Rattle/Slap/Knock

[mafoose]

My 1984 318i has a rattle/slap/knock thing going on when you first start it after it's been sitting about an 1hr or more. It goes away when the oil pressure light goes off (usually 1-2 seconds after start).

After it's been decently warmed up, it will pull to redline smooth as butter.

Once it gets fully warmed up, like 3/5-1/2 of the temp gauge, it will still pull smoothly but it is just noticeably noisier when doing so.

Am I right to suspect the timing chain tensioner/guides? Or is the engine toast (bearings/pins/etc)?

I recently did an oil change and put in 20w50 conventional.
Ideas?

[peete]

Throw a new tensioner at it and see what happens. But it sounds like your oil pump and oil pump chain need replacing.

[JdmEuroNorth]

main bearing clearances are probably too loose.

you're going to need to rebuild your motor, no mechanic in a can with fix that.

[mafoose]

Is there any other tests I can do to check that?
Other then tearing off the oilpan and bearing caps that is...

[Spinning Tires]

If you go out one day and it seems noticeably faster. prepare yourself cause its about to blow

[Jean]

Mine has been doing that for months, it also goes through oil like crazy and on cold mornings it now takes 5+ seconds to build up pressure. Gotta love it, I still beat the crap out of this m10.

Not worth the effort to rebuild imho, pick another motor, prep it and drop it in

[mafoose]

It doesn't take that long to build oil pressure and it also doesn't burn any oil (though it does have a slight leak at the oil pan gasket, but very minimal).

I'm going to do the tensioner, and possibly the guide rail and see if it get's better.

[mafoose]

Put the new chain tensioner, and the knock on startup is quieter and goes away quicker.
The chain tensioner had a lot of wear on it, it might be the rail guide that is bad.

I'm really hoping I don't have to do a motor swap...

[Jean]

You are quick! Should have done those at the same time though :)

[mafoose]

I didn't because they didn't have it in stock.
It's on order.

Still hoping thats the problem, if not I guess I'm driving it til a rods comes out the side.

[Holland]

Probably cheaper to pick up an M10 than fix it. lol. Little things are slow but damn near indestructible.

[mafoose]

Know of any for sale?
I'm willing to drive anywhere in AZ for one, or Las Cruces/El Paso is pretty close too...

[mafoose]

Damn. The chain tensioner rail is on back order...
And crap, I thought it was changeable by just removing the top timing chain cover, but I guess that isn't the case.

Well, for a whole timing cover seal kit, both guides and the tensioner, I'd be into M10 swap cost territory.
Shit. This car was supposed to be a decent daily warrior.

[Jean]

And that's how it starts.