I have a 1994 Chevy Suburban 1500 4x4 5.7L with 290,000 miles. It was my fathers for years, until he pasted away. The Burban has sat for awhile. I got it running for awhile and just drove it some. I changed the oil in it, and used 10W-30. I couldn't remember the oil my dad used before. After the oil change things came up and it sat again for a few months. Today after some minor things, she is running again. But, smokes horribly. It smoked pretty bad before, but this is more. Still drives fine and everything. Just smokes. It's a white (maybe a little blue-ish?) smoke. I got to thinking, if I changed the oil again and put 10W-40 in it would it help? It might just be burning the oil, but I'm not sure. She's and old truck and means a lot to the family. Hope you guys can help
~SMITTYMAN~

 

Quaker state make a high mileage oil that may help, but you are about at the end of the life of that motor.

 

Welcome to the forum. Might try a can of Restore. I've had good luck w/ it but never tried on an engine w/ that much mileage.

 

Today I changed the oil and used 10W-40 High Mileage. Hoping the thicker oil will help. I've used SeaFoam in my Jeep before, and it's worked wonders. But the Jeep has under half of the miles as the Suburban. I'm afraid that it will clean out the gunk and everything... but the gunk might be what's holding everything together. Haha. Since I've driven a little bit in the past two days, the smoking has somewhat toned down. But, still a lot.

 

The valve seals probably have become brittle from sitting. They are actually not that difficult to replace if you have some mechanical skill. Does it smoke more on initial start up?

 

Yep, right when it starts it's smoking. Then somewhat tones down. It does again while accelerating. Only a tad at idle. While cruising though, it seems fine. I do have some skills... but I'm not sure if I'd feel up to doing it myself.... maybe.

 

Definitely fits ALL the symptoms of valve seals. You must have a air compressor to do the job. You will have to screw a fitting into the spark plug hole that puts air into the cylinder to hold the valve closed.