Hmmm...

[onemeekmutha]

Hello everyone,

Thank you for taking the time to view my post.

I have a 2002 AWD Astro Cargo van with 150,000 miles on it and up until a week ago when ever I started it up I could barely even tell it was running because the engine was so quiet, aside from the vortec. Now when I start it up I can hear the pistons moving up and down. This only happens while the engine is cold. After it warms up, the noise goes away and it is as silent as the day I got it. The only thing I have done to it recently is had the oil changed about 1,000 miles ago... Sorry I just remembered I was experimenting with gasoline octanes and at first I was running 87octane, then tried 91 octane for 3-4 tanks (roughly 60-80 gallons for 900-1200 miles) to see if MPG would improve and when I did not notice a difference, I switched back to 87 octane. I have been back on 87 octane for about 1-2 tanks of gas or 300-600 miles.

Is this noise something I need to worry about? Any suggestions?

I asked one friend and he suggested that maybe the mechanic who changed the oil needed to put a heavier/thicker weight oil? I believe it currently has Mobil 1 synthetic 10w 30.

Thank you very much in advance for your help,

Jonathan

[rev_les]

Are you sure it's not the lifters ticking? If you hear pistons going up and down, it's usually not for long.( followed by a big BANG)
Spec weight is 5W30, some use lighter weight.

[Shad0wXCalibur]

The oil put in could be on the light side but I doubt it. Some engines do have lifter noise until they warm up. It's completely normal and won't hurt anything. You could even be hearing other things like the fan, A/C compressor, pulleys. There's plenty of things underneath the hood that can make some noise.

[RECox286]

Do you have any friends who are car savy ? If so, take it to them, and ask if they would give you a heads up to what they think it is. Very difficult to try to diagnose noises from

strange places, especially if you can't hear the darned thing. Or try holding the phone a bit closer to the engine compartment... I'm sure you understand. We wouldn't want to

steer you wrong with a guess.

Bob

[Lumpy]

...Very difficult to try to diagnose noises from strange places, especially if you can't hear the darned thing. Or try holding the phone a bit closer to the engine compartment...

Like the guys on CarTalk.

"Would you say the sound is more like VROOM VROOM VROOM or more like WAHEEEE WAHEEE WAHEEE?"


Lump

[RECox286]

It has been ages since I caught a "Car Talk". Are Manie, Moe, and Jack still on the air ? Boy, that takes me back... I wouldn't be surprised if Bob and Ray were close to dead by now.

Bob

[Lumpy]

Click and Klack, the tappet brothers.

http://www.cartalk.com/


Lump