Big end problems. Advice on what to do.

[acarmody]

Maybe one of the lifters is blocked so no oil?

What do you think, just change the lifters and see how I go?

I'm really thinking its not the bearings anymore.

 

[Immortality]

Try a bottle of lifter free (nylon brand i think) run that for a bit or some thicker oil, although generally they suggest for a couple 100km's but I wouldn't in your case. Also, try running it without the serpentine belt for a minute so the noise is clearer and not muffled by the belt squeal. Maybe keep the camera a bit back so the noise doesn't overpower it.

before you start, wipe down all the rockers to remove all the oil, then start the engine, let it idle and see that all the rockers are getting oil pumped up, it should show fairly quickly.

Cheers

 

[acarmody]

I'll throw one up in a few minutes.

 

[acarmody]

Great camera is flat.

Anyway the results are this. Serpentine belt off, cleaned rockers near the pushrods oil feed hole.

Most off them filled up pretty fast, the drivers side closest to the firewall rocker took twice as long as the rest of them. For some strange reason, car sounded more rough-ish, no idea why. And oil pressure was 70psi at idle now. WTF?

 

[GTP 85]

Too much noise fr the pulley to hear the sound u speak of. Have u checked if a pushrod is rubbing the casting dag of one of the heads?

 

[acarmody]

Too much noise fr the pulley to hear the sound u speak of. Have u checked if a pushrod is rubbing the casting dag of one of the heads?

Pushrods are the thinner chrome-moly one, they have been in the engine for 2.5 years.

I've been charging my phone up, will try another video.

 

[acarmody]

Found out why the car was rough-ish, left an injector unplugged, DOH.

Anyway here is a video with serpentine belt off.

 

[Immortality]

Great camera is flat.

Anyway the results are this. Serpentine belt off, cleaned rockers near the pushrods oil feed hole.

Most off them filled up pretty fast, the drivers side closest to the firewall rocker took twice as long as the rest of them. For some strange reason, car sounded more rough-ish, no idea why. And oil pressure was 70psi at idle now. WTF?

Oil pressure will be higher when the oil is cold. That's a good thing.

running a little rougher can be because the alternator isn't working so the system voltage is down, although it might not be directly related to your problem, what sort of condition is your battery in. While we are on that subject the ignition system, have you pulled the plugs and taken a look at those?

As for the oil thing, the engine feeds oil into the passenger side lifter galary at the front of the motor, it then goes along the block, through the passage in the rear block cover (that also used to feed the balance shaft bearing) and then into the drivers side lifter galary at the back of the engine, so the last lifter to receive oil if the front drivers side lifter.

I guess you could pull the rockers and push rods out of the rear drivers side cylinder and pull the injector plug and see what it does, this is how the active cylinder management works on the LS engines, it basically lets the lifters bleed down so they don't open the valves. I've never tried this though so I can't guarantee that it will work.

PS. don't run it to long without the serpentine belt as no coolant will be circulating and you don't want to cook the engine.

cheers

 

[Immortality]

Found out why the car was rough-ish, left an injector unplugged, DOH.

Anyway here is a video with serpentine belt off.

Sounds like a valve train noise to me.

The fact that the noise goes away when you idle the engine but comes back as the revs rise (and it does sound mechanical) would suggest that a lifter is collapsing as the valve train speed increases.

 

[acarmody]

I'm going to get a new set of lifters tomorrow. Its a fairly easy fix so I will try that and see how I go.

I'll also put each rod in my dads metal lathe and look for any wobble. And also give each rocker a thorough inspection.