For some reason over the last week or so my truck has developed a knocking sound on startup. It only happens in the morning when I start it for the 1st time of the day ar if it has been sitting for a long time. It sounds like its coming from the passenger side of the engine bay. After the noise stops( Usually last 3-4 secs) the truck runs normal. Almost sounds like sompthin loose? Has anyone else had this problem or know what it might be??

 

Have you done an oil change recently? Maybe an oil filter without an anti-drainback valve got put in.

 

I'm actually about do for an oil change. About 500 more miles or so. Its weird cause it seems like the noise has got louder over the last few days. Its almost more of a rattle than a knock but only on cold start ups.

 

That's a bad-a$$ looking truck, Trooks!

Mine seems to idle extrememly rough for the first five seconds on cold starts. But I'm not hearing any rattle.

 

I actually get a little vavle clatter / piston slap on cold starts, but it goes right away after about 3 seconds.

-Master

 

Wow, I have the same problem and I'm about due for an oil change as well. I'm running RP synth. It is definitely a rattle, I thought it might be my tensioner pulley but when I went under the hood to check it didn't do it. It does sound as if it's loose, maybe a loose pulley. Let me know what you find out and I will as well.

 

I got my girlfriend to start my truck while i popped the hood and listened and its def coming from passenger side of engine bay more toward the front. Not that that helps any but figured I would update.

 

Thats where the tensioner pulley is, push and pull on that from different angles and have her start it as well to see if it rattles. Just rest your fingers on the arm of the tensioner and you can feel if it is it. There are many other things it could be but start there.

 

Thanks man! I'll try that when she gets back from work and let you know what I find out.

 

i say put in some new 5w20 and a MOTORCRAFT filter if thats not whats already in there and see if that helps then go from there. i cant see it being a pully if it only does it at start up. sounds like oil drainback or you using to thick of oil.

 

Mine does that too. The first time I give it gas in the mornings it really roars. Then it's fine after a few seconds.

 

Bringing this back from the dead guys. I finally stopped the "cold start knock" couple of days ago. I asked my auto tech teacher about it and he said to put half a quart of Lucas oil http://www.lucasoil.com/products/dis...tid=2&loc=show in with my next oil change. I did this 3 days ago and no rattle at cold start since

 

I'm sure it's your filter, you changed it right? I used a Wix filter from carquest this time and it got worse (never again will I buy wix). I think I am going to drain the expensive *** Royal Purple as I just changed it, and add a quart of that lucas oil, and change the filter again. I hate doing this ****.

 

I thought that at first. This is the 2nd time Ive changed since the start of this thread b/c of knock. It continued w/ new filter and oil . After this change which I added oil, filter, and hlf qt of lucas NO KNOCK

 

You bought Lucas Oil Stabilizer right, that is all I'm looking for. I'm going to go do it now. I don't want to show the truck to this buyer and have that lame knock happen.