Low oil pressure and strange noises

[Xentro]

While driving around Saturday some strange buzzing noise can be heard from under the bonnet.


It seems to be rpm related and only happens when the engine makes enough rpm (about 120km/h in 5th)

I was thinking maybe the bearings of my alternator were shot.. and i replaced the alternator on sunday and tough I'd found it because the bearings of the alternater were shot..
Also adjusted the valves while I was at it and the engine sounded good.
But when I drove to work today the sound is still there.
I've also noticed I got a low oil pressure on idle(in the red) and even when cruising it doesn't even get up to halfway. But i'm not sure if it wasn't already low before this happened.

Any suggestions what this could be?

I was thinking about the balance shafts or a spun bearing on one fo the shafts. Can that be it?

[Cookiemonster]

I was thinking about the balance shafts or a spun bearing on one fo the shafts. Can that be it?

Quite possibly. That would explain the noise and the low oil pressure.
Get it to a competant mechanic quick smart and get him to verify the oil pressure and try and locate the noise.

I would not be driving it around if at all possible. If it is a bad balance shaft bearing then you risk a complete engine rebuild ($$$) unless you address it ASAP.

[Xentro]

Well i Managed to drive it home without the sounds getting any worse.
I guess i'll take it apart this weekend.
The sound is definatly the sound of something with excessive play so i wonder what i'll find

[Xentro]

Took the pan off this weekend.. and guess what I found


Guess that's the end of the balance shafts
So I took the oil pump out and cut off the balance shaft and plugged the oil channel with a screw & some loctite



I'm still thinking if i'll just leave the other one in the engine or take it out and somehow plug that hole and the oil galleries.

Any suggestions what would be a easy way to do that?

[ProZac]

Right size frost plug will block up the hole in the front plate, and rotate the bearing shell in the block to close off the oil pathway. I don't think there's anything else you need to do with the second (belt driven) shaft.

Dont just leave one in there, they're designed to work in tandem.

[Xentro]

Actually i was thinking of leaving the belt driven on in the engine with just the belt disconnected.

How would you get to the 2nd bearing to rotate it? it's pretty far into the engine and hard to reach..

[David]

I hope you mean tapped the hole and used a bolt - a screw probably won't hold, but it may be OK, but is risky. Keep in mind the oil against it is under pressure.

Also keep in mind the stub will flog the bearing (or rather the housing since there is no bearing) out - so you might want to replace the bolt on top of the pump gear with a round one (with a hex-key slot) and use needle bearings inside the oil pump.

You can use a core plug to seal the top hole. Don't forget to rotate the bearings first - to stop the oil flow. Make sure you leave no oil lines open.

Regards
David

[Xentro]

Thanks,

I did use a bolt and screwed it in up against the other bolt before I used a hack saw to cut of the bolt head.

It's got enough loctite in there so I'm sure it'll probably never come out again.

I also have a second oil pump assembly and i noticed the bearing surface of the original is larger (longer) so i'll keep using that one.

Was this changed at some time? because the engine the shorter bearing pump came out of also had a slightly shorter crank (about 1 cm shorter where you put the cambelt sprocket on)

Well it'll only need to last untill I find all the parts I need to build-up that 16V engine

[ProZac]

Ahh, very good point Xentro, my engine was out of the car on the floor when i did it... i can imagine doing it with the block in the car would be a pain.

[TD05]

Xentro

good one, how easy is it to remove the oil sump on the Stazz, did you have to remove the crossmember?