🔧 Technical 04 Tahoe - Lower Oil Pressure

[DEEZUZ]

Why aren't the OA's picking up high wear metal counts?

I’ve been a GM dealer tech for 20 years and seen this exact same scenario with this type of oil pressure concern at least 200 times. But hey, what do I know. Believe whatever you want to believe

And that's great... But I just asked why it won't show on oil analysis... Do you know something I don't?


And I know a dealer tech too... I was in his shop once and watched other dealer techs using the ugggaa duggaaa gun to torque head bolts soooooo0000ooo00

 

[bikrboy128]

And that's great... But I just asked why it won't show on oil analysis... Do you know something I don't?


And I know a dealer tech too... I was in his shop once and watched other dealer techs using the ugggaa duggaaa gun to torque head bolts soooooo0000ooo00

Wait. That's not how you torque head bolts?

 

[DEEZUZ]

Ugga dugggaaa

 

[CMNTMXR57]

Works for me too.

Former GM Tech here too since we're whipping out johnsons. Point is, there are a lot of knowledgeable people here when it comes to cars.

 

[DEEZUZ]

Dealer tech honestly means nothing to me.

I get 2-3 trucks a month that are pulled from dealers due to shit work or they can't find the issue. And we are not cheaper really.

Also were going on 5 times the highlander has been to the dealer. They left parts off, broke more stuff, etc. We're borderline taking legal action RN

 

[DEEZUZ]

While we're at it I don't have a single Another Sorry Excuse of employee certification

 

[CMNTMXR57]

Agreed. So many in our service department were "by the book" parts changers there for the 7 - 3/4 paycheck. Going from dealership to dealership.

 

[rocco]

Those oil analysis are BS. If anyone wants to believe that stretching out your oil changes to 10k and beyond is ok for your engine, then go right ahead. We get cars towed in everyday that prove otherwise.

The top layer of bearing material on the cam bearings is worn away. It won’t lose anymore material at this point or show up on any OA (if you believe in that nonsense) but will contribute to a lower than normal oil pressure. There will be no rod or main bearing wear for this instance.

And for that one guy who walked into the dealer that one time and happened to spot some guy torquing down head bolts with an impact, lol. No you didn’t.

Lots of former/has been/DIY experts with all the answers but no fix and that’s ok. They’ll bring it to me eventually

 

[Yaj Yak]

 

[Yaj Yak]

While we're at it I don't have a single Another Sorry Excuse of employee certification

DEEZUZ which category do you fit into?

Lots of former or has been or DIY experts

 

[Bob Kazamakis]

Whenever I hear “I work at a dealer” I think “Parts replacer”

 

[Bob Kazamakis]

Oh wait where’s Stink Star, he’s a dealer tech with an opinion I’d trust.

 

[DEEZUZ]

Whenever I hear “I work at a dealer” I think “Parts replacer”

I think of "all systems are in working order no repair necessary" or "replace the PCM"

 

[Yaj Yak]

Those oil analysis are BS. If anyone wants to believe that stretching out your oil changes to 10k and beyond is ok for your engine, then go right ahead. We get cars towed in everyday that prove otherwise.

The top layer of bearing material on the cam bearings is worn away. It won’t lose anymore material at this point or show up on any OA (if you believe in that nonsense) but will contribute to a lower than normal oil pressure. There will be no rod or main bearing wear for this instance.

And for that one guy who walked into the dealer that one time and happened to spot some guy torquing down head bolts with an impact, lol. No you didn’t.

Lots of former/has been/DIY experts with all the answers but no fix and that’s ok. They’ll bring it to me eventually

id put money on the cars getting towed in "proving otherwise" with 10k+ oil changes, likely weren't getting oil analysis done.

 

[Yaj Yak]

I think of "all systems are in working order no repair necessary" or "replace the PCM"

where's forcefully remove heatshield fall into place

 

[DEEZUZ]

My favorite tickets are the one that's a dealer diagnosed as bad PCM replace and reflash PCM no Diagnostics

 

[DEEZUZ]

Then I install a PCM the truck does the same exact thing yet they wanted to save a hundred sixty bucks for an hour of Diagnostics to pay me a thousand for the PCM

 

[DEEZUZ]

Then I question why didn't they have the dealer change a PCM since they trust their diagnostic so much

 

[DEEZUZ]

Oh wait where’s Stink Star, he’s a dealer tech with an opinion I’d trust.

Truth

 

[CMNTMXR57]

Those oil analysis are BS. If anyone wants to believe that stretching out your oil changes to 10k and beyond is ok for your engine, then go right ahead. We get cars towed in everyday that prove otherwise.

The top layer of bearing material on the cam bearings is worn away. It won’t lose anymore material at this point or show up on any OA (if you believe in that nonsense) but will contribute to a lower than normal oil pressure. There will be no rod or main bearing wear for this instance.

And for that one guy who walked into the dealer that one time and happened to spot some guy torquing down head bolts with an impact, lol. No you didn’t.

Lots of former/has been/DIY experts with all the answers but no fix and that’s ok. They’ll bring it to me eventually

I don't take oil analysis results as a means of whether or not I extend my change intervals. I would think that many here are the same. We take it as a "health of the engine" test.

 

[Stink Star]

Oh wait where’s Stink Star, he’s a dealer tech with an opinion I’d trust.

So what you really need to do is put an actual oil pressure gauge on an adaptor that screws onto the oil filter boss. Until then you’re just guessing.

As previously stated in here the oil pressure switch on the back of the valley pan is notorious for being bad so you can’t really trust a scan tool for reading oil pressure. But the real issue is there’s a screen under the oil pressure switch that gets clogged with schmoo and makes the sensor give a bad reading. You NEED to replace that if you’re doing a new oil press sender.

If the pressure is actually low it is 1 of 2 common things. A oil pickup o-ring (less likely) or worn can bearings. If it’s worn cam bearings it’s fucked. Technically you can replace them but going that deep into an engine is a job for a machine shop, not a technician at a auto shop. It’s likely easier to just get a new motor plus there’s 1000 other things that’ll be new along with the cam bearings.

 

[Chester Copperpot]

id put money on the cars getting towed in "proving otherwise" with 10k+ oil changes, likely weren't getting oil changes done.

fixt

 

[DEEZUZ]

.

And for that one guy who walked into the dealer that one time and happened to spot some guy torquing down head bolts with an impact, lol. No you didn’t.

Lots of former/has been/DIY experts with all the answers but no fix and that’s ok. They’ll bring it to me eventually

 

[Turbocharged400sbc]

Most 4 cylinder head bolts are 3-4 dugga-duggas.

The only ASE tests that were even remotely "hard" are L1 and L2 and they're pretty easy.

It's kind of like slapping a Corvette emblem on a Cavalier and while most of the parts are there it's not quite a Corvette.

It's like any other industry with a bell curve distribution of skillsets.

Just remember a vast majority of doctors working on you are C students

 

[PANDA]

Procrastinated with sending the oil to blackstone. Finally did. Took 7 days to go 3 hours away to Fort Wayne. Fuck USPS.

In other news 2000+ miles on the M1 oil and no noticeable loss in oil pressure.