I bought a 2002 Suburban lt 5.3 135000 on it, this summer and some problems sneaking up on me now. I found some minor water (yellow deposits) on the dipstick last week and immediately checked the cap which although is a little rust colored, no cheesy crap was evident. Any ideas what may cause it? Thinking about the intake manifold, but other posts say water shouldn't run through there on a 2002 5.3. Is that right?
The car has also been getting a humming noise after it has been driven for 20 miles upon de-acceleration down in the 10-30 mph range which I misdiagnosed as wheel bearings. (Mechanic said they're good.)..Could this have ANY remote connection at all to engine issues and water in oil? After going to the mechanic on the bearing idea, they couldn't come up with anything that may cause it besides the auto 4 wheel drive being on and possible problems in the 4wd. Went to 2wd setting and it did get a tiny bit better but not perfect. It seems to get louder on a slow turn also..

 

does it burn coolant?

when was last oil change?

 

No it doesn't burn coolant and it usually gets oil changed at 3,000 but I took it on a trip 2 weeks ago and I checked the oil at about 4000 (when I saw the yellow film on the dipstick)and it was down 3/4 of a quart and so now its at 5,000 and wife is getting the oil changed as we speak.
The guy that I bought it from mentioned the vehicle goes through a half quart between oil changes and has since he bought it new. I thought the part about "has since it was new" was BS; but the money and title had already changed hands by the time he mentioned it, so no reason to start anything then.

 

AND - I also should mention there are absolutely no leaks anywhere on the motor or the ground....and doesn't smoke..

 

my old Tahoe would burn 1/2 quart or so, but it's hard to tell if you ever get all of it out or how much the filter's holding back....

what's the manual say the oil change interval is? the 07s+ have oil life monitors.

I don't know how worried I'd be unless it was happening to the oil right away... within a day or 2 of fresh oil...

5k miles on a truck with 135k... could be a problem or it could just run like this for another 100k... hard to tell...

 

Thanks,
I'll keep an eye on the oil color and level. I change oil every 3000 anyway. It just got away from me this time.
Any idea on the de-acceleration noise in lower gear? I've put half a million miles on tahoes over the years; never had this noise on any one of them with brakes, trannys or bearings and this is my first Suburban . Although the noise and feel of this is close to what I hear and feel when bearings start to go out; I had 2 different service places check for bearings and they both say "fine". The noise does gets louder and feels more apparent after it has been driven 20 miles or so and it seems to be most apparent when slowing down to around 20 mph down through about 8 mph when it seems to disappear. Can't hear it or feel it at 30-80 mph or even on acceleration at all. Just slowing down (coasting or braking makes no difference). My guess its in the tranny somewhere, but I just dumped 900 on new brakes rotors and and other parts hoping that the noise might go away with that and don't want to dump a fortune right away on transmission work if I can find a fix to get me through. Hoping someone else would chime in saying "this is exactly what I went through" with explanation of what it might be. But no luck..