2007 Tahoe Oil on Rear WIndow/Hatch

[spascoeinstl]

I bought a used 2007 Tahoe with ~90,000 miles. Following three long trips (in excess of 100 miles) I have noticed a fine splattering of an oily substance on the rear window and hatch. Both the dealer and my local mechanic feel its oil but have not been able to determine where it is from. The dealer put a dye in the transmission, stating it may be blow by. It is a clear oil and is a failry light weight, almost like oil from the A/C compressor and not oil or tranny fluid. ANybody else exprience this or have any ideas? Thanks

 

[clkelley]

Welcome to the neighborhood!

Without being able to get under the truck I cannot speak to where it may be coming from. However, did they check the power steering and brake lines. If it is a clear fluid that looks to be light weight, I would start there. The high pressure lines on the hydroboost units are known for beginning to leak and that could be the issue. But if you are getting the drops on the back of the truck then the source of the leak should be pretty apparent, you have to be leaking a good amount for the drops to spray up on the back of the truck like that going down the road...

 

[spascoeinstl]

Thanks for the welcome and the reply

I hadnt considered brake or power steering fluids, but based on the viscosity and color those seem to more logical than oil or tranny. A little more informaiton is it is a fine mist and covers the entire tailgate. Also it only seems to occur after I have been driving at high speeds on the highway. It has never happend in my 30 minute commute to work, nor weekend trips here and there. Only after extended (im guessing greater than 60 minutes on the highway) driving and maybe associated with heat or pressure.

Anyway thanks for the info clkelley, if when I determine what it is I'll proivde and update.

"I prefer my Tahoe to my previous BMW 550!!!"