Spark plugs

NANA828

MEMBER
2001 CADILLAC DEVILLE
4.6L
V8
FWD
AUTOMATIC
133,000 MILES

Engine overheating. Have changed sensor for fans, coolant tank. Radiator is leaking. Was told to check spark plugs to see if really clean. If so, engine is blown. Have new radiator but not mfg transmission coolant line. Have to have one made. Do not want to invest more if engine is blown.

1 Reply

HARRY P

MECHANIC
2,292 POSTS

One of the biggest causes of an overheating engine is the thermostat. A little $8.00 part that takes ten minutes to replace. Any time I have temperature issues with my cars, the first thing I do is get a new thermostat. The thermostat is supposed to open up as the engine warms up, allowing coolant to flow through it. A bad thermostat can either get stuck shut (causing an overheating issue), or get stuck open (causing the engine to take forever to warm up). Again, a bad thermostat is a very common problem. So, obviously, that is what I would start with.

Also, to check and see if there is a serious engine issue here, check the oil. If it looks like nice clean engine oil, then there is no head gasket issue. If, on the other hand, it looks something more like chocolate milk, then you probably have a blown cylinder head gasket.