leaking coolant out of rear of engine???

[MgRohlfing]

I just bought a 98 Explorer XLT 4.0 and there is coolant leaking from the bottom of the transmission where it bolts to the engine. Any suggestions to what it might be? It has 187XXX miles. I'm thinking maybe a frost plug on the back of the engine??? Thanks!

 

[2000StreetRod]

Sohc v6?

If you have the SOHC V6 the leak may be due to a cracked lower thermostat housing. It's fairly common on engines with more than 150K miles. The coolant runs aft down the valley between the heads and then down the rear of the block. There are no freeze plugs on the rear of the block.

 

[drdoom]

^+1 have seen it before thermostat housing split.

 

[frankcal]

Mine was dripping down the same spot and it was indeed the lower thermostat housing at about 97k miles. Took me a while to trace the leak since it was in the back but once you move hoses out of the way you could easily see a puddle where the housing sits.

 

[MgRohlfing]

would it be the same with a push rod engine?

 

[lobo411]

would it be the same with a push rod engine?

Unlikely. Check for signs of leakage around the housing, and for signs of spraying that might indicate a pinhole leak in the housing itself (due to corrosion). IIRC the reason the SOHC housing is prone to failure is that it's plastic, while the OHV uses a metal housing.

I'd lay my bet on these, in order of likelihood:

1. A leaky hose/connection
2. A leaking lower intake manifold gasket
3. A leaking head gasket (externally)