Knocking in 2.25

[I Leak Oil]

Long shot but did you have the valve cover off for any reason? I once had it off to adjust the valves and when I put it back on it was slightly out of postion causing one of the rockers to rap against the cover. When I first started it up I nearly pooped my pants wondering what type of horrific damage I had somehow caused. Figured it out in short order and 3 acorn nut adjustments later it was all good.

[rbbailey]

OK, I little more running of the engine to update you on.

I live on a steep hill, it is almost exactly 1/2 mile up from the bottom. It is a 700 foot climb.

I warmed the truck up a bit, then drove it down the hill.

On start after initial warm up and after releasing the choke to set the idle at medium low it shows about 8-10 psi on the oil pressure gauge in the dash. Engine sounds and runs fine.

I turn the car around and get going back up the hill. I don't have to gun it or anything, but I can really only get up half way in 3rd gear before I have to shift down to 2nd and crawl the rest of the way. Again, I do this without really stepping on the gas, it just crawls up at a fairly respectable speed.

3/4 of the way up, the engine does start making a gravelly/knocking sound. Something like you might expect from a rusted exhaust or cat converter. But it is coming from the back of the engine. By the time I get to the top of the hill, the vehicle is fully warmed up, at about 170 water temp. So the thermostat should be open, fully warmed up.

But as I take my foot off the gas, and slow to turn into my driveway, the idle drops significantly, the oil pressure light comes on, the knock is noticeable, and the oil pressure is down around 4 psi.

The next day I started it up again. No problem, no weird sounds, no oil pressure issue. I let it warm up, and I did some slow off road driving for about 8-10 minutes.

So.... right now I'm going to pull the rocker cover off and see if I can tell if oil is actually being delivered to where it is supposed to go, or if I see anything else...

[SafeAirOne]

When the oil heats up, it thins and you lose some oil pressure as a result. Just like having the oil pressure light come on at idle after a period of highway driving. That's my theory, anyhow.

And you describe a fairly normal slow drive up a 4% grade, as far as downshifting goes.

[bugeye88]

4 to 8 PSI, man that is low oil pressure! Something is up with that, the knock could be the oil isn't getting to where it needs to be under those PSI. Oil pump or other oil delivery issue needs to be looked at. The knocking certainly could be related to this. This unless you are reading the pressure as kg/cm squared in which case it would be OK. PSI should be more like 20+PSI with no light.

[SafeAirOne]

PSI should be more like 20+PSI with no light.

Ha!

Thank goodness I don't have a PSI gauge--Just a malfunctioning idiot light.

[rbbailey]

Opened the cover and found lots of oil. Even when I put it into low idle and with the PSI light on, I can see oil droplets flying up and getting all over my nice clean engine bay. So... oil is getting to the top of the rocker arms.

[JimCT]

put some 20w-50, some lucas oil additive and run it till something happens. They are pretty much tractor engines at best

[rbbailey]

Did exactly that a few days ago.

Also, as far as I can tell the tappets are all right at .010, except for #4 seemed a bit tight, but I could still get the gauge in there without forcing.

At this point I'm going to gently drive it a few places and see what happens. Thanks for the info.

[gwmaxhunter]

Hi i think center bearing has cut into the crank about .020 or better. it is a rebuild and maybe a new crank or complete engine.....or my favorite answer install a chevy 2.5L.........

[bugeye88]

Gwmax,

Have you actually seen the center bearing, or are you gazing into a crystal ball?

[rbbailey]

So, I really have not had a chance to drive it much, but I'm pretty scared to.

Deep growl/knock when engine is at higher RPM's after it has warmed up.

I can't shake the feeling that oil isn't getting to where it is supposed to. However, I know it is getting to the top because not only did I pull the cover, but when I put the cover back on it leaked badly on front and back ends -- so I'm working on replacing the cover tonight....

Anything else I should look for?

[SafeAirOne]

...

[rbbailey]

Despite the fact that oil is certainly getting to the top of the engine, I think I have some kind of oil delivery failure.

As said before, the oil pressure starts a bit low, then gets lower as it warms up. It idles around 5psi! I took it out for a short drive and the pressure just continued to drop so that by the time I got home the driving psi is only 10, and a pronounced knock is coming from the engine -- not a ticking, an actual knock.

The engine keeps idling, but it drops to something like 3 psi and even a slight rev in neutral won't get the pressure back up.

I assume I should re-open the pan and take a look at, what was when I last saw it, a very clean lower engine, and no gunk build-up at all in the pan or oil screen. What should I look for before pulling the pump and doing a rebuild?

UPDATE: Oil is fresh looking, but has a grayish appearance and a fine metallic silt in it. Very fine, like soft beach sand. I suppose if parts of the engine are not getting enough oil, this would be expected. No metallic bits or chunks.

Thanks for your help.

[rbbailey]

........Grrrrrrrrrr.........

[gwmaxhunter]

Hi, ya i have gazed into my crystal ball and from the 2 pics there it looks like my bearings out of my 64 2.25L it isn'ta oil lube problem. It is the way the cranks are built, at higher RPM they start to flex..(or bounce up and down).. so no amount of snake oil miracle engine re-build in a bottle or any super slippery thick slime snot is going to fix or cure this. So options are........ 1- dont rev engine alot over 2800 rpm......2- dont be overly panicky about 4000RPM but keep new mains in stock and change them EARLY and BEFORE the crank gets scratched.....(that is what i was gonna do but i wanted more power)........so i did option 3 - install a engine capable of high rpm and having 5 main bearings......the 5 bearing rovers are stronger but still have the same design flaw... i went with a chevy 2.5L and 110 HP.......i am very happy to go up hill in high gear............... i put 800 bucks into my rover head, hard seats for unleaded fuel and everything was done...... now it needs a new home.