Hi Guys,

Have developed a strange noise. Replaced head gasket 2k ago. No metal in oil or filter. Didn't bleed lifters but did squirt with WD, any ideas? Idles fine noise appears 2000rpm & over. Have lifted valve cover all looks okay, cam timing marks still aligned, but stumped ideas appreciated. Video below...

 

sounds like a exhaust leak to me.

 

I'll second possible exhaust leak. I would double check the exhaust manifold bolt torque specs, and where the turbo meets the manifold, and the downpipe.

Any chance that any of those gaskets might be bad? Did you use a fresh exhaust manifold gasket when replacing the head gasket?

 

I did not replace the multi-layer manifold to head or manifold to "turbo" gaskets when doing the HG. The multi-layer looked to be in good shape, I soaked it & blew it out with compressed air. All bolts were torqued to spec & again after a few heat cycles from inside out.

When driving which I haven't since this developed it does make a sound reminiscent of a light deisel exhaust brake on decel & in between gears. I also did an EGR delete during the HG replacement by means of a hex threaded stopper in the head & fabricated a plate that I fit under the EGR itself for good measure (I thought) which might keep the EPA or cops away from that area.

Thanks for the suggestions fellas I'll investigate exhaust leaks & report back in a day.

Rich

 

okay so i replaced ex manifold & mani to turbo gaskets still the same. sounds mechanical to me maybe like oil supply to head or collapsed lifter maybe, never heard one so unsure. another video below. any ideas?

https://youtu.be/MzyVUNGVYms

 

I'm fearing rod knock honestly. Motor is internally stock, stock turbo, e85 with 1000cc injectors on alt maps, EGR block off at head & valve itself. 28psi for the last 80K, had 160K Klm on it. No smoke at exhaust been super reliable to date.

 

pull your valvecover, at this point thats the only thing left to do before you self diagnose a rod knock, might be something loose in the valvecover hitting the valvetrain, or could be a flung out rocker making all the party noise

 

doesnt really sound like a rod from what i can hear. does it get louder if you rev to about 3k or 3.5k? a rod knock will get louder, like say you rev to 3.5krpm when the rpms start dropping down is when you will hear the rod knock clack clack ect.. lifters stay about the same throughout the revs.
is it a built engine or is it all original internals?

 

In this engine, to my ear, valve noise = rod noise = piston pin noise. At least it isn't balance shaft noise like was usually the case with a dsm. So, if it were my engine, I'd check for the worst possible scenario, pull the pan and check for play in any of the rods. If they are all okay at least you know it isn't going to immediately detonate and you have time to tinker and possibly locate the source. Do all the usual stuff like checking drained oil and filter for sparkly stuff.