Another Rod Bearing Thread
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Changing bearings at 100k seems super excessive. Doing an oil analysis will tell you the approximate health of your bearings. Driving on track is something completely different, but I have buddies tracking their cars at 180k miles with good bearing health. It comes down to maintenance. If the car saw excessive oil temps, the bearings will wear faster than if not. You can track a car for hours and as long as oil temps stay low, the bearings should theoretically be fine. The worst time for bearings is on start-up when cold when there is no oil pressure. But oil quality and temperature is the key factor here.
If someone is tracking a car and seeing high temps constantly, the bearings will wear faster as the oil shears and stops lubricating as effectively. This is why an oil cooler is a great upgrade for people who track a lot. Also adding oil pressure and temp sensors/gauges as insurance helps a ton.
If someone is tracking a car and seeing high temps constantly, the bearings will wear faster as the oil shears and stops lubricating as effectively. This is why an oil cooler is a great upgrade for people who track a lot. Also adding oil pressure and temp sensors/gauges as insurance helps a ton.
I have always been sympathetic to the car on the track - Not going all the way to redline, only 1-2 hot laps, using expensive oils.
Without monitoring oil pressure and temps as you have suggested (and possibly an oil cooler?) we're guessing!
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From: Munich - Germany
Maybe the Oil jet bolts have failed and therefore Journal Nr. 4 runs with lower Oil pressure.
So far i have seen 3 sets of disassembled oil jet bolts - one from me - and in every set allways three Bolts have failed and one was O.K.
And it´s allways cylinder nr. 4 wich causes trouble. That´s a hint - A BIG ONE ! - in my opinion.
Something to read:
https://www.s2ki.com/forums/s2000-un...w-pics-102067/
https://www.s2ki.com/forums/s2000-un...bolts-1204068/
So far i have seen 3 sets of disassembled oil jet bolts - one from me - and in every set allways three Bolts have failed and one was O.K.
And it´s allways cylinder nr. 4 wich causes trouble. That´s a hint - A BIG ONE ! - in my opinion.
Something to read:
https://www.s2ki.com/forums/s2000-un...w-pics-102067/
https://www.s2ki.com/forums/s2000-un...bolts-1204068/
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Yes, they're accessible. The only issue is cylinder 1 where the oil pickup tube is kind of in the way. However, you can still get it in pretty easily with some patience.
I should probably get on this at this point but none of my friends have changed their bolts and are fine. I'm at 164k miles and my bearing health is optimal. Hell, I don't even think a lot of high-mileage owners know about this issue. It's worth doing on an early AP1 with the 2-hole bolts (swapping to the updated 4-hole bolts).
I should probably get on this at this point but none of my friends have changed their bolts and are fine. I'm at 164k miles and my bearing health is optimal. Hell, I don't even think a lot of high-mileage owners know about this issue. It's worth doing on an early AP1 with the 2-hole bolts (swapping to the updated 4-hole bolts).
Last edited by MaintenanceObsessed; Apr 14, 2026 at 10:33 AM.
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From: Munich - Germany
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Thanks again!
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On a scale of 1-10, I'd rate this at like a 6 or 7. It's probably on par with a valve adjustment. Honestly, the hardest part will be removing the oil pan and torquing the bolts down properly. Follow the service manual and you'll be fine.
https://www.s2000.club/
Go there, download your version of the service manual, and follow the instructions.
https://www.s2000.club/
Go there, download your version of the service manual, and follow the instructions.
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Joined: May 2018
Posts: 1,563
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From: Munich - Germany
Just take your time, be carefull and use a real high quality torque wrench.
The oil jet bolts have a spring valve inside wich should close below 2 bar Oil pressure. I am pretty sure this was designed by the engineers to keep the Oil flow to all bearings sufficent and equal(!!) when the oil is hot and the engine idles.
In this working condition the oil is hot and thin, the Oil pressure is low. Thats is critical. More critical as driving on the Race track.
While the engine will not grenade instantly, i rather like to have non-broken, working oil jet bolts in the engine. And if it´s only for peace of mind.
The oil jet bolts have a spring valve inside wich should close below 2 bar Oil pressure. I am pretty sure this was designed by the engineers to keep the Oil flow to all bearings sufficent and equal(!!) when the oil is hot and the engine idles.
In this working condition the oil is hot and thin, the Oil pressure is low. Thats is critical. More critical as driving on the Race track.
While the engine will not grenade instantly, i rather like to have non-broken, working oil jet bolts in the engine. And if it´s only for peace of mind.
Joined: Aug 2012
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A saying I use often, be careful your preventative measures don't end up causing the very thing you were trying to prevent.
In this case, engine protection. Botched oil jet bolt install causes engine destruction, rather than prevent it.
It comes down to two things:
- working with oil dripping on you whole time
- that last bolt, getting it started without cross threading
Top tip, starting an awkward bolt, turn it backwards by hand until you feel first thread engage, then go fwd. Threads engage right away.
Thread engagement feel is when bolt kind drops into place.
In this case, engine protection. Botched oil jet bolt install causes engine destruction, rather than prevent it.
It comes down to two things:
- working with oil dripping on you whole time
- that last bolt, getting it started without cross threading
Top tip, starting an awkward bolt, turn it backwards by hand until you feel first thread engage, then go fwd. Threads engage right away.
Thread engagement feel is when bolt kind drops into place.