possibly overtreated engine oil with LubeGard

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Hey, folks, not new to wrenching and I'm usually careful with my additives. Maybe not today, though. Or maybe I got lucky :)

I just finished an oil change in a 2012 Grand Cherokee (5.7 Hemi) that had an oil pressure/flow issue, with an aftermarket rebuilt engine with 35k on it. The oil issue appears gone, but I need some advice on whether I have too much LubeGard in there.

Here's a little history.

There was a fairly substantial valvetrain "tick" at idle, along with startup clatter, but no indication of bearing issues in the low end. This of course is the 3rd gen Hemi with (in some but not all cases) a history of lifter roller bearing/camshaft failures, a non-perfect upper end oil distribution system, and VVT & MDS in place. None of this scares me, but maybe it should, haha! I've done a decent amount of research on oil vs lifters in these engines, and in a nutshell Redline is usually pretty successful, along with putting in a decent 5w30 (not 20) plus LubeGard at a ratio of 3oz per quart of oil.

I just recently bought the vehicle, and knew about the noise. It was priced very fairly, so I pulled the trigger. It had a non-functional oil pressure sensor. PO gave me the sensor - he hadn't installed it & was tired of working on it, and he had a new truck, so I got it cheap. It just felt like it was something fixable. Two engine codes were present: 0520 (oil pressure signal out of range) and 1521 (ECU thinks that the wrong grade of oil is in the system).

With that background, here's what I did: I installed the new sensor first, then checked the oil pressure with the old oil (looked fine, actually) and filter still in place. It was pretty low, even at the high end where the pressure relief valve does it's thing.

So, I then did the oil/filter change, filling with 6 quarts of oil, filling the filter before installing - and not adding the LubeGard, but checking the oil pressure numbers again. It was the same; low pressure and noisy at idle.

I decided that I would put the whole 32oz of LubeGard, to really up the amount of protection (because it looked like really low oil pressure) and also to see if the additive cleaned anything out. Apparently it might have.....

I cleared those two codes (0520 and 1521) from the ECU, started/stopped the engine a couple of times and very carefully drove around the block, with the oil pressure displayed in the dash. This model has a center display and oil pressure can be monitored - the data is from the same sensor that I replaced. After doing all this, my oil pressure is reasonable at idle when hot, and goes up a little higher than it did before at speed.

It sounds like a success story, but I'm going to give it time before relying on it.

So, I now have a nicely running engine with minimal upper end tick (sounds like a normal V8), decent oil pressure numbers, and 6 quarts of Mobil 1 EP 5w30 and 1 quart of LubeGard in the sump. And this is real real early, but no CEL or codes so far.

Should I expect any short term problems with that much LG in the oil? I mean significant problems, in terms of hard damage like bearings & other metal surfaces, and possibly a clogged lifter and the like.

I have no issues draining some oil/LG mix out & putting in more oil to reduce the concentration. Just looking for a little advice or experience.
 

capacitor

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This is a 7qt system (I was surprised too but this is my 1st Hemi gen3) :)

I kind of think I'm fine. However, the jury is still out on the oil pressure. I let it sit for about 2 hours, and came back out and started it up. It exhibited the same behavior as before the oil change - tick on startup, and very low idle pressure. After running it for a couple of minutes, idle pressure stabilizes around 15psi, and startup sounds normal. I took it up and down the highway as well as a little in-town driving, sitting at a stoplight & watching the pressure vs idle speed. I can't see the immediate startup pressure because of the screen's operating system, but I can see it after the usual prompts disappear.

I know that there's an anti-drain valve in the oil and maybe that could be bad (the previous filter did the same thing) but the difference between cooler pressure on idle, vs when warmed up, is something I didn't expect. I'm going to hook up a mechanical pressure sensor & see what it says.

I don't think the LubeGard did anything here (yet), but I'll continue to debug and report back if that changed.

I do feel better in general having it in there, though. It may be total coincidence (or more likely, placebo) but it seems to run smoother.
 

OVERKILL

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The lubeguard definitely won't increase the viscosity, which is what dictates oil pressure.

Also, the HEMI doesn't have oiling system issues, that's lore/urban legend based on a few weird takes on the engine design. Yes, it has a known, but low rate of occurrence, issue with lifter failure, which is a materials problem with the lifters themselves, which is why there have been a ton of revisions made to them.

15psi is LOW, especially if it had been sitting for 2 hours.

The ADBV in the filter will only work to eliminate start-up rattle (the first few seconds after a start before everything gets oil), it would have no bearing on ongoing noise.

Redline, which is often recommended, has the same HTHS as an xW-40; it's a MUCH heavier oil than the grade would suggest, and yes, there's a certain tribe that pushes that as a solution for noise. Of course if the noise is lifter failure, no oil is going to stop it. In reality, the vast majority of noise cases are exhaust leaks, which this engine, and several others, are notorious for.
 
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You're good. Lubegard will act as a good safety cushion against bad engine design. Won't heal it, but may postpone the failure a little. Lubegard ups the additive content, but it still isn't as balanced or effective as a factory blended oil. So I personally would just go with a stronger oil to begin with, than trying to strengthen the weaker oil. My oil of choice would be one from list below, because these are well loaded with additives, well balanced for additives to properly work together, and engineered to go the distance. Also picking these oils will be cheaper than buying less-capable oil and adding Lubegard (or any other additive) to it to up its performance.
1) Mobil 1 FS 0W-40/5W-40
2) Quaker State Euro 5W40
3) Castrol Edge 0W30/0W40/5W40 in A3/B4 flavor.

Or there is a great boutique oil that's kicking some me serious butt lately, made by High Performance Lubricants. Sold on "advlubrication.com". Pricey, but looks like it's worth every penny. To save on shipping, buy by the case. I have yet to try it, but from seeing the results of others here - I may end up biting the bullet once my M1 0W40 stash runs out.
 
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Are you supposed to substitute engine oil for the amount of Lubegard you put in or just add Lubegard in addition to the normal oil capacity ?
 

capacitor

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Thanks (both of you @Vladiator and @OVERKILL ), that's exactly what I thought about the low pressure as well :) But I'm from the school of old, and know that so I don't assume anything and always learning. I absolutely freaked when I saw single digit pressures (which is why I said screw it, it's only another $10, put the whole quart in).

I wish I had done the engine rebuild, so I knew what lifters were in there. I've read a few conflicting studies/opinions about the Hemi design, but that's a very common point (as well as cam surface hardening & material). It's a lower cost rebuild, probably from AutoZone/TriStar.
 

capacitor

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@Hall I believe they would say strictly replacement, but I've heard that a certain, reasonable amount of overfill is fine if not useful. In this case, no overfill, just 50% more concentration than what I've read.
 

OVERKILL

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Thanks (both of you), that's exactly what I thought about the low pressure as well :) But I'm from the school of old, and know that so I don't assume anything and always learning. I absolutely freaked when I saw single digit pressures (which is why I said screw it, it's only another $10, put the whole quart in).

I wish I had done the engine rebuild, so I knew what lifters were in there. I've read a few conflicting studies/opinions about the Hemi design, but that's a very common point (as well as cam surface hardening & material). It's a lower cost rebuild, probably from AutoZone/TriStar.
Yeah, you should have somewhere between 25-35psi hot at idle. Here's our 5.7L with 0W-20 in it, showing 31psi with oil temp at 216F:
A3AD1590-A9A7-4BCE-897A-864A8337AEB6_1_105_c.jpeg


Sounds like some really loose rod and/or main clearances were used with this rebuild unfortunately.

On the cam/lifters thing, the lifters have been revised many, MANY times. The original (non-MDS) HEMI didn't have any lifter failures. I think they changed suppliers after they added MDS and we've seen failures with both MDS and non-MDS lifters, as well as on the Hellcat engines, which don't have MDS. GM has the same problem, but their lifter failure is more dramatic as they use a different design.

The issue is compounded by the fact that FCA chose to use SADI cams vs billet (GM uses billet). So the GM cams are sometimes saveable if the issue is caught early enough. That's not the case for the HEMI cams, as soon as the roller stops rolling, that lobe is done.
 

capacitor

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Yeah. I heard that as soon as the surface is compromised, those cams are toast.

Makes total sense about the rod/main bearing clearances! I wonder if that's what's going on - when the engine is cool, the oil pressure on startup and idle is really low, but once warmed up it's reasonable. Does that make any sense? I'm trying to figure out why cold == low pressure, hot == reasonable pressure in this design.

I did check for bearing noise under load before pulling the trigger, but nothing was obvious.

I'm thinking I'll get by short term with this engine (eg babying it), and do a rebuild with billet cams if available + the best/latest lifter design available. I'm loving the platform in general, other than it's weighs more than I would like - but hey, so does my girlfriend.
 
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OVERKILL

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Yeah. I heard that as soon as the surface is compromised, those cams are toast.

Makes total sense about the rod/main bearing clearances! I wonder if that's what's going on - when the engine is cool, the oil pressure on startup and idle is really low, but once warmed up it's reasonable. Does that make any sense to you?
No, that's completely backwards. Startup pressure, when the viscosity is higher, should be much higher. You definitely want to check that with a mechanical gauge.
I did check for bearing noise under load before pulling the trigger, but nothing was obvious.

I'm thinking I'll get by short term with this engine (eg babying it), and do a rebuild with billet cams if available + the best/latest lifter design available. I'm loving the platform in general, other than it's weighs more than I would like - but hey, so does my girlfriend.
LOL!

Yeah, plenty of aftermarket bumpsticks available with a billet core :)
 

capacitor

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Thanks, that's exactly what I thought! There's something going on that I don't comprehend, haha! Non-intuitively, whatever is happening is making the reported oil pressure low when it should be high. I'll check it with a mechanical gauge.

Edit: great to hear about billet cam availability :)
 

capacitor

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So I do testing to make money, and I'm fairly decent at it. I just did another test drive.

After recreating the scenario (meaning driving it, waiting a couple of hours, and watching things carefully during startup), it definitely seems like the oil is raising pressure as the engine warms up. This is a totally seat of the pants analysis, but the pressure is not directly correlated by coolant temp; it seems like it is more by the temperature of the internal components, if that makes any sense. In other words, the mass of the metal components of the engine (specifically the crank, rods and related components that are close by) are gradually raising in temperature, and that increase is directly correlated to the increase in oil pressure.

So the idea of having bearing clearances that are wider when colder, then tighten up when the internal components (crank, bearings) warm up more, seems to be a really solid theory at this moment :)

This is all by feel, but if I understand the system I'm pretty good with this stuff, just fyi.

There is a lag between coolant temp and the oil pressure rising. My max is 45psi, and I think that's at least 10psi lower than what the oil pressure relief valve will provide.

If I start the engine when warm - but not up to operating temperature - the low/idle pressure at around 600rpm is really low. Sometimes it kicks off the low pressure alert, sometimes not. Warming up a few minutes raises the low/idle pressure into a somewhat useable range, which is lower than it should - around 15psi.

When I start the engine when it's been recently run to operating temperature, it starts quietly and idles at around 15psi.

All of this gives a lot of credence (imho) to the observation that high clearance bearings are causing a low oil pressure in general, and especially when the mass of the engine is cool.

I need to move to the Bahamas!
 
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From what I've read it's a design flaw. I bet some new valvetrain parts are needed and it won't be that cheap. Good luck.
 

OVERKILL

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So I do testing to make money, and I'm fairly decent at it. I just did another test drive.

After recreating the scenario (meaning driving it, waiting a couple of hours, and watching things carefully during startup), it definitely seems like the oil is raising pressure as the engine warms up. This is a totally seat of the pants analysis, but the pressure is not directly correlated by coolant temp; it seems like it is more by the temperature of the internal components, if that makes any sense. In other words, the mass of the metal components of the engine (specifically the crank, rods and related components that are close by) are gradually raising in temperature, and that increase is directly correlated to the increase in oil pressure.

So the idea of having bearing clearances that are wider when colder, then tighten up when the internal components (crank, bearings) warm up more, seems to be a really solid theory at this moment :)

This is all by feel, but if I understand the system I'm pretty good with this stuff, just fyi.

There is a lag between coolant temp and the oil pressure rising. My max is 45psi, and I think that's at least 10psi lower than what the oil pressure relief valve will provide.

If I start the engine when warm - but not up to operating temperature - the low/idle pressure at around 600rpm is really low. Sometimes it kicks off the low pressure alert, sometimes not. Warming up a few minutes raises the low/idle pressure into a somewhat useable range, which is lower than it should - around 15psi.

When I start the engine when it's been recently run to operating temperature, it starts quietly and idles at around 15psi.

All of this gives a lot of credence (imho) to the observation that high clearance bearings are causing a low oil pressure in general, and especially when the mass of the engine is cool.

I need to move to the Bahamas!
@clinebarger would know better than I would, but on your weird inverted oil pressure situation, I'm wondering if the pick-up is REALLY close to the bottom of the pan and its cavitating trying to suck the oil when it's cold, but has an easier time when it is hot? Just a wild theory, otherwise, it simply doesn't make sense what you are observing. Definitely verify with a mechanical gauge to confirm this is indeed what is taking place before we consider this any further IMHO.
 
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What's a design flaw? HIs issue (low oil pressure) is almost assuredly unrelated to anything valvetrain.
Probably talking about the poor engineering choice of using a SADI core with a roller lifter that has a practically designed-in tendency to bounce on the lobe, causing damage to the roller, spalling of the lobe, and/or general failure after ingesting enough of its own parts o_O

IMO essentially every "green" technology they've introduced to save fuel (DoD, MDS, VVT, AFM, kitchen sink, etc) have so negatively affected the reliability of previously solid engine designs that it's an absolute guarantee the owner has wasted more energy fixing their vehicle than the green technology would ever have saved! We have failed cams. Failed lifters. Failed phasers. No way were these technologies a net win for the consumer!
 
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