[bforbushx]

So, I bought this car about a month ago, it's a 2001 Focus ZX3, automatic, 108k miles. Seems to run fantastic, as long as you don't pay attention to the awful noise that the engine makes on start up.

I'm pretty mechanically inclined, but i'm clueless right now. Here are the symptoms:

Engine at less than operating temperature, it has a consistent tick. Not a deep knock, definitely a tick. It's not fast enough for 4 lifters to be ticking. What stumps me is that when I hold the throttle at about 1000-1500 RPMs the engine sounds normal, except as soon as you let off the gas you can hear it come back slightly.

The noise seems to mostly go away after driving for about 10 minutes, sometimes its still there a little bit, sometimes the engine is dead silent. I know these engines are known for being loud, but this noise just isn't normal.

Edit: Check engine light is on for insufficient EGR flow, if that makes any difference.

So any ideas? I may be able to post a video tomorrow if that helps. I've heard exhaust leaks? spark plug gaps? Any ideas at all?

 

[iroc34]

2 things these Zetecs are famous for. Cam bucket noise, and a Throw out bearing . But since you have and auto we will rule that out. Oh another noise is the injectors them selves. Pretty noisy engines they are ! After it warms up its a little quieter , like you said. Low EGR flow, is usually a DPFE problem. check around for vacuum leaks also. The PCV hose as it turns towards the intake, Usually soft or cracked there. If it is soft , look at while idleing it will collapse on itself..

 

[frednumber15]

Flush the oil (Gunk?) and change to synth?

 

[bforbushx]

If it was cam bucket noise, is that a big deal or something I should address? The oil was just changed 500 miles ago, and it did not make a difference at all unfortunately.

Here is a video I took this morning (just click the image, it will take you to photobucket):

 

[iroc34]

Deffinetly not bucket/lifter noise. Get another video under the hood. I cant tell .
Is the noise coming from the top or bottom of engine. You might want to get a stethoscope and see if you can pin point it. One thing is for sure, it wont get better on its own.

 

[bforbushx]

That's a bummer. Sounds upper to me, the video makes it sound a little bit deeper than it does in person. I'll take it to a shop when I get a chance. Any more opinions?

 

[bforbushx]

Update:
Took some more videos today. I have a new theory on what may be going on after messing around with it today, but someone correct me if this is crazy. It sounds to me like there is something rattling on the engine, not internal. My reasoning behind this is that the noise is more intense on cold start (when the engine vibrates the most), and ALMOST goes away after the engine is warmed up. However the noise is still there a little bit all the time.

Another reason that I think this is because when I rev the engine, even just a little bit, the noise disappears. It doesn't follow the RPMs at all. But as soon as I let off the gas you can here it start to come back.

Videos:
Cold start, just leaving work (whenever you hear the noise go away, that is me revving the engine to about 1.5-2k rpms):



and another:



After driving home about 6 miles, engine is at operating temp:



Another, under the hood.




Just take a peek if you have a minute, I would really appreciate some input on this! Thank you!

 

[alz focus]

That's the same sound my SPI is making. Car runs and drives great, just has that noisy knocking. Very interseted to hear your outcome.

Edit: After listening to the last video, maybe it's not the same.

 

[bforbushx]

I will keep ya posted for sure. Mine drives fine too, no weird engine vibes or anything.

 

[bforbushx]

Any ideas after those videos?

 

[BC_ZX3]

Sounds "rotational" to me, particularly the "cold" running first vid. I'd suggest the accessory belt idler pulley or perhaps the belt tensioner. Hard to say. Generally bearings spin "better" as they go faster and after they are warm. Worn bearings sometimes chatter at low speeds.

You could check by removing the accessory belt and grabbing hold and spinning each pulley. The only one that shouldn't spin freely, smoothly and with no noise is the crankshaft pulley (obviously). To make a noise like that, a dud bearing should be easy to spot.

 

[bforbushx]

That is a fantastic idea, I have no idea why I didn't think of that haha. Thank you very much, I'll pull that apart saturday when I do the brakes. I hope that's it, because that's much better than internal engine problems.