Quest for Timing Chain Rattle, part Three

[misnomer]

OK, I've pulled off the valve cover and upper timing cover. The rattling seems to be the chain against the guide opposite the tensioner. Now to figure out what to do about it, and what to replace. . .

The upper timing chain itself seems to be in good condition, no noticeable wear. The motor has 150k miles on it, I bought it at 107k, but dunno if the timing chain was done before I bought her. It seems that way, I'd expect a 150k mile old chain to be more worn :P

Anyhow, I'm mainly looking at what I should replace to solve my rattle. I assume the upper tensioner. Can't find a part at CourtesyParts for the guide on the other side, though I figure I'll replace that as well. The upper guide has been gone for a year.

While I'm this far, do y'all figure I should drain the coolant and pull the lower timing cover as well?

Either way, I need to consult my service manual :-) (gotta find out timing for when I put the distributor back on as well).

If there is enough interest, I'll do a writup of the process.

Cliff notes (for you lazy sons of bitches out there):
-What to replace while I've got the front upper timing cover off

[96SEChick]

I'm not sure how to get to everything, but I have read and the dealership here told me that the upper guide is not even needed--so they don't even put it back on when doing a timing chain job--and that the upper guide in particular is the one that starts making the noise (well, the guide doesn't make the noice, but you now what I mean).

My problem was a little more complex--my lower guide (it's about 6" long) had began to chip away (it was missing a 2" chunk out one of the edges at only 75k miles-- ). The dealership said they hadn't seen one do that before, so I wouldn't think that's the issue w/ your car.

I think a write-up would be great--a lot of people are learning more about this issue w/ the KA, and it would definitely be an extremely useful FAQ thread. But, only if you've got the time and energy to do it

Good luck!!

[240Driver39]

there is a lot of info if u do a search here and FA. Trust me, i read a lot b4 i went ahead and removed the 2 guides for the upper chain. i can dig up links to those if u want, a lot of good info in em.

these are off my car:

lower guide for the upper chain
upper guide that u said u removed already

u can see the wear in each

(links arent workin, i have these if u care to see, IM me at s13driver39)

heres a good link:

timing chain guides

there are few more i could dig up, plus ive already removed my lower guide for the upper chain and have had no problems and can help out with that.

[misnomer]

Lauren: My lower guides, from what I can se, are in good shape. The problem seems to be slack on the upper chain allowing it to rattle on the lower guide.

Excellent link on FA, though they did confuse the motors a couple of times (no plastic guides on the DOHCs). I tend to take forum posts with a grain of salt unless I know the poster, anybody else know for sure that the tensioners are driven by oil pressure? Somebody on FA kept talking about a spring. . . The tensioners themselves move OK, if they're driven by oil pressure, I can't imagine they'd be the problem. Maybe it's time to hook up a bona-fide oil pressure guage :-)

I could understand how that could be the problem, the oil pump is powered off the crank, so the faster the motor spins, the faster the pump spins, the higher the pressure. Less pressure at idle, less pressure to drive the piston on the tensioner, more slack in the chain, rattle rattle. Then again, maybe I'm just cheap and would rather get away with removing the lower guide :-)

I'll try to get ahold of a digital camera and snag some pictures to do a writeup. In the meantime (can't work on the car till Thursday), I need to teach myself how to adjust the timing. I'll be sure to include in the writeup "MARK THE POSITION OF THE ROTOR!!!"

[240Driver39]

Yeah, u just got to weave through the different motors, but there are a few specifically good posts in there.

i believe the lower guide and the upper guide are parts that are niot replaced. They have been removed from the parts books due to that fact, this is just my understanding.

i have had both guides removed and no sound since, i have had absolutely no problems also since. bout 6k later.

YES MARK THE DISTRIBUTOR! lol, technically if u are careful about how u do it and mark it, u will not have ne timing issues, but it would be a good idea to know how as a backup, trust me, a guy on another board didnt and it was quite difficult tryin to explain it to him.

and yeah, they are driven off oil pressure, if u look at the fsm, u can see the oil passages, including one to the tensioners, almost sure i read that the other day.

like i said, if ya want i have pics of my two guides off the upper chain, u can see the wear, i can show em to ya if u want.

[deviousKA]

all of your timing guides should be replaced now while you have it apart. i would suggest a whole timing kit from ITM gaskets. this is not an expensive kit and one of the best in my opinion ( ive used a lot of brands) the chain guide on stock ka is plastic and very prone to cracking possibly sending a chunk of plastic into the gear, skipping the chain. valves are really expensive and if this happens you will crash them into the pistons. imo it is best to replace all of those parts you will save money and headaches

[deviousKA]

ok correction. im not sure if dohc ka had plastic guide. im sure that nissan would have upgraded the part. i would still opt for new timing set anyway

[misnomer]

Devious: The DOHC uses metal guides. The upper one DOES tend to break. Mine did, and was (luckily) just sitting on top of the chain, causing a fearsome racket. I didn't even pull out the bottom part which is still bolted to the head :P

I'll see if I can come up with a basic explanation of timing (for the spark plugs) and include that in the write-up

[96SEChick]

Originally posted by misnomer
Devious: The DOHC uses metal guides.

Too bad I just threw away the old parts from my warranty work from last March--seriously I just threw it away about a month ago while cleaning the garage. The guides that they took from my car were plastic! Very odd.............

[YellwMonky]

How loud is the rattle when your guides are going? My car isn't VERY loud at idle, but it doesn't sound good. When I'm driving it seems to go away, but when it's idling it's ugly. I was thinking of going in and taking off the upper guide. There's absolutely no need for it...? why is it there then..?

[misnomer]

It was there originally as a safety backup, incase the tensioner went out. It has become a problem, though, as it tends to crack and completely snap off of it's mounts. The danger of it snapping and damaging the valves seems to preclude it's use as a failsafe, so it is deleted. OUT WITH IT!

Lauren: very odd indeed. My upper guide (and lower upper guide, damn this is getting confusing) are both metal. Mayhaps they had been replaced when the car had it's 100k timing belt job before I bought it. . . Anyhow, out with them too!

I think I've got the timing issue taken care of. According to my FSM, sparks at tdc, thus I set the #1 piston at TDC by the crank pulley, and find the rotor spot for spark at #1 cylinder at that point, then adjust with the timing light. Excellent.

[240Driver39]

haha, yeah, always have to mention which chain u are talkin about.

thats being said, 96SEchick, which guides did u say were plastic? the ones for the upper chain or the ones that had to be replaced on the lower chain?

im not positive about the material for the guides on the lower chain.

the guides for the upper chain are metal brackets with a plastic material on the actual guide surface. This how the guides are on all the dohc cars ive read about and mine personally

just to clarify so people readn this dont get confused.

dohc has 2 chains, upper chain and lower chain. in no way are the guides for the lower chain to be removed and not replaced, that jsut wouldnt work at all haha, if u look at the diagrams. But there are also 2 guides for the UPPER chain. a guide on the top and one to the right, these can be removed like i and misnomer have said.


and the noise isnt terribly loud, but definately noticeable, like a marbly sound at the front of the vc.