I my 1999 Isuzu Rodeo V6 has been loosing fluild and recently overheated. I notice coolant coming from the front of the engine (passenger side). I changed the water pump, timing belt and tensioner. Cranked it up ran fine, coolant starting leaking again, same place.
Any suggetions where to look next???
You could have a leaking freeze plug, blown head gasket, or maybe the intake
manifold. Pressure test the system, move things around to pin point the origin
of the coolant leak. Make sure it's not a hose or gasket around the thermostat
area. You may have to remove the timing belt cover to check the leak. A coolant
pressure tester will help you a great deal.
I recently worked on a 98 Rodeo with a V-6. Coolant leaked from same area; however it was coming from the valley of the v-block beneath the intake manifold. If you take a flashlight and shine it down into the valley beneath the intake manifold you might see coolant. I thought is was one of the hoses beneath the intake manifold that began to leak. I siphoned all of the coolant out of the valley and then watched for a leak again, the valley began to fill up with more coolant.
What I discovered was a bad sealing washer that supplies and returns to the heater core. There are 2 metal hoses that run from the back of the thermostat assembly that have o-ring washers. One of these was cracked due to age.
Drain the coolant from the engine, radiator and block. Get a new thermostat while you're at it, cause you will not want to have to do this again if you use the old thermostat and it fails. This is not an easy task. Make note of which way the thermostat came out, it has a slide looking water guide on the bottom side, and can only be installed one way.
You have to remove the intake manifold (just unbolt the lower manifold bolts, you don't have to unbolt the upper portion of the intake manifold).
Remove the fuel injector rails, the EGR valve and any other piping that runs to the exhaust gas recirc system. Remove the upper cooling hoses. Remove the upper timing belt cover.
Unbolt the metal cooling lines from the backside of the engine that run to the heater core. Remove the flexible cooling lines that run to these metal lines.
Replace all flexible cooling hoses that run beneath the intake manifold while you're at it; just to be safe.
Unbolt the metal cooling lines that come out the rear of the thermostat housing. Pay attention to how you took things apart, because putting it back together requires some order due to how you tighten down the bolts, and put hose clamps back on. Use the screw down type of hose clamps, not the OEM spring tension type.
Thanks. This is great information!