1999 Cadillac Seville overheats

1999 CADILLAC SEVILLE
120,000 MILES • V8 • FWD • AUTOMATIC
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DSEW1962
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  • 1 POST
This car will not overheat while idling but as soon as you put it in drive it starts overheating. Have changed the radiator, thermostat and have done a tuneup. No water in oil. Unhooked catalytic converter to see if it could be clogged. Heat does not work but ac does not sure if this is related.
Jul 5, 2008 at 6:38 PM
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RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
Have it block and pressure tested-do the block first to pinpoint a combustion leaking into the cooling system or a gas analyzer to sniff for hydrocarbons at the radiator fill neck.

Pressure test: do not do a pressure test if there's leakage at the headgasket this might cause coolant into the cylinders and lock it up or bend a connecting rod if cranked thereafter. The headgasket should be repaired before doing the pressure test.

If the block and pressure test passes check the following: Thermostat,Pressure test the Rad. cap,Clogged radiator,Fan clutch,Radiator electrical fan,collaspe hoses,water pump.
Jul 5, 2008 at 11:14 PM
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