Heavy Line

coronetrt101 · December 28, 2005

I have a 2003 Silverado 2500HD with the 8.1 and Allison with 4.10 rear end.

Currently my truck has been drinking oil at the rate of 2 1/2 quarts for 1100 miles. This was confirmed by the dealer as they were performing the Oil Consumption Test. Can anyone tell me what is being done when the Tech performs the Oil Consumption test. Do they just check the oil with the dipstick or is there more to it??

The last time it was checked it was no where that bad. This is the 3rd official visit where they did the test and my current odometer reading is only 17,300 miles. I do not do much driving.

Currently the dealer scheduled me for 10 hours on the Heavy Line. Does anyone know what the Tech will do on the Heavy Line???

Thanks,

Jeff

GM-Tech · December 28, 2005

Heavy line is pretty much what the word heavy describes... The techs that do the heavy work... major engine repairs/replacement, etc., are considered "heavy line" techs.

The "oil consumption test" is nothing high tech. We simply release the vehicle with the oil exactly on the full mark and you drive it for x amount of miles or until sufficient oil has disappeared. You record the amount of fuel you've used in that time and the dealer should know the mileage when you went out and when you came back, low on oil. Then it is simple math to determine how much oil you've consumed in how many miles or how many gallons of gas.

Oil consumption based on gallons of fuel used is more accurate than that based on miles driven. Someone who whomps the gas all the time in the course of 1,000 miles is going to use much more gas than Aunt Clara who never goes over 30 mph. So the gas whomper will use more fuel in a 1,000 miles and more oil is consumed under these hard driving conditions as well.

2.5 quarts in 1100 miles is quite a bit.

coronetrt101 · December 28, 2005

So was the Dealer using the DIC to record the amount of gas used??? I was never told to record it... They just told me to come back in 1000 miles...before this it was 2000 miles...

Also I had been towing but its not like I had the pedal to the metal the entire time... There were several hills I had to go over but I actually averaged 7 mpg over the entire trip. Quite a bit of the trip was across level ground...

The previous time the oil was checked by the Dealer I had also towed the same weight (10K lbs) over a similar distance (700 miles). Do you have any idea what could cause an oil consumption anomaly like this???

Should I allow them to tear into the engine or should I wait another 1000 miles and check the consumption again????

GM-Tech · December 28, 2005

Actually, the fuel vs. oil consumption is used more for diesel engines, not gas. I see you have an 8.1. There's a TSB on this to replace the intake bolts for an oil consumption problem. Have they done that yet?

coronetrt101 · December 28, 2005

No they havent done anything as of yet.... From what I read in other posts the intake bolts did not make much of a difference... Do you know where I can find a copy of the TSB???

Thanks,

coronetrt101 · December 29, 2005

This afternoon I decided to check the oil level myself because the idea of 2 1/2 qts of oil seemed to high. Well I discovered that the Tech overfilled the oil by about 2 qts.

I high tailed it back to the dealer before any seals blewout and they drained my oil completely and refilled it with the correct amount oil. As of this moment the Service Manager has no idea why the Tech overfilled my engine oil and neither do I.

Anyways, since I do consume a good amount of oil, the service writer wants to still replace the manifold bolts.