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Discussion Starter · #1 ·

So far have removed belt + tensioner (started car only for a short period) but still made the noise.

All heat shields have been removed. Pre-cats were in good condition checked previously then gutted them while i checked. Rocker cover seal changed and checked timing chain tension which seemed ok but i didnt spin it around, not sure if you need to to be 100%?

Looking through forums+youtube are pointing to all different potential issues. Thought id come to the forums with the noise before proceeding. What do you think??

It has been losing oil some how although no visible leaks or smoke coming from exhaust, oil level lower than id have liked it to be (probably about 2-2.5L when i drained tank excluding filter) when i dropped it out + refilled but oil light had not come on prior.
 

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My gut tells me rod knock, though I'd think it would stay the same after it warms up. Is the car from '00-'03? If so has it been burning oil or have you noticed the level too low at any point?
 

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Discussion Starter · #5 ·
My gut tells me rod knock, though I'd think it would stay the same after it warms up. Is the car from '00-'03? If so has it been burning oil or have you noticed the level too low at any point?
It is an 02 year car. It has been burning oil and i have had it not show on the dipstick. However the oil light didnt come come on. I drained the oil to confirm how much was in because i don't trust that dipstick and there was only about 2l left in the engine.
 

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It sure sounds like rod knock, though that usually gets louder with increasing engine temp. Assuming your tensioner is OK and the sound is actually coming from inside the engine, and since the knock doesn't go away with temp, I would still suspect a worn-out big-end bearing or 2. Before you tear into the bottom -end of the engine, or order a new one, I suggest these steps, in order:
1) remove the oil filter, cut it open and spread out the filter media inside. You should not see any metal bits or any silvery dust, If you do, you have your answer: rod bearings and possibly additional damage.
2) Check your valve clearances. this is supposed to be done roughly every 90K miles anyway. If some of the clearances are too big (out of spec) that will make noise and also put a lot of extra stress on the valvetrain. This can result in dropped valves or significant valve seat wear.
 

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Discussion Starter · #7 ·
It sure sounds like rod knock, though that usually gets louder with increasing engine temp. Assuming your tensioner is OK and the sound is actually coming from inside the engine, and since the knock doesn't go away with temp, I would still suspect a worn-out big-end bearing or 2. Before you tear into the bottom -end of the engine, or order a new one, I suggest these steps, in order:
1) remove the oil filter, cut it open and spread out the filter media inside. You should not see any metal bits or any silvery dust, If you do, you have your answer: rod bearings and possibly additional damage.
2) Check your valve clearances. this is supposed to be done roughly every 90K miles anyway. If some of the clearances are too big (out of spec) that will make noise and also put a lot of extra stress on the valvetrain. This can result in dropped valves or significant valve seat wear.
Thankyou for your words of wisdom i shall investigate this further!
 

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Do you have a mechanic stethoscope? This works wonders to pinpoint the source of the noise. Top end, lower end, side to side. Also I wouldn't hesitate too much to drop the lower oil pan and have a look-see. Also if you have a oil pressure gauge, put it on the oil pressure sender port and see what gives.
 

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Pull the plugs one at a time and see if the noise goes away. It will run rough but with zero compression the affected cylinder won't make nearly as much noise.
 

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Discussion Starter · #11 ·
So it turns out it was the rod bearings.
Wood Gas Metal Household hardware Auto part


Do you think that this journal is beyond saving? All other 3 are very smooth mirrored finish
Automotive lighting Gas Auto part Machine Bumper


Also might be a silly question (fairly new to this) but when you put top and bottom bearings in, are you only checking the clearance with plastigauge on one side or do you need to do top and bottom? Can you even do the top side?
 

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You can try new bearings and measure with plastigage. Put both bearing halves in and one little piece of plastigage under the cap and then install and torque to spec. Then remove.

the bearing surface looks scratched but not grooved. If the scratches are shallow you can polish them out in place with emery cloth.
 

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Discussion Starter · #13 ·
You can try new bearings and measure with plastigage. Put both bearing halves in and one little piece of plastigage under the cap and then install and torque to spec. Then remove.

the bearing surface looks scratched but not grooved. If the scratches are shallow you can polish them out in place with emery cloth.
Thankyou, i will give it a shot!
 

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Discussion Starter · #16 ·
you really want a mirror finish to assure long bearing life. There is special polishing film available for this purpose. Even 1000 grit wet/dry paper is not good enough.
Can you link me to this film or suggest any products please?
 

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So it turns out it was the rod bearings. View attachment 84449

Do you think that this journal is beyond saving? All other 3 are very smooth mirrored finish
View attachment 84450

Also might be a silly question (fairly new to this) but when you put top and bottom bearings in, are you only checking the clearance with plastigauge on one side or do you need to do top and bottom? Can you even do the top side?
Hard to be certan from a [photo, but that rod journal looks too far gone to be recovered by just polishing with emery cloth (andthe condition of the bearing inserts kind of confirm confirm that). It is quite likely though that a automotive machine shop could turn the crankshaft so that you could use undersized bearings. You might only have to go 0.0010" under - whatever it takes to clean it up good. I've done that with my British sports cars (never to the Spyder) and gotten many more satisfactory miles from them.
 

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Hard to be certan from a [photo, but that rod journal looks too far gone to be recovered by just polishing with emery cloth (andthe condition of the bearing inserts kind of confirm confirm that). It is quite likely though that a automotive machine shop could turn the crankshaft so that you could use undersized bearings. You might only have to go 0.0010" under - whatever it takes to clean it up good. I've done that with my British sports cars (never to the Spyder) and gotten many more satisfactory miles from them.
Just note, it is not emery cloth that you use for the initial cut, it is wet or dry paper. You can start with 400 grit, then 600, and then 1000. Then if you get the grooves out, you can try to polish with journal polishing strips. All of this is done wet.

Dave
 

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You can get emery cloth in those grits and use wet. It's nice because it is strong and flexible so it fits in well and doesn't tear as it gets soaked with water. I have used 400 to 650? to 1000 to 2000 all wet with good results. Don't use the 400 for long or the journal will end up too far under size. And don't use much pressure, loop it around and gently polish.
 
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