Sludge In Oil

paulstruck · June 28, 2009

I have a 1999 silverado 1500 with the 5.3 engine. It has 96000 miles on it and is driven only short distances (12 miles round trip to work). I use valvoline 5w30 oil and change it every 3000 miles. I've had quite a few oil changes in the last year and a half were a large amount of sluge(about a 1/4 cup) is plugging the oil pan drain hole. It is the consistancy of grape jelly. The oil is black in color and has no unusual smell. My neighbor has an identical truck that has the same problem. Does anybody have a clue to what may be causing it.

bill190 · June 28, 2009

Might want to poke around here...

"Bob Is The Oil Guy" forum...

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=cfrm

Stylous · July 1, 2009

What about an engine treatment like seafoam before your next oil change? Clean it all out and then see what happens.

Does your neighbor use the same type of oil? If so, maybe one of you should switch to see if that makes a difference.

paulstruck · July 2, 2009

What about an engine treatment like seafoam before your next oil change? Clean it all out and then see what happens.

Does your neighbor use the same type of oil? If so, maybe one of you should switch to see if that makes a difference.

Yes, I did use the sea foam and it was clean for a while. My neighbor was using Penzoil when he discovered the sludge. I don't know what he uses now, he has been in really bad health and I have not seen him for a long time.

Alljackedup408 · July 2, 2009

weird... mine has ZERO.... and its a 99 5.3. with 101000miles

zackafee · July 2, 2009

ahhh...just drive it harder. haha

Stylous · July 2, 2009

What about an engine treatment like seafoam before your next oil change? Clean it all out and then see what happens.

Does your neighbor use the same type of oil? If so, maybe one of you should switch to see if that makes a difference.

Yes, I did use the sea foam and it was clean for a while. My neighbor was using Penzoil when he discovered the sludge. I don't know what he uses now, he has been in really bad health and I have not seen him for a long time.

If I were you I would do seafoam again then switch brands and/or go synthetic.

Draenor · July 2, 2009

My best guess is that you are not running the engine long or hot enough to burn off the moisture in the pan/crankcase/etc. Switching to a synthetic would help.

fraso · July 3, 2009

See BITOG: What Causes Sludge?

Your owner's manual recommends 5W-30 Starburst oil for normal operation. 10W-30 and 0W-30 grades are also recommended. If you don't have an owner's manual, visit the GM Owners Center (use Internet Explorer) to download one.

For an older engine like yours, there is no reason that you could not be using a Heavy Duty Engine Oil (HDEO) rather than a Starburst oil. HDEOs have strong deposit control additives to keep your engine clean. If you want to stick with 10W-30 dino HDEOs, you can use Shell Rotella T, Brad Penn HDEO, PetroCanada Duron-E, and Exxon XD-3. You can also use a synthetic 30-weight HDEO but these are generally available as 5W-30 or 0W-30 because synthetics flow so well in cold temperatures.

Starburst Oils has friction modifiers and lower levels of Phosphorus (800 ppm max for the ILSAC GF-4). HDEOs don't have friction modifiers but are allowed up to 1200 ppm of phosphorus, which is the anti-wear component of ZDDP.

ACCCC Engine Oil Article