I noticed that when the car is started when cold,I get a knocking noise and after a few seconds it goes away.if I let it set awhile it does it again.Could my pump be going bad? thanks

 

when I first read this I was thinking the common piston slap, but you said it comes back after it goes away? I not sure I understand, but how is your oil pressure ? need more info

 

Oil pressure is around half (40)way and rises with acceleration. If the car sits awhile i get the noise for maybe 5 seconds then goes away.With the oil hot it's ok.If I let it get cool again the noise comes back and goes away when th eoil heats up.

 

does it increase with rpms ? how does it drive ? it could be so many things, like broken lifter, valve sticking start of a rod knock or mabe soemthing simple like a spark plug backed out.

 

Yes.It increases with rpm. I just had my head gaskets replaced and my mechanic checked the lifters,valves,etc.so I don't think that's it. It drives fine.

 

I just went outside and started the car and it didn't make any noise. It has been setting for 2 hours. The car just hit 74k miles and I have used Royal Purple 10w-30 with a K&N filter for the last 5 yrs.Should i try something else since my miles are getting higher?Thanks

 

Try a different oil filter.. The napa gold have a very good adbv in them. I had the very same issue when I used the k&n filters. Not a single prob with the valve in the napa golds. At least its cheap and easy to try.

 

Yeah,the k&n has a good adbv on it too.makes me wonder if it's bad?

 

Check you oil and see if you can see some metal flake on the dipstick.. I'm thinkin its a rod knocking. ( spun bearing )

 

Yeah, it sounds like a bearing might be on its way out, which sucks since you're using such high quality oil and have good pressure. See if you can get it to a mechanic with a stethescope to see if you can find exactly where it's coming from.

Side note: I like the K&N simply for the fact that no one else puts a hex head on the bottom so I don't have to use the stupid filter wrench which is nearly impossible with a short filter and LT's.

 

just a thought, but i had the same thing happen on my last car and the one i have now, but it sounds like it could be a lifter bleeding down, and making that tapping noise at first. and it did the same thing, increased with rpms, and once it pumped back up if thats what you call it, it stopped. and every time it sat for enough time to bleed back down, and i would start it, it tapped again. just a thought, hope you figure it out.
mike

and when i spun my bearing..the knocking was there all the time, but it was spun pretty bad, there was like prolly 1/8 or 1/4 inch of bearing missing from one end,lol

 

I get a misfire on #1 now and I can hear the noise coming from there.With the hood down it sounded like it was coming from underneath the car,with the hood up,I could tell where it was coming from.I can put mu hand on the valve cover and feel the vibration.The head gaskets have just been done 3 weeks ago,and he checked everything,so I don't know what it could be?I checked the wires and pliugs and don't see anything obvious.It's going to the mechanic in the morning.

 

If it's a lifter, then it may be very hard to tell if it's good without fully taking it apart. He probably just rolled the tip and if it wasn't rough, put it back in. I hope that's your problem since it's pretty simple.

 

I assume that this would cause a misfire code? Since it's not working properly?The car runs like crap.

 

Maybe, maybe not. Never had one. I don't think it would, though.

If the car runs like crap and not just a little rough, then that makes me think it's more than just one lifter. Couldn't hurt to pull the intake and check, though.