7M engine noise problem HELP! plz

[Trowa]

Hey

I got a problem. I have a weird ticking noise coming from engine. Now it's not the injectors, it's different. The noise in best heard with the hood closed from the passenger side wheel well. And also with the hood open right on top of the engine, around cylinder 3 and 4.
It also best heard when the engine at idle, the lower the rpm the more you can hear it. Mostly cause the other engine noises drown it out at higher rpm...
The noise also speeds up with the engine rpm.
Now when i use the stethoscope on the engine I CANNOT hear the same click anywhere (ie head, injectors, valve covers) other then the exhaust manifold shield. When i put the stethoscope on the shield i can clearly hear it.
Now i checked the exhaust manifold and I'm not getting exhaust leaks. Or at least i'm not getting any charring marks you would get with a leak....
I took off the valve covers and checked clearances on the cams and they are all within spec so I'm kinda stuck right now as to what it can be.....The lobes are kinda worn unevenly on the top of the lobe so i dunno if that has anything to do with it...

Oh yeah, the engine is rebuild and has only about 7K km on it. The head had a 3 angle valve, and the cam clearances were reset.

One more thing, just to give an idea of how it sounds right now, it sounds like a diesel engine....

help?

Thanks

Andriy

 

[jdub]

Exhaust leak at the exhaust manifold...you may or may not get the visual indications depending on the severity. Check your torque on the manifold studs...say a quick prayer to the 7M gods that one or two are not stripped.

 

[Trowa]

Exhaust leak at the exhaust manifold. Check your torque on the manifold studs...say a quick prayer to the 7M gods that one or two are not stripped.

Well the bolts arent stripped cause i helicoiled them during the rebuild....
Wouldnt i get black marks where the exhaust is leaking though if i had a leak?
Gonna check it out for sure though...

Andriy

 

[jdub]

Well the bolts arent stripped cause i helicoiled them during the rebuild....
Wouldnt i get black marks where the exhaust is leaking though if i had a leak?
Gonna check it out for sure though...

Andriy

Smart move on the helicoil They still may have loosened up on ya and you may not be able to see it, especially on the bottom or rear end of the manifold. If you have an EGR cooler...that is another source.

 

[Trowa]

Smart move on the helicoil They still may have loosened up on ya and you may not be able to see it, especially on the bottom or rear end of the manifold. If you have an EGR cooler...that is another source.

No, no EGR =P

Andriy

 

[jdub]

Hmmm...check the torque and go from there. It could be a failure of the gasket itself...the new exhaust manifold gaskets Toyota sells (at least in the US) look a lot like a multi-layer steel MHG. Very stout...I used ARP stainless 12 point nuts/washers with new stock studs when I did my head (helicoiled too) and went to 40 ft/lbs torque.

 

[Erkenz]

I had an exhaust manifold leak and it made the same type of noise. I puled the manifold off, and the metal gasket had some sort of wierd bulge in it, probably from all the heat. But there were charring marks from the leak (it was a big leak tho) So I replaced the gasket and it sounded fine after that.

PS: That was a tough job because I had to remove the turbo to do it!

 

[Trowa]

ok, not an exhaust leak.....must be something in the head....cams maybe...

Andriy

 

[mkiiSupraMan18]

Did you try removing the heat shields? Check the studs on them to make sure they aren't loose/broke/missing. That would make it sound like a diesel. Just trying to help.

 

[ViR2]

Or it just could valves check valves clearance if nothin else helps

 

[Trowa]

Or it just could valves check valves clearance if nothin else helps

I did check the valves and all of them came out right in the middle of the range they are suppose to be....

And the heat shields arent loose, did that as well.

Someting that was suggested was that the cams, might be not set to proper clearance, and in statuc they will give good valve readings but when moving the came will move just enough to bring them out of spec and make noise...

Also I have some weird wear pattern on the lobes of the cams, The edges of the lobes are all shiny while the middle is not....

Thanks

Andriy

 

[jdub]

Ever figure this out?

 

[IHI-RHC7]

you check the turbo-manifold flange?