the PureOne oil filter is more restrictive than the Wix brand. The only way that this could result in a reading that showed the PureOne to present guage readings of lower pressure than the Wix, would be that the pressure meter's sender/sensor was downstream of the filter AND the pressure relief valve on the pump which is opening (perhaps more so than the Wix filter).

The relief valve is between the pump and filter, so if the filter presents higher backpressure, than the difference to the point of the filter's bypass valve actuation pressure differential, could cause the pump's relief valve to open and result in a lower possible pressure beyond the filter due to reduction in flow potential (resistance to flow = back pressure).

If this seems confusing, the wine I'm having is only helping to make my conveyence of thought only that much worse than is commonly the case.

Off to sleep-off the effects.

 

[Highroller]

It's kind of confusing for a young buck like myself but Ok, let me try to understand this so i can ask someone about this...

For this to happen, the relief valve has to be between the oil filter and the pump. The oil sending unit has to be downstream of the filter, am i correct?

I got a pic here that might show something like this, i hope it works... this is supposedly from a titan repair manual... you can barely see the bottom link's pic, i hope i can get another one.


http://www.titanspot.com/phpbb2/files/oil_pressure_sensor_427.jpg

http://www.titanspot.com/phpbb2/files/thumbs/t_oil_pump_173.jpg

 

[12glocks]

First let me say thanks to all the posters so far.

Highroller thanks so much for the info. I just read your entire thread. Thansk for the schematics as well. An uncanny resemblence really. We both change to Wix filters and get higher oil pressure. Whether or not it is because the sending unit is upstream or downstream I guess is the question. Glad to know we have a real sending unit and I see no need to install a "wet" gauge.

I think the bottom line is that we are not hitting the high mark. Even if the bypass did open, it should only be for a few seconds to protect the filter from high pressure right? Good oil pressure has got to be a sign of a healthy engine since it will circulate the oil well. Tolerances must be tight etc.

I purchased one Wix filter to try and do a UOA on with the plan of buying a case of them from fleet filters because the price is so great. At this point I guess I will have to decide if I want to switch back to OEM or not. I have not seen posts in your thread indicating that some harm will come from the oil pressure gauge reading at the 3 bar mark. I will continue to drive my truck gently during warm up.

Vearing off topic a moment, I just love my truck. Being a member at TT, I have heard of no problems with the engine or tranny what-so-ever, just the early break issues and the e-locked rear end issues. I personally think our 5.6 is the most impressive production V8 I have ever driven (I'm 41). Holy cow that thing will run like a raped ape.

Thanks again everybody.

 

[sootyoil]

quote:

---

Originally posted by 12glocks:
First let me say thanks to all the posters so far.

Highroller thanks so much for the info. I just read your entire thread. Thansk for the schematics as well. An uncanny resemblence really. We both change to Wix filters and get higher oil pressure. Whether or not it is because the sending unit is upstream or downstream I guess is the question. Glad to know we have a real sending unit and I see no need to install a "wet" gauge.

I think the bottom line is that we are not hitting the high mark. Even if the bypass did open, it should only be for a few seconds to protect the filter from high pressure right? Good oil pressure has got to be a sign of a healthy engine since it will circulate the oil well. Tolerances must be tight etc.

I purchased one Wix filter to try and do a UOA on with the plan of buying a case of them from fleet filters because the price is so great. At this point I guess I will have to decide if I want to switch back to OEM or not. I have not seen posts in your thread indicating that some harm will come from the oil pressure gauge reading at the 3 bar mark. I will continue to drive my truck gently during warm up.

Vearing off topic a moment, I just love my truck. Being a member at TT, I have heard of no problems with the engine or tranny what-so-ever, just the early break issues and the e-locked rear end issues. I personally think our 5.6 is the most impressive production V8 I have ever driven (I'm 41). Holy cow that thing will run like a raped ape.

Thanks again everybody.

---

In a very few words the main cause of the issue at hand is simply a "restrictive filter"
next trip at the store pull as many brands of your filter and compare manifolds/i/e. the holes that allow oil to roll in on top of the filter.
all of them will have a different design and measured flow rates will be different between brands, most relief vlaves are at the pump and activate under severe conditions the buypass in the filter will activate long before the pressure relief comes to play.

look for a new brand of filter

 

[sootyoil]

quote:

---

Originally posted by 12glocks:
First let me say thanks to all the posters so far.

Highroller thanks so much for the info. I just read your entire thread. Thansk for the schematics as well. An uncanny resemblence really. We both change to Wix filters and get higher oil pressure. Whether or not it is because the sending unit is upstream or downstream I guess is the question. Glad to know we have a real sending unit and I see no need to install a "wet" gauge.

I think the bottom line is that we are not hitting the high mark. Even if the bypass did open, it should only be for a few seconds to protect the filter from high pressure right? Good oil pressure has got to be a sign of a healthy engine since it will circulate the oil well. Tolerances must be tight etc.

I purchased one Wix filter to try and do a UOA on with the plan of buying a case of them from fleet filters because the price is so great. At this point I guess I will have to decide if I want to switch back to OEM or not. I have not seen posts in your thread indicating that some harm will come from the oil pressure gauge reading at the 3 bar mark. I will continue to drive my truck gently during warm up.

Vearing off topic a moment, I just love my truck. Being a member at TT, I have heard of no problems with the engine or tranny what-so-ever, just the early break issues and the e-locked rear end issues. I personally think our 5.6 is the most impressive production V8 I have ever driven (I'm 41). Holy cow that thing will run like a raped ape.

Thanks again everybody.

---

In a very few words the main cause of the issue at hand is simply a "restrictive filter"
next trip at the store pull as many brands of your filter and compare manifolds/i/e. the holes that allow oil to roll in on top of the filter.
all of them will have a different design and measured flow rates will be different between brands, most relief vlaves are at the pump and activate under severe conditions the buypass in the filter will activate long before the pressure relief comes to play.

look for a new brand of filter

 

[12glocks]

quote:

---

Originally posted by Gary Allan:

Your normalized oil temp should always reduce the filter to below 2PSID ..usually to so many inches of water column.

---

I'm not sure what you mean here Gary. In health care we sometime measure pressure in cm of H20. Is it something like that?

quote:

---

Originally posted by Gary Allan:

Do these engines have any VVT or cam advancers or something like that??

This is the situation with Ford PS (some years anyway) and some marine engines.

---

Yes they have variable valve timing DOHC (chain driven). Since I'm a RN, not a mechanical person by trade, I have no idea what effect this would have. I thought it was a multilobe cam design modulated by rpm's to keep the valves open optimum amounts of time for a given rpm range. That is why, I think, the Titans make gobs of power down low.

One person has suggested changing from the Wix filter to another brand. Does anyone else believe that to be true? With the oil pressure going up to 3 bars (or 3 out of 4), I don't see that as alarming.

What was alarming initially was the change especially after I had anticipated slightly lower oil pressure and swithing to a lighter weight synthetic oil. I changed 2 variables, the oil type and filter type. Highroller changed just one variable, the filter and had almost the same identical result with the same brand of filter.

I am guessing by all the support on this board for Wix filters, it's probably not junk. I'm still on the fence about switching back to OEM. It certainly won't hurt anything except the pocketbook.

Thanks once again to all those that contributed.

 

[Gary Allan]

quote:

---

Originally posted by 12glocks:

quote:

---

Originally posted by Gary Allan:

Your normalized oil temp should always reduce the filter to below 2PSID ..usually to so many inches of water column.

---

I'm not sure what you mean here Gary. In health care we sometime measure pressure in cm of H20. Is it something like that?

---

Yes, except it's metric instead of inches. I think that's it's 17" of W.C = 1lb.

quote:

---

Originally posted by 12glocks:

quote:

---

Originally posted by Gary Allan:

Originally posted by Gary Allan:
[qb]
Do these engines have any VVT or cam advancers or something like that??

This is the situation with Ford PS (some years anyway) and some marine engines.

---

Yes they have variable valve timing DOHC (chain driven). Since I'm a RN, not a mechanical person by trade, I have no idea what effect this would have. I thought it was a multilobe cam design modulated by rpm's to keep the valves open optimum amounts of time for a given rpm range. That is why, I think, the Titans make gobs of power down low.

One person has suggested changing from the Wix filter to another brand. Does anyone else believe that to be true? With the oil pressure going up to 3 bars (or 3 out of 4), I don't see that as alarming.

What was alarming initially was the change especially after I had anticipated slightly lower oil pressure and swithing to a lighter weight synthetic oil. I changed 2 variables, the oil type and filter type. Highroller changed just one variable, the filter and had almost the same identical result with the same brand of filter.

I am guessing by all the support on this board for Wix filters, it's probably not junk. I'm still on the fence about switching back to OEM. It certainly won't hurt anything except the pocketbook.

Thanks once again to all those that contributed.

---

Wix is as good as it comes from a construction standpoint. I would bring this up with Wix via email and ask their take on it. It's something that is giving you the preception that something is "unright".

 

[Highroller]

I think i changed two variables also..
I used pureone's and mobil 1 5w30
I used pureone's and GC 0w-30 (thicker weight)
I used wix and GC 0w-30.

I proved to myself that the switching oils along with my pureone's still started out at the midpoint mark at startup. It was using the wix that elevated my pressure.

Also, i've been researching alot from titan forums and the consensus seems like alot of people get pegged at the H mark

and after warmup operations, the needle goes back to the midpoint. Many believed that the sending unit was bad or what not. Im determined to find out some more info. as to where the relief valve is and etc.
Someone also told me that they switched from pureones and to wix and that their starting pressure was higher after switching to the wix also..

Hope this is a better picture from the second bottom one:
http://www.titanspot.com/phpbb2/files/oil_pump_173.jpg

[ September 16, 2006, 08:26 PM: Message edited by: Highroller ]

 

[Highroller]

I didnt know we had a VVT?

12glocks, you're an RN too? Same here!
Trying to get my BSN right now. What year is your titan?

 

[12glocks]

Yep, we definatley have VVT. Thats how the Titans make that power down low, according to Nissan anyway. They even put there HP and Torque power curve in the broshure.

Yep, doing the RN thing for 10 years now. No regrets there. I have started on my BSN a couple of times now. We just got a CRNA program less than an hour from here so now I am really compelled.

There is a post in the Auto and Lube General Topics about a traveling vehicle from another RN. He want to go traveling.

My Titan is an 06, which I am happy about. At least I am happy that I don't have the 04. As much as I love it I am REALLY interested in the light duty diesel that they keep talking about. If I don't get that, I will keep my truck for 250K (at least that is my goal).

BTW, I just mailed my oil sample to Blackstone. IDK how long it takes to get the results but I will be posting them. I saw that you had posted one for your truck in the past.

Thanks again for the new pic and everything else.

Gary, I think I may email wix like you suggested. I'll post the response that I get as well.

 

[Highroller]

Very nice. Im looking forward to see your oil analysis.

I will be sending mine in soon also. Right now, i have about 18,800 on the odometer (will dump it out at 21k). I will be doing a 3k oci with my GC to compare with my previous 3k oci that i had with my mobil 1 T&SUV 5w30. Then afterwards, i will graduate and move on to a 5k oci.

Although it's tempting even for me to go get that titan diesel, my thinking is telling me to stay away from first year productions. It took me only about less than a week and a half to get my results back.

 

[12glocks]

Thanks for the info. I am planning on 4K run on Penzoil Platinum since 3750 is there harder driving recomendation. I live in the mountains which is not like motoring across the midwest or wide open spaces of the west.

My goal is to work up to 5K also, maybe 6, but I am really not interested in long OCI's. These trucks cost to d@mn much which is why we are here probably obcessing a bit about our maintainence.

I had that thought about 1st year vehicles as well. I think everything in the truck will handle a diesel except for the dana rear end. We'll certainly see.

I'll look for your results as well.

I looked around here and none of the Autozones carry GC. Next time I am on a trip I may look for it unless I am completely satisfied with PP.

I just went to the Wix website and they want your address in order to email them. I'll just call there tech hotline during the week.

 

[Highroller]

Yes, i too believe we shouldnt run long OCI's due to our vehicle's chain driven DOHC. In other words, i believe it'll beat the **** out the oil if driven for LONG OCI's (esp. if doing alot of stop-n-go's) haha... 5k is max for me.

The one thing i desperately want to do to this truck is to replace the stock tires. These 18" tires are horrrrible; very poor tractions. Hydroplaning is a reoccuring theme with my tires on wet roads going about 50-60 mph.

 

[Nebraskan]

Didn't know Texas had.... wet??

 

[Gary Allan]

Texas has it all, baby. And all of it is BIG.

 

[Nebraskan]

I don't think the holes in the top of the filter make much difference. Take a look at the pictures at this thread: http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=36;t=000647

Notice the GM OEM Part for use with the oil cooler? I didn't have the center post of the oil filter threads in this picture, but a lot of people have used this type of setup with bypass filters and basically nearly 90% of the oil is passing through that little poppet valve ... just the one. Diameter when the spring opens is about 1/4" and probably a lot less.

The engine is the main "back up" of the oil pressure not the full flow filter IMO.

Vern