I have an 2002 Chev Sub Z71 4x4. I want to check the oil pan for sludge. How hard is it to pull the pan on a 4x4? I hope a hoist is not needed..
Thanks
BUC  

man thats alot of work to do to check for sludge.1st off you have all the suspension and drive train to get out of the way,and i cant remember if the crossmember bolts on or if its welded to the frame rails. and itd be just as hard to go through the engine compartment...if your worried about sludge then you can take it to a dealer that has or a quick lube like outfit that has an engine cleaner that they hookup to your oil filter and drain plug on the pan and flush it out w/hot asss cleaning detergents...thatd be the best.  

I've got 78K miles and the famous GM piston slap and noisy lifters at startup (Getting a little longer now days). A mechanic said GM's are notorious for sludge regardless what oil is used. He said check pan to see if full of sludge, might be some oil circulation problems if alot of sludge. I keep the oil changed every 2.5 to 3K miles...

BUC  

If you don't want to do a flush at a dealer, there are cleaning detergents that you can put in the crank case oil yourself just before changing and run the amount of time stated on the container.

How many miles do you drive between start up and shut off.  If you are doing a lot of short trips, sludge builds up a lot faster.  Even though engine temp gets to full operating range it takes a bit longer for the oil to get up to full temp. (the oil needs to get up to full operating temp range for a minimum amount of time or more).  You need to drive a minimun of 7 miles continous.  If you do a lot of short trips you will want to change at least every 2000 miles.  I hope this sheds a little more light on it.  

good point GM, alot of short driving will do that to an engine also ive noticed on rigs being driven short distances w/out being up to temp is that the oil will start to change colors to a light tannish color and be sorta bubbly in the top of the engine...  

Sludge only forms because your are either using low quality oil or you are not changing your oil often enough. Extended oil change intervals are just about a sure ticket to sludge build up long term. Clean oil has the ability to safely suspend contaminants in oil until it becomes overwhelmed and then it starts to settle out of oil and sludge forms. Using quality oil and changing it often will prevent this. I use about 3K miles as the standard here. In a new tight engine you might be able to go a bit further but 5 to 7K and more is really too long for conventional oil if you want it to stay clean. (even if you use syn oil, it still can get dirty too) As far as flushing it, this can be dangerous because it can suddenly break sludge loose, overwhelm oil filter and plug it and then circulate the sludge and grit thru bearings. If you think your engine is dirty, use some quality 10w30 oil and change oil often a few times (every 1500 to 2000 miles or sooner if it get dirty) and this will safely clean engine. (you should do this in warmer weather too) If you do want to try to flush it, replace filter BEFORE you flush it so that you are starting with a fresh filter so to be able to better catch and contain the sludge when you break it loose.  

sno's got a good point too...but when i was doing the engine flushes on older engine, kinda knowing that alot of sludge is there we did it twice to make sure the engine was clean and the filters never got clogged.  

keithpapa:
sno's got a good point too...but when i was doing the engine flushes on older engine, kinda knowing that alot of sludge is there we did it twice to make sure the engine was clean and the filters never got clogged.

Then engine was not really dirty or sludge was not removed. I have seen more than a few engines over the years that died to bearing failure during a flush and short drive when filter plugged. Even my son found this out the hard way a few years ago.  

I use Pennzoil High Mileage 10W30 in the Summer and 5W30 in the Winter (Central Al). My trips are 10+ miles. I don't really know IF the engine has sludge AND it is cleaned if it will help the startup noisy lifter / piston knock issue.. or if I even need to worry about it. GM say's its 'Normal'..  

when i had my 99 sierra w/4.8 v8 and even my silverado 99 w/5.3 v8 both engines made the same slappy noise and the dealer said it was "normal" too...but my engines never came apart or had issues w/them except for noise...
they never really told me what causes it...  

Long ago GM used to hand fit pistons to bores for proper fit. Now they do not due to increasing labor costs so some pistons are looser in fit and that causes them to rattle in bore and create noise. 5.3's seem to be the worst with 4.8 and 6.0 having less problems. It seems to be the worst on 99 through 04 models.  

ya sno, ive seen that plenty of times at the chevy dealer i worked at up here in montana...and figured that was the reason w/so many complaints that came through the service bays...but no fix on those yrs except for a complete tear down on a couple of them...warranty!  

They have a product called engine flush for cleaning the engine internals. You warm up engine and then add 1 quart of engine flush. Let it idle for about 5 to 10 minutes if I remember correctly then change out oil and install new oil and filter. Basically the cleaning agent is kerosene if you smell it with a few extra chemicals. Or maybe use marvel mystery oil and do same procedure as above. Instructions or on the can, buy at local auto parts house.