Starting Problems

[Maty]

I found this new noise today. After starting up, i started revving it to about 3000 rpms, going up it sounded fine. But once I let go of the gas and it starts coming down, from the 3000 rpm to the 2000 rpm range (about) it makes like a *clack* *clack* *clack* noise. Not super fast but fast enough to where it is one *clack* after the other and you can tell the pause in between.

[olopezm]

I've also used Carb cleaner without problems.

Try disconnecting each sensor TPS, IAT and MAF and start the engine to see if any of those help.

Also check the spark plugs; today I found out why my car was hard to start, one of the spark plugs had a WAY LARGE gap. It's weird, the rest were down to 0.054" and that one was more than my gauge could read (you get the idea). They are supposed to be at 0.060". Don't know why one would open and the rest would close. AFAIK they all should open with normal use and wear....

Oscar.

[olopezm]

The noise could be lifter noise. It's normal on GM engines to make that when cold and should go away after some seconds or minutes as it gets up to normal temp.

[Maty]

THANKS!! I've looked into the "lifter noise" and it is exactly that, I guess it has nothing to do with the ignition issue. I'll look into the sensors, I'm not familiar with the auto terminologies.

[olopezm]

Yeah, lifter noise happens because the oil in the hydraulic lifters in the engine (they ride on the camshaft and their function is to move the pushrods and rocker arms to open the valves) bleeds out and some slack develops between the pushrod and the rocker arm causing that noise. It goes away when the lifters have been "pumped" (become filled with oil) and the gap (lash) is now zero.

Cheap oil filters (like fram) have faulty anti-drain back valves which causes the oil pressure to bleed down and causes more lifter noise than usual. That's why you should avoid buying those to prevent excesive wear to the engine.

Oscar.

[Lukas111]

Anybody has problem with starting on 3.8 engine?
It seems like it starts and then just shut off?
Just clean throttle body very nice and let it dry.
Easy job.

[FISH96]

the 'ticking' piston slap, not lifters. there are gm tsb on the web as well as blogs addressing this issue. do a search.
please explain how an oil filter anti drain back valve ( check valve) holds oil pressure to the lifter. these components are not directly connected with a closed 'piping' system.
oil pressure is nonexistent upon engine shut down.
the oil filter does not maintain any significant pressure on shut down and any pressure will bleed down in a very short period of time.
the antidrainback valve is added ( not all filters have them) to prevent a dry start caused by an empty filter. regardless of the valve used, all will allow the filter to partially empty during the 'unused period" how many of you prefill your oil filter during replacement?
mind you, must be n[very careful to maintain cleanliness as you are adding oil to the clean side of the filter. for those that can use filters without the anti drain back valve. you may add the oil to the filter from the dirty side( the smaller inlet holes)