2011 Denali 6.2L No Oil Pressure
 

I have a 2011 Yukon Denali that I bought new in 2010. Its always seemed to have piston slap when its cold but goes away as soon as the temp gauge reaches the 1/4 mark. In December I was at 99K miles and decided to drop it off at the dealer to get their opinion before it went out of warranty. They changed the lifters; it didn't really change the noise. Now at 104K miles I lost all oil pressure today as I was nearing my house. Any one else had problems like this out of their 6.2L engines? Any advise is greatly appreciated.

Re: 2011 Denali 6.2L No Oil Pressure
 

Hi Greg, if you are baseing the no oil pressure from the dash gauges (normal assumption) I suspect a bad sender for the gauge. If you truly had no oil pressure lifters would sound like typewriters and then get worse. I would suggest screwing a mechanical gauge into the sender hole when you go to replace it and see first hand what is going on. On youtube someone had your scenario posted and it was an oil pump issue that gm revised if I remembered correctly. If oil pressure is low, take it to the gm dealer and let them see for themselves what is going on, even though you are just out of warranty. Hope this helps, Brian F.

Re: 2011 Denali 6.2L No Oil Pressure
 

I would argue its still under warranty since it was just worked on a few thousand miles ago.

Re: 2011 Denali 6.2L No Oil Pressure
 

Thanks for the responses. I was going to have it towed to the GM dealer but decided it could be the oil filter. I'm basing that on a lot of reading on Google searches. I just changed the oil a couple of weeks ago. I'm pulling off the K&N oil filter and replacing it with a Mobile 1. I'll update the thread once I figure out if it resolves the issue.

Re: 2011 Denali 6.2L No Oil Pressure
 

The filter for your truck (PF48) has a built in By-Pass, If the filter were to clog completely, The By-Pass will open & still have oil pressure.

If the aftermarket filter has no By-Pass, And clogged/collapsed...That could cause this. The odds of the planets aligning in such a way is far fetched.....You would have to buy the wrong filter that miraculously screwed on, Then Clog.


I agree with Brian F., Install a mechanical gauge & see what's going on, A "Diagnostic Trouble Tree" will say to do this first.
The down side is most oil pressure test sets only include NPT fittings, LS engines use Metric "Gasket" Straight thread fittings on everything.

Here is a fitting that will adapt the Metric port to 1/8" NPT http://www.summitracing.com/parts/atm-2268

GM dealers have a 12 month 12,000 mile warranty on repairs, But this may or may not be related to the problems your having.

Re: 2011 Denali 6.2L No Oil Pressure
 

Yup, the filter was not the problem. Its at the dealer now. Service manager was as puzzled as I was. When the pressure drops to zero there is an odd clunking you can hear in the cabin with all doors closed but you cannot hear it with the drivers door open. Its worse in gear than in park. Should know something on Monday, I'll update the thread. I appreciate your suggestions.

Re: 2011 Denali 6.2L No Oil Pressure
 

The problem may be the oil pressure sensor filter screen could be clogged... It happened on a friends 07. If you follow the on-board oil life messages and do extended oil change intervals, the screen will clog and show 'no oil pressure' among other problems.

No matter what the vehicle says, you still need to change the oil every 3k. The fact that the dealer has changed the lifters already is 1 "tell" of this extended oil change interval problem.

Re: 2011 Denali 6.2L No Oil Pressure
 

I run synthetic oil and have always used K&N or Mobile 1 filters. The lifters were noisy from the time the truck was new on cold starts. I appreciate your response but I will respectfully disagree with the oil change interval. But if I find out Monday that there is in fact a screen on the 6.2L and its clogged then you may very well be correct. Thanks for the response esbstuff.

Re: 2011 Denali 6.2L No Oil Pressure
 

One other thing... Check to see if the oil you are using meets the newer GM specifications. Some (most) oil does not and will cause oil problems. Its called Dexos Additive (Spelling?)

Re: 2011 Denali 6.2L No Oil Pressure
 

I use Pennzoil Platinum 5W-30 which meets Dexos1 certification.

Re: 2011 Denali 6.2L No Oil Pressure
 

OK, here's an update. The dealer actually changed the sensor, dropped the pan and changed the O-Ring. Test drove and pressure is still going to zero. To change the oil pump and for all the work done we are at $1290 + tax. GM is willing to pay $650 as assistance. The dealer mechanic is confident there is no damage to the engine, I'm very uncomfortable with that analysis. So I'm faced with changing the oil pump and rolling the dice that the engine is unharmed, or just replacing the engine at roughly $8K. Wow this sucks!!

Re: 2011 Denali 6.2L No Oil Pressure
 

Are we sure it isn't a gauge problem? That thing has a portion of the sender that will cut of fuel if the PCM reads that the oil pressure drops below a safe level. They have been using that as a safeguard for many years going back to the days of the TBI . I'm sorry for doing the bottom of the page type thing I thought I had something to add and if that has been covered please forgive me and I'm sorry for your situation. I also sense that your not the type of guy that would replace a 6.2 with a junkyard 5.3 for a thousand or $1500 bucks just to get the ride up and going for another 75 thousand or so, I understand and respect that. I do hope you get it figured out. It is very uncommon for any of that LS family of motors to lose pressure like that the pumps are such an efficient design. Good luck Jim

Re: 2011 Denali 6.2L No Oil Pressure
 

I'm pretty sure that your 'knocking' issue is just piston slap. Those engines have short piston skirts and tend to rock a bit inside the cylinder until warmed up. I know this is a real big issue with the 5.3l. I could be wrong though. Here is my thought. If the low pressure wasn't an issue until the mechanic touched it, then I'd want to know what he might have done to the motor to cause the issue. It sounds to me like you are really just paying for some one else's mistakes. I'd be talking to management and starting to demand that you won't pay if their work don't fix the issue. They can learn to play with motors on their own time.

Re: 2011 Denali 6.2L No Oil Pressure
 

No Parts should have been installed on your truck until the oil pressure was checked with a mechanical Gauge! This is basic stuff.

This is why I do not work for dealers anymore. Watching inexperienced techs throw parts at a customers car on the customers dime & Flag Hours is something I can't deal with.

Re: 2011 Denali 6.2L No Oil Pressure
 

Clinebarger, couldn't agree more with you on your sentiments towards the dealership environment. If I had the pan down, at least pull a main cap and see. I got tired of arguing with coworkers/service mngrs about proper repairs. Don't get me started on brake job fubars. Enough of my rant. If the truck owner lived close I'd put a new short block in for cheap just for fun in my garage!

Re: 2011 Denali 6.2L No Oil Pressure
 

Update. Dealer installed new oil pump, sensor, and o-ring. Pressure still goes to almost zero after engine is warmed. Mechanical gauge shows the same as the cluster gauge. Dealer committed to finding the cause even if it means disassembly of the engine at no additional cost. I saw the engine with the oil pan off, clean as a new engine internally, and tech states there was absolutely no metal in the pan or screen when removed. I don't know enough about the modern engines to make an educated guess as to root cause or next steps. I'll up date the thread as I find out more. I appreciate all the input and advice from everyone.

Re: 2011 Denali 6.2L No Oil Pressure
 

I'll throw in my wager on cam bearings shot. About time a mechanical gauge was threaded in.

Re: 2011 Denali 6.2L No Oil Pressure
 

Just an armchair quarter-back here:

Sounds like the oil pressure is fine while warming up and then suddenly drop off like someone opened a valve to release the pressure. Do the LS engines have a oil bypass? Maybe something there? seems like it would be more apt to do that when cold though.

If the oil pump was slipping on the crankshaft, they probably would have seen that when they replaced the pump.

Heck of a puzzle...

Re: 2011 Denali 6.2L No Oil Pressure
 

Yea, I'm gonna agree on cam bearings. That's where I'd head to peek.

Re: 2011 Denali 6.2L No Oil Pressure
 

when i was in auto tech schooling in the 70's we had an oil filled bladder that you hooked up to the sender hole and introduced pressurized oil into the engine and with the pan removed you could see the rain coming down from the worst offender. These engines are not that hard to work on and any clearance wear area job in my mind says you might as well remove the block and get on with it. If the lifters were the fix for some of the noise are they possibly fed down stream from the cam bearings? If so excessive wear in the cam bearings means less supply from there on to the rest of the engine. (my ls book is on loan) Good luck.

Re: 2011 Denali 6.2L No Oil Pressure
 

Motor is out and torn down. The crank is scored on the rear. Dealer is putting in a new crank and bearings, new cam and bearings. Here are a couple of pictures. I almost threw up when I saw this.

Re: 2011 Denali 6.2L No Oil Pressure
 

Good to be this far along! I assume they will be looking over all of the engine parts but with the past conditions to me this isn't a big surprise. Hope all goes well once it is all back together. As a suggestion i would say slightly sooner oil changes. The synthetics keep internals cleaner than conventional oils. Short story; boss is amziol dealer that believes in 10-12k oil changes. Secretary lured in by this mindset. Comes to me with engine noise complaint, sounds like a typewriter (lifter noise). I listen, check oil, full, 10k winter driving, barely stays on dipstick when checking, smell of gas on dipstick. Suggest to immediately get a oil change, quick lube place that evening. Noises gone by the time she gets home. Moral of the story? I don't care what oil you use you still get oil dilution from gas and combustion (acids etc) entering into the oil stream and breaks it down. The only remedy is oil change/ oil change interval. One additional oil change a year will probably make a substantial difference in engine longevity. I tell friends and coworkers 4 oil changes at a normal gm dealership a year costs about $100-$125. They can be held responsible for a basic underbody fluid check in the process. Small cost in my mind. Problem arises, you guys are changing and checking my truck on every change! This rant is in no way an insult, just been in the oil change interval courtroom before. I drive late model 2014/2015 vehicles and the only oil change i do is on my 68c10. Good luck greg!

Re: 2011 Denali 6.2L No Oil Pressure
 

So today the dealership called to say that the Crank is on back order. If I were willing to pay $1500 they will put in a new crate 6.2L with a 3 year 100K mile warranty. Guess what I choose to do! In a previous update I mistakenly said the crank was scored on the back journal but it was actually the the front. Fingers crossed, I'll get my Yukon back on Friday after three weeks of being in the shop.

Re: 2011 Denali 6.2L No Oil Pressure
 

Wow. That's tough luck but to get a brand new 6.2 for $1500 out of it isn't all bad. Not as nice as having the original motor with no problems but still...

Re: 2011 Denali 6.2L No Oil Pressure
 

Picked my Denali up yesterday after 4 weeks in the shop. Final bill with new engine, water pump and belt was $2100. I'm angry that the motor only lasted ~104K miles but happy that I have a new crate motor with 3 year 100K mile warranty. One of two things happened, the engine was bad since new as it always had lifter noise and piston slap when cold or the mechanic got trash in it when he replaced the lifters at ~99K. I've not noticed any rattle or piston slap with the new engine but then again I've only got ~60 miles on it thus far. I'm going to change my oil every 5K miles, use GM oil and filter, and not use synthetic with K&N filters like I did on the original engine. At least thats what I'm thinking at this point. I might change my mind, time will tell.