Title pretty much says it all.

After driving for 5-10 minutes the engine gets really hot and starts leaking coolant. However, the radiator is cold. Oddly, the coolant leaking out is also cold.

Could this possibly be solved by bleeding the coolant system (i.e., cheap fix)? Or does it need a new water pump (i.e., expensive fix)?

Or, or, or...?

This is a 1987 944S with a 3.0L S2 engine, and otherwise everything seems to be running fine. Thanks.

 

The most likely reason is the thermostat is stuck closed. Take the lower radiator hose off, get the thermostat out (potentially a huge pain in the *** depending how the snap ring is oriented) and test in a pot of boiling water.

Bleeding air out of the system is always a good idea if there is ever any question. Try that first.

 

Yep, thermostat. Had the same issue in the past.

 

it is also possible that the impeller fell off the water pump - I've heard of that happening on other cars.

 

I would defiantly start with the Thermostat..check the temps on the hoses to see if it is plugged or stuck.

 

I had the same problem. I went to change the thermostat and found it gunked up with oil. It ended up being the oil cooler gasket. It got a new thermostat, and several cooling system flushes before all was well.

 

As above the thermostat is most likely stuck closed not allowing water to transfer thru the radiator. The link below will tell how to R&R the Water Pump if necessary. The Water Pump thermostat snap ring is hard to remove without a good pair of snap ring pliers OR a large pair of 90* needle nose pliers. If the holes in the snap ring are not easy to reach use an awl to move the holes to the 12 o'clock position. The video is in 3 parts.


Cheers,
Larry

 

+1 on this. Had the same symptoms on my S2 - turned out to be the plastic impeller loose on the WP shaft. Luckily I caught it in time before any other damage.
Cheers,
Mike