1998 GMC Sierra overheating

240,000 MILES • V8 • 2WD • AUTOMATIC
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OTEGOREPAIR
  • MEMBER
  • 1 POST
engine was overheating, fixed leak in rad. replaced tension pulley, replaced thermo, replaced cap. I am still getting a overheat problem. about 10 miles it starts to over heat, fills overflow. I get a lot of pressure when taking off cap, not a lot of water. after that i fill about 2 gal of water and is ok for 10 miles. I think it could be intake manifold gasket? after i shut off engine i get steam coming out exhaust pipe for a few minutes?
Apr 3, 2010 at 12:40 PM
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JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,246 POSTS
Can you see anywhere the coolant is leaking from? Two gallons in 10 miles is a lot. If you don't see a leak, check the oil to see if it is mixing with it. Also, if you see white smoke from the exhaust, that indicates coolant is getting burnt in the combustion chamber. That is normally the result of a bad headgasket.

Check the oil and exhaust and let me know what you find.

Joe
Apr 3, 2010 at 4:19 PM
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