mwc951

My car sat all winter, as I took my time doing the water pump, timing belt & balance shaft service.
It wasn't started for probably 4 months.
I fire it up after the job and got this horrible rattle. It sounds like it is coming from the #3 intake runner.
Spark plugs plugs are tight, heat shields are not rattling. I noticed some oil on the top of the head. Looks like an oil vapor trail from the #3 intake runner/head junction.
The fasteners are tight. Any chance the noise is simply the valves, but louder due to a failed intake gasket?
The injector by that runner is dirty as well. Looks like maybe a o ring leaking a wee bit?
I made sure the fuel rail is tight and fiddled with that injector to seal it at the fuel rail. No change in the noise.
Thanks for your assistance, I have 10 hours in trying to determine where the noise is coming from.
Videos below.

Tom M'Guinn

Very hard to tell from that video. I just had paint work done on my car and it sat for several months without running. When we finally fired it up, one of the lifters was indeed flat and making a loud clatter. I hadn't touched anything under the hood, so assumed that was the cause even though it really sounded like an exhaust leak or something worse. By the time I got home (10-15 miles or so) the lifter quieted down and the motor sounded fine. Sounds like you may have other things going on with leaks and such, but certainly possible the noise itself is a dry lifter that just needs to be run a bit to pump up. Whenever I've missed a bolt hole on an intake gasket, the car essentially runs on three cylinders and has an obvious lumpy miss -- and from what I can hear, your car seems to be firing on all 4...

mwc951

Thanks Tom. I saw your post about your paint work. Turned our really nice.
I drove the car for about 20 minutes to bleed the coolant.
Other threads I've read on this issue, guys recommend to drain 1qt of oil and replace with ATF, run it, drain and change oil & filter.

Tedro951

I'm with Tom. After a prolonged storage, I had a lifter that was loud. After a few minutes of idling, I held the RPM at 2500 or so for a minute or two. Returned to idle, and lifter was less noisy. Two more rounds of this and it was silent. No ATF, Marvel, or Rosary beads were needed. This was many years ago, and it hasn't done it since.

Paulyy

what's your idle oil pressure like? if it's low, give it a rev to get it to 5bar. and if it is a lifter with out oil it'll help feed oil back in it.

mwc951

Idle oil pressure is good.
I drove it around for 20 minutes while bleeding the cooling system.
I've run it in the garage, holding the rpms at 2000-3000 for short periods.
Gonna try to change the oil and take it out for a drive,

kev951

poor audio, but , it does not sound like a lifter to me.... can you affect the tone of the noise by pulling a spark plug one at a time? that would indicate a connecting rod.. it doesn't sound like the bottom end though.. it could be hardware in the cam box.. or a broken valve spring, or a piece of a valve keeper

Tedro951

I confess I didn't listen to the vids with my first reply.

However, that noise sounds like "every rotation", not "every other".

That makes me think its not valvetrain related. The plug wire trick is effective for rod bearings, but again, every other rotation.

Use a dowel rod or similar against your ear, then poke it around until you find the culprit. Or a stethoscope, if you have one.

I hate to ask, but is there any chance you rotated the crank and felt any resistance while doing the belt job?

Raceboy

you can pull injector connectors and hear if the knock goes away. If it does, it's rod bearing. And start with cyl2, for obvious reasons...

Tedro951

My outside "pick of the week", if the injector/spark plug test isn't conclusive, is possible bent intake valve.

You mentioned you have over 10 hours invested in trying to find the noise. Pulling the intake shouldn't add much to that, and you could get a close look at that valve.

mwc951

Put a can of Gunk Engine Clean in it.
Let it warm up, reved the hell out of it for 15 minutes, no change.

Oil & filter change, OEM filter w/6.5 qts of Valvoline VR1 Syn.
Warmed it up, reved the hell out of it, no change.

Took it out for drive around our neighborhood.
Got it up on boost a couple of times.
Came home, opened the hood, much better, very slight tapping.

Took it out today for a bit longer drive, boosted several times hard,
noise all gone. So I ASSume it was a lifter.

Thanks guys for all your assistance.