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Going in for the big surgery tomorrow.. rod bearings replacement

18K views 98 replies 32 participants last post by  jamiepeers 
#1 ·
This is it. My beast has accumulated 128k miles recently and on a cold start i'm hearing what sounds like rod knock. ONLY on a cold start though. I've heard it before many many times but every time i would pop the hood to listen it sounded like it was my vanos. I cold started my car while it was parked next to a wall when i was leaving work and i heard the noise again but this time it sounded like the sound was coming from underneath my car. After a little bit the sound disappeared. When i got home i pulled into my garage and revved slowly but i couldn't hear any knocking.

Is it possible to have intermittent rod knock????? I always thought that once rod knock was present, it was always there.


Anyways, I'm scheduled to take the beast in tomorrow after work to get the rod bearings replaced. Qais over at South Bay Autohaus is the specialist i'm entrusting with the work. South Bay Autohaus - Hawthorne, CA
I was going to spend the money i've been saving on a super charger but i figure that a super charger kit is pretty useless without the car. I'll keep you guys posted.
 
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#52 ·
Qais hasn't called me back yet! still waiting on what he has to say. If it's an issue with my exhaust then thank god.. hopefully i'll find out in a few minutes.
 
#54 ·
UPDATE:


The first thing Qais said is that my the engine is flawless. He couldn't find a drop of oil :D i guess i do an okay job when i work on my car in the garage. The only thing is.. he couldn't listen to my engine on a cold start. He had one of his employees start my car and wait while he moved all of the other cars out of the way to put it on a lift. i asked him to keep it another night. hes going to start the car tmrw morning and then just listen. maybe it'll be an exhaust problem after all
 
#55 ·
It never made the noise when the car was at my mechanic. Mine only seemed to make the noise when the oil was cold (not really cold) or slightly warm. I wish I could remember exactly what the exhaust was banging on. It was something toward the front of the car, I believe.

Either way, good luck! I know I was scared to death thinking about chain guides and it turned out to be the exhaust. Thinking about where the sound is coming from when you are in the cabin, it only makes sense. I was blinded temporarily by paranoia.
 
#56 ·
Not to be gauche but how much is the estimated bill? I recently started mine really cold (well for Cali anyway probably in the low 30s F) and heard a new metallic knock that went away pretty quickly...

I am starting to be a bit more hesitant after spending literally thousands on PM items; considering the car is really only worth probably ten grand or so, but then again if i missed doing a couple grand worth of critical work which lunches the motor, its essentially scrap with nothing else even remotely as interesting out there to replace it with...

If i understand the work correctly, basically you are dropping the crankshaft right? Is this a good time to do piston rings, or if you want to get really silly pistons and rods?
 
#58 · (Edited)
Qais quoted me about $2100 to do the job.

There are 2 ways to change your rod bearings: 1) yank the motor out 2) drop the front sub frame and drop the oil pans to get to the rod bearings. The cost difference in labor between the 2 methods is ridiculous. :eek:
 
#57 ·
From my understanding, you don't drop the crankshaft. You drop the lower and upper oil pans, which will require lowering the front subframe. Then you loosen the rod caps to get at the rod bearings. For the mains, you might need to go deeper, but no one has documented main bearing failure just yet. It's not terribly complex, but you need someone in the trade who has the know how to do it right, which is so damn hard to find on S62 engines these days.
 
#60 ·
tws :D
 
#62 · (Edited)
This oil is way to thick for the car if not "tracked".The bearings have a certain clearance built from the factory and they build these motors tight being there n.a. with high compression.These and lot's motor's tend to starve on cold start up's using a thick oil like tws rather then the factory recommended 5w30 castrol.

The e60 m5,e49 m3,e92 m3 need this oil due to the high revving which leads to oil temps way to hot for a thinner type and cause thermal break down.Stick with the factory spec oil and change it every 5 k and do your regular maintenance to keep your M5 healthy.
 
#77 ·
I don't care what you use. You were saying DON'T use and were spouting other not trues, that is what I care about. People can make up there own minds on what to use. I just posted what took the engineering staff 3 years to accomplish over the marketing department. When you get a job as a M engineer you can change it back.
 
#80 ·
NOT ANOTHER OIL THREAD?!



still waiting on Qais to give me an update. i've called several times through the day but he's always too busy to talk :sad1:
 
#82 ·
UPDATE: Qais gave me a call and asked that i come down to his shop in the morning tomorrow. He said he can hear a faint knocking sound but he doesn't think its rod knock. Im gunna ask him to put the m5 up on a lift and have him check out my exhaust. Even if my rod bearings are fine there's still obviously something wrong when i can hear something knocking on every cold start.

Any other suggestions on what i should have him check out? i'm all ears.
 
#85 ·
Based on Op recent threads "help me spend $2000 quickly!" and "extra $1000 burning a hole in my pocko", I'm gonna guess the bearings were just fine. hiha
 
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#89 ·
my rod bearings were perfectly fine indeed :)

Sell me your dinan stuff? :cheers:
 
#90 ·
Yea Qais is definitely the man. Mighty5 you're not Joey (jowe) are you?
 
#93 ·
Qais found a small small exhaust leak and a bad power steering pump hiha
 
#95 ·
i haven't done it yet. the new pump has been sitting in my garage along with 10 or so other things i bought just waiting to be installed :sad2:
 
#97 ·
My cars not there anymore. I may be going in this weekend for some other things though..
 
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