Oil Consumption

[nonickatall]

I am curious on the compression results.
Also how often do you run a tank of fuel through the engine? Are you using primarily LPG? Or do you change back and fourth?

The cold start runs with fuel, after approximate 1 km it switches to lpg and if my lpg tank is not empty, i drive with lpg, because i pay at the moment 1€ for 1liter, while gasoline costs at the moment 1,80€. That means that with my consumption, i spend as much as a Hyundai i30 driver, with a 1 liter 3cylinder engine, which would be not used as a starter for real engines by GM when my car was made. I had that car recently in holiday is a rental car. You always have to step on the asseleration paddle, because the engine has nothing what would be called power.

When i go to Berlin, what i prevent if i can, i drive with 100liter lpg the 600km. A friend of mine works at VW Audi dealer and they recently drove an Audi e-tron electric ******** to Berlin for a customer. He told me, that they have to charge two times for 53€, so that means, that they invest more in electric energy than I in LPG....

And the funny thing is when people see me in Germany with my truck, the people always say: This car must have a huge fuel consumption...

 

[cjmcglaughlin]

Still early morning here so I'm doing my best to think clearly. So, your Escalade has 170,000 km on it right now? If so that is roughly 105,000 miles. I would not think that your valve guides are worn. My Silverado did not start excessively consuming oil and making valve noise until 390,000 miles, or 628,000 km. So I am fairly confident you have a few kilometers till your guides are worn badly.

Now, if I remember correctly, you do have a 2006. So AGE may have taken its toll on the valve guide seals, and they COULD be leaking. They are not terrible to do... however they are not fun to do if you don't have the space or equipment to do them with the heads on the engine.

However, your rate of consumption seems high for just guide seals.

In 2003 General Motors switch the PCV valve from the old rattle valve to a fixed orifice that continuously pulls a vacuum. It is for lack of a better description, a controlled vacuum leak. There were a few revisions to correct heavy oil consumption by these engines. The drain holes in the metal deflector were enlarged to help keep the oil from clogging them. The clogging lead the imitation pcv to act as a straw and suck oil out of the valve covers. You couldn't really see oil smoke at highway speed but you could on startup and heavy acceleration.
I cured this on BOTH of my 2006 5.3 vehicles (Tahoe and Silverado)by installing an older style PCV valve cover from 2001 vehicles and an oil catch can on them.
The Tahoe has gone to virtually zero oil consumption between oil changes. The Silverado has dropped from 2 quarts per 1500 miles (1.9 liters per 2400km) to 2 quarts every 3000 miles ( 1.9 per 4830km). But it also has now 414,000 miles give or take ( 667877.76 km approximately). So oil consumption is expected.

If you have the ability to do some fairly easy work on it, I would start by inspecting the inside of the valve cover where the "PCV" is and see if the drain holes are clogged. I personally think that is possibly your culprit. And it requires just time, a little cleaning solution( degrease liquid), some pipe cleaners to clean the little holes and maybe a valve cover gasket set. Fairly inexpensive here in the States. But, it is winter... so if you do not have an indoor place to work, it can get a bit cold.

Would you recommend installing the older style valve covers over newer ones meant to resolve this? I don’t have high consumption but I was thinking about the Dorman ones with the slotted baffles just to be safe.

 

[Mudsport96]

Would you recommend installing the older style valve covers over newer ones meant to resolve this? I don’t have high consumption but I was thinking about the Dorman ones with the slotted baffles just to be safe.

You could use either style. But whichever you choose, open the drain holes more. I have had no issues running the older style but unless you are going to the junkyard to find them, you may have a hard time finding some. As I believe the updated ones are all the stores sell now.

 

[nonickatall]

I now found the time to care for my car and i guess my engine ist finished and need an overhaul.

The engine runs good, makes no noise, but have oil consumption and coolant water is disappearing in some way.

Today i use an endoscope and made a pressure test.

I have on cylinder 1,2,3,4,6,7,8 around 210 PSI, but on cylinder 5 only 160PSI.

And when i look with the endoscope, i have cracks between the valves in most cylinders and i think my valve steam seals are finished, because i see oil on most of the intake valves. That is not a big problem, but in cylinder 5 there is a crack near the valve seat with missing material, which makes me think, it is better not to drive anymore, because if the valve seat falls out, i guess i can bring the engine to the graveyard.

I think that is the reason for the bad compression on this cylinder. So i guess i need two new heads and when i do that, i makes sense to make a complete overhaul.

I uploadet the videos on YouTube.

I would really appreciate if you guys, who are experienced with the LS/LQ Engine could tell me your thoughts, especially about cylinder 5, what to do and what you think about continue driving the engine, until i have time for an overhaul.

And what do the experts think about the overall condition of the combustion chamber, cylinder surface?

Here are the videos:
Sorry for the wobble, but it is very difficult to hold the endoscope steady and maneuver it correctly

Cylinder 1

Cylinder 2

Cylinder 3

Cylinder 4

Cylinder 5

Cylinder 6 https://youtu.be/o5GvQHSaxFw
Cylinder 7 https://youtu.be/3yXkXcqLphM
Cylinder 8 https://youtu.be/AsnaFQvsRh4?si=O1Enubd2M7C_16lD

 

[Doubeleive]

@swathdiver @iamdub

 

[swathdiver]

I looked at 1, 2 and 5. I think you have a blown head gasket on 5, it's washing the piston clean. I'm not well versed enough with LS engines to tell if those cracks are in the material or carbon build up or casting slag.

There's a leakdown procedure that can tell you where the compression loss is happening.

If it is a head gasket, you could be back on the road in short order without spending a ton of money on an overhaul or new engine, unless that is what you want and are ready for.

 

[Mudsport96]

I did not see the crack you were speaking about. I believe the valve stem seals are shot by looking at the videos. Also you will see more buildup than other engine. The fact you run propane or CNG is the reason. Liquid fuel washes the oil buildup away when it is introduced to the cylinder. Vapor fuel does not.

 

[nonickatall]

I did not see the crack you were speaking about. I believe the valve stem seals are shot by looking at the videos. Also you will see more buildup than other engine. The fact you run propane or CNG is the reason. Liquid fuel washes the oil buildup away when it is introduced to the cylinder. Vapor fuel does not.

Here you can see the place I'm talking about. The dark spot right on the valve seat and the dark groove above the dark spot, where it looks like the valve seat is loose somehow.

I'm wondering if the reduced compression could also be a head gasket issue. But as far as I know. If the head gasket is blown, there will be pressure in the crankcase or cooling system, depending on where the leak is located. what do you think?

 

[nonickatall]

I looked at 1, 2 and 5. I think you have a blown head gasket on 5, it's washing the piston clean. I'm not well versed enough with LS engines to tell if those cracks are in the material or carbon build up or casting slag.

There's a leakdown procedure that can tell you where the compression loss is happening.

If it is a head gasket, you could be back on the road in short order without spending a ton of money on an overhaul or new engine, unless that is what you want and are ready for.

Yes properly I have a head gasket problem because there is also a consumption of cooling liquid.

What leakdown procedure do you mean?

 

[Mudsport96]

Ok. I looked again. That may possibly be a production flaw that just looks different than the rest of the cylinders. But if you are concerned, it is good enough reason to inspect better.
As for the coolant loss. Do you know that it is consuming coolant? Or is it possible that it is leaking somewhere else? Do you have rear heat? The lines that run to the rear could be leaking. Or a slow leak at the water pump.