engine getting hot when idling at red lights,etc, losing coolant somewhere? no water in oil, do smell antifreeze. bubbling noise, but no steam or water from radiator. 154,000 miles, 96 model.

 

Engine? The 3.3 & 3.8l (pre-2001) are notorious for water pumps and radiators. Obviously, the best thing to do is locate and fix your leak.

 

Hve you verified that the fan is working when the engine over heats? When moving the air is flowingthru the radiator. When at a stop light if the fan is not working no air will flow thru the radiator causing over heating.

One other thing to check for your coolant loss is the soft plugs. They can corode especially if you do not change your anti-freeze regularly. They will start to seep around the edges. This will cause you to smell anti-freeze being heated on the engine block, but does not leak enough to show on the ground. However the loss over time will be enough to cause low coolant levels and thereby cause over heating.

You may have a cracked head or blown head gasket. This can happen from over heating the engine. Your anti-freeze loss is possibly due to anti-freeze being burned in the combustion chamber. Do you smell anti-freeze at the tail pipe? To verify ahead gasket/craked head problem. Run each cylinder to top dead center and put 100psi of air in the spark plug hole using a spark plug air hose adapter (available at most auto parts stores). You may need to keep a socket with breaker bar on the crankshaft bolt to keep the air from pushing the cylinder down while testing it with the air. If when applying air toa cylinder the coolant in the radiator starts to bubble, then this verifies you have a head gasket/cracked head problem on that cylinder.

 

A faster and easier way to check a head gasket is to find a shop with a CO sniffer. Typically CO can be found with the sniffer in the neck of the radiator, when the engine is running of course, if the head gasket is blown and forcing exhaust into the cooling jacket.

 

The sniffer does not always work with cracks. Especially if the crack does not open up until the engine is under load or is very well heated. I have had many cars in my shop thatmy emission sniffer could not detect combustion gases in the cooling system, but leaks were found under air pressuer in the combustion chamber.

 

It could be a number of things bad hose water pump if possible put some carboard down and see where the leak is coming from you don't want to keep driving with it overheating as you could damge you engine more such as cracking a head or ruining the engine you can also remove the cover on the inner fender and try to see where the leak is coming from if it is on the passenger side