Bought a 94 suburban with 180000 miles on it awhile back and coming up on my first oil change. Any thoughts on what type of oil to use. I have heard synthetics can cause problems in older vehicles with alot of miles. The guy i bought it from used some Northland Synthetic blend. Cheap oil in my opinion but should i stick with that or try something else? Any ideas appreciated. I have the 5.7 engine.
Just use a conventional oil and add a can of
http://www.restoreusa.com/Engine_Restorer.html to help the engine keep it's compression up in the cylinder's. You engine has to many miles on it to just start using synthetic oil. Save your self some money and keep up with the oil changes at 3,000 miles or 5,000 KM and add a can of Restore.
1994 GMC TRUCKS SUBURBAN 5.7L 8-cyl Engine Code [K]
Engine Oil Grade 1......API* Above -18C......10W-30 / All TEMPS......5W-30 SAE 5W-30 is preferred.
1988-99 models
Do not use synthetic lubricant in axles using RTV sealant.
Synthetic lubricant will chemically attack RTV sealant.
American Axle has only approved the use of Synthetic
Lubricant 75W-90 GM part no. 12378261, as follows:
a. All 8.6 inch rear axles are compatible.
b. All 9.5 inch rear axles built before mid-February 1998
(RTV sealant used to seal cover pan) are not compatible
c. All 9.5 inch rear axles built after mid-February 1998
(equipped with cover pan & gasket) are compatible.
d. All 10.5 inch rear axles built prior to March 3, 1999 are
compatible if axle shafthub RTV sealer is replaced with GM
gasket part no. 327739.
CAPACITIES:
Engine, W/ OOP, with filter..........7.5 liters
Engine, W/O OOP, with filter..........4.7 liters
TORQUES:
Oil Drain Plug.....20 ft/lbs