Engine Knock on cold start up? [video]

[eduJ]

I have been noticing a noise when starting my 98 QX4 lately. I am not sure if this is cause for concern or if all pathys sound like this. I live in Vancouver and it's about 4 degrees Celsius (aprox 39 degrees Fahrenheit).

Basically, it's a knocking sound that goes away as the engine warms. The car runs great otherwise. I guess my question is, is this normal? If not, what is probably wrong and would fixing be an expensive/major repair?

I've always changed the oil on time and the oil level is not low. What could be the cause?

Thank you in advance. I'm not sure how to embed, but here is the link to the video:

[youtube] https://www.youtube.com/watch?v=3FiwkXC ... e=youtu.be [/youtube]

[The noise is most audible at the 1:25-1:40 mark.

[eduJ]

I did a little bit of research, and suspect that this might be piston slap? Does it sound like piston slap? Any opinions appreciated!

[eduJ]

Sorry to bump an old thread, but I have been unable to find any consensus with regards to this noise. Some say that it's harmless, while others say that the valves may need adjustment. Are the valves on our qx4 adjustable?

[KYOTE]

I'm not sure if we are talking about the same thing but i have a similar tick/knock sound that also occurs on my 2001 pathy when i start up as well. i've thought that it might be a timing issue, but the sound does go away after about 5 mins of driving so its hard to know. i also have a 3.5 not a 33 but I don't think it makes much of a difference. Valves could also be a possibility

[atraudes]

Sorry to bump an old thread, but I have been unable to find any consensus with regards to this noise. Some say that it's harmless, while others say that the valves may need adjustment. Are the valves on our qx4 adjustable?

For the 3.3's, valve clearance is not adjustable. I see notes about having it checked if valve noise increases in the 3.5's FSM and even how to do it, but the 3.3's FSM doesn't have the same mention. They both have a section on checking valve guide clearances which may be the key to your problem, but I didn't see any correlation made in the FSM between valve noise and checking the guides.

It's somewhat of a shot in the dark, but getting the valve guide clearances checked may be worthwhile if you think it's the valves making the noise. I watched the video you posted and it sort of sounds like valves, but the audio is muddy (as is to be expected under the hood )