Bad noise comming from valve cover.

[grantf]

Removed the Crank pully, AC pump bracket, lower coolent inlet and water pump. Water pump looks good. Front crank seal was leaking so fixing that will be a bonus.

The front cover is off. Take a look at this:

[tlorber]

That seems like a pretty severe angle at which the chain hits the tensioner. Is that normal?

[olzed]

The tensioner looks like it's close to popping out, if not already out.

Are the wear strips worn out?

[grantf]

Yes the guides are way worn. It's academis at this point. A new timing set is on order. I think that removing the cover was the right thing to do, albeit a lot more work than I thought. A bright note: the gasket for the oil pan and head are in good condition after removing the front cover

A sad note: the front cover has a small hole in the bottom with two cracks emenating from it. I am taking the cover to my coworker to see if he can weld it. He has welded cast aluminium many times for us. If not it looks like Nissan still has them for about $175.00.

Or anyone here that could help that has a spare front cover in there pants pocket?

[siteunseen]

Like Slim Pickens said in Blazing Saddles "Dang that was close. Almost lost a hundred dollar hand cart".

[Lazeum]

If you haven't touched the cam sproket, your chain is defenitely way too loose.

When you rebuild the chain mechanism, the gap between the tensioner and its housing should be 0mm. So yours is out of specs.

Check the chain guides and see if they haven't slipped. The top bolt on the guide next to the tensionner is used to adjust tension also.

The noise you've experienced could very well come from the dramatic angle the chain is having agaisnt the tensioner.

Your cam timing is probably also way off (check notches on cam sproket) if it is only the chain which is creating such lash.

If I were you, I would at least check at autostore if they haven't some front cover gaskets. Yours look like it could be reused but I would take the opportunity to change it "while I'm at it"

and regarding front cover, I would be surprized if nobody from the state would have a spare one. I even found one in Europe (you could very well put some JB weld also but it is not such a clean solution)

[mjr45]

When I was replacing the head on mine, I didn't have the chain properly tensioned and had to remove the front cover, not to hard, but it was on a stand, replaced the chain, tensioner and guides. Gives you a little piece of mind that everything is new and hopefully won't need doing again anytime soon. Just be careful when putting the cover back on not to pinch or fold up the head gasket.

[emptech]

On one of my older engines, my chain tensioner stuck out like that, it was because I had so much milled of the head, the

chain got loose. So that the tensioner wouldn't pop out, I machined an extension for it, ran for years, not because of

worn chain guides. I cooked the engine one time, warped the head real bad, had to shave both surfaces of the head,

decreasing the distance between the two sprockets. Don't recall from the thread, did you have the head shaved?

Eventually I bought a new head and all dimensions came back to normal and I was able to go back to the proper tensioner.

Of course, a stretched chain would do that too.

If I recall, it is pretty much a straight shot from the lower sprocket to the cam sprocket on the "pulling" side, whereas

the tensioner simply takes up slack. Would seem to me that a lot of the plastic would have to be missing to cause such

a problem.

Jim

[madkaw]

Good catch. Just replace everything like you said. I imagine with new chain and tensioner the tensioner will be back in it's place. Check your FSM for the proper placement of your guides.

I agree with the statement about your valve timing- this should make your engine run different and probably better.

You can find timing covers used pretty cheap on these forums, winding spend much money trying to fix that one.

[grantf]

Not much to do until the new timing set arrives. I did find a used cover on ebay for $200.00. What a joke I could get a new one for 175 from courtesy Nissan.

Anyhow I gave the cover to my machinist coworker, he will weld it up for me this weekend for $0.00. He does great work. He has even machined aircraft parts for my brother.

I have read up in the FSM in regards to installing the new set and I have viewed Blue's write up also (thanks again Blue).Looks pretty straight forward.

One question: Anything special about removing the crank sprocket?

If I were you, I would at least check at autostore if they haven't some front cover gaskets. Yours look like it could be reused but I would take the opportunity to change it "while I'm at it"

you must be joking, the gasket is a goner. Even if it looked ok I would replace the gasket. New ones come with the kit anyhow.

Like Slim Pickens said in Blazing Saddles "Dang that was close. Almost lost a hundred dollar hand cart".

I love that movie.

Edited July 21, 2012 by grantf

[Lazeum]

you must be joking, the gasket is a goner. Even if it looked ok I would replace the gasket. New ones come with the kit anyhow.

My bad, I though you were saying you could save it . Since it is difficult with pictures to really tell if the gasket is in shape, I just provided a comment. Good to hear for sure it will be replaced.

[az240z]

If you need another cover let me know.