Smoking

[S1nemesis1s]

Hello All,

My Tahoe has 173763 miles on it. Since I bought it I have noticed some lifter click, heard it was pretty typical of these trucks, never paid it any mind. I recently moved, didn’t tow anything but did make short trips. I noticed after letting the truck sit for a couple of days upon start up some blue smoke came out of the tailpipe. Is this just a sign of age and the need of a valve job eventually? It is not my daily driver, but I depend upon it for getting big stuff around. Other than this the motor idles great and oil pressure holds steady when running, goes up when I have to goose it, but right back down. Can I keep on driving her and just adding oil if need be? I estimate it may use a quart between oil changes every 3000k-2500k

 

[iamdub]

All sounds normal for the mileage and nothing detrimental. If the smoking goes away after driving it and doesn't do it again until after it has sat for a while, then it's just worn valve seals. Just continue to keep an eye on the oil level.

 

[S1nemesis1s]

Will do. It does go away, just happens after its been sitting for a couple days. I know she is getting older, but I love that truck. I have put so much time and energy into it. Just had the front hubs replaced. I am hoping to get to 200k+ with her. Now that I have a second car I daily drive the stress is off her. She isn't much to look at, the drivers side door is dented in a few spots, and someone repainted the rear drivers door poorly and the wrong shade. But I have worked like a beast on the cooling system, drivetrain, brakes, exhaust, electrical system. So the bones are good I think, just need to watch the oil level. I honestly have it changed about every 2000k miles at my local ford dealership (close to work), so I don't think it will be that big of deal.

 

[06Escalade]

Blue smoke at startup is an indicator of failing rubber valve seals. High mileage oil can sometimes swell or nourish the seal enough to minimize the problem and give you a few more years. I would try maxlife 5w30 for a few oil changes, see what happens.

 

[S1nemesis1s]

Blue smoke at startup is an indicator of failing rubber valve seals. High mileage oil can sometimes swell or nourish the seal enough to minimize the problem and give you a few more years. I would try maxlife 5w30 for a few oil changes, see what happens.

Good tip, I will give it a shot for sure. Worst case here is that I would need a valve job at somepoint?

 

[ta08hoe]

A sitting vehicle seems to wear out faster than a daily driven one in my opinion but yes I agree nothing to worry about

 

[06Escalade]

Good tip, I will give it a shot for sure. Worst case here is that I would need a valve job at somepoint?

HM oil worked for several old cars I've had including a 2.4L Camry DD I had. Those engines were notorious for bad valve seals. Blue smoke at startup, oil consumption, what you describe.. Made it another 100k, to 350k before the body fell apart. Thanks to HM oil there was never a teardown.

I'm not an advocate of HM oils unless you need to. If it aint broke, don't fix it. If its not a rubber issue like seals or leaking gaskets, no reason to use the suff. Modern oils already have excellent cleaning and wear additives. But in your case I definitely think you should try it. Will leaking valve seals lead to a valve job? Potentially if the leak is bad enough and the valves get heavily coated with carbon buildup from burnt oil.

One other thing to mention.. I read about issues with the built in PCV valve in the valve cover of the 5.3 and 6.0. If they somehow fail, you get oil consumption issues. People swap the valve cover out, and its like a miracle, oil consumption is gone. Would a faulty PCV put pressure on your valve seals, make them leak? Yup. Consume oil in general? Yup. If you have someone follow you, stomp on it and ask them if they saw that blue smoke, can help with diagnosis.

So, I would try the Maxlife HM oil first for 2-3 short oil changes. Then maybe the $100 valve cover fix if the HM oil doesn't work in 10-15k miles. Then costs go up significantly. Why I recommend that order.

Note: If the valve seals are going bad, use of full syn may make it worse. Because it creeps and flows better than conventional. Mobil 1 makes a HM oil. Its a fantastic oil, fantastic additives. But I wouldn't go there just yet. Go the Maxlife route.

 

[iamdub]

Burning oil through the PCV system is an issue when it's running. Sure, his may be burning some oil, but probably not enough to be visible when driving. If the smoke coming out of the tailpipe was bad/dense enough to be seen even when being blown by the wind rushing by, then it would be losing more than a quart every 2.5k-3K miles. Even fresher/lower-mileage engines burn oil at high RPM, it's kinda the LS way!

His smoking at startup is just common worn valve seals. It really won't do anything other than requiring him to keep an eye on the oil level.

Donald, unless you get a hell of a deal on the oil changes at that dealership or unless the oil is getting dirty after only 2K miles, there's no reason to change it so soon. Just add oil to it if it's low when you check it and have it and the filter changed around 5K +/- 1,000. It takes one quart to go from the low mark (hole) in the dipstick to the full mark. Anywhere between that is ok.

 

[rockola1971]

Good tip, I will give it a shot for sure. Worst case here is that I would need a valve job at somepoint?

You are confusing a valve job with valve seal replacement. Two very different levels of teardown. Valve seals can be changed out by removing valve covers and roller rockers while inducing compressing air into cylinder via a spark plug hole adaptor to keep the valves from dropping into the cylinder while valve locks are removed.