Rod knock

B

B-man

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Dec 12, 2006
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Ok guy's , I have hurt my baby and I am polling for suggestions
Just did a re-build on the engine and have followed the break in "rules" and am now having rod nock
what are my options? pull it apart and replace all the main and connecting rod bearings ? or do I have to start from scratch with the machine shop?
I talked to my machinest and he said to try running 10W 40 but I think it's too late for all that. can I get away with changing out the berarings?

all the bearings are new and the wrist pin bearings are also new. Flaw on my part , not having the fireing order rite on inital startup and the oil was fouled with gasoline = bad for bearings

I figure is better to shut her down now and fix it on the fresh engine rather than throw a rod any thoughts?
 
Rennat

Rennat

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Dec 6, 2005
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did you assemble the engine with just oil or lube? and who did all of the work?
check your bearing clearances with plastigauge? also do you trust the machine shop that did the work?
 
JDMDrift

JDMDrift

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Jun 15, 2008
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The machine shop that did the work did they warranty anything they did?
If you assembled the motor I would check a ll clearances as you take things apart and document it all to make sure where something went wrong.
 
S

suprahabsfan

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Sep 28, 2007
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B-man;1053694 said:
Ok guy's , I have hurt my baby and I am polling for suggestions
Just did a re-build on the engine and have followed the break in "rules" and am now having rod nock
what are my options? pull it apart and replace all the main and connecting rod bearings ? or do I have to start from scratch with the machine shop?
I talked to my machinest and he said to try running 10W 40 but I think it's too late for all that. can I get away with changing out the berarings?

all the bearings are new and the wrist pin bearings are also new. Flaw on my part , not having the fireing order rite on inital startup and the oil was fouled with gasoline = bad for bearings

I figure is better to shut her down now and fix it on the fresh engine rather than throw a rod any thoughts?
Click to expand...

Stop driving and fix it. No reason to damage your engine any further
 
B

B-man

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Dec 12, 2006
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thanks for the help guys , I put the engine togeather and trusted the machine shop for the math part. I dont think I put a rod in backwards but dumb things have happened like that lol. I used castrol GTX to assemble the engine as instructed by the machineshop. I dont think I have a leg to stand on as far as warrenty goes because I put it all togeather.

I will take it off the road and order some new bearings and replace them.
 
simpsons7s

simpsons7s

Its pronounced Nu-clear..
Oct 9, 2005
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I just had the exact same thing happen to me but on a wrx motor. machine shop put it together to the longblock and I finished it, they used assembly lube and I added castrol gtx just like they said. 270 miles later I'm sitting on the side of the freeway with rod knock, no warrenty, and now I don't know what to do. Fight with the machine shop? fuc it and get a new shortblock from the dealer or try rebuilding it?
 
FullNelson

FullNelson

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Sep 17, 2007
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simpsons7s;1055056 said:
I just had the exact same thing happen to me but on a wrx motor. machine shop put it together to the longblock and I finished it, they used assembly lube and I added castrol gtx just like they said. 270 miles later I'm sitting on the side of the freeway with rod knock, no warrenty, and now I don't know what to do. Fight with the machine shop? fuc it and get a new shortblock from the dealer or try rebuilding it?
Click to expand...

If i were in your shoes and i just spend how ever many thousands of dollars on a motor that should be running for the next hundred thousand miles, i would be bitching up a storm. No way would i pay for another block.
 
B

B-man

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suprarx7nut;1054841 said:
I dont think the use of gtx was the downfall here...
Click to expand...

Thankyou , I dont think that assy lube would have made a difference either.
The engine is lubricated by engine oil so why not build it with engine oil ? Thats what I have alwayse been tought.

I have not had time to check into this but I have one possablity that could be causing my problem. I had to change the CPS O ring because it wasnt done when I built the engine , my bad.

So that being said I may by slight chance have put the CPS in a tooth off. But I marked it before I took it out on TDC on #1 cyl and put it back in the same position...........

So this could........ be a detonation problem , but wouldnt I get a code from the nkoc sensors???
I will re check my timing on the weekend and go from there.
 
JDMDrift

JDMDrift

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That Lube is pretty important I mean it lets everything go together well when you start the engine the Oil hasn't seen any parts yet and it takes a sec for it to get ( acquainted ) to the new parts, iv' always used the lube and found it to be the best way, i would bring the motor back to the shop now* and tell them your problems if you truly find out there is a huge * or small * problem with your motor.
 
FullNelson

FullNelson

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Sep 17, 2007
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B-man;1056654 said:
Thankyou , I dont think that assy lube would have made a difference either.
The engine is lubricated by engine oil so why not build it with engine oil ? Thats what I have alwayse been tought.

I have not had time to check into this but I have one possablity that could be causing my problem. I had to change the CPS O ring because it wasnt done when I built the engine , my bad.

So that being said I may by slight chance have put the CPS in a tooth off. But I marked it before I took it out on TDC on #1 cyl and put it back in the same position...........

So this could........ be a detonation problem , but wouldnt I get a code from the nkoc sensors???
I will re check my timing on the weekend and go from there.
Click to expand...

I woudlnt think it would be your timing. If that were the case the car either wouldnt start or if it did it would run very rough. Usually rod knock is very pronounced and is present during all RPMs. Where as I would think detonation would only occur at near to WOT conditions. I could be wrong on that though.
 
simpsons7s

simpsons7s

Its pronounced Nu-clear..
Oct 9, 2005
253
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Riverside, Ca.
I don't think Castrol was the problem either I am sure it is a machine shop error. I won't know on mine till I get enough time to pull it again. Good luck with yours, I don't think that it being a tooth off would kill it unless you where doing WOT pulls, even then you would run like crap enough that you would back off it.
 
jdub

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
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Feb 10, 2006
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B-man;1056654 said:
So this could........ be a detonation problem , but wouldnt I get a code from the nkoc sensors???
I will re check my timing on the weekend and go from there.
Click to expand...


A code 52 indicates a problem with the knock sensors or it's circuit...i.e. some sort of failure with either. Knock itself will not trip the code. You kinda have to look at the knock sensors as an "explosion detector"...by the time they have a chance to transmit to the ECU and the ECU to pull timing, it's too late.

It's unlikely detonation will cause rod knock (unless it's severe)...burned piston or valves is a different story.

BTW - assembly lube is just a form of light grease. It is better because it stays put until oil gets a chance to flow to the parts where it's needed. Using motor oil is fine too, you just need to make sure the motor doesn't sit too long and allow the oil to seep away. Pulling the EFI fuse and turning the motor over with no spark plugs installed will get oil to where counts before you run the motor for the 1st time.
 
a_sesshoumaru

a_sesshoumaru

Suprita
Jan 7, 2007
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everytime i have put an engine together i just put some oil in the bearins and cylinders and when is time for the first start i unplug the coils and crank it for almost a minute, at least that way as was told to do it. I had a similar problem like six months ago, i did everything the right way and 100 miles later i started to hear rod knock, take the engine out and it was piston slap not rod knock, definitely machine shop fault`s cause they bored my block
 
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