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-   -   6.2 hot idle oil pressure. (https://www.performancetrucks.net/forums/gmt-900-trucks-general-discussion-188/6-2-hot-idle-oil-pressure-549671/)

1994Vmax 07-14-2017 10:20 AM

6.2 hot idle oil pressure.
 
Test drove a 2011 L9H truck yesterday and noticed hot oil pressure was 20 lbs or even less... seems pretty low. The truck has 68000 miles on it. I know the gen iv stuff is on the lower side of the equation but from what I remember that's a good 10 to 15 lbs less than my LY6 equipped 09 2500HD had at hot idle. In fact it's closer to what said LY6 did when we ran it once it ate a lobe off the cam.

The truck ran nice and quiet but it's a been beat up a bit which to me is okay because I want it to not give a damn about. That said I want it running well... The L9H doesnt have afm to bleed off oil pressure but still has stupid pressure relief in the pan.. however that should not affect idle.. Thoughts?

FFDP 07-14-2017 11:04 AM

My 5.3 is just over the first line on the dash when hot hot, so that's like 25ish I'd assume. I run regular 5W30 synthetic in mine. I wouldn't think much if at all is different between the oil pumps on a 5.3 and 6.2, so that's shouldn't matter.

Just a random thought but if the oil isn't new and the filter isn't working right it could cause a small loss in pressure but that may not even be the case here.

1994Vmax 07-14-2017 01:55 PM

Just seems pretty low... it was fresh oil but I don't know what they have in it... some bulk 5w30 I imagine. I ran multiple oils and filter brands on the 09 6 liter I had and the pressure never varied any amount on the guage anyway. Probably needs main and rod bearings in it... or cam bearings.... or all of the above lol. I have another 2011 6.2 with almost identical mileage to go look at monday... can always see where it's at too.

MrHorsepowerLSx 07-15-2017 07:53 AM

I have a 17 Denali with 3k miles and the oil pressure when hot is maybe 30psi, like FFDP stated his needle just being over the first bar, my needle is the same. Goes up soon as I drive. Also remember you spend more time driving then at idle

silver-mod-o 07-15-2017 10:00 AM

2012 L94 here with 90K. Hot idle is 25-28psi and hwy cruise is right around 40. I don't like it since my other truck idles at 40 and cruises at 60 but every other stock, healthy GEN IV engine I've seen is right about the same...

1994Vmax 07-15-2017 10:50 AM

I need to check this one's hours but I think its done a lot of idling.... and I know I will... more than driving time in fact. My 05 as example has 190000 miles on it but 6000 hours run time lol. Weird a 17 is that low... my 15 6.2 truck was 40 according to the stock gauge.. but then I used 5w30 too and not 0w20 lol. So this one is low either way as it's not even making 20 at idle. Probably junk lol.. like the rest of the truck is. Drivers seat is trashed... covered in scratches... reeks like smoke after detailing. .. and the carpet is still full of mud. Dents here and there... but it's worth 24 grand... I offered 18 all in which is still too much and they actually got mad at me lol. The next truck I mentioned is also a 2011 but a sierra and basically at 68k as well... got a pic this morning that it had bushwhacker flares that rubbed through the paint all the way around which are not on the truck... and they still want 26 grand with it like that lol. Pretty sure I will just buy a new or year or 2 old f150 and forget this idea lol. Both of these gm junkers will need shocks and a front end right away from where I work... and they are at the mileage these gmt900's fell apart from our environment so that's a factor too. If I got them for in the high teens somewhere like they are worth I wouldn't care... but not for 25 to 30 grand like these assholes want. I can get a loaded 5.3 14 or 15 for the money they want for these trucks with less miles lol.

tgui 07-19-2017 09:59 AM


Originally Posted by silver-mod-o (Post 5414315)
2012 L94 here with 90K. Hot idle is 25-28psi and hwy cruise is right around 40. I don't like it since my other truck idles at 40 and cruises at 60 but every other stock, healthy GEN IV engine I've seen is right about the same...

My 150k mile 6.2 L92 does about the same. I am not worried. These 6.2's run lower oil pressure it seems.

FetzerValve 07-20-2017 11:32 PM

My 6.2 has about 83K miles and is consistent with the rest of the responses. Just above the first mark at idle and about 40 when cruising.

BIGRED811 09-12-2017 01:55 PM

2013 5.3L gauge reads the same as everyone's response, needle just enough over the first line for it be fully visible

1994Vmax 09-13-2017 09:09 PM

I didn't buy an old 6.2.... couldn't be bothered at the prices guys wanted for trucks that were junk. My new 17 has an L96 6 liter... it was dropping to like 25 psi hot initially but after I changed oil in it the engine seems to hold about 30 at idle.... dealer used it as a demo and did 2 oil changes and I wouldn't doubt they put in 0W20 instead of 5W30 lol. WOT is like 55 psi which makes sense with that stupid relief valve above the oil filter. See if this thing lasts.... my last LY6 ( same as the L96 but smaller injectors) ate a lifter at 60000 miles so we shall see lol.


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