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

[IJ.]

"Blew out a front seal" WTF?

Unless the Motor has horrible blowby or some idiot Cletus PCV mod this should never happen in a 7M as none of the seals are under Pump pressure... :nono:

 

[IwantMKIII]

"Blew out a front seal" WTF?

Unless the Motor has horrible blowby or some idiot Cletus PCV mod this should never happen in a 7M as none of the seals are under Pump pressure... :nono:

it did (with no PCV mod)....the mechanic was surprised too, it actually happened during a boost leak test (at about 14psi)...air creeped into the crank case and popped right out...didn't know what that 'popping' noise was until it was too late...

 

[IwantMKIII]

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?

You can monitor frequency outputs via SAFCII...i always keep an eye on it

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:


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.

Unfortunately i cant make it to the shop. Its 350 miles away...i have to do this on my own time :nono:

I will attempt the listening method most likely tomorrow, im losing light quick now. Its coming from the front of the engine, cylander 1 and 2. The mechanic said that's no surprise since they are the last to get oil apparently. Valve tap is almost non existant as the head was rebuilt with the engine :icon_bigg

I'm currently using Federal bearings....ever heard of them? The guy who races 7m's i guess uses them and changes them yearly.

 

[jdub]

Never used Federal bearings...IJ might chime in on them.

Oil feeds from the filter to a channel running the length of the block...the channel filter inlet is between the #2 & #3 cylinders. This channel feeds the squirters and main bearings...oil from the mains feeds holes in the crank, which in turn feeds the rod bearings.

The #1 & #2 bearings are actually closer to the filter inlet feed...#6 is the most distance from the source (filter).

One other thing...if you yank the bottom end apart, replace the squirter bolts and clean the nozzles well. The squirter bolts are basically a controlled leak. They have a ball/spring valve inside that should actuate at ~40 psi keeping pressure up to the main/rod bearings. These valve springs get worn and/or crudded up...if one or more is stuck open or opens early, it will affect pressure going to the respective bearings.

 

[IwantMKIII]

Never used Federal bearings...IJ might chime in on them.

Oil feeds from the filter to a channel running the length of the block...the channel inlet is between the #2 & #3 cylinders. This channel feeds the squirters and main bearings...oil from the mains feeds holes in the crank, which in turn feeds the rod bearings.

The #1 & #2 bearings are actually closer to the feed channel...#6 is the most distance from the source (filter).

see i thought #6 was the last to get the oil....i didn't really expect him to remember something like that off the top of his head though and be 100% accurate

 

[SPD TRP]

You can monitor frequency outputs via SAFCII...i always keep an eye on it



How are you doing this with an afc.

I have mine monitoring Vf, but didn't know I may be able to monitor knock.

Could you clue some of us in?

Thanks

Wayne

 

[IwantMKIII]

You can monitor frequency outputs via SAFCII...i always keep an eye on it



How are you doing this with an afc.

I have mine monitoring Vf, but didn't know I may be able to monitor knock.

Could you clue some of us in?

Thanks

Wayne

you can monitor 4 channels. i do thrtl, RPM, fuel adjust. and knock readings but you can select whatever you want...its notdifficult to figure out

 

[Rennat]

if you were leaking that 14psi into the oil pan wouldnt that mean your rings never set in?
And if the race shop builds supra motors, i dont see why he just didnt cut the crank and set the proper oil clearance. what was the condition of the crank before the rebuild? rod knock?

To me it just sounds like a lemon rebuild... and im really sorry to say that, because i know its the most frustrating thing in the world to happen.....

and just once running low on oil could have been your cause. although i've overheated my motor i think 2 or 3 times now.... and i have no bhg. hahaha

 

[Clueless]

what do I need to do to fix a spun bearing?

 

[Rennat]

thats a broad question.
resize the rod, or get a different one.
i would just cut the crank to whatever would make all of the nastyness go away, either .10 or .20. and then get new bearings, shim the oil pump 5-8mm, and do a bunch of other stuff...

 

[IwantMKIII]

if you were leaking that 14psi into the oil pan wouldnt that mean your rings never set in?And if the race shop builds supra motors, i dont see why he just didnt cut the crank and set the proper oil clearance. what was the condition of the crank before the rebuild? rod knock?

To me it just sounds like a lemon rebuild... and im really sorry to say that, because i know its the most frustrating thing in the world to happen.....

and just once running low on oil could have been your cause. although i've overheated my motor i think 2 or 3 times now.... and i have no bhg. hahaha

Well if you think about it, there is still space between teh cylander and the wall or the piston couldn' t move so air getting by. Then multiply that space times 6 on a boost test, and leave the air in there long enough to seep and it isnt the end of the world if it gets by

 

[jdub]

thats a broad question.
resize the rod, or get a different one.
i would just cut the crank to whatever would make all of the nastyness go away, either .10 or .20. and then get new bearings, shim the oil pump 5-8mm, and do a bunch of other stuff...

Rods need to be resized on a rebuild...period. Orginals or not.

Cut the crank journals over .010" (10 thou) and it will need to be rehardened (Nitrated).

Bearings have to be fit to the cut crank journals to proper undersize, rods resized to provide proper clearance.

Shimming the pump is not required, but is a good idea. Nothing to do with fixing a spun bearing...easy to do though while the pan is off.

Well if you think about it, there is still space between teh cylander and the wall or the piston couldn' t move so air getting by. Then multiply that space times 6 on a boost test, and leave the air in there long enough to seep and it isnt the end of the world if it gets by

Still shouldn't have happened...crankcase pressure is vented to the valve covers (behind alternator), then out the PCV fittings on top. Even air seeping past the rings should have had no problem escaping. Something is amiss here

 

[IwantMKIII]

well im heading out today to try to target the problem. someone suggested to simply remove the sparkplugs one by one and listen for the knock to quiet down significantly......makes sense to me, anyone ever try this method?

 

[jdub]

Yep...doing the same thing using the injector clips is a better option IMO. Less chance of getting a good jolt

 

[IwantMKIII]

Yep...doing the same thing using the injector clips is a better option IMO. Less chance of getting a good jolt

Well removing spark plugs didn't make any difference actually.

I took a couple vids.


This was taken after engine was running about 5 minutes, coolant temps didnt even hit 120 yet. Its steady here. I find the knock to be loudest towards the head actually, but i havnt been able to get underneath the car yet

[youtube]1e6yj0WsOUo[/youtube]


Heres the next. It was taken almost at Op temps (about 160* coolant temps). Take notice the knock is now intermitten sound wise. Given it should get quieter as it gets warmer but intermitten comes off as strange to me?

[youtube]-lvrCUEOVcI[/youtube]

 

[IwantMKIII]

i just can't win.......now im throwing code 12 sothe car won't start

edit: nvm...fixed it along with my high idle i've had since the rebuild

 

[jdub]

I hate listening to vids...it's just too hard to tell. Not your fault, but to be honest, I don't want to say one way or the other...I know that doesn't help, but :dunno:
If I was in your neck of the woods, I'd come over

Makes me wonder since the sound did not diminish when you pulled the plug wires.

In any case, rod knock will be very obvious if you listen to the block with a metal rod to your ear...like I said, a stethoscope is better. The sound will come loudest from the block in the area of the bad bearing.

Did you check the crank bolt?

What kind of cam gears do you have and are they torqued down tight?

 

[IJ.]

Auto or manual?
(too lazy to backtrack and check)

 

[jdub]

Pretty sure he's manual Ian.

 

[IwantMKIII]

I hate listening to vids...it's just too hard to tell. Not your fault, but to be honest, I don't want to say one way or the other...I know that doesn't help, but :dunno:
If I was in your neck of the woods, I'd come over

Makes me wonder since the sound did not diminish when you pulled the plug wires.

In any case, rod knock will be very obvious if you listen to the block with a metal rod to your ear...like I said, a stethoscope is better. The sound will come loudest from the block in the area of the bad bearing.

Did you check the crank bolt?

What kind of cam gears do you have and are they torqued down tight?

yeah, sorry SQ kinda sucks buts its all i could do. When i removed a plug, the knock actually got a little louder probably b/c of the idle speed slowing down so its easier to pick out?

if i can get a hand on a stethoscope i will do....i just don't have a metal rod handy that would be long enough right now so thats on hold as well

Out of curiousity....lets say the crank bolt was loose, why would it cause a knock noise???? sliding back and forth hitting the bolt?

off the top of my head i believe they are OBX. they were torqued to 36ft-lbs? i believe that's what spec was....ill check again if they are tight tomorrow as its dark now.