Loud ticking noise when engine started

2001LS with 3.8L, 69,000 miles...

Here's a new one with this car... Started it up this morning (cold) and I hear a very loud ticking noise, like a stuck valve or something... I've never heard that noise before... Let it run for about 15 more seconds and the noise continues... I shut the motor, check the oil... Oil reads about 1/2 quart low so I add 1/2 quart of oil... Start it up again and the noise goes completely away after about 30 seconds... Drove the car for the next hour with no noise or problems... I'm letting it cool down for a few hours and then I'm gonna start it up and listen for the ticking noise... Any ideas?!?!

And I'm still trying to determine my mystery coolant leak after the dealer did a pressure test and said everything tested OK...

BTW, Merry Christmas to all EXCEPT General Motors!! LOL....

Sounds like a lifter was collapsed and just took a while to pump up. Coolant leaks on these engines can be a littany of issues, upper intake number one, lower intake gaskets, various hoses and fittings, usually a pressure test will show something unless it is internal, then it will only show it is not holding pressure, no quick answer for that one.

What causes a lifter to collaspe?? Never happened to me before...

I just restarted the car after it was sitting for 5-6 hours... NO ticking noise at all... But I hear a gurgling (spell??) fluid noise as I increase the RPM's a little... I wonder what that could be??

As far as the coolant leak is concerned the dealer did a pressure test and told me they kept the system under pressure for nearly 1 hour with no loss in pressure... Yet the low coolant level light keeps turning on and off... Maybe the sensor itself is gunked up, yet each time I open the radiator cap the level is 1-2 inches below the filler neck... I top it off, yet the light keeps coming on... I check the level and it's down 1-2 inches again...

Can a bad head gasket cause any of this??

(I'm probably mixing up two seperate issues here...)

take out plugs all should be lt brown. if one is white or very different than the other plugs your head gasket is starting to go.the ticking on start up is usually a dirty lifter. if coolant gets into the engine, sludge created will cause this.also dirty oil or oil containinated because PCV valve or hoses not working....if coolant drops its leaKing somewere and if it can't be readily seen head gasket is a good possibility.

These two issues may be in fact related. Lifter noise at startup associated with coolant loss can be caused by the coolant getting into the lifter and contaminating it, as a result of a leaky intake gasket. The ticking noise is most likely a lifter for sure. You could be leaking coolant both in the engine and also it could be getting into the intake port and burning through combustion. The EGR passage is another problem with these engines too. Have the intake gaskets ever been changed? Intake gaskets, like maxwedge mentioned are very common for these engines, and must be closely maintained/watched. In my opinion, take a close look at those gaskets and get a second colling system pressure test.

...... Have the intake gaskets ever been changed? Intake gaskets, like maxwedge mentioned are very common for these engines, and must be closely maintained/watched. In my opinion, take a close look at those gaskets and get a second colling system pressure test.

The upper intake gaskets were changed by the dealer about 6 months ago... But not the lower intake gaskets...

Last weekend I topped up the coolant via the overflow tank... The gurgling noise has gone away, and after 1 week of driving there appears to be zero coolant loss and the low coolant warning light has not turned on...

In addition, after adding 1 quart of oil when I initially heard the loud ticking noise at startup, there has been no lifter noise at all... I always change the oil when the change oil light comes on...

The upper intake gaskets were changed by the dealer about 6 months ago... But not the lower intake gaskets...

Last weekend I topped up the coolant via the overflow tank... The gurgling noise has gone away, and after 1 week of driving there appears to be zero coolant loss and the low coolant warning light has not turned on...

In addition, after adding 1 quart of oil when I initially heard the loud ticking noise at startup, there has been no lifter noise at all... I always change the oil when the change oil light comes on...
you have added 1-1/2quarts over the past week your oil consumption is excessive especially 69kmi on vehicle.find out why leak or engine damage. not enough oil changes.....

This is exactly what happened to my 99 alero. Lifter ticking when started. Happened on and off for several years. Finally, the oil cap had swollen and started turning milky. My oil never "appeared" to have coolant in it until this happened. After removing the lower manifold, it was obvious that the leak was right over the rear drive side lifter. After I replaced the lower manifold gaskets, it has never ticked again. It has been over a year since repaired. Good luck.