Rod knock....already? are you serious?

[IwantMKIII]

6+K miles on new engine and rod knock??

Now i've heard rod knock before from my brothers supra and his was waaaaay worse. I've heard the tapping before, i noticed it got louder as i changed the timing. Now i changed the timing last night to more of a stock setting compared to where its been at....its never registered on my knock sensors before this morning

about 48Hz and goes up gradually with RPM ......is this really bad timing with a mix of bad gas or am i f*cked? :1zhelp:

FYI this is not throwing codes

Just set the timing back to where its been.....much less audible however knock sensor readings still same about:

38Hz idle......when i step on the gas it varies by how much throttle i give it....if i give steady throttle it evens out to about 90~100Hz


Edit: for those just catching up....


Engine still somewhat cold:

[youtube]1e6yj0WsOUo[/youtube]


Near Op temps, take notice the varying knock levels....kind of strange IMO
[youtube]-lvrCUEOVcI[/youtube]

 

[a_sesshoumaru]

rebuilt or used engine? did you cut the crankshaft?

 

[jdub]

And did you have the rods re-sized?
Clearances on the rods?
Did it EVER run low on oil after the build?

 

[IwantMKIII]

rebuilt or used engine? did you cut the crankshaft?

rebuilt professionally

crank work includes balancing, magnufluxing and micropolishing, no cutting

 

[IwantMKIII]

And did you have the rods re-sized?
Clearances on the rods?
Did it EVER run low on oil after the build?

rods were resized, checked for straightness, balanced, magnafluxed

I don't show any clearance specs on the rebuild info, only weight specs

I ran it on low oil once about 2 months ago, blew out my front main and didn't know it, noticed intermitten low to no oil pressure during acceleration and babied it, pulled off and got oil ASAP, showed no signs of knock/damage.......but then again maybe it takes a long time to show signs of the damage?

 

[jdub]

Answers ONE question

 

[IwantMKIII]

Answers ONE question

im editing it as i filter through the rebuild paperwork

 

[jdub]

All it takes is once...even running a quart low and getting slosh in the pan that uncovers the oil pick-up will do it. Once the bearing is scored, it will just get worse and sometimes won't become apparant right away.

What grade/make oil you using?

 

[Kurb Appeal]

Micro polishing without a cut on the crank can be an equal casue as having low clearences. It can acually cause low clearences. As your crank is run through the engine over time it can develop an egg shape from hard use and abuse. If all they did was polish it they could have removed some wanted material. and made it more or an egg shape. I have seen so many people just get a polish on the crank and then trough a bearing.


If the clearences were low to begin with then theres your problem. Although I could be wrong. How long after you started adjusting timing did it start to knock?

 

[IwantMKIII]

All it takes is once...even running a quart low and getting slosh in the pan that uncovers the oil pick-up will do it. Once the bearing is scored, it will just get worse and sometimes won't become apparant right away.

What grade/make oil you using?

Can't remember make off hand TBO, possibly NAPA oil which is bottled by castrol...one of the bigger companies? Had Mobil SYN in there till oil seal blew then i needed something to last me till next oil change so i got a little bit cheaper stuff since i owed the bank about $1 at the time :aigo:

and 10W-40

 

[IwantMKIII]

Micro polishing without a cut on the crank can be an equal casue as having low clearences. It can acually cause low clearences. As your crank is run through the engine over time it can develop an egg shape from hard use and abuse. If all they did was polish it they could have removed some wanted material. and made it more or an egg shape. I have seen so many people just get a polish on the crank and then trough a bearing.


If the clearences were low to begin with then theres your problem. Although I could be wrong. How long after you started adjusting timing did it start to knock?

well i redid the timing last night, drove home (about 1.5miles). Went to mc d's last night (round trip about 1.5miles) and noticed it this morning....so very soon

again though, i heard it slightly before i changed teh timing....but it wasn't registering anything on my sensors so i figured it was something else

 

[IwantMKIII]

So lets assum i threw a bearing....its in the very front of the engine from what i can tell so im thinking its rod #1 or 2. Now this is still a fresh build....

what are my options....?

im guess pull the motor, drop the oil pan and work from the bottom only? Keep in mind im at school and will PROBABLY have to pay a mechanic

 

[jdub]

It would be good to know what the clearances were and and if under sized bearing were used. The condition of the crank journals is an unknown too...I have to agree, if the journals were not cut to round, it can cause problems.

The reason I asked what weight oil is sometimes you can buy a bit more time by using a heavier oil...at this point, it really doesn't matter. Your only option is to use a 50W multigrade (since a 40W is not working) to quiet it down and that is only going to last a short time. The risk is you throw a rod...you will have to minimize the time it's run and NO hard runs of any kind.

You'll have to pull the motor and replace the bearings...the only way to be sure if the crank is good is to measure each journal from several different angles for roundness. It too may have to be pulled and cut. If you do that, the cylinders will have to be honed and the rings replaced.

 

[IwantMKIII]

It would be good to know what the clearances were and and if under sized bearing were used. The condition of the crank journals is an unknown too...I have to agree, if the journals were not cut to round, it can cause problems.

The reason I asked what weight oil is sometimes you can buy a bit more time by using a heavier oil...at this point, it really doesn't matter. Your only option is to use a 50W multigrade to quiet it down and that is only going to last a short time.

You'll have to pull the motor and replace the bearings...the only way to be sure if the crank is good is to measure each journal from several different angles for roundness. It too may have to be pulled and cut. If you do that, the cylinders will have to be honed and the rings replaced.

Possibly a stupid question, but i've never built a motor's internals: if the crank needs to come out, couldn't i just unbolt all the rod caps, main caps and drop it that way without removing the pistons? If not, why do i have to do this?

 

[jdub]

No stupid questions...only stupid answers

You could get away with it...depending on the condition of the rod ends. I would at least check to be sure they were properly re-sized and are round. Kinda hard to do with them in the motor, but you could with the proper tools. It would save a re-hone and new rings. I tend to be pretty anal about this kind of thing.

Here's what's very important:
- The crank journals (main and rod) are round and not scored
- The rod ends are round and not scored
- the correct size bearings are installed to put clearances (main and rod) in TSRM spec
- Thrust washer clearances are in TRSM spec

I am questioning the ability of the shop you used (especially since you blew a front seal)...the problem with "professional" rebuilds is the shop may or may not have experience with 7m, 1J or 2J motors. Some of these shops do fine with Chevy and Ford motors, but Toyota engines are a different story...they do not tolerate any sloppy assembly.

BTW - Does the shop you used offer any sort of warranty?

 

[IwantMKIII]

No stupid questions...only stupid answers

You could get away with it...depending on the condition of the rod ends. I would at least check to be sure they were properly re-sized and are round. Kinda hard to do with them in the motor, but you could with the proper tools. It would save a re-hone and new rings. I tend to be pretty anal about this kind of thing.

Here's what's very important:
- The crank journals (main and rod) are round and not scored
- The rod ends are round and not scored
- the correct size bearings are installed to put clearances (main and rod) in TSRM spec
- Thrust washer clearances are in TRSM spec

I am questioning the ability of the shop you used (especially since you blew a front seal)...the problem with "professional" rebuilds is the shop may or may not have experience with 7m, 1J or 2J motors. Some of these shops do fine with Chevy and Ford motors, but Toyota engines are a different story...they do not tolerate any sloppy assembly.

BTW - Does the shop you used offer any sort of warranty?

Actually, the shop it was taken to was chosen because the mechanic builds supra motors for a guy that races professionally, and they've never had a rod bearing go on that 7m

Anyway, looks like im gonna need a parts list.

Now i have ARP rod bolts in there...can they be retorqued? or need to be replaced?

I have Federal main and rod bearings in there. I see a lot of people go for Clevite (i think thats what it is)...are they that much better? If so, where's the best place to get them?


News flash -I just got off the phone with the mechanic....its still under warranty however im 350 miles away from the shop :aigo: and he can't even guarantee he'll cover it. He's a real nice guy. He's emailing me the specs on clearances on monday night and part numbers. He said based on my symptoms and the fact the knock isn't that bad its a clearance issue and the bearing is not spun. But he also said to make sure nothing else is causing the knock just in case....(don't know what else it could be)

 

[ABQMK2]

Ok, Now I have a few stupid questions. Dont the knock sensors detect predetination/ignition? How can they detect a bad bearing type knock? Maybe im reading the first post wrong but I Think youre implying that since your not getting a code then it shouldnt be the rods? trying not to sound like a smart ass here...Im far from knowing your reason...just trying to learn.

Everytime supraguy31 had any material what so ever removed from his crank he developed rod knock. it happened at least 2 times before we made sure he got a perfect crank.

Is that what happened here? to much material removed from the crank?

 

[IwantMKIII]

Ok, Now I have a few stupid questions. Dont the knock sensors detect predetination/ignition? How can they detect a bad bearing type knock? Maybe im reading the first post wrong but I Think youre implying that since your not getting a code then it shouldnt be the rods? trying not to sound like a smart ass here...Im far from knowing your reason...just trying to learn.

Everytime supraguy31 had any material what so ever removed from his crank he developed rod knock. it happened at least 2 times before we made sure he got a perfect crank.

Is that what happened here? to much material removed from the crank?

First off, yes, detonation can be detected but usually only sets small levels on knock readings....anywhere from 0-60hz or so in my experience. However they also detect rod knock, its just a much higher frequency level, in my case 48hz idle and 100hz+ any throttle. Its mostly a constant Hz reading at constant throttle and goes up dramatically the more you step on the pedal.

My point about throwing no CELs was that the knock isn't THAT bad yet compared to someone who spun a bearing lets say.

My crank was NOT cut, it was micropolished which smooths the surface by removing very very little material.

If your friend had rod knock twice from cutting crank then he most likely has trouble measuring proper clearances per TSRM

 

[ForcedTorque]

Since we are all learning here........How are you getting these reading (48 hz, 100hz)? I'm assuming that has absolutely nothing to do with checking your codes. What did you use for that?

 

[jdub]

Clevite are repackaged NDC bearings...they are what I use. If you can find NDC bearings, they will likely be a bit cheaper and just as good.

You should be able to reuse ARP rod bolts...measuring overall length to make sure they were not over stretched is a good idea. Take a look at this (Proper Rod Bolt Stretch): http://www.arp-bolts.com/Tech/TechInstall.html
Make particular note of this statement:

If any of the rod bolts have taken a permanent set and have stretched by .001˝ or longer you should replace the fastener IMMEDIATELY! The stretching is a sure indicator that the bolt has been compromised and taken past its yield point.

The knock sensor's highest voltage output is at 7 KHz...they will not set a code if they detect knock, the ECU retards timing in response to knock detection. Code 52 is due to a bad circuit or bad sensor.

I was going to suggest making sure it's the rods. Check your crank damper (pulley) bolt and make sure it's not loose. Get a metal rod or a long screw driver and touch the block/accessories while holding to your ear (a mechanic's stethoscope is better)...listen for where the noise is greatest while running the motor. The valve train can make tapping noise too.

If it is a rod, I would suggest it get trailered to the shop...if you have a failure enroute, it will FUBAR the motor and it's likely the owner will not cover it.

Is that what happened here? to much material removed from the crank?

Wrong size bearings, cutting the crank more than 10 thou and not re-hardening the journals, not re-sizing the rods...