My Impala (base model, 3.4l, V6, 92k miles) has developed a ticking noise on startup that really seems to be getting worse (louder). After the car has been idling for about 3 minutes, however, the sound completely goes away. Now, I know the car has the intake manifold gasket leak problem (which hasn't been fixed yet). My last record had it losing about a quart of coolant over about 1200 miles or so. Are these two problems related? I'm thinking that after the car is turned off (especially overnight), some coolant is leaching back into the cylinder(s). The dipstick looks OK, level and color and it's only been about 2900 miles since the last oil change.

These engines had piston slap almost from new, is this a recent problem, Fix the coolant issue asap, also. Is the oil coolant contaminated?

Yeah, even when new the engine always had a kind of ticking/clock-like rhythmic sound on startup, but it's definitely louder now. It really doesn't sound good. As far as coolant contamination in the oil, I can't see any. If there's any coolant in there, it's probably only trace amounts that could only be detected by a chemical test. I really need to get the gaskets changed out, but I want to do it myself. Can only do it on a very long weekend, or after I get my dormant third car back on the road (needs a fuel pump in its tank, possibly other stuff ... hasn't been driven in 5 years)...

i think that the intake leak might have a little to do with that but i think the biggest reason that you are loosing coolant is because you have blown head gaskets.

This thread is too old to continue, please not the dates before replying. BTW the intake is the most common issue here, to say the hd gaskets are bad is unwarranted without a full diagnosis.