RPHARRIS

Looks like it finally happened. I hadn't started the car in a couple months, but last time it was running pretty well. I turned over the engine for no less than 30 seconds with the ignition and fuel pump disconnected ...but apparently not long enough to get sufficient oil pressure. When I fired it up, the oil pressure instantly started climbing but then came the clacking and knocking sounds. It definitely sounds like rod knock to me.

I'm pretty bummed, I still have that supra engine in my garage but I had really been enjoying the stock engine lately and was considering selling that thing. What's a guy to do? How much work would it be to go the low budget rebuild route and replace the bearings and rings? cost?

I would really appreciate advice from people who have been around these cars for a while. It's really tempting to spring for big budget 2.8l / 3.0l monster but I'm young and I think it would be irresponsible to draw so much out of my beer and strippers fund.

333pg333

Could just be the main bearings and cheap (compared to the other options you've listed). Can't imagine you've done too much bore damage under those circumstances.

Duke

Sounds odd that you would get rod knock from just starting it up with low oil pressure.
Are you sure it's not the lifters hammering?
it can take a while before they get filled up with oil after a long time without starting the engine.

Chris White

You should not be able to do that kind of damage at idle - even with no oil pressure!
My guess is a severly collapsed lifter. A ticking sound is the normal sound for a failed lifter but occasionaly they completely collapse and it does sound like rod knock.

If it is rod knock your oil pressue will drop off a lot. If its lifter then oil pressure will be normal.

333pg333

Hope you're right Duke, but 'knock-knock-knock' sounds different from 'tap-tap-tap'. Could be that RP was right on the edge of something happening previously and then when restarting the motor after a long absence all the oil had drained down into the sump and it just went over the edge on startup?
Having re read the OP it does sound a bit weird. Hope it's just a lifter.

Chris White

The cold thick oil will cover up all but the worst rod knock – but not a completely collapsed lifter

theedge

RPHARRIS take a video if you can.... Lets compare scary engine sounds Mine started making a knocking sound on friday, still have to figure out whats up.

KuHL 951

I say lifter also. I had my 83 sitting for about 8 weeks once. When I started it it sounded just like a rod knocking. Oil pressure was fine. I let the car run for about 2 minutes and then turned it. Once some heat soked into the block I restarted it 10 minutes later...the noise was still there but quieter and went away completely after a full warmup. It's hard to believe you can toast a bearing with cold oil at startup. If it needs an oil change anyway add some Seafoam to your oil, warm it up, drive it gently a few miles, let sit for a few hours, and change the oil.

Zero10

Collapsed lifters can make one hell of a racket, when they get really bad they even go "CLUNK" instead of 'tap'. I agree as well, typically rod bearings do not fail at idle as very little oil is required to keep them safe below 1000RPM.

How long did you let it run once you noticed the noise? It can take 5-10 minutes before the lifters quiet down. Let the engine (and oil) get up to operating temp and see if the noise persists.

Zero10

Collapsed lifters can make one hell of a racket, when they get really bad they even go "CLUNK" instead of 'tap'. I agree as well, typically rod bearings do not fail at idle as very little oil is required to keep them safe below 1000RPM.

How long did you let it run once you noticed the noise? It can take 5-10 minutes before the lifters quiet down. Let the engine (and oil) get up to operating temp and see if the noise persists.

RPHARRIS

Lifters definitely crossed my mind actually! What's the best way to get them pumped back up? But jesus that sound was awful!

RPHARRIS

WEIRD! the sound went away for 3 or 4 minutes and then came back. Oil pressure is great, at the top of the gauge. I took a video so let me know what you think.

333pg333

Swap in some good lifters and see if it goes away?

RPHARRIS

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http://www.youtube.com/watch?v=mlZ0Z33bi74

Dom1

Lifters. I had a turbo do this on and off for a short while while then it stopped completely and never came back.