Broken bracket under valve cover...what's it for?

[Monkey87]

I was replacing a thermostat in my 95 240SX SE, all stock with the KA24DE, and when I cranked the car back up to make sure the thermostat was working, I heard a knocking under the valve cover. Popped the valve cover off and there was a metal bracket laying on top of the valves. It looked like it was broken off from the front of the head, right behind the timing gears. As far as I can tell, it was supposed to be right in between the cams. There aren't really any marks on it, but there is a small groove or lump at the bottom. If anyone can tell me what this is for and what may have caused it to break, please do. Thanks in advance.

[dickie]

can you take a picture of it please? maybe its your front timing chain guide?

[Monkey87]

I'm in class right now. Still have about an hour and a half left, but if I can get my camera to work I certainly will. It just looks like a square metal piece with a 90 degree angle in it. You have any idea what might cause it to break like that, other than just age? The car has 230k miles on it, but the drivetrain is still pretty strong. Either way, my RB20 is being released from customs this weekend, so I'm ******* STOKED!!!! Thanks for the help, man. I'll get that picture up here ASAP.

[dickie]

if it is your upper chain guide, which from your description it sounds like it is, it can get whacked by your chain if it has any slack in it, resulting in the problem you are now facing.

although its not technically necessary to keep it, the fact that it actually got hit hard enough to break off means you should consider replacing your timing chain and tensioners in the near future.

[leper421]

It definitely sounds like the upper timing chain guide. Nissan released a Technical Service Bulletin a few years back that said the top and side guide for the upper timing chain are not needed and should not be replaced when replacing the chains and tensioners. However, as d!ck stated, you should replace the chain and (most importantly) the tensioners. Once the tensioners go, the chain will start to eat away at a coolant passage in the lower timing cover, eventually dumping all your coolant into the oil pan.

[Monkey87]

Thanks for the info, guys, and sorry I couldn't get a pic up for you. My camera isn't working right, and I haven't had time to check the forums in a while. I did check the timing chain while I had the valve cover off, and it didn't have any slack in it, it was very taut and didn't appear to be damaged from what I could see. I just got word last week my engine is on it's way to me from Customs, so hopefully I will soon be stuffing an RB20DET under my hood. I still need to do a little more research before diving in, but I'm excited. Thanks guys!

[dgms240]

definately upper chain guide.... classic 240 prob. simple fix though. they wear out pretty easy from contact with the chain. i replaced mine at 130xxx miles.

[dickie]

definately upper chain guide.... classic 240 prob. simple fix though. they wear out pretty easy from contact with the chain. i replaced mine at 130xxx miles.

thanks?