2019 Trail Boss Oil Pressure Question

[JayTrailBoss]

I have just over 1,000 miles on the 2019 Trail Boss 4.3L motor. This morning for the first time I noticed the oil pressure gauge dropped to 30 when pulling into a parking spot and then sitting idle. When I revved the engine a little bit the pressure went back up to about 50-60. I have never seen it at 30, mostly stays like 40-60 range. Any cause for concern? As a reference I drove about 10 miles, mostly highway, and it is 60-64 degrees outside.

 

What do you all get for pressure readings with your motors - maybe list idle pressure and cruising pressure with the motor type.

 

Thanks!

[Sierra Dan]

1 hour ago, JayTrailBoss said:

I have just over 1,000 miles on the 2019 Trail Boss 4.3L motor. This morning for the first time I noticed the oil pressure gauge dropped to 30 when pulling into a parking spot and then sitting idle. When I revved the engine a little bit the pressure went back up to about 50-60. I have never seen it at 30, mostly stays like 40-60 range. Any cause for concern? As a reference I drove about 10 miles, mostly highway, and it is 60-64 degrees outside.

 

What do you all get for pressure readings with your motors - maybe list idle pressure and cruising pressure with the motor type.

 

Thanks!

I am not sure about the 4.3, but with the 5.3 and 6.2 many members have reported the same observances as you. Myself included.

They are 2 stage oil pumps and it is deemed "normal"

Now if you dip below 20 or have no pressure at all, that would be cause for concern.

[Grumpy Bear]

2 hours ago, JayTrailBoss said:

I have just over 1,000 miles on the 2019 Trail Boss 4.3L motor. This morning for the first time I noticed the oil pressure gauge dropped to 30 when pulling into a parking spot and then sitting idle. When I revved the engine a little bit the pressure went back up to about 50-60. I have never seen it at 30, mostly stays like 40-60 range. Any cause for concern? As a reference I drove about 10 miles, mostly highway, and it is 60-64 degrees outside.

 

What do you all get for pressure readings with your motors - maybe list idle pressure and cruising pressure with the motor type.

 

Thanks!

Timely question. I have a 4.3. It's in a K2 but same motor. Warmed up the needle down the road 55-60 mpg reads a half needle under 40 and a needle above 30 when at idle. It will peak above 40 at the top of each gear and if I run it up over 3600 rpm, the second stage trigger point it will lurk around 60. I thought that a bit low so bought a Scan Gauge and that really scared me. Said I was dipping under 20 psi at idle and around 25 psi down the road. Ears pinned be barely 50 psi. So I took it to Deegan's and had Jason do an oil pressure map. I found out the both my instruments were liars and my oil pressure was in fact as high as he had ever seen. Hot idle 44-48 at the OBDII port and 4-6 pounds higher at the filter block with a Snap-On mechanical test gauge. Thing will hit 60 psi before the second stage kicks in. It will tag 80 psi when over 3600 rpm. My cold idle pressure was 50 psi! Looks pretty much like an early SBC Gen I profile to me. 

 

My dash gauge is somewhere between 10-15 low during first stage and 20 psi low under second stage and the Scan Gauge off by a factory of 2X. It's not a real expensive instrument and does everything else very well (we tested that against the Snap-On OBDII device). 

 

Point is, if you have concerns have a filter block test done and ask for the specific readings. A GM member here gave me the following: 

 

22 psi @ 1,000 rpm

30 psi @ 2,000 rpm

33 psi @ 3,000 rpm

3,600 rpm second stage trigger with no spec on pressure he could find. 

Takes a minimum of 22 psi to latch the AFM and 19 psi to hold it in DOD

Minimum oil pressure before the warning light comes on is....8 psi. 

Lastly I'm told that the 4.3, 5.3 and 6.2 all share the same specifications. Use mostly the same parts. One part that is different is the VLOM screen and it's location. 

 

These are the MINIMUM values before GM will bat an eye but 'normal' is quite a bit higher. 

 

That's all I know, hope it was helpful. 

[MaverickZ71]

Seriously?  A Trail Boss with a 4.3L V6?  And no 6.2L available in the Trail Boss.  What was Chevy thinking?  Go figure . . . 

[Sierra Dan]

5 minutes ago, MaverickZ71 said:

Seriously?  A Trail Boss with a 4.3L V6?  And no 6.2L available in the Trail Boss.  What was Chevy thinking?  Go figure . . . 

6.2 With 10 speed is available for 2020 on Trail Boss

[MaverickZ71]

1 minute ago, Sierra Dan said:

6.2 With 10 speed is available for 2020 on Trail Boss

Cool.  I was wondering why the big engine wasn't available on all of the top trim levels.  Personally, I think they should make all engines available on all models.  A Trail Boss with the small diesel would also be good, with good torque for crawling on trails, and the potential for good range on a tank of fuel.  

[JayTrailBoss]

2 hours ago, Grumpy Bear said:

Timely question. I have a 4.3. It's in a K2 but same motor. Warmed up the needle down the road 55-60 mpg reads a half needle under 40 and a needle above 30 when at idle. It will peak above 40 at the top of each gear and if I run it up over 3600 rpm, the second stage trigger point it will lurk around 60. I thought that a bit low so bought a Scan Gauge and that really scared me. Said I was dipping under 20 psi at idle and around 25 psi down the road. Ears pinned be barely 50 psi. So I took it to Deegan's and had Jason do an oil pressure map. I found out the both my instruments were liars and my oil pressure was in fact as high as he had ever seen. Hot idle 44-48 at the OBDII port and 4-6 pounds higher at the filter block with a Snap-On mechanical test gauge. Thing will hit 60 psi before the second stage kicks in. It will tag 80 psi when over 3600 rpm. My cold idle pressure was 50 psi! Looks pretty much like an early SBC Gen I profile to me. 

 

My dash gauge is somewhere between 10-15 low during first stage and 20 psi low under second stage and the Scan Gauge off by a factory of 2X. It's not a real expensive instrument and does everything else very well (we tested that against the Snap-On OBDII device). 

 

Point is, if you have concerns have a filter block test done and ask for the specific readings. A GM member here gave me the following: 

 

22 psi @ 1,000 rpm

30 psi @ 2,000 rpm

33 psi @ 3,000 rpm

3,600 rpm second stage trigger with no spec on pressure he could find. 

Takes a minimum of 22 psi to latch the AFM and 19 psi to hold it in DOD

Minimum oil pressure before the warning light comes on is....8 psi. 

Lastly I'm told that the 4.3, 5.3 and 6.2 all share the same specifications. Use mostly the same parts. One part that is different is the VLOM screen and it's location. 

 

These are the MINIMUM values before GM will bat an eye but 'normal' is quite a bit higher. 

 

That's all I know, hope it was helpful. 

Wow, that was great information, thank you! I guess my only concern was this is the first time I have ever seen the oil pressure this low. Could it be the engine is getting broken in now or some other anomaly? I just don't know why all of a sudden it would drop like this when i have always been between 40-60. I appreciate the input, so basically no worries at this point unless it drops to less than 8. The ranges you mentioned are the acceptable low limits based on rpm's right? 

Thanks again

[Grumpy Bear]

1 hour ago, JayTrailBoss said:

Wow, that was great information, thank you! I guess my only concern was this is the first time I have ever seen the oil pressure this low. Could it be the engine is getting broken in now or some other anomaly? I just don't know why all of a sudden it would drop like this when i have always been between 40-60. I appreciate the input, so basically no worries at this point unless it drops to less than 8. The ranges you mentioned are the acceptable low limits based on rpm's right? 

Thanks again

No, what I'm saying is if you have a concern get it checked. The dash gauge is totally unreliable. 

[diyer2]

If you had an oil pressure problem the computer would tell you to shut the motor off.

[Grumpy Bear]

38 minutes ago, diyer2 said:

If you had an oil pressure problem the computer would tell you to shut the motor off.

Yes but not until you only have 8 psi! It's a problem well before that. Right? 

[K455]

First time with it in warm weather? warmer weather psi will drop a little bit. 30 or a little above 30psi at a hot idle is what my 5.3 sits at.operating temp

[diyer2]

18 hours ago, Grumpy Bear said:

Yes but not until you only have 8 psi! It's a problem well before that. Right? 

Maybe.

Everybody concentrates on psi because that's what they have available with an oil pressure gauge. 

Oil flow in GPM has to be considered.

A high mileage motor with worn main bearings can have low oil pressure right ?

 

 

[Grumpy Bear]

41 minutes ago, diyer2 said:

Maybe.

Everybody concentrates on psi because that's what they have available with an oil pressure gauge. 

Oil flow in GPM has to be considered.

A high mileage motor with worn main bearings can have low oil pressure right ?

 

 

Sure it could. Pressure is flow vs space in it's simplest term. Thing is while the rods and mains don't rely on hydraulic pressure and may not care in the hands of a skilled operator. But the VVT and AFM do care. The AFM has a 22 psi minimum latching pressure. Low pressure is the cause for non-materials related lifter failure, right? Things are not as simple as Dad's 36 Chevy Stove Bolt 6 that used dipper spoons instead of an oil pump. There must be a reason for GM's minimum pressure requirement. I'd guess the few components that utilize the system for hydraulics might be that reason. 

[KARNUT]

Cylinder deactivation raises its ugly head again. I know, I can’t help it.


Sent from my iPhone using Tapatalk

[Shawn Lovejoy]

 

If you had an oil pressure problem the computer would tell you to shut the motor off.

Yes, my computer said that in my 5.3 2019 with 10k miles. I stopped  and the the engine started smoking and smoke coming through the vents....I hope it's not too bad and can be fixed?