Is It Rod Knock Or Valve Problem?

[Hexar]

Hi Guys,

First post here.

I bought a 2001 Lexus IS300 automatic with 145k miles today.

The car has this knocking sound when running, my ears are not that great, but it seems to me the sound comes from the top of the engine, but I am not 100% sure.

It has the following CEL codes: P0300 P0301 P0303 P0304 P0305. So it misfires too.

The engine revs to 6,7000 rpm seems fine, although much louder at that RPM, and the car drives, quite gutless, although it can be driven to 7,80 km/h.

I am wondering if this is rod-knock or it has problems with valves? When an engine has rod-knocks, will it have full (or near full) power? Mine does not have that much power right now, so I am thinking maybe some valves got bent? The noises sound like valve taps too, and that would also explain the mis-fires?

What do you guys think? Where should I start looking/checking?

Thanks guys!

[lenore]

I would suggest doing a compression check....sounds bad to me.

[Hexar]

I would suggest doing a compression check....sounds bad to me.

Thanks!

[IanH]

Is this the same 2001 w / 145K that's been on the forums in the last month ?

Use a screw driver as a stethoscope to see where the noise is coming from.

No Rod knock normally will not reduce power much till something breaks and goes through the block.

Pop the front top valve cover / timing belt cover and look at the belt for damage, its quick and easy.

[Hexar]

Is this the same 2001 w / 145K that's been on the forums in the last month ?

Use a screw driver as a stethoscope to see where the noise is coming from.

No Rod knock normally will not reduce power much till something breaks and goes through the block.

Pop the front top valve cover / timing belt cover and look at the belt for damage, its quick and easy.

Thanks Ian, was there a 2001 w 145K last month? Would you mind give me a link to that post? The car was bought in Calgary, Alberta, Canada, on Nov 20/2011 BTW.

I took the top timing belt cover off, and it seems to me the belt aligns correctly with the timing marks on both cam pulley.

Thanks,

[IanH]

So did the teeth on the belt look good ?

I listened to your video and cant tell, rod knock sounds a lot louder when you give a short burst of throttle, and goes quieter as you get off the throttle even though revs are still up.

Probably not the same car I think it was in the USA, and on another forum.

BTW my car has 154K miles

[IanH]

but sound does seem to be coming from the front half of the engine. Is the VVT working OK?

[Hexar]

So did the teeth on the belt look good ?

I listened to your video and cant tell, rod knock sounds a lot louder when you give a short burst of throttle, and goes quieter as you get off the throttle even though revs are still up.

Probably not the same car I think it was in the USA, and on another forum.

BTW my car has 154K miles

Here are some photos, after taking off the upper timing belt cover. Teeth seem good, although the belt has cracks on it, and there is "quite bit" of slack on it, as I can sort of "flip" it.

http://s1113.photobucket.com/albums/k516/HexarAndHexanon/IS300/

Honestly, I don't remember the sound after giving it a bit more gas... Hate to try it now, fearing I may break anything than it already has.

[Hexar]

but sound does seem to be coming from the front half of the engine. Is the VVT working OK?

How do I check if VVT is working or not? He drove it to my house, and we did not go faster than 70 km/h (~45mph).