Gel/sludge in oilpan

[liftedtahoe]

I have a 2004 z71 tahoe 186k miles, i bought it used, changed the oil and everythimg looked fine, drove it about 1k mile and changed it again (i do this with all my used vehicles) anyways when i pulled the drain plug, nothing come out, i slid a small screwdriver in the oil pan and gel/sludge inside, finally it started draining a little, and puking out sludge, i filled it back up (after about 3 hours of waiting for it to drain) i drove it long enough to get the engine hot, and drained it again! It drained alot better but still puking out sludge in the process, i did this about 3 to 4 times within 1k miles, now i have started running synthetic oils, my question is what is causing the gel/sludge? It should only have so much right? I have also heard, that antifreeze getting into the synthetic oil will cause it to gel up.... does anyone know if this is a fact or a myth? Thanks everyone in advance!

 

[mizzouguy]

Strange it drained fine the first time...what color is the sludge/gel? Any pics?

 

[liftedtahoe]

Strange it drained fine the first time...what color is the sludge/gel? Any pics?

See thats what i was thinking, it drained fine the first time, i went with some cheap(er) oil because i knew i was going to change it real quick anyway, thought maybe it was the oil, but it all should be out of there by now, i dont have any pics(as of now but ill get some, its a dark black color but when u wipe it its the color of oil out of the jug, i dont understand it! Thank you for your reply

 

[mizzouguy]

I bet it was an accumulation of crap in the pan (dark) and the fresh oil and temp cycle started breaking it loose (new oil color). Did it sit for a long time before you bought it? I bet the previous owner didn't change oil very often...

 

[liftedtahoe]

I also ran some engine flush thru there, the stuff you put in there to break the sludge down, you let it idle for like 5 mins then drain. Ihave done that a couple times, still have sludge, also the other day my check engine oil level light came on, it was barely touching the stick, i have no oil leaks anywhere and it doesnt smoke, so where did my oil go?

 

[liftedtahoe]

I bet it was an accumulation of crap in the pan (dark) and the fresh oil and temp cycle started breaking it loose (new oil color). Did it sit for a long time before you bought it? I bet the previous owner didn't change oil very often...

See i thought the same thing but the oil being changed that much should have cleared up by now right? Or i would think it would... see im wondering if the oil in the oilpan is turning to sluge... since its going somewhere and i cant figure out where... i have great oil pressure, although i do have that annoying clatter on start up, but both of my tahoes do that and my past tahies did too, im just confused about the sludge, an where my oil went!

 

[mizzouguy]

If not not ending up in the coolant or burning it, im not sure...may have a piece of sludge stuck somewhere blocking return flow. I'd almost pull the valve covers to inspect the valve train for sludge. Id say keep at it with the flush at this point and hope all the sludge makes it to the pan. Maybe someone with engine building experience can chime in too.

 

[mizzouguy]

Or pull the pan and clean it out but thats a decent amount of work on the 5.3

 

[liftedtahoe]

Or pull the pan and clean it out but thats a decent amount of work on the 5.3

If i had a bigger suspension lift it wouldnt be nothing, im just trying to keep from pulling that oilpan right now unless i just absolutely have to! I just hate to pull the differential and all that, taking a chance of it not fixing it ya know lol ! Thanks for your input!

 

[liftedtahoe]

Please HELP me make since of all this! Anyone and everyone!