Where's It Going (coolant)???

[SnowBuck]

2005 XL...adding 1/2" a week. Three garages + the Dealer all say: "I dunno"!
No symptoms like rough idle (could balance a nickel on it), loss of MPG (none - gets 22 on the road), smell outside-or-in (none).

Did the big 4 Tests multiple times at different garages: Visual look, Pressure test (always good), Dye Test (no visible leaks), Head Gasket test (fine).
Then why have I added 1/2" coolant weekly for the past year???

 

[wjburken]

I’m assuming your oil is good as well?

 

[915_Tahoe]

@wjburken +1

how is the engine oil, also the trans oil

 

[mattbta]

Condensation on oil fill cap?

When you say pressure test always good - how long did you leave it @ 15PSI?

Have you pulled the valve covers for a look?

 

[Doubeleive]

send your oil in for a test (blackstone)

 

[bill1013]

Is your pressure cap leaking? I had the same problem with my 99 Tahoe. The radiator cap was no good. It gave out at 7 psi and vented a small amount of coolant overboard. It might be as simple as a defective cap. Aloha!

 

[OR VietVet]

"D" all the above. What test was ran as a "Head Gasket Test"?

 

[Larryjb]

Because cracked heads are common, a quick and easy check involves removing the valve cover and pressurizing the cooling system. Then you can look for seeping coolant in the head.

Check post #31:

https://www.tahoeyukonforum.com/threads/latest-oil-change-oil-filters.99646/page-4

I did not have condensation in the oil cap, no milkshake in the oil. My oil did thicken and darken between oil changes. Since doing the heads, the oil is still almost clear by the time I change it now.

The signs were VERY subtle for me.

 

[SnowBuck]

I’m assuming your oil is good as well?

Yes. Clean and clear. Even hit it and the oil cap with the UV - nuthin'

 

[SnowBuck]

Condensation on oil fill cap?

When you say pressure test always good - how long did you leave it @ 15PSI?

Maybe a couple of hours.