SeeBurb

So every 2-3 weeks or so(sometimes longer) i have to top off my coolant because my light comes on, The reservoir tank is usually about a quart low. It is not leaking out while it's parked. There are no visible signs of leakage anywhere. Had the system pressure tested and new coolant about a year ago.
One of the things that seemed to set off the light at first, was whenever i would park where the Suburban is tilted either higher on the drivers side or pass side. But now it will just come on randomly as i am driving.
My biggest concern is maybe the Head Gasket. What do you guys think? I am going to talk to my mechanic about it soon, someone told me to put a dye kit in the coolant so i could see where it's going.

2001 Chevy Suburban 1500 LT 4x4 5.3L

Jen
Note: not sure if this should go in General Tech instead? let me know if I should move it.

73shark

Welcome to the forum.

This is the best place. Have you checked to see if it's going in the oil? A compression check can check the head gasket.

SeeBurb

so far there has been no coolant in the oil.
sometimes it seems that the exhaust is whiter than normal, could that be happening if the coolant leaks into the intake manifold? but wouldn't it show up in the oil too?

73shark

Not if it went only into the intake runners but not sure how that could happen.

DoubleO7

My 1999 Tahoe with the 5.7L was leaking coolant into the oil via the intake gasket. As well as to the outside at the back.
The oil was clear and normal looking, not one bit cloudy.
But there was condensation under the oil fill cap that was antifreeze.
That was the only evidence of coolant in the oil.
I changed the intake gaskets and ever since, the underside of the oil fill cap has been bone dry.
I am thinking that cloudy or milkshake oil comes into being only when the amount of coolant leaking into the oil is too much to get evaporated.
So a tiny, small leak will not be obvious via that milkshake oil evidence.

in2pro

Excellent observation DoubleO7 and that is great info to have for troubleshooting.

Chevy-Lover

had same problem with my 01 Burban! Nothing noticed during driving for about a year. even no white exhausts.... no water in oil,... - so nothing to worry besides that little water loss. Checked it regulary, so no prob I thought... found on each oil change some muddy yellow-white stuff. Looked like a typical sign for a short distance vehicle as it is... so didn't worry about that either.
Just one crazy thing happened during that time: my oil dip stick blocked. Couldnt get it pulled. finaly it broke. It broke just at that point where it was riveted. It was sized up in the tull!
Last week I wanted to replace that dip stick and tull. So I took the oil pan of and fixed my problem. Everything looked perfect - nothing to worry: Clean oil, clean pan,...
I let the burban on the auto lift for that night without oil and pan... next day I finished my work.
First try to run the engine: rattling from the engine. Ok, thought all oil left the engine during the night so probably it just has to dispenses in the engine. Suddenly warning "Low Oilpressure". Shut the engine off and waited a few moments. Then I tried again: still rattling and a low oil pressure but no warning. At 1500rpm I had oil pressure at 40 and rattling stopped. Even in idle it was ok then. Just oil pressure was not around 40 as usual, it was at >20 in idle! Started to drive carefully and pressure kept at 40.
Even a day later same pressure. Tried to drive 50-60mph but oil pressure didnt get higher and it started to rattle again. Driving slow was still ok at 40 pressure.
Took a closer look today: almost no coolant left!!!
Put the oil pan off again and found all full of white-yellow mud in there. All the oil was full with coolant!
Discomposed the first head and again
Two cylinders had some water in it! Besides the aspected damaged head gasket I found something strange: nearly all water conduits of that gasket were totaly plugged - just two were free!!!
Checked the valaves with help of gassoline: two of them are damaged. Looks like the valve seating is broken, burned or whatever.... two valves even look like they got damned hot once!!!
Tomorrow I will put off the other head and take a look whats up over there.
Guess it's time for pulling the engine to get it repaired.

Battle47

Well I had the same problem for years. I finally found the problem. I had the intake off and did not see a lot of coolant stains, so I started looking else where. I found that the o-ring on the drain screw was bad . The coolant was leaking out of the drain hose beside radiator. You won't see it because the coolant drop down a track that the radiator sits in. Replace o-ring on drain screw and no more loss of coolant.

MDTAHOE

There is no coolant in the intake of the 5.3 engine.



bulletin No.: 06-06-01-019B

Date: June 12, 2007

INFORMATION

Subject:
Information on Gradual Coolant Loss Over Time With No Evidence of Leak Found
Models:
2004-2006 Buick Rainier
2001-2006 Cadillac Escalade Models
2001-2006 Chevrolet Avalanche, Blazer, Silverado, Suburban, Tahoe, TrailBlazer Models
2001-2006 GMC Envoy, Jimmy, Sierra, Yukon Models
2001-2004 Oldsmobile Bravada
2005-2006 Saab 9-7X
with 4.8L or 5.3L VORTEC(R) GEN III, GEN IV V8 Engine (VINs V, T, M, B, Z - RPOs LR4, LM7, LH6, L33, L59)

Supercede:

This bulletin is being revised to include engine RPO L59. Please discard Corporate Bulletin Number 06-06-01-019A (Section 06 - Engine/Propulsion System).

Some vehicles may experience a gradual coolant loss over time. A very low percentage of cylinder head(s) manufactured with an embossed Castech logo may develop a porosity crack in a very specific area.

Inspect the cylinder head assembly to determine if the casting was manufactured by Castech. This can be accomplished by inspecting for their casting logo located on top of the intake port, under the rocker arm support rail and in the spring deck cavity portion of the cylinder head.

If the cylinder head(s) are Not a Castech casting, follow normal diagnostic procedures in SI to determine the cause of the coolant loss.



Refer to the illustrations on how to identify Castech casting and/or the very specific areas of the cylinder head(s) for a coolant leak from porosity.

Cylinder head(s) location of the Castech manufacturing casting logo (1).



Close up view of the cylinder head(s) showing the Castech manufacturing casting logo (1).



If the cylinder head(s) is a Castech casting (1), inspect the area around the five oil drain holes for witness marks indicating coolant seepage over time (2).

If No evidence of coolant loss is found on inspection of Castech casting cylinder head(s), follow normal diagnostic procedures in SI to determine the cause of the coolant loss.



The crack location can be found in any of the five cylinder head(s) oil drains. This can be seen as a clean or shiny area, on an otherwise stained surface (1). Pressurizing the cooling system at this time may reveal coolant, air, or a combination, weeping in the described area. If inspection reveals evidence of coolant witness marks (1), replace the entire cylinder head(s) assembly.