so without knowing if hptuners can disable this on the hybrid. I'll check later on when I can, it's got 130k miles on it, 2 owners before but mostly carfax showed regular oil changes. closer to 9k between them than 3k but if the dealer kept synthetic in it, I'd hope that's good.
so say alls good for now, and turning it off isn't an option. the top plate with the solenoids seems to be around 200$ from gm looks ready to drop on. I have no problem with pulling the intake and swapping in a new plate, which would hopefully keep oil leaks from loose bolts away as well, plus replace the screen.
does this seem like a worth while thing to do to try and kick this failure can down the road another 100k?
sds
just to follow up, I got lazy and didn't pull the intake to install the oil block off to the vlom till just today, took about 3 hours never having done one. the oil pressure sensor died, pegged 80psi with the engine off haha. so it was time, all went well. surprisingly the hybrid is actually easier to pull the intake off than a normal Tahoe/yokon. there's no accessories in the way.
so popped the intake off, pounded in the block off spacer, went ahead and clipped the gasket where oil could build up between the lifter and the solenoids, new intake gaskets just because, new oil pressure sensor and all's good. since mine never dropped the lifter, I might not have needed to do all of that. just turn it off in the tune. but I was in there, so why not. plus it went 130k with 4cyl mod active.
as for the interesting note about always finding a bolt or 2 on the plate loose. mine were all nice and tight. the plate itself was kind newer looking than the rest of the aluminum and seemed to have black plastic spacers on the bolts, so you didn't over tighten them, but could also crank down a little more than you'd expect. maybe it was changed or just different on these and that's why the bolts were tight and it made it 130k? car fax showed it got oil changes but spread out pretty far sometimes. all just interesting info.
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I'm not very familiar with a whole lot on the specs of the variable vein pump systems. I know they are in the direct injection engines but I was unaware of them being in the hybrids before direct injection was released. I honestly have not even worked on one of the GM hybrids at all. They are so far and few in between I have never seen one in my shop. I have heard a lot about them because people contact me when they're working on them in hopes I know something more. I guess I do know some information simply because of that. Second hand knowledge is better than no knowledge at all. As far as your oil pressure code situation you're asking about. You're going to have to verify whether it's low or high that's triggering the code. If you have a code for it you should have some sort of freeze frame data to look back on and see if it was lower high. I'm going to go out on a limb here and guess it was low. If it was low then chances are you have something like a bad cam bearing causing too much volume to leak by for the pump to make up for. It is very common for LS based engines to have a second cam bearing failure due to the VVT groove in the camshaft for that bearing.
just ordered one of your galley plugs to finish the mechanical side of this delete. ugh all the hybrid stuff in the way make that look like a mess haha. I'm replacing the oil pressure sensor with oem gm one while I'm there too.
any thoughts on the variable displacement oil pumps that are on this hybrid engines only? said to save 2 hp? maybe that's the reason for the difference specs I see for psi to rpm?
for others, I found this poking around pro damand this morning, I guess the oil pressure spec is different on these engines.
oil pressure spec hot
36psi @1000
42psi @2000
45psi @4000
not sure if the oil pressure warning is set the same, but it said if the ecm seen 6.8psi Lowe than expected or 7.3 psi higher than expected for 10 seconds. it would set a DTC.
interesting stuff.
here a link to the info on hptuners forum, since 99% of searches lead to dead threads that say no lol
https://forum.hptuners.com/showthread.php?37738-2012-Tahoe-Hybrid-speed-limiter&p=678791&viewfull=1#post678791
Awesome thanks, if anyone in the future reading this can also confirm the above isn't just a fluke. Please add your input. This is great news for hybrid owners!!
I don't typically mess with the oil pumps since they don't really fail. They do make a higher than stock high volume pump that can help take up the gap in something like a failed second bearing though. I think there's a 11% over and a 18% over. Something like that anyway, but I typically delete the system and if needed do the cam bearings. Since it's a hybrid, that's not a ideal solution unless you can tune it out. Perhaps somebody will hop on this forum in the future and comment on it if they have used one.
oh yeah, the ls cam bearings. forgot about those.. ugh, they really didn't need to be so soft.
I've got a 08 c6 with 110k and oil pressure has always looked good but for a split second as I'm hitting the throttle hard, the pressure dips just a pound or 2 and then builds, I've always wondered if it's cam bearings. but I don't wanna fix it till it gets bad lol. man that car is a hassle to work on.
any thoughts on the so called 2 stage oil pump used on these? somewhere I saw it saves some fuel. but I wonder how it effects this.
thanks for the reply, I'm definitely going to see if hp can disable it and then re-watch your video about the mods, I know you sell the oil block off spacer, to try and prolong it. hopefully the lifter tray hangs in there. I really don't wanna pull heads and this is some odd ball cam specs that I'd have to replace with a oem one or the computer would probably freak out.
a
As far as I'm aware HP tuners isn't able to disable but have never had one in to try so can only go off what I've been told. I've also heard the it's backwards but can be done so I'm really not sure. I know lt1swap.com previously mentioned not doing it but maybe he has found a way by now. I haven't asked in over a year. Doing the VLOM isn't going to help necessarily unless you did find an issue. 2 major sources of failure are the VLOM bolts and the filter screen under oil sensor. Ultimately it comes down to oil pressure though. The VLOM bolts being loose won't show low pressure on the Guage though. So be sure to check that. If at any point you are seeing under 30psi then you are at risk of failure. One thing far too many people overlook for why oil pressure is low, is that second camshaft bearing. It's common to bleed out a lot of the oil pumps volume thus drop pressure. Getting another 100k out of it though will be luck of the draw. The 9k oil changes certainly won't help the case any. Even if it was full synthetic, it should still be changed before 6k miles. 9k is far too long before new oil. There are so many failure point that all you can do is the above mentioned and cross your fingers. Why? Simply because of the poor lifter guide design for the AFM lifters. Even if you prevent a lifter collapse the guide could fail and leave you with a spun lifter. Odds are on your side for another 40-50k though. Most that I see fail are after 180k
just a quick follow up, I did find a thread on the hptuners board, it will turn off afm/dod, it's just labeled backwards. it's disabled stock, so change to enabled to turn it off. odd, but more than one says it works. so that's great news. I'm not sure what the company you send ecms to, if they use hp. I'd think they could do it too.
one step closer to keeping these trucks on the road. supposedly there's a lithium pack out now too for them. half the weight, and almost double the reserve for less than a oem pack from gm.