Sugar Bears 2015 GMC Terrain SLE-2 2.4 AWD

[Grumpy Bear]

157,200 Services

 

01/31/2022

 

PCV valve installation complete and short term tests look good. ALL free moisture is GONE! Clean side is clean and moisture free as well and should never plug again as reversal of flow is now literally impossible. Took only 25 miles to dry is out. Before you could drive all day in freezing weather and never drive the water off. Idles and runs like a dream. 

 

 

I "T" into the brake booster vacuum supply line. This is a 15/32" line and good luck sourcing a "T" that size locally. I used 1/2" and silicon greased the snot out of it and still didn't drive it fully home but it isn't coming off, ever!

 

From the "T" toward the PCV valve is a short length of 1/2" Fuel/PCV hose just long enough to allow the step down via a 1/2-3/8 to 3/8 PCV hose. Actually it's also fuel/PCV hose. A Dorman cap was bored and a PCV grommet fitted. PCV valve installed and done. 

 

Nothing has to be done to make it functional and the motor happy. Fresh side air is drawn downstream of the MAP sensor so all metered air accounted for. All air is filtered. Highly filtered.

 

Now that I've done this once I will fret out all the proper bits and pieces for a cleaner fit up and do the Buick. At that time I will put up a list of part numbers. 

 

If anything it may be over drawing and if it proves to be so a restrictor orifice is easy-peasy.  OR source an adjustable unit   

 

There is an item of concern. The valve cover is NOT baffled on the vent side as nearly all are today. The baffle is on the clean air side. Odd but true. It is shielded but not baffled. A much small issue than water near 800 ppm. 

[Grumpy Bear]

157,321 Mile Services

 

2/1/2022

 

1,621 mile OCI

 

5 Quarts Kirkland 5W30

No filter change this OCI.

Used 4.5 ounces or a quart in 11,500 miles.

This is JUST inside the engineering upper limit of .05% per gallon of fuel. 

 

Adjust tire pressure. 

Gave her a really good bath. 

 

Edited February 2, 2022 by Grumpy Bear

[Grumpy Bear]

2/5/2022 Breather Update

 

500 miles on this OCI and it has been quite cold. Hovering below zero at night and low teens in the daytime. These are the perfect conditions for a 2.4 breather system to ice over. Actually the TSB states anything under 17 F needs to be watched like a hawk and it has been this motors custom to comply with the nature of the weak breather system it wears. Or...use to

 

After 250 miles of shake down I filled her up and added a bottle of Techron and the wife took Dizzy on a work trip yesterday amounting to about 250 more miles round trip almost all Interstate at 65 mph on cruise. Too dark last night and too cold and windy so this morning I took her pulse. 

 

Zero moisture anywhere in the system. A small amount of wet gas in the PCV to intake line which is normal for any motor. Around an ounce of oil used which on this trip is a new low and on track for something under 0.5% of fuel placing it in the 'normal' range or very close to it. Remember it always starts this way on fresh oil. so...... We do not know if the fuel issue is solved yet. (I should not be this good at reading a dipstick) That said no trace of fuel smell!!! 

 

Fuel economy is sharply up over the last three tanks. Between 8 and 10%. Yes yes, the data set is small but the conditions have also been brutal. Cold. Long warm ups. Interstate speeds. Winter winds. Snow. And it still is using less. 

 

I am very happy with this setup and will duplicate it on the Verano with a better parts selection. 

 

We have been delayed a week or so on getting the fuel system pressure checks. Shop closed for a few days.   

Edited February 5, 2022 by Grumpy Bear

[Grumpy Bear]

158,156 Mile  Report

 

On the previous OCI fuel cycle 1667 miles on 71.557 gallons of fuel = 23.30 mpg

This OCI so far? Two tanks 888 miles / 34.056 gallons = 26.1 mpg or 12.0% increase

 

Not all from the breather and ignition repairs. Some on tire pressure and operational/environmental. But directionally relevant. 

 

I'm starting a new metric. Oil consumption as a percentage of fuel usage. Knowing from an engineering viewpoint that "normal" is .03% to .05% of fuel consumed I will be reporting on this basis instead of miles per quart. 

 

So you need a point of reference. Currently this number is .0562% or 12.4% over the 'normal' HIGH. A huge improvement

 

But where did we start? 3.13% of fuel! 62.5 times the upper limit of normal. That's nuts!  

 

GM's marker would be .36% of fuel based on 29 mpg EPA estimates. Or roughly 10X the engineering standard. That is a quart in 2K miles. 

 

[Grumpy Bear]

PVC Parts List:

 

PCV Valve: A list of part numbers than are all the same valve: You need one

 

Car Quest PCA1008 

FRAM FV309

Standard Motor Products V293

AC-Delco CV938C or CV1006C

Borg Warner PCV 352

HONDA 17130-PK1-003

Purolator PV1026

Toyota 12204-10020 

WIX 66083

 

PCV valve grommet DORMAN 42330 or 42058. One is Ford the other Toyota. Same part, different label. OR 

BECK/ARNLEY 0396428 or Toyota 1057A033, 9048018001, E30113338A, E7GZ6A892A, MD179909 Again all the same grommet. 

 

Car Quest 10099 oil cap in which you will drill or bore a 19 mm hole central. (.748") Yes 3/4 will work. 

 

You need a 12 mm X 10 mm X 12 mm 'Tee" in brass. If you decide to use a 1/2" you better be King Kong to get a full seat. 

 

And a length of 3/8" ID PCV hose (Fuel Hose) and some clamps of your favorite flavor for each connection. 

 

You're going to splice into the Power Brake Booster Vacuum line next to the hose hanger with the "Tee" and the 10 mm (3/8) end pointing up. Bore/drill the 19 mm hole in the cap. Install the grommet into the cap. PCV valve into the grommet and plumb the PCV to the "Tee" with the 3/8" hose. Boom, a working PCV system that does not freeze and never back flows. 

 

Extra notes: Next time you have the intake manifold off for whatever reason you can plug the 1/16" OEM breather hole. It will work without this modification but it does not need it. 

 

For the Catch Can crowd. Install the can between the "Tee" and the PCV valve in series. No clean side separator is required. As you know how I feel about cans in general I will say as the system was not designed for a cap located PCV valve there is not ANY baffling as would be present in clean sheet design. Nor is there room to install a demister pad. The cap is shielded but not baffled. A case could be made for one in THIS UNIQUE situation. However, I'm starting off without one and unless the throttle body starts showing signs of distress, it will remain can free. Just putting it out there. 

 

Oh, before fire up assure the clean side is totally clear of obstruction. It WILL draw air from somewhere if it is. Like a main seal.  

 

[customboss]

11 hours ago, Grumpy Bear said:

PVC Parts List:

 

PCV Valve: A list of part numbers than are all the same valve: You need one

 

Car Quest PCA1008 

FRAM FV309

Standard Motor Products V293

AC-Delco CV938C or CV1006C

Borg Warner PCV 352

HONDA 17130-PK1-003

Purolator PV1026

Toyota 12204-10020 

WIX 66083

 

PCV valve grommet DORMAN 42330 or 42058. One is Ford the other Toyota. Same part, different label. OR 

BECK/ARNLEY 0396428 or Toyota 1057A033, 9048018001, E30113338A, E7GZ6A892A, MD179909 Again all the same grommet. 

 

Car Quest 10099 oil cap in which you will drill or bore a 19 mm hole central. (.748") Yes 3/4 will work. 

 

You need a 12 mm X 10 mm X 12 mm 'Tee" in brass. If you decide to use a 1/2" you better be King Kong to get a full seat. 

 

And a length of 3/8" ID PCV hose (Fuel Hose) and some clamps of your favorite flavor for each connection. 

 

You're going to splice into the Power Brake Booster Vacuum line next to the hose hanger with the "Tee" and the 10 mm (3/8) end pointing up. Bore/drill the 19 mm hole in the cap. Install the grommet into the cap. PCV valve into the grommet and plumb the PCV to the "Tee" with the 3/8" hose. Boom, a working PCV system that does not freeze and never back flows. 

 

Extra notes: Next time you have the intake manifold off for whatever reason you can plug the 1/16" OEM breather hole. It will work without this modification but it does not need it. 

 

For the Catch Can crowd. Install the can between the "Tee" and the PCV valve in series. No clean side separator is required. As you know how I feel about cans in general I will say as the system was not designed for a cap located PCV valve there is not ANY baffling as would be present in clean sheet design. Nor is there room to install a demister pad. The cap is shielded but not baffled. A case could be made for one in THIS UNIQUE situation. However, I'm starting off without one and unless the throttle body starts showing signs of distress, it will remain can free. Just putting it out there. 

 

Oh, before fire up assure the clean side is totally clear of obstruction. It WILL draw air from somewhere if it is. Like a main seal.  

 

Great work to solve a sad problem left for you by GM. 

 

Grumpy, were you ever able to source design spring tension  of all those PCV valves?  I ask because in the past 42 years of automotive oil analysis we would see aftermarket valves cause issues on a given stock engine and install the stock called for PCV valve and the problem would solve, we surmised it was spring tension variation among designs but I never drilled down hard enough to confirm. The customers were happy to find that a solution regardless. 

This effect was particularly noticeable with Toyota 2000's 3.0 L V6 that did not breathe well to begin with and had a major class action lawsuit when the narrow galleys blocked with carbon. 

With solenoid controlled systems and internal vents and baffles on our GM truck engines it takes the spring out of the equation.  Or do you see the spring as a mechanical on off switch? 

 

 

 

 

[Grumpy Bear]

5 hours ago, customboss said:

Great work to solve a sad problem left for you by GM. 

 

Grumpy, were you ever able to source design spring tension  of all those PCV valves?  I ask because in the past 42 years of automotive oil analysis we would see aftermarket valves cause issues on a given stock engine and install the stock called for PCV valve and the problem would solve, we surmised it was spring tension variation among designs but I never drilled down hard enough to confirm. The customers were happy to find that a solution regardless. 

This effect was particularly noticeable with Toyota 2000's 3.0 L V6 that did not breathe well to begin with and had a major class action lawsuit when the narrow galleys blocked with carbon. 

With solenoid controlled systems and internal vents and baffles on our GM truck engines it takes the spring out of the equation.  Or do you see the spring as a mechanical on off switch? 

 

That list of part numbers above is a minor slice of about 50 part numbers used to 'package' the exact same valve, made in the exact same factory in Mexico. Same part, different box on a different day. MOST are specified for I-4 ICE's in the 2.0 to 2.5 liter range. Most of those pre 2006 models and yes some with VVT. 

 

I'll be preaching to the choir cause I know you know this stuff. But here goes.

 

You can under draw the crankcase as GM has on the 2.4's use of an unchecked orifice. That is the bypass volume exceeds the the orifice flow potential for MOST cases of load/leakage and draw/vacuum. Result is moisture/acid/fuel in the oil and nothing good happens there, right? Underdrawn it when the crankcase fresh air side is clear and the flow reverses into the fresh side and it goes right back into the manifold. Underdrawn when the vent 'freezes' and Pop goes the Weasel. Gasket or main seals leak/blow. 

 

So what happens if you have a system that overdraws? Nothing bad actually if well baffled. Fresh side is all metered air thus the AFR stays correct. You remove all nasty stuff that is vapor at the operating temperatures and pressures. If the system is well baffled nothing liquid at any measure that matters is passed. About the only time you could have an issue is if the PCV valve is passing more air than the throttling condition asks for. Think vacuum leaks. Why the orifice is so small in the OEM design. Keep the idle nice and clean. With a PCV valve high manifold vacuum at idle CLOSES the valve or nearly so and ring leakage is nil under these conditions IF the rings are working right. If not once again over pressure back flows the fresh air side and you get liquids where they should not be. Don't need a can there. Need the rings working.  

 

Not quite a light switch however. Vary the vacuum and the PCV valve shuttles between two springs in some and a signal and pill mass in others to throttle the flow according to the signal and spring balance. Thing is....it isn't rocket science in NA applications and more than enough is not a problem. If it really needs the fine a tune, there are adjustable PCV valves on the market to fine tune with. 

 

Ya know in some of my race motors we put a venturi in the exhaust collector with a low weighted check valve and let the exhaust draw on the crankcase as hard as we could get it to pull. Some motors we even installed true vacuum pumps. 

 

Bottom line. If the spring is weak enough to close the valve at idle....and ported large enough to pass normal gas volume under load the world is good. And sir...that is a range a bus can drive through. 

[Grumpy Bear]

159,000 Mile Services

 

2/13/2022

 

159,065 actual

1,734 miles this OCI

6 ounces make up oil 

.071% of fuel 9,245 miles

142% of spec

 

5 Quarts Valvoline 5W40 Euro

1 Purolator Pure One filter PL15436. 

 

Still fuel diluted viscosity break. Start higher is the reason for this SAE Grade change until the issue is solved. I won't bore you with the delays. 

 

 

Edited March 2, 2022 by Grumpy Bear

[Grumpy Bear]

160,289 Mile Services

 

2/24/2022

 

1,224 miles this OCI

 

Replaced passenger side head lamp projector bulb. 

Rotated and balanced tires. Lots of tread left. 

 

And the fun stuff we've been waiting on. Low pressure pump is on the very bottom of the normal range and something to keep an eye on. Not allot of life left in it but for now we are good.  

 

The HPFP runs in range. Higher end actually. HOLDS pressure when shut down well within the factory leak down rates. So both it and the injectors are holding tight and not leaking. LTFT and STFT are dead balanced in the middle of the spec. This is good news indeed. 

 

Worth noting. The 5W40 over the first 750 to 1000 miles used at the same rate, give or take, as the 5W30 BUT not the end of that story. 

 

In the past the 5W30 would use nothing I could measure for say 750 miles then start using at a rate that doubled every 250 miles thereafter or until the next change. So 2 ounce say at 1K then 4 ounces by 1250 and 8 more by 1500. Not exact but you get the idea. 

 

The 5W40 so far is using a pretty steady 1 ounce per 250 miles at a linear rate. 

 

Last item in this report. I did add a baffle to the PVC system. I made it from sheet brass and placed between the filler cap then valve cover below the PCV valve. Started with a small hole and adjusted that size until I had, at idle, 5 to 10 inches of water draw on the dipstick with the fresh air side open to the filter box as per normal. In the service book it calls for this spec at 1500 rpm and I can't tell you why as the MAP is identical when the motor is unloaded in neutral. Yes I have a 40" water test gauge from days gone by in instrument training. Never thought that would come in handy. 

 

Time to consult with my Tribologist. All going to plan so far but I've run out of plan...  

 

 

[Grumpy Bear]

Items of note: 

2/26/2022

 

1.) She used more oil in the last 250 miles than the previous 1250 miles and a good volume of crankcase gas when the cap is removed. Well that's not good. This may be a fight I can't win. Last tank was awful and it feels sluggish. 

 

2.) A horse beaten to death and yet still I am her student. When you pull the dip stick on this POJ you drag oil up the tube as it's route is convoluted. Yes even when hot so you can NOT get a clear and repeatable reading.  So pull the stick FIRST and wipe but only reinsert about 1/3 of the way while you fuel up or whatever your doing. 8-10 minutes or so is long enough. Push it to seat fully and withdraw to read. You get ONE shot at it. Mess it up you start over. Hot or cold matters little and I've found doing it this way is allot less sensitive to being on a dead level surface (front to back). Fact is once I started dong this 3* +/- of hardly matters. 

 

3.) Going back in the shop. Seems there is an rpm spec for the primary fuel pump that was overlooked. Quick in and out to put it on the scope for a look. I didn't ask but that sounds to me alike a brushless DC motor with a PWM regulator and a hall sensor. Which sounds expensive LOL. 

[Doublebase]

It looks like your rings are shot, and when I say shot, I don’t necessarily mean “worn”, I’m saying they are stuck in their lands, can’t expand like they’re supposed to and because of THAT they are allowing blow by and they may have also done a little bit of wear directly on to a cylinder wall (or two). Unfortunately this is something I’m seeing with low tension, direct injected engines. Toyota had a problem with this, there have been many others. The blow by is leading to fuel dilution, and oil consumption. I imagine you’re getting oil tracking up into your intake as well. Those rings just can’t expand and break through the carbon/soot that is building up on the sides of the pistons. And the rings are stuck. Sometimes a treatment can free them up, but usually not. When these things get stuck they’re tough to move even if you can get your hands on them and pull them out. 
 

This guy explains it pretty well on a Toyota.

 

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiqp4H39p_2AhXejIkEHXf1A-8QwqsBegQIAhAB&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Dh6XnNAfQ904&usg=AOvVaw16LZHdtiALvfJ6suw_JCPa

 

But you’re doing a great job keeping this thing going! You might be able to get another 50,000 out of it. And I imagine weather conditions might be playing a small part. Summer months may be a little more forgiving with that thing being able to heat up quicker and stay warmer longer? Best of luck to you! If anyone can keep it going it’s you. 

 

 

[Grumpy Bear]

49 minutes ago, Doublebase said:

But you’re doing a great job keeping this thing going! You might be able to get another 50,000 out of it. And I imagine weather conditions might be playing a small part. Summer months may be a little more forgiving with that thing being able to heat up quicker and stay warmer longer? Best of luck to you! If anyone can keep it going it’s you. 

 

Thanks you Mike. I watched the video. What a perfect set up for OCI. This guy did 10K changes and the mechanic in this film suggest 5K changes. Well guess the length of the oil changes that crashed this motor? 

 

5,000 miles and the rings still went south.....

Quaker State Ultimate Durability and most of that time WIX filter.

Much shorter recently. 

 

I have another one of these Ecotec 2.4 pigs in a Verano that has only 14,000 on the clock. Not a chance that one will see 5K OCI's   

 

BTW did you notice that only the power cylinder in that motor on the oil side of the motor looked bad? Cam towere, crankcase lower, cam chain box all looked pretty clean. 

 

I also agree with the owner math. Motor replacement is worth it IF the rest of the vehicle is good to go. IMHO of course. 

[KARNUT]

I wonder if that model is bringing higher trade in value. If so I’d trade it in at a Chevy dealer. I get a CPO Malibu or Impala. One of those so called less desired vehicles. Or sell it to carmax and drive the Buick until prices stabilized. Carmax has warranty on cars they sell, protecting the new buyer. Unless tinkering with that thing is a fun past time for the owner. A replacement engine is going to have the same problem. Is it not. It seems man vs machine and the machine is winning.

[Doublebase]

1 hour ago, Grumpy Bear said:

 

Thanks you Mike. I watched the video. What a perfect set up for OCI. This guy did 10K changes and the mechanic in this film suggest 5K changes. Well guess the length of the oil changes that crashed this motor? 

 

5,000 miles and the rings still went south.....

Quaker State Ultimate Durability and most of that time WIX filter.

Much shorter recently. 

 

I have another one of these Ecotec 2.4 pigs in a Verano that has only 14,000 on the clock. Not a chance that one will see 5K OCI's   

 

BTW did you notice that only the power cylinder in that motor on the oil side of the motor looked bad? Cam towere, crankcase lower, cam chain box all looked pretty clean. 

 

I also agree with the owner math. Motor replacement is worth it IF the rest of the vehicle is good to go. IMHO of course. 

Yeah I did notice where the wear was. He’s shown a few other videos similar. Toyota recommends 10,000 intervals on their vehicles now, been that way for a while. Obviously that’s open for debate. Lol.

 

If that weren't a direct injection engine I imagine things would have went south maybe a little quicker. Then again there is the camp that just say this is not the oil, or interval, it’s simply a design flaw and there is nothing that will prevent it (just luck). And there’s plenty of people running around nowadays doing extended drains to maybe prove that. But it depends on the engine. 
 

Good luck! Keep up the good work. I hate it when things go south and you’re stuck there trying to come up with solutions. And they sometimes don’t work (or they do). Dealing with a chimney situation at home right now (with me trying to figure why the thing is weeping into the attic wall. Hasn’t been fun…and it’s cost me a lot of money. 
 

I thought when you had 7 ppm of iron on a short interval that something was amiss with those rings and cylinder wall. And with low, to non existent other metals. I bet your engine looks great outside those cylinders. 

Edited February 27, 2022 by Doublebase

[Grumpy Bear]

6 minutes ago, Doublebase said:

Then again there is the camp that just say this is not the oil, or interval, it’s simply a design flaw and there is nothing that will prevent it (just luck). And there’s plenty of people running around nowadays doing extended drains to maybe prove that.

 

Very popular thoughts indeed. (bold type or CAPS is for emphasis. I'm not yelling)

 

Me? I just don't think luck is a term used in mathematics, chemistry or physics. There is 'probability'. A bag of 100 marbles for example where all but one is black and the last one white. If ten people are allowed to pull ten marbles each the probability of getting that white marble is 1 in 10. The guy that got the white marble isn't lucky or unlucky. He just got a white marble. It's a FACT. 

 

Lets change the conditions or parameters to: A 100 guys are to be allowed to draw one each then the probability of getting that white marble is 1 in a 100. 20 guys odds are now 1 in 5. 2 guys is 50/50. 

 

"Plenty of people" being successful has more to do with the conditions/parameters of use and choices than luck or happenstance. 

 

Design flaw. Yes a condition can be the result of a design flaw OR simply a different design parameter that needs a different regiment in which case you have to CHANGE your thinking on what is workable, useful. The ridged thought.....that is the flaw that causes damage. And in this case the design flaw was ME.  

 

I WHIFFED this motor badly. One of two in my near 70 years of life and I WILL learn the lesson it is trying to pound into my hard head. The other oddly a Toyota 

 

I KNEW that the 7,500 GM OLM suggested interval was CRAP. It was already failing badly enough for GM to be in court over it. Then I ASSUMMED that cutting that to 5,000 and using a LICENSED OIL would PREVENT a condition I KNEW was an issue with THIS motor. I TRUSTED GM to know even after they FAILED AND LIED and that is just insanity on my part. 

 

I did not use the oil that has been successful for me even in GDI motors for 30 years but is not licensed. I did not adhere to my 'cut it (OCI) in half or more' practice. I FAILED to trust my experience and observations. The motor just did what motors do when they don't get what they NEED.

 

My bad.