How to fix a coolant leak at the water outlet on a 2.4L GM Pontiac Grand Am

    The coolant leak is a major one and hard to pinpoint. It appears to come from driver’s side of the engine. It continues to leak as the car is parked. Inspection reveals a very wet spot on the rear of the engine below where the water hoses exit the engine. Some dis-assembly is needed to locate the source of the leak.
1) Unplug electrical connector from the spark plug assembly.
2) Unplug electrical connector from between the valve banks
3) Unplug electrical connector from sensor in water outlet.
4) Remove large rubber air intake hose to get view of PS pump and coolant union.
The leak is now apparent at the bottom of the black plastic water outlet where it seats on the engine. The upper radiator hose exits here as well as a heater hose and an overflow from the recovery tank.

The water outlet

5) Drain coolant. Remove clamp from lower radiator  hose with vice grip pliers. Use channel lock pliers to free the stuck hose.
6) Reattach hose, clamp with screw clamp and put coolant into a bottle.
7) Strain coolant for reuse if desired.
8) Remove heater hose clamp from hose at water outlet.
8) Detach heater hose from water outlet. Used blow dryer to heat hose when it wouldn’t come off cold. Some coolant escaped.
9) Detach upper radiator hose from water outlet.
10) Remove the 10mm bolt holding mounting the overflow line just above and to the right of where it comes into the outlet.
11) Unbolt the two 10mm bolts holding the outlet to the engine.

Use a 10mm socket to remove the two bolts holding the outlet

12) Pull the outlet out and disengage from the overflow line. The inner part of the outlet had deteriorated and separated from the seal, causing the leak.

The outlet disintegrated

13) Get a new water outlet. I got one from Advance Auto sold under the name Factory Air part # 85164. For $10.39. Made in China. OEM was $29. I prefer OEM in most cases, but this is hard part for the after marketers to screw up.


                                                                         Installation
1) Remove the temperature sensor from the old part. Clean the threads and apply teflon tape to the threads. Install on new outlet.
2) Install a  new o-ring on the water outlet.
3) Install a new o-ring on the return line. This is included with the replacement water outlet.
4) Clean the water outlet mating surface on the engine.
5) Insert the return line into the water outlet
6) Careful insert the outlet into it’s port on the engine. It will not seal all the way with hand pressure.
7) Hand thread the two 10mm bolts water outlet bolts.  Then alternately tighten them up with ratchets. I used a ¼” drive on the hidden one along with a 6 inch extension bar. 3/8” works on the exposed bolt.
8) Seat the heater hose on the water outlet and clamp down. I used a new 1 inch screw clamp.
9) Seat the upper radiator hose onto the water outlet. Use a new clamp.
10) Seat the heater hose and install a new clamp.
11) Re-install the air intake duct
12) Fill with coolant
13) Run engine and check for leaks.

                                                        


Here are a couple of videos I made of this job.