[nordy200]

My 2000ZX3 has started a little noise when cold-reminds me of engines that need a valve job. The noise is loudest (but still isn't very loud) at about 2.5K and then goes away completely when the engine is fully warmed up. If I drive it easy when cold, I don't hear it at all. It still starts and runs great but the noise has me worried. One of my thoughts is that maybe the oil flow is insufficient when cold-not enough presure? Or could it be piston slap that goes away due to thermal expansion? I first noticed it about 3-4 months ago and it hasn't gotten worse since then.
I have used Mobil 1 exclusively since new at about 5K change intervals. I run about 7.5 lbs boost max on my JRSC; noise started before I installed the 2.3" pulley.
Thanks for the feedback!

 

[Just4Looks]

I have the same problem, but only when morning temp is below 70's. It sounds like a knock but also sounds like the valves chattering. Only does this when its cold. In the summer I dont have this problem. I also use Mobil 1.....could it be out beloved oil. I do use 5W-30 in the winter and 10W-30 in the summer. I hate this noise, anyone know what it is...should we be worried.

 

[FocusOnPunk]

i heard that the valvetrain is just loud by nature...but that also some of the clicking noises is fuel injectors.

 

[nordy200]

The noise I am hearing is something new-never heard it until about 48K miles and even with my exhaust and engine mods is audible, but only when cold. WTF? I Just can't figure out why it goes away when the engine is warm. Is there any kind of temperature sensitive pressure change in the Zetec oiling system? I know that some cars used to reduce pump pressure when cold to avoid overpressurizing the oil system.
Anyone else have advice on this?

 

[Jibberish18]

I have that sound too....Sounds like very light metal chattering. You can barely hear it with my hood down but it only happens when the car is cold. Once warm you don't hear it anymore. I don't know what it is and I never really cared enough to worry.

 

[OmniFocus]

I also have what sounds like a valve tick.. It has been with me ever since I bought the car... Mile 5445 to mile 70918. It is only present when cold in the morning, and is loudest under load at low RPM... say 1k-2.5k.

I fully intend to reshim the valves some day, but... after this long if it was a real problem it would have reared it's ugly head.

 

[nordy200]

Thanks for the replies on the noise. At least I'm not the only one who has it. It hasn't gotten worse since I first started hearing it and the car still runs well so I will try not to worry about it unless it gets worse.

 

[StickShifter]

Just turn the radio up louder...

...Actually, I think 4-cylinder engines are just naturally loud for some reason...My PZEV has had a 'ticking' sound since new...Valves or something...I never noticed if it went away when its warm (but I dont think it does) ...The thing runs fine, though...So Ive never worried too much about it...

 

[ZTS_Dude]

I always assumed that most of the noise that was to be heard out of a 16v DOHC 4-cyl was made by all the valves. In a V6 and a V8, you have enough of a hum where I don't think you hear the valves as much as you do in a 4-cyl? Just an idea.

 

[nordy200]

The noise I and others were referring to was a noise above and beyond the normal valve train noise of the Zetec engine: more of a rattle or slight knock that wasn't there before and goes away when warm. It is a relatively noisy engine though-I can't even hear the engine on my 2004 F-150 when its running and it's an OHC engine.

 

[silvermach]

I have a 2002 Mach and I switched to Mobil 1 5w-30 at about 5000 miles. Since then I have had a knocking noise above the normal valve train, almost like a piston slap. So last night after 10,00 miles with Mobil 1, I switched back to the recomended 5w-20 motorcraft. The noise is still there when the engine is cold, but when it warms up it is gone. I hope I dident cause any damage to the engine by using Mobil 1, I dont see how i could have. Other than that I love my little Mach.