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Discussion Starter · #1 ·
Is it possible to change the rod bearings by removing the oil pan? Is this something a novice should attempt? Thanks in advance.
 

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There is more to just removing the old bearings and putting in new ones.
Yes you can remove the pan only to get at the bearing.
 

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yes make sure u really know what are you doing, can turn worst if u mess up with those bearings.
 

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Discussion Starter · #5 ·
Thanks for the replies. I'm in Tallahassee. I was late to school this morning, so I was hauling ass on the interstate. When I got out of class I started getting a pretty bad knocking, and I think that I've slipped a bearing. I successfully replaced the head-gasket a couple summers ago, thanks in part to some help I got from these forums, but I have no formal training. So... what else is involved and should I attempt this?
 

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A decent amount of precise measuring. A cheap way of doing it would be to buy a telescoping gauge and an outside micrometer. Both of these tools are found in different sizes, and I'm not sure what size you would need for this particular engine. Perhaps someone else here knows.
I have only rebuilt engines on a stand, never in-car.

Basically you remove the crank, clean off the oil and measure the diameter of each journal to find taper and out of round (I take at least 6 measurements per journal).

Then put the main caps back on (minus the crank), and torque to spec. These measurements are a bit more tedious. The telescoping gauge will be a vessel for transferring the measurements from the block to your external micrometer.
Again, and in the same steps as the crank, you should take at least 6 readings per journal for taper and out of round.

Basically you'd have to subtract the opposing readings and that difference should be filled by the bearings.

This is just a rough and quick explanation. If you are capable, then do it yourself, otherwise it's $$$$
 

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If it was knocking, just pull the engine. Chances are, that rod (even if it is a rod) is out of round now, and you'll just be wasting time and a bit of money.
-Aaron
 

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If it was knocking, just pull the engine. Chances are, that rod (even if it is a rod) is out of round now, and you'll just be wasting time and a bit of money.
-Aaron
Yup, that's why you want to take so many measurements per journal. If it is out of round or tapered, bad things have happened.
And I had misread your post about it being a rod problem, sorry. :duh:
What I mention would be testing the crank to block clearances. Although measuring the rod to crank is performed in the same fashion.


I'm sorry to say it, but you most likely will need to rebuild your 5m :sadsmilie
Knocking has occurred in two of my previous 5m engines. Both blew shortly there after, darn those high miles!
Does the knock increase with RPM?
Could be piston slap or a connecting rod/wrist pin problem.
 

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i have a rod knock in one of my 85's. just got new rod/main bearings and thrust washers from aaron. havent had a chance to install yet though. i also got pistons/rods from celica fanatic so i might end up having to use them.

im going to try to do the whole thing without having to remove the engine. i will document my repair and let you know how it goes. should be getting to it this weekend.
 

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It takes practically no time to pull the engine. Are you lacking space??? No where to work??

If I were doing this the engine would be on a stand.
 

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Garette. Put down the peace pipe, or pass it. Practically no time, eh? Sure, for guys that have done it a lot, and know every little thing that needs be be disconnected, its a fairly easy job. 5m Rob. If you end up needing to get it done, want some help, and are not too far from Tanya, give her a call and some cash. She'll probably come help. She knows what she's doing.
-Aaron
 

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Tallahassee is about 10 hours away, not really feesible for me to come up and help at this point.

Must absolutely be positive it is rod knock though, before you go and yank the engine, there's a couple of others sounds that can be confused with rod knock. A seizing timing belt tensioner, bad water pump bearings, a bad crankshaft keyway.

Try running the engine, and with rubber insulated pliers, pull a spark plug wire to see if the engine knock and idle change. Plug it back in and do it to each cylinder. If the knocking noise goes away after you've pulled a plug, you found a problem cylinder.

Also want to try using a stethoscope to determine whether it's coming from the front of the engine or the bottom, etc.

p.s. removing engine/trans is highly recommended. doing a bearing/crank replacement in the car would require you to remove the subframe. you also need to bring down the crankshaft and use a micrometer on it. if a bearing really did spin it most likely needs to be machined
 

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Discussion Starter · #13 ·
Well... I tried to drive the supra this morning. It's way worse than I thought. I don't know if it's worth trying to repair the engine at this point. I think I'll buy a cheap car to get me around till I can afford to drop a better engine in. Anyone know where to get a relatively inexpensive 6m or 7m motor?
 

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Couldn't you buy a good condition crank, all new bearings, and then check the problem rod? Assuming the main bearings were untouched. 700 dollars got my 85-p and a 7m-ge because the owner's wouldn't/couldn't fix the knock:D (also the main bearing journals were perfect on both)
 

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Discussion Starter · #16 ·
It's not really a knock anymore. More like the sound of grinding, breaking metal. I literally heard pieces falling down into my oil pan. :eekfacepalm: It was catastrophic. I thought it was going to throw a rod for sure. It looks like I'm gonna have to park the supra for a while.
 

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:sadsmilie
 
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