Knocking in 2.25

[rbbailey]

OK, so many of you have helped me in getting this thing back together, and I'm happy to report that all the front end seals, the oil pan, gaskets, etc... all seem to have turned out just right. No leaks! After clearing the apparent vapor lock in the upper fuel line, she started right up for the first time in 2.5 years. I ran it a little yesterday with the wings off so that I could closely inspect for leaks and such. And while she ran fine, I did start noticing what I thought might be a little knock in the back end of the engine.

Today, I ran her for about 10 minutes and the knock seems to be for real. At the same time, the oil pressure light is coming on at idle....... :confused:

So.

What do I do? where do I start? What do I inspect?

I can tell you that when I first pulled the oil pan off I was impressed with how clean the lower part of the engine was. No sludge in the pan. Very clean, metal still showing, dark brown oil, that's it.

I have not seen under the valve cover. The engine has always been a good runner, smooth, but has always liked a bit of a fast idle or she sputters a bit. These past few days I've seen gray smoke at start up. Not heavy at all, enough to notice.

[bobzinak]

My S2A original owners manual says that the oil light may come on at idle. and it is nothing to worry about. as far as the knocking goes I can't really say. if it a heavy knock or just a tapping. My advice is to let the engint gt to operating temp to see if it goes away. I have hasd an older engine that would have a slight knock untilit reached operating temp, that about all I could recommend you to do. ROVE ON bobzinak.

[rbbailey]

Never knew the manual actually said that. Interesting.

In years past, the light has come on at low idle -- I'm worried about it because this is a long time since it has run, and because of the knock.

I'm going to have to investigate it.

[o2batsea]

Well, no good deed goes unpunished. Now that you have the oil pan gasket squared away it is time to pull the pan again. This in order to pull the caps off the rods and plasti gauge the bearings. If they are indeed shot, which is likely, then you will have to take off the cylinder head in order to get the piston and rod out for repair. The engine can stay in the truck.
Thing is, that a rod bearing renders the entire engine's health suspect. It may be rebuild time.

[SafeAirOne]

The oil pressure light illuminates around 7 or less PSI IIRC, so there isn't a whole lot of pressure in the system when the light illuminates. Excessive clearance (wear) between the connecting rod bearings/main bearing and crankshaft as O2batsea suggested, combined with not enough oil filling the normal lubrication space between the bearings and crankshaft could cause a knock.


Engine Fault Diagnosis from the 90/110 WSM:

http://farm4.staticflickr.com/3718/9239497180_fa6b07f957_o.jpg

[rbbailey]

Thanks, but no thanks, if you know what I mean....

It started instantly this morning with little exhaust. I'm letting it idle to get warm and then I'm going to check for the noise with a video. Is there anything else I should do before pulling the pan again to check that oil is flowing where it should?

[jonnyc]

What weight oil are you using? I made the mistake once of running with 10/40 'cuz that's what I had. Returned to 20/50 and it quieted right down.

[I Leak Oil]

A) What is your idle set at when the motor is warmed up?
B) What does your oil pressure gauge [you have one right?] reading at various RPM's?
C) Have you checked your timing? Sometimes poor timing can mask itself as an engine rapping.

[stomper]

Are you sure it is a knock, and not a really loud tappet? I agree with the two above posts. oil viscosity and timing, as well as verifying the pressure of the oil by a mechanical gauge.

[o2batsea]

Honestly if it were me in your position, I would just drive it. As suggested go up one viscosity on the oil.

[rbbailey]

Yeah, I am thinking of just driving it for a bit, carefully, to make sure I know what I'm hearing and such.

Moving to higher oil -- I did think 10/40 was a bit thin as I poured it in, but I was thinking that this is higher than what I usually use... on my Audi and Discovery...

If the gauges are to be believed, I'm running at about 5psi at low idle (I do not have tachometer). It runs at 8-10psi at smooth high idle. And when I rev it and hold it at driving RPM's, I'm in the 40psi range. This is with engine at temps of about 150 to 160.

[o2batsea]

You can go for quite a while with a loose rod bearing. While you are out there tooling around contemplating the ultimate demise of the old 2.25, you should be saving up a for a transplant donor. It is way easier on your entire feng shui to rebuild a second engine and have it ready and waiting for that Cosmic Convergence Saturday when you yank out the old and drop in the new.

[I Leak Oil]

If the gauges are to be believed, I'm running at about 5psi at low idle (I do not have tachometer). It runs at 8-10psi at smooth high idle. And when I rev it and hold it at driving RPM's, I'm in the 40psi range. This is with engine at temps of about 150 to 160.
I run 10w40 all year with no troubles. At temp and speed my engine is between 40 and 50 psi. However, that 5-10 psi at idle does sound low, mine hovers right at 20 psi at idle. Sounds like you need to do some more trouble shooting before you pronounce it or go driving off too far from home.

[NC_Mule]

Sometimes you can pin point a knock/noise with a wooden dowel. One end in your ear the other on the engine. Actually pretty cool how much you can hear doing this. You said the knock is at the back of the engine, any chance something in the clutch is sticking from sitting? Have you taken it for a drive, does it get worse under load? Is your gas 2-1/2 years old or are you using new stuff?
Are the points in spec? These engines have such low compression I don't know if pinging could be a problem. Never heard a engine ping at idle but may be with crappy old gas and poor timing.
Just rambling out easy things to check.
Engines are very tough and they don't know if they have been sitting for 30 minutes or 30 years. 2-1/2 years is not that long, if it didn't knock before and you didn't do any internal engine work (sounds like you just changed seals) then I would look outside the engine and make sure it's in a proper state of tune before you get worried about a major internal repair.

Edit: Whoops I read the first few posts on the first page then posted, didn't see all the posts on the 2nd page. Carry on, looks like you have a plan.

[bugeye88]

Another thing to consider is "piston slap" that occurs when an engine has had a few rebuilds, with some boring going on with each. I've heard engines sounding like a Diesel knock or rod knock due to piston slap. Some engines can go quite long with this though.
Rob

[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]

86578658

........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.

[I Leak Oil]

Until (or if) you get into it you might never know what has taken out the bearing. Mileage, lack of oil pressure, mechanical failure, perhaps your neighbor secretly drag raced it at high RPM's while you were sleeping....

I'm surprised you got advice in this thread to just run it and see what happens. Once a motor starts to knock it's too late and it's done, they never get better, only worse and that happens quickly in most cases.

There is a SIII motor on GnR for $550 right now in NY state....Might be worth the inquiry.

[NC_Mule]

Sorry to hear is was something major.
We don't know the exact cause of this failure but this is the first I've heard about over revving a 2.25. I feel like I rev mine a pretty good amount, mostly because it's a 2.25 4 cylinder and I remember revving the heck out of the 2.0 in my old Fiat Spider. Although that was a 5 brearing crank now that I think about it. What's the safe range for these engines? I have a tach I can install and see what range I have been driving in.
pb

[SafeAirOne]

Without re-reading this thread, I don't think that over-revving was involved. Just low oil pressure and increased wear on the consumable parts (and the non-consumable cylinder bores too). Normal engine rebuild stuff (aka "nothing lasts forever").

[I Leak Oil]

Without re-reading this thread, I don't think that over-revving was involved. Just low oil pressure and increased wear on the consumable parts (and the non-consumable cylinder bores too). Normal engine rebuild stuff (aka "nothing lasts forever").

That's probably a good guess and that's what I'd chalk it up to as well.

[Revtor]

Does anyone have any insight as to how well these 2.25's were balanced from the factory? Has anyone weighed their pistons/rods? One day i'll have mine out again for major work and it's something I would do..

edit
although reading the wikpedia article, inline 4's are inherently unbalanced due to the pistons moving faster at the up to down stroke vs the down to up stroke. Hence balancing shafts used in most modern 4's.. also the non overlapping power strokes. I guess perfect component balance wouldn't be of much smoothness benefit. id still do it though

anyway

[rbbailey]

The history of this engine is relatively unknown. I bought it after it had sat in a barn for 12 years. The original owner had given it to his best buddy when he died those twelve years before. He had driven the thing a lot, the motor is not original, but an import at some later date. (It has a plate on the side.)

When I bought it, it ran, and ran fairly well. I decided to take care of it, but to keep a hands off approach since it was running -- ain't broke, don't fix it. I sold the car, then bought it back. In that time, it got new ignition components, new fuel pump, and I believe it got the sump cleaned out -- at least, it's hard to believe how clean it was when I opened it up.

When I bought it back, it still ran well, but I didn't drive it long before shutting it down to take care of new break system, rust in... blah, blah.... In the course of that work I did the main seal, checked the sump, new water pump, etc...

Fast forward 2.5 years when I FINALLY get this work done and it starts and runs well... but then it is low oil pressure and ect... and here we are a few weeks later.

All of this to say that I do think this is normal wear that was simply pushed over the edge when the engine sat for 2.5 years.

Also, I would like some input on the following:
1. Could worn bearings be the CAUSE of the oil pressure problem?
2. A mechanic told me NOT to bring it in to him before doing what he would do to his car first (since it's very likely a full rebuild anyway) since it seemed to run well, why not change the bearings that can be changed from below the engine first? He told me how he's done it without removing the engine. And he told me how I can test the wear on the shaft. His view is that it *might* work. At least, the $150 bucks for a set of bearings that might do the trick is better than jumping off the bridge for several thousands worth of a rebuild or a mod to a diesel.

[SafeAirOne]

1. Could worn bearings be the CAUSE of the oil pressure problem?
2. A mechanic told me NOT to bring it in to him before doing what he would do to his car first (since it's very likely a full rebuild anyway) since it seemed to run well, why not change the bearings that can be changed from below the engine first? He told me how he's done it without removing the engine. And he told me how I can test the wear on the shaft. His view is that it *might* work. At least, the $150 bucks for a set of bearings that might do the trick is better than jumping off the bridge for several thousands worth of a rebuild or a mod to a diesel.

1) Tricky question. Wear could cause low oil pressure because there will be no backpressure in the lubrication system due to the enormous gaps between the parts, but the cause of the wear could be (but doesn't HAVE to be) an oil supply problem like a worn pump. How's that for a foggy answer?

2)You could just change all the main and rod bearings and thrust bearings pretty easily, and probably prolong a rebuild for a while (presuming the oil pump is up to snuff), but looking at the amount of wear there, it's probably safe to presume that all the other components that rely on the lubricating system and some that indirectly rely on it are similarly worn when you get to the stage that you can hear audible knocking in the main and rod bearings.

You can just about count on the cam bearings and rocker bearings being in a similar state along with pretty loose pistons, I'd guess. Just depends on how much time and money you have to spend on it at the moment, but know that just replacing the main and rod bearings probably is a short term solution. This could mean 'months' or 'years'. Who knows.

[rbbailey]

OK, so I've made my decision on what to do. I think there is too much scoring on the main shaft to make it worth putting bearings in just to see if it works. The low oil pressure may not be solved by putting new bearings in.

I could put a 200Tdi in, but.... could and should are very different. I just don't have the money to do it without really biting the bullet, and then what? What condition engine would it be anyway? To get one that was really good, I would be spending close to $10k when all is said and done.

So I am going to get a 2.25 in running condition. I'll take all my good parts (lots of "new" stuff on this engine) and swap it out. I will keep the old block and slowly restore it so that when the engine in the truck is done, I simply swap. I could go through quite a few swaps, many miles, before matching the cost of a conversion. And conversions are great, but they always have their own set of problems. Besides, if I'm going to get a Tdi Rover, I think I would rather build a D110 from parts than to hack what is essentially a stock 1965 IIa.

Thanks for all the help and info.

Anyone have an engine for sale?

[SafeAirOne]

Speaking personally, I think you've made the wrong decision.--Unless you just want to put a $500 engine in and roll the dice, that is.

Can I ask you why you'd seek ANOTHER USED ENGINE when your's only needs a fairly-routine, $1200 rebuild?

There's nothing special about scored journals on the crankshaft--Machine shops deal with these a half dozen times a week.; All they do is polish/machine them down to a particular size so you can fit commonly-available oversize bearings.

I urge you to talk to your local machine shop BEFORE you buy an unknown used engine. Yours is still a potentially good engine, unless you know something we don't..

[rbbailey]

Actually, that is pretty much what im doing. I will have the engine rebuilt on my own time -- out of the car -- with my own hands. I have a running engine from a trusted source that I can get for $700 (no shipping cost). It isn't new, but the owner drove it regularly before simply deciding he needed a Chevy in-line put in. I will swap my new parts onto it, have a running truck while im rebuilding an engine on a stand in the garage. In the end, I would at least have a backup engine for parts or to simply swap when the time comes.

Also, the bearing and shaft rebuild is a roll of the dice on whether it will fix the oil pressure issue. I think that a complete teardown is needed, but it will take me a year to complete.

You could simply say I've decided to keep it stock and I'm buying an engine to get me on the road since the car has been in my garage for 2.5 years and my kids are getting older and I simply want to drive.

[SafeAirOne]

Ahh...OK, got it.

That's exactly what I've got going on right now...a temporary engine while my primary engine (eventually) gets fixed.