Engine overheat what are the best head gasket sealers for aluminum heads

REBELROB

MEMBER
2004 PONTIAC GRAND AM
3.4L
6 CYL
2WD
133,000 MILES

In January it overheated off the highway, I parked it. Next day started it drove 5 minutes, got warm fast. I smelled coolant, but the engine light wasn't on yet. Been sitting since then. Three days ago, I started it just fine, engine light on and runs rough on idle. The coolant is not leaking that much. Over flow stays at same level, but the oil looks cloudy a bit.

1 Reply

ASEMASTER6371

MECHANIC
52,797 POSTS

Good morning,

It may be a bad head gasket but needs to be confirmed. I would have a leak down test done to see if there are bubbles in the radiator.

https://www.2carpros.com/articles/head-gasket-blown-test

You remove all the plugs and insert shop air into each cylinder 1 at a time. If a gasket is leaking, the coolant level in the radiator will rise and flow out the fill cap.

As far a sealers, there are no sealer that work. They advertise they will but there is no sealer that can contain 150 pounds of compression. Besides, all that sealer does is compound the problem by clogging up the radiator and heater core and prevent coolant flow.

Roy

Important: Remove the Power-train Control Module (PCM) and the ignition fuses from the I/P fuse block.

1. Disable the ignition.
2. Disable the fuel systems.
3. Remove the spark plugs from all the cylinders.
4. Remove the air duct from the throttle body.
5. Block the throttle plate in the open position.
6. Measure the engine compression, using the following procedure:
6.1. Firmly install the compression gauge to the spark plug hole.
6.2. Have an assistant crank the engine through at least 4 compression strokes in the testing cylinder.
6.3. Record the readings on the gauge at each stroke.
6.4. Disconnect the gauge.
6.5. Repeat the compression test for each cylinder.
7. Record the compression readings from all of the cylinders.
The lowest reading should not be less than:
70 percent of the highest reading.
No cylinder reading should be less than 689 kPa (100 psi).
8. The following list contains examples of tile possible measurements:
When the compression measurement is normal, the compression builds up quickly and evenly to the specified compression on each cylinder.
When the compression is low on the first stroke and tends to build up on the following strokes. but does not reach the normal compression, the piston rings may be the cause.
If the compression improves considerably with the addition of three squirts of oil, the piston rings may be the cause.
When the compression is low on the thirst stroke and does not build up in the following strokes. the valves may be the cause.
The addition of oil does not affect the compression, the valves may be the cause.
When the compression is low on two/adjacent cylinders, or coolant is present in the crankcase, the head gasket may be the cause.
9. Remove the block from the throttle plate
10. Install the air duct to the throttle body.
11. Install the spark plugs.
12. Install the Power-train Control Module (PCM) fuse.
13. Install the ignition fuse to the I/P fuse block: