Ok where to start. I have an ap1 with 141k on it. I recently bought it from a friend. The engine had died on him one day when he was driving. He pulled the valve cover and found that the intake cam had been starved of oil and chewed through the cam tower. He didn't have the time or motivation to fix it so I bought it from him. I cleaned everything up and pulled the oil pan to check for metal and pulled the oil filter apart. Neither had any metal so I got a replacement set of cams and cam towers. The car started and ran just fine. But it only lasted about three weeks of daily driving and it happened again. Intake cam starved of oil and chewed up the cam tower. This time I also noticed the timing idler gear collar and washer were chewed up. So replaced those and another set of cam and cam towers. This only lasted two days before it did it again.

So my engine has now chewed through three sets of intake cams. Each time there were different after effects. Here's what everything looked like after

1st time- don't know how tight the cam cap bolts were because friend had removed them. Several cam caps were cracked. Bolt holding timing gear on cam was tight

2nd time- three cam cap bolts were finger loose, particularly the two over the oil port cam cap. No cracked cam caps. Bolt holding timing gear was finger loose and the key way pin sheared

3rd time- no loose cam cap bolts. One cracked cam cap. Bolt holding timing gear was finger loose. Key way pin sheared

All three times it was the intake cam with no damage to exhaust cams. I'm at a complete loss as to how fix this. My first guess would be the loose bolt for the timing gear. But that didnt happen the first time. Any help would be appreciated.

 

I always thought the rocker arm assembly and cam caps must be bought as a complete set as they are line bored as a set. If you are mixing cam caps and rocker arm assemblies they won't necessarily work together. The other thing is that a loose idler gear bolt will destroy the top end every time if it isn't tightened properly (maybe that is what started the process the first time). Torque values and torque sequence of the bolts is critical when assembling the top end. Lastly, the oiling system could be blocked on the top end causing a starvation issue, check the vtec solenoid screen for any metal shavings.

 

Had the same thing happen to my original motor (f20c) at 195k. Timing gear was loose too. Never inspected further just replaced with a f22. The only thing I had done recently was tried to reseal the vtec solenoid with silicone, so I blamed that for blocking the tiny oil feed to the head.

Im interested in seeing if you figure it out.

 

I believe one of the theories from billman when I posted mine was possible crank walk and/or dropped thrust washer. You said you pulled the pan so you would have noticed one of those. Also no metal though. Hmm.

Heres a pic of mine.

 

Yeah I know not to mix the top and bottom halves. Lol. The ones I replaced with are from the same set. Besides both were destroyed. Mine look like AE_Racers picture. Also I torqued everything down the way its supposed to. It even happened after replacing the idler gear with a new one. I never thought about the vtec solinoid. But my understanding is its fed by a different oil port.

 

Also yeah the other reason I pulled the pan was to check for the thrust washer but it was fine.

 

There was a great thread with pics of the oil port but the pics arent working atleast for me.

https://www.s2ki.com/s2000/topic/875...30-weight-oil/

The oil feed to the head goes through the vtec solenoid.

 

Interesting. The pics didn't work for me either. But you learn something new everyday. I'll take a look at my VTEC solenoid after school. I also use Mobil 1 10w30 if that makes any difference.

 

No chance that the portion of the head where the intake cam lies, is warped? Cam turned freely, with rocker arms not in head?

 

I don't believe its warped. It's definitely an oil starvation issue