Can't find coolant leak
This sounds like you have two problems: a vacuum leak and a coolant leak. First the hissing sound you are hearing is more than likely a slow vacuum leak caused by a disintegrating rubber PCV elbow. The length of the PCV tube is mostly plastic with a foam rubber insulator. At each end are rubber connectors that joint an engine vacuum port (near the throtle body) to the PCV valve. The "connectors" are made of a cheap rubber that disintegrates with the presence of oil. Replace the tube with an updated part number from Ford. These are easy to over look and often missed. Next, the coolant over heating issue. I would have the system pressure tested by an independent, reputable Radiator shop. Nowadays most technicians use an infarred thermo-sensing device (you can get yourself one at Sears for about 70 bucks). You should start the vehicle and allow it warm-up normally. Once the vehicle has been running long enough check the difference in temperature of the thermostat housing (looking at the transverse-mounted engine the front of the motor is facing the passengers side of the vehicle, the thermostat housing is on the drivers' side just under the coil-pack for the ignition) and the upper portion of the radiator. Keep in mind the thermostat is the most common leak point for these engines. If there is a major difference and the radiator is relativly cold, then the radiator is plugged and needs to be replaced or this could indicate the thermostat is stuck closed. If the upper radiator hose is hot and feels firm, then I would suspect the radiator being plugged. If the Hose feels relatively cool and soft, I would suspect the thermostat.
My guess is that the thermostat housing is leaking. This is a very common problem with these. If you find that the housing is leaking, you should also find that there is probably stagnant coolant on the top of the bell housing of the transaxle, located directly beneath the thermostat housing. At this point you should replace the thermostat housing, thermostat and gasket (usually sqaure rubber).
Hope this gives some direction and helps you!
Apr 02, 2009 |
1999 Ford Escort