M1097A2 Oil Pressure on startup

[RayGunSlayer]

I was just looking to see if I could get some information about my Hmmwv. I recently bought one to drive quite frequently and on startup, if cold, the oil pressure can take anywhere from 2-5 seconds to finally register on the gauge. Now i don't have the original hmmwv gauge. Instead i had bought and installed the Speedhut gauge kit for hmmwvs. The oil pressure on startup goes to 60. At warm idle it sits at 25-30 and warm 2k rpms is around 50-55. Any information would be greatly appreciated because i don't know much about diesels and really don't want to hurt my 6.5 engine from the oil pressure taking so long to build up.

 

[fpchief]

I was just looking to see if I could get some information about my Hmmwv. I recently bought one to drive quite frequently and on startup, if cold, the oil pressure can take anywhere from 2-5 seconds to finally register on the gauge. Now i don't have the original hmmwv gauge. Instead i had bought and installed the Speedhut gauge kit for hmmwvs. The oil pressure on startup goes to 60. At warm idle it sits at 25-30 and warm 2k rpms is around 50-55. Any information would be greatly appreciated because i don't know much about diesels and really don't want to hurt my 6.5 engine from the oil pressure taking so long to build up.

Sounds perfect to me.

 

[Coug]

just make sure the oil filter has an anti-drainback valve in it.

 

[RayGunSlayer]

I use the M1-302a mobil one filter so i would imagine it does. Thank you guys for the responses

 

[juanprado]

Is the gauge mechanical or electric?
If electric did it come with it's own sending unit and is it 24v?

 

[RayGunSlayer]

Is the gauge mechanical or electric?
If electric did it come with it's own sending unit and is it 24v?

The gauge is electrical but did not come with its own unit. When I changed the gauges out I did buy a NOS pressure sender because of how bad the connection looked on the old one. It’s designed to be plug and play with the original Hmmwv connections. Yes it is 24v

 

[DREDnot]

Definitely confirm the anti-drainback feature. There are identical GM filters that fit that are with and without the ADV. That would cause a slow pressure reading.

For peace of mind, buy a mechanical oil pressure test gauge. Take off the stock oil pressure sender and screw in the test gauge. When you start the engine, you will see what the oil pressure is doing in real time.

 

[RayGunSlayer]

I will definitely hook up a mechanical pressure gauge to be exact when I get back home. I do notice that the gauge does have a delay because yesterday I was sitting at a redlight and the oil was at 30 psi. Well when I revved it while sitting there it would take about a second and a half to 2 seconds before I would see the oil pressure jump up and then fall back down. Plus here in the next couple of days I’ll be changing the oil so I’ve already got a K&N filter order that is a replacement for the m1302a that has a anti drain back valve. I do have one other problem that I didn’t know if any of y’all on here has experienced. Right at 40 mph I get what feels exactly like torque converter shudder. The only thing is when I bought my Hmmwv it only had, from what govplanet said, 1,100 miles on it. Now it’s only got 100 more than that but the transmission fluid level is perfect and a nice red color. So I’m a little confused how it even could be the torque converter. All u-joints were replaced about 40 miles ago so very recently.

 

[Coug]

I run the M1-302A as well. It's ranked as one of the best filters out there from my research.

(it's not actually on the list below, but it's a slightly upgraded version of the M1-302)

Parts List - Filters

 

[juanprado]

I looked at their website and was surprised that it used the OE sender. In my parts selling days a lifetime ago, aftermarket gauges normally used their own unique senders. It does say that the gauge has a micro processor built in. Maybe it has a slight delay but that is a guess on my part?

They look like a cool quality gauge and they have done their homework on the wiring and are 24v compliant.

Humvee Gauges: Universal-Fit, High-Performance and Custom | SPEEDHUT®

The ultimate aftermarket automotive gauges for any vehicle. Shop our huge selection of high-performance and customizable Humvee Gauges - backed by a Lifetime Warranty!

www.speedhut.com

a fresh oil change and filter will tell you more.

 

[fpchief]

So does taking 2-5 seconds not sound correct? My last two HMMWV took about same time and the one now does too...6.5's. That is when cold. When having already ran it is pretty much instant.

 

[fpchief]

I will definitely hook up a mechanical pressure gauge to be exact when I get back home. I do notice that the gauge does have a delay because yesterday I was sitting at a redlight and the oil was at 30 psi. Well when I revved it while sitting there it would take about a second and a half to 2 seconds before I would see the oil pressure jump up and then fall back down. Plus here in the next couple of days I’ll be changing the oil so I’ve already got a K&N filter order that is a replacement for the m1302a that has a anti drain back valve. I do have one other problem that I didn’t know if any of y’all on here has experienced. Right at 40 mph I get what feels exactly like torque converter shudder. The only thing is when I bought my Hmmwv it only had, from what govplanet said, 1,100 miles on it. Now it’s only got 100 more than that but the transmission fluid level is perfect and a nice red color. So I’m a little confused how it even could be the torque converter. All u-joints were replaced about 40 miles ago so very recently.

First of all, the miles shown really dont mean much. I have personally pulled speedo out of a hmmwv and replaced it with one that was brand new.

Pull your doghouse and just maybe there is a decal on the transmission bell housing showing a rebuild date.

 

[fpchief]

Here is what mine looks like.