Cam Sprocket won't Reach!!

[viparz]

Hey guys,

I put my new head on, the rockers and then the cam, torqued it all down correctly and now when I put the timing chain over the camsahft sprocket it will not reach the dowel joint (comes up about 6mm short)

For some reason my TDC mark actually shows TDC at cyl 6, while #1 is at the top of the exhaust stroke. The car was running perfectly before it blew a head gasket, I wedged the timing chain, marked the sprocket position in relation to the chain.

I cannot think of anything that would have caused this other than dropping a link over the crank sprocket, but I wedged everything..............

HELP, I dont know what esle to try before I pull the timing cover off.

[Jeff G 78]

If it's that short, your chain wasn't wedged properly. The tensioner might not have popped all the way out though, so if you are lucky, you might be able to re-align the tensioner. Shine a flashlight down next to the wedge and see if you can tell if the tensioner is slightly out of place. A small mirror on a handle might help see what's going on down there. The tensioner has to be fully seated before the sprocket will slide on. You can reposition it with a long skinny screwdriver and a lot of patience. Good luck and don't feel bad. We've ALL been in your shoes at one time or another. The good news is that it probably won't happen to you again once you learn exactly how it all works.

[Pir0San]

drop your oil pump, and shine a flashlight up into the timing cover, and see if the tensioner has popped out. Unless you wedge it just right, it will pop right out. Sometimes if you are lucky, you can push the tensioner back in with a long screwdriver via the oil pump hole. Good luck!

[zack_280]

If the tensioner did come out you should have heard a 'pop' sound when you first pulled the sprocket. If it is the tensioner, I would expect that you will have to take off the timing cover. Good luck.

PS This has happened to me too and I wasted my time trying to 'realign' the tensioner. Once it's out, it will be extremely difficult to get back in.

[viparz]

So I spent a day trying to jigg the tensioner back into place and thought I got close......but no cigar. So the timing cover is coming off........I needed an oil change anyway.

Thanks for your help guys. Your knowledge is invaluable.

[Ramses]

That sinks. I did that to a '72 twenty years ago before I knew anything about cars. It was not fun.

[Jeff G 78]

Sorry to hear that you couldn't wiggle it back on. While you have the cover off, you can fine tune your wedge design. Try it out before you put the cover back on so you know exactly how to wedge it next time. Removing the cover really isn't that bad to do. It's annoying that you have to do extra work, but it's a pretty straight forward job. Don't forget to install new gaskets and a new front main seal while you're in there.

[viparz]

having never been inside a timing cover before I am a little confused as to what exactly a front main seal does.........as in where does it fit etc.

Once again thanks for your help.

[JimmyZ]

It's the seal that wraps around crank snout. When you get the crank pulley off you'll see it. Make sure that you install the new one using something flat so that it goes in straight. (Block of wood etc) It is easier to install the new seal with the front cover off the car.

Make sure that the front cover and corresponding area on the block has all old gasket material removed. They make a spray gasket remover which helps. It's important that the sealing faces be clean or water and oil passages may leak.

My2c

Jim

[VaGuS510]

Didn't Nissan make a tensioner that wouldn't fall out. Or was that an aftermarket piece. I have had this happen to me a few times before, it really sucks. When I build my engine I hope to devise a way to prevent the tensioner from falling out. Not that I plan on removing the head, but it will make it much easier if I have to remove the head. Good luck.

[viparz]

Does anyone have a photo of a front main seal that they could post. I am unable to access the car right now and am trying to buy up all the parts I will need. A photo would help to avoid me buying the wrong part.

Thanks

[2003z]

Does anyone have a photo of a front main seal that they could post. I am unable to access the car right now and am trying to buy up all the parts I will need. A photo would help to avoid me buying the wrong part.

Thanks

here you go. its the black rubber/plastic ring in the hole on the right side of this picture.