1989 Camry 3SFE Engine Knocking

[Calfreerider]

Hi Guys,
Need some help finding the problem with a 1989 Toyota Camry with a 3SFE engine. Has over 250k miles on it. Has been running good both engine and tranny. Just recently had to replace the alternator and was running good for about a week. Then one morning at start up it started knocking very loud, clanking sound, it sounds to be coming from the top end. If I give it gas it stops knocking or once the car is warm it stops making the sound.
The car has no check engine lights on, I checked the codes anyways but I get nothing. I few things I did after knocking sound:
1- Checked oil level, needed about 1/2 a quart, so I topped it.
2- Checked spark plugs, #1-#3 look good, #2-#4 have carbon build up. I replaced them. No oil or fuel smell on plugs. Dry.

Recent things I did prior to the knocking sound.
1- Replaced alternator.
2- My son ran the car almost on empty (Gas).

I know there is many of you guys who are very knowledgeable on these cars. I'm hoping you can guide me in the right direction here.
Thanks

['88 All-Trac]

I've run mine right out of gas with no ill effects. Check the compression across all four cylinders, should be up above 170psi. 150 is okay, but is in the range of "Needs service!"

Could be low oil pressure... My Geo used to knock when it would run low on oil or if pressure would fall. I would do the oil and use a real oil pressure gauge instead of the "idiot light" in the dash. Actual pressure should be around 100psi in a healthy engine, at least for the Suzuki G16. Not sure on the 3sfe.

[AlmightyCamry777]

Since the noise goes away there's hope for the engine, low oil pressure is the first thing to check as 88 al trac says, there needs to be a minimum of 10 psi per 1000 rpm (30 psi at 3000 rpm etc.) a healthy engine will usually show 40 psi even at idle. The compression check is in order to make sure the engine is worth putting any more money into, hopefully the compression reads high. If not then you find out whether it is rings or valves that need replacing by dumping in a few squirts of oil down the spark plug hole, if the number increases the rings are bad, at which point you need to decide if you want to overhaul it, or perhaps replace it with a used japanese engine.

If compression check shows good, the temporary noise is the only noise from this engine, and you just have low oil pressure, change the oil pump and cross your fingers because this is very high mileage engine, after all...

in the meantime try using the lowest viscosity oil toyota recomends. This will get oil to the parts that much faster.

[Calfreerider]

OK Guys,
I did a compression check and it's low. On all cylinders I got 115psi dry and 125psi wet.
Pretty consistent across the board.
If the compression is low, wouldn't that just produce less power?
Would that be the cause of the hard knocking?

So are the rings bad? Since the compression went up when I added oil.

[89Camry89]

Not certain what is causing your knocking.

I can tell you on my 3S-FE (Also 1989) it knocks for the first 5 seconds or so when I first start the car in the morning, or after it sits for a few hours.

In my case, I spun a rod bearing about 1,000 miles ago.

I replaced just that bearing, but there was lateral play between the sides of the connecting rod and the larger portions of the crankshaft. In other words, the new bearing left it tight against the crank journal, but it could wiggle noticeably left and right across the crank shaft.

So it knocks when I start it. The time it takes it to stop knocking is about equal to the time it would take to fill the oil filter.

At high RPM hints of that same sound are present, especially if the engine is neither pushing or pulling, like right as you ease off the gas at 3,000 RPMs.

When the original knock started, I was convinced it was under the valve cover and on the passenger side. I listened with a hose and with a metal object engine-to-ear and I was just sure. I was completely wrong. It was the cylinder all the way on the driver side, where the oil pan is the shallowest.

I guess the sound travels right up the engine block.

[AlmightyCamry777]

Originally Posted by Calfreerider

OK Guys,
I did a compression check and it's low. On all cylinders I got 115psi dry and 125psi wet.
Pretty consistent across the board.
If the compression is low, wouldn't that just produce less power?
Would that be the cause of the hard knocking?

So are the rings bad? Since the compression went up when I added oil.

Yes, unfortunately the rings are shot and a rebuild/replacement engine is going to be needed..

['88 All-Trac]

Rebuild may be easier. Can you use a stethoscope or a long screwdriver to find the source of the noise? In-car rebuild for ring replacement isn't too bad. Can be done without removing the head if the cylinders are in good shape.

[stanno]

Originally Posted by 89Camry89

Not certain what is causing your knocking.

I can tell you on my 3S-FE (Also 1989) it knocks for the first 5 seconds or so when I first start the car in the morning, or after it sits for a few hours.

In my case, I spun a rod bearing about 1,000 miles ago.

I replaced just that bearing, but there was lateral play between the sides of the connecting rod and the larger portions of the crankshaft. In other words, the new bearing left it tight against the crank journal, but it could wiggle noticeably left and right across the crank shaft.

So it knocks when I start it. The time it takes it to stop knocking is about equal to the time it would take to fill the oil filter.

At high RPM hints of that same sound are present, especially if the engine is neither pushing or pulling, like right as you ease off the gas at 3,000 RPMs.

When the original knock started, I was convinced it was under the valve cover and on the passenger side. I listened with a hose and with a metal object engine-to-ear and I was just sure. I was completely wrong. It was the cylinder all the way on the driver side, where the oil pan is the shallowest.

I guess the sound travels right up the engine block.

I have a similar sympton when the engine is started (cold).

The knocking sound is quite noticeable. It doesn't increase in volume or speed with rpm.

And when the engine is warm it's gone. I'd like to get rid of it though. I want the engine to as sound smooth as it is at 700rpm.

[oscaryu1]

250k? Don't rebuild it, swap it out. Guarantee you'll have a tapered bore and in need of an overbore.