I have no clue why but my motor sounds like it threw a rod. Can't figure why it would.


7MGTE

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Sorry for your loss, JZ swap time

 

...... Sorry for your loss, JZ swap time

Or yah know... just fix the crank pulley and dont waste your time or money on a 1jz when you have a perfectly good 7M.

 

Check your crank pulley. A loose pulley will knock and sound like a spun bearing.

 

have you tired using something as a stethoscope to see if you can pinpoint the source of the noise?

 

i went out this morning to check on the car...maybe by the grace of god or some religious ritual it would cure itself...took the front timing cover off and everything is still there. Crank pulley LOOKS to be ok. It really just sounds like something internal in the #1 or # 2 cylinder. I still have good oil pressure. I will check it out Monday. I just can't believe the motor would let go like that. Oil Pressure was good, Mobil 1 Every 3500 miles and I built the bottom end so I would have this issue. Go figure!!!!!

 

i went out this morning to check on the car...maybe by the grace of god or some religious ritual it would cure itself...took the front timing cover off and everything is still there. Crank pulley LOOKS to be ok. It really just sounds like something internal in the #1 or # 2 cylinder. I still have good oil pressure. I will check it out Monday. I just can't believe the motor would let go like that. Oil Pressure was good, Mobil 1 Every 3500 miles and I built the bottom end so I would have this issue. Go figure!!!!!

Just saying..... lol

 

How did you check the crank pulley? Did you try to re-tighten the bolt with a torque wrench?

 

i did not retighten the bolt but it really does sound internal. I much as I hope and wish you were correct, it just really sound like something is coming apart inside the block. i thought it was a tensioner but that seems to be ok. i cant see the crank gear so it sits until Monday. I also cant see the bottom end giving out. I can tell you the 1 block I drove it home it had no power. So off to enjoy the rest of my weekend.

 

had the car towed to work...So far we all think that its a bottom end failure...cant figure why or how but it sure sounds ugly...oil pressure is still fine car starts right up...not sure at this point without taking it apart...

 

If you had good oil pressure, then it was the TUNE... that's what the rest might tell you..

 

Oil pressure can be perfect if you spun a bearing.

When you rebuilt the engine did you have the rod ID checked for proper size?

 

yes...everything was done correctly. At this point motor is done. The debate is wether to rebuild what I have, put a short block in it, swap a 1j into it or just sell it as is...not sure which way im going yet

 

2j on 7m electronics.

 

Have you drained the oil yet? checked for any metal.
Have you checked the oil filter for any metal?
there is a lot of things that "Sound" like rod knock.

 

if it's fast knocking then it could be cam journals?

 

Or wrist pin.

Spun bearings do not allow for perfect oil pressure. Once they spin, they wear quickly. An oil film clearance 2x size of stock doesn't yield 2x the bleed off. It's more like an exponential thing. 2x the clearance can make 4x the bleed off. 3x the clearance can make 8x the bleed off, and so on. That's literally engine building 101.

Cam journals won't be a fast noise. In fact, they are slow since they are 1/2 the speed of the crank rpm.

 

Shhhhh

I said spun bearings CAN be the case with perfect oil pressure because often it blocks off the oil delivery hole in the crank. I have seen it many, many times. Clearance makes no difference when the source of the oil no longer exists.

 

I lost a 7M-GTE to the shitty stock oil filter housing/bypass setup - the springs in it relaxed too much, allowing too much oil to simply go through the line to the cooler and back to the pan instead of going through the filter & into the engine. Got rid of that assembly using the 7M-GE union bolt & the oil pressure jumped about 15psi with the same oil in it.
Obviously, at that point it'd be good to get a proper sandwich adapter for a proper oil cooler setup.

 

Since when did rebuilding a block with stock internals become a build bottom end???

 

www.Honda-tech.com

 

Mine is built... Cryo hypereutectic 0.5mm over "chrome moly" rings, shot peened rods, arp rod bolts, main studs and flywheel bolts. Modded oil pump and -10an oil line, Clevite 77 rod and main bearings. Is it not built because its not cp pistons and eagle rods?

 

Oh and flubyu cam journals can make a fast noise as well depending on the situation. Load on the camshaft changes depending on which lobes are compressing the valve springs. With enough clearance it can knock whenever it opens corresponding sets of valves. I've seen this as well.

Stop pretending you're en expert and understand all possibilities of engine failure. I certainly have a lot to learn, but i've seen enough interesting cases to know weird things happen, and will happen.

I'm beyond your "engine building 101", smartass.

 

I don't see how my comment was smart assed. Unless everyone who disagrees with you is a smart ass... If that's the case, you might not want to be on the Internet.

I have valve train noise and it's the same speed as the injectors, which is slower than the bottom end spins. And the cams don't make a heave knock noise. It's lighter than that. You know that full well so dont try to disagree.

And what happens AFTER a spun bearing spins and blocks the oil galley? It does what YOU said for a VERY short period of time until the bearing is completely starved of oil. At which point, the Babbitt is eaten away. Once that's gone, and the copper is exposed, there is alot of play on the journal. And after that has too much play, there isn't much to keep that bearing from NOT continuously spinning on the journal, which will open the oil galley back up. Since the oil film clearance went from 0.0015" to blocked to 0.150", I'd say that would be where noise could come from. That period of time that you suggested wont be very long... So short that it would have likely passed before the op noticed a noise. Once the noise occurred, your diag is moot. And the condition has cascaded into the events that point to MY diag.

A shifted bearing shell will do as you say, no dispute. Stop being so sensitive. I'm just saying, if that's the case, it wouldn't be making noise yet. But it is... So if it is the rod bearing, it's already past the time frame of your diag.

 

have you actually found what is making the sound? or just assuming the bottom end is bad? could be a bad injector causing a lean condition in 1 cylinder giving it predetonation which will kill power. rod knock you will still have all the power. btdt. no power tells me it is something else. maybe the timing belt jumped on one of the cam gears. that will allow it to start just fine but no power, and depending which way it jumped could cause some detonation to be going on etc... point is, find out exactly what is wrong before you just give up.


btw chris, if you have valve train noise, why havent you done a valve adjustment? ive got over 150 shims!. lol

 

Good call onthe motor functionality.

Lol... I didn't want to screw with it honestly. If I was goin to tear into it, I wanted to just do shimless 1sz buckets. But I only wanted to do those for the sake of new cams. Maybe once I get my tb and alt bracket back, I'll bring it over and let you do, er I mean, help shim the valves.

 

No no... I mean the oil hole in the crank is rather completely or partially blocked by bearing material that has adhered itself to the crankshaft due to the extreme temperatures. The malleability of the babbit material leads to it often creeping into the oil hole and relieved area around it. I am not saying it is probable, but as i said is not out of the question.

 

I will certainly attest to that part. I pulled a knocking motor apart and found the remnants of the bearing shells friction welded to the rod journal. I don't doubt the oil pressure looked "normal" in this guys case.

 

change the oil and look for metal shavings...?

 

A 7M never spins bearings! This is unheard of! THE OUTRAGE

 

Yeah. Darrel is right. I don't think I know of any engines that the oil has to pass thru the crank first. It's usually that the galleys branch off. The oil pressure would drop severely of each thing was sequential. But, since everything is run in parallel, if one branch sees a big loss in restriction, all the others will suffer from oil pressure loss. Makes me wonder if the scored cam journals I've seen in the past were linked to loose bottom ends.