Knocking when cold

I got an 01 2.7L. When I start it up and accelerate at first when it is cold I hear what sounds like a knkocking noise in the front somewhere. Do you know what it might be?

 

Anyone know what it may be?

 

Valves?

 

what oil are you using? could be too thick.

 

I used the 5w-30 I think it was Pennsoil. Its due for a change in about 1,100 miles.

 

hmm weird, that oil is fine.

so it's a knocking sound, not a ticking. I would hope it's not the rod bearings or something like that.

 

Please correct me if I'm wrong....The valves would knock if the oil cannot get through due to bent cyls?

 

It hasnt always done it. But it only seems to be when its cold. If I start it a few minutes before i drive or after I get about a mile down the road I do not hear it.

 

When the engine warms the cyls expand, allowing passage.

Hopefully I'm wrong with what I'm saying. It happened to one of my vehicles and for me it was either pay big bucks to fix it or get rid of the vehicle.

 

knocking almost always means low oil pressure or worn rod bearings (the bearings between the connecting rods and the crank shaft). I suggest starting the truck about 30 seconds or more before setting off to allow the oil pressure to come up.

 

If you can, take a LONG screw driver - the longest one you can find or borrow - , and with the engine on, put the metal end of the screw driver near each of the valves. Put your ear on the handle part. The sound will travel up the metal and you should be able to hear where exactly the sound is coming from.

 

It sounds to me like you are having Piston Slap. This is the piston moving sideways in the bore and striking the sides of the walls. If you are mechanically able here is a way to check for it. http://wiki.answers.com/Q/How_would_you_know_if_its_piston_slap

Good Luck.

 

Most likely is piston slap. Piston slap that goes away within a couple of minutes as the engine warms up isn't usually harmful, and is not a reason to tear down an engine. I had a '76 Chevy with piston slap. It slapped for 22 years, and was never problematic. I also had a '93 Toyota with a 22RE engine that slapped when cold. No problems from that one either.