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Blubaron66,
That is by far, the worst tensioner I've ever seen!!! I replaced my upper tensioner and I'm still hearing chain slap. I am getting ready to do the lower soon.

I have heard the lower guide wearing out is often the cause for the lower chain rubbing on the valve cover. As bad as your upper tensioner was, I am very curious as to what your lower tensioner, and especially what your lower guide looks like???




smj999smj,
I know you didn't say that, and I understood what you said just fine. What I'm saying is, if you felt like it, you could do the whole job using TDC 4 (which is actually 1 and 4, got it) and then at the end you could make sure the distributor was still pointing at 4. If you did it like that though, the cam gears mating marks would not be in the same position as the pictures I posted, so it would be a silly idea. I don't know why I even brought that up.

See that's what I was thinking too, if you spun the crank fast enough, and with all the inertia from the crankshaft weights, and pistons, you could bend a valve. It's not like the valves point strait down, they are angled, making it easier to bend the side closest to the piston.

Well at least I know to always turn the crank slowly, so I'm happy with the conversation :)
 

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Discussion Starter #22
Nice and shiny ! Timing marks lined up and all went together smooth...check out how dull the teeth on the smaller idler gear are.



New lower tensioners and gears...I thought I purchased a complete timing chain kit but I guess the exhaust cam gear, is not included.. Oh we'll I guess I will order one on Monday.

 

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NF Mod/Nissan Master Tech
2006 Pathfinder LE, 2003 Frontier SVE
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Looks like your exhaust cam gear is new. It's the intake cam sprocket, or "VTC spocket," that is usually not included in the sets. This is probably because the gear is over $500 from Nissan.
 

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You don't mean the VTC intake gear (the one on the left with the large VTC thing attached to it) do you? That thing is like $500. If yours is worn out, you might want to get one from the junkyard. I have never heard of one braking (other than the teeth), so it should be reliable even if it's used.

Could you please show me some pics of your old lower tensioner and lower guide, or describe how much they were worn?
 

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Ya, I'd reuse that one as long as you weren't getting any VTC codes from the ECU beforehand. Those teeth look good, as do the ones on the exhaust side (but may as well replace that one if it came with the kit anyways).
Why is the intake VTC sprocket so expensive? 'cause it is... That's my reason and I'm sticking to it...
 

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NF Mod/Nissan Master Tech
2006 Pathfinder LE, 2003 Frontier SVE
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Cost might have something to do with the machine work required inside the gear. If you ever take one apart, you'll see what I mean. Still, $500 is a large hit on the wallet for a timing gear!
 

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I will tell you why it's so expensive: it's because your only choice is to buy a genuine Nissan one. It's not made by any aftermarket company. Why don't any aftermarket companies make it, most likely because it seldom brakes and there is no demand for it to make it worth their while.

A 1994 Sentra ga16de waterpump costs $88.65 from the dealer, and it's 17.52 from Rockauto.com. So it costs 5 times more for a genuine part from the dealer. So if an aftermarket company made the VTC sprocket, it would probably cost about $100, which is much more reasonable.

I once read that some rich guy decided to build an entire car from dealer parts and it ended up costing him almost a million dollars. He did it just to poke fun at the dealerships.

It looks like there is a lot of youtube videos where the VTC started making noise on the SR20's though:

It looks like the newer designs are much more simple and I'll bet reliable:
 

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Discussion Starter #30
just an update....put the motor back in the car this weekend....reconnected the wiring harness, hoses,cables and filled with fluids....cranked the motor over and two seconds later it fired up...the motor is quiet just as it should be... thanks to all you guys who helped me out with this process...
 

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Gotta like that taste...
 

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I am going down this same road. I drove the car into the garage, got the engine down to the point I could rotate manually to TDC and now I feel like I am hitting interference. Using a breaker bar and 27mm and extension. I am stuck and can't get the engine to turn one revolution. Makes no sense that I drove it in now I can't spin it. Plugs are out Distributor cap is off. My idler gear is really worn down as I have 250k and I assume this is the first chain change.

I don't want to force anything but since this is my first chain on this engine I was wondering how much resistance is normal to rotate the engine.

Thanks in advance.
 

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Ok. Disaster averted. Worked the engine manually some more and put a coat hanger in #1 cylinder and watched it go up and down for two full revolutions and now have the distributor pointing to #1 plug. I have the TDC and #1. Idler gear is so worn it has jumped timing and marks on top chain no longer align with sprockets. Will start again in the morning. At least the interference seems to have gone away. .
 

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When my cylinder walls were dry, engine & bearings void of oil, sitting for a year or so, I had a 1/2" breaker bar on the crank pulley bolt and had to stand on the end to get it to move when one of the pistons hit the top of the cylinder (with the heads off). I suppose because every cylinder wall out there is ever so slightly tapered.
Then I pulled my head out of my ass and wiped down the cylinder walls with a shop rag soaked in fresh oil and all went much smoother afterwards.
If the engine was hot/warm when you tried to spin it by hand, ya, it probably would be a bit tight. Pistons/rings expand, make for a tighter seal. I'd bet when it cools down completely, it gets easier.

I direct you to my saga of changing out the idler gear.
https://www.youtube.com/watch?v=GJvC4fQrnyg

Is the idler gear the only reason you're going to go ballistic on the engine?

A few of my notes:

-Easier to get to the thermostat and everything back in there if you disconnect the bolt holding down the power steering lines on the passenger side tower and move those lines out of the way a bit.

-You WON'T be able to get the idler gear out without removing the timing cover. It'll look like you can. It'll feel like you can. It'll be just like "if I can move it one more millimeter that way, I can get it out", but you won't. I play that game a couple times already. Won't happen. Other people have suggested going to town with a dremel and cutting away some of the aluminum on the cover so as to gain access to the idler gear. Dumb way of going about it in my book.

-You don't HAVE to pull the head to get the timing cover off and you CAN put the timing cover back on without disturbing the head gasket (the portion that hangs out over the timing cover). You WILL take the risk of oil leaks if you do it that way.

-Jack up the front of the car at least a foot and support it on the rear of the lower control arms. That'll help get to the support rods that run from the front and back of the block to the transmission housing. Those have to come out to get the oil pan off.

-If you're going to pull the head, work on the exhaust manifold first. Once that thing is out of the way, the alternator and a pile of other stuff is a LOT easier, even before you get to working on the head. Not to mention you'll probably end up breaking the exhaust flange bolts and have to get those reworked as well. Start spraying them all down with a penetrating fluid now, a few times a day if possible. I ended up replacing all of my flange bolts/nuts/washer, broke a couple of exhaust manifold bolts, ended up just buying a new set.

-If you go the route of replacing everything on the front of the engine (upper exhaust sprocket, idler sprocket, chains, crank sprocket, upper/lower chain guides/tensioners, etc...in other words, a full timing set), BEFORE you finally button everything up, I'd suggest (only because I did and it made me feel a lot better) rotating the engine a full 72 turns. Yes, 72. That's how many complete rotations it took for the crank, cams, sprockets, chains, etc. to cycle around so that on the 72nd rotation, all of the timing marks were back to where I started. It's got to do with the odd number of teeth on the idler gear. Sounds stupid, but that's the way it works.
 

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Great tips. I am doing the whole front end, timing set, covers oil pump, gears, both tensioners, all guides.

I am not planning to pull the head but understand about the need to drop the oil pan. I have already pulled he power steering fluid reservoir loose as well as the relays on the passenger side.

One tip I saw was prime the lower tensioner piston in oil to insure good start up.

Had a brief detour with a clogged sink hairball but plan to be back at it in th morning

I will watch that video.

Thanks for your detailed reply. I just want to get another 40-50k out of this car or 2 years hopefully. Then I should be able to purchase another much newer commuter car. Everything else is working great on it.
 

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Great tips. I am doing the whole front end, timing set, covers oil pump, gears, both tensioners, all guides.
And compare your new parts to the old ones...e.g. count the teeth, make sure they all match up. I got sent an idler gear with 26 teeth (or was it 25?) on one of the sprockets. Put it all back together, was doing the initial 'spin the engine around, make sure nothing binds' check, and it ended up running into valves after 1 1/2 turns. Took me a solid few days to figure out the idler sprocket had one more (or one less) teeth. It was otherwise exactly identical except for that one tooth.

I don't think I'd worry about the oil pump itself unless you're fairly sure the engine has been abused as far as oil changes go (e.g. lots of sludge buildup under the valve cover). Mine was practically perfect for 168K miles. Even the cylinder walls didn't have a ridge at the top and I could still easily see the factory cross-hatch in a lot of places.

I am not planning to pull the head but understand about the need to drop the oil pan.
Pulling the head is semi-optional for the reasons given above (head gasket sealing at the top of the timing cover during reinstallation). Otherwise, I'm glad I pulled mine (aside from needing the obvious valves to get fixed after jumping the chain). The surface of the head was ok, but it was "micro-pitted" (for lack of a better phrase), aluminum corrosion (or more exactly-dissimilar metal corrosion). And now, I've got a brand new FelPro head gasket on there and nothing to worry about.
Dropping the oil pan is not an option. Has to be done to get the oil pickup tube off the timing cover.

I have already pulled he power steering fluid reservoir loose as well as the relays on the passenger side.
One tip I saw was prime the lower tensioner piston in oil to insure good start up.
I didn't do that, but if I would have thought of it, I sure would have. Let it soak, actuate the plunger a handful of times, good to go.

Thanks for your detailed reply. I just want to get another 40-50k out of this car or 2 years hopefully.
Why are you pulling it apart in the first place? Because of the teeth on the idler gear? Got some pics? I tore mine apart because a couple of teeth were all but missing. If I hadn't seen those teeth missing, I wouldn't have had any problems just leaving it alone.
 

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I am pulling it apart because it runs like crap and won't hold timing. The upper chain is thrashed from 1000s of miles metal on metal on the upper tensioner and I have to believe the lower tensioners and guides are also gone. I have everything lined up for the next step it appears this morning (main pulley timing mark on point, rotor pointing to #1, and #1 piston at TDC). The upper idler teeth are sore worn compared to the new gear I have, I just don't see it lasting or running well if I ignore it. Also when trying the set the timing the mark on the pulley jumps about 30-40 degrees and will not hold steady with the timing strobe on it. I am assuming this is the slack in the chains causing this variation.

I will start with comparing parts before moving on. The oil pump came with the entire front end kit.
 

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I am pulling it apart because it runs like crap and won't hold timing.
A dozen different things could cause that, but ya, chain tensioner has to be up there near #1. Another good one is the crank pulley itself and rotten rubber between the crank part and the pulley part.

The upper chain is thrashed from 1000s of miles metal on metal on the upper tensioner
Seems like the upper tensioner only tends to last about 150K anyways.

and I have to believe the lower tensioners and guides are also gone.
I think you'll be surprised how LITTLE wear the lower tensioner and guides will actually have.

I have everything lined up for the next step it appears this morning (main pulley timing mark on point, rotor pointing to #1, and #1 piston at TDC).
That's the easy part. Make double-dog sure you count those teeth correctly on the sprockets. One tooth off on either the upper or lower chain will still spin around without smacking pistons/valves. Two teeth WILL smack pieces/parts. Guess how I figured that out! :)

Also when trying the set the timing the mark on the pulley jumps about 30-40 degrees and will not hold steady with the timing strobe on it. I am assuming this is the slack in the chains causing this variation.
Ya, but 30-40 degrees is an awful lot. The book says it'll bounce around about 5 degrees or so and you're kinda supposed to average it out in your head as to where the timing actually is. It sounds stupid, but try flipping the timing light 'connector' (the part that goes on the plug wire) over. Those things have a sort of 'polarity' to them. I've got a few timing lights handy. 2 of them seem to work better if the movable part of the clip is facing up, the other works better facing down. Don't ask why. I dunno. Just the way it is.

Did you put the ECM in "Timing mode" before checking the timing? If the chain is making a lot of noise, possible that the knock sensor is hearing it, and therefore the ECM is dicking around with the timing as well. In "timing mode", the ECM is out of the loop, not messing with the timing at all, nor the idle speed...base timing, base idle rpm.

The oil pump came with the entire front end kit.
Can't go wrong there. Put a bit of assembly lube in the gears and you're golden.

Also, exactly which engine/car combo are you working on? It matters as far as which guides go back on the upper parts. The uppermost guide was deleted/removed from the later models.
 

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Upper most guide was not there when I pulled this apart so I believe deleted. 97 200SX SE. This is a lot of work - the 18 year old bolts and stuff are not making this any easier
 

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A great thread with good write-ups and pictures. Thanks to all who contributed. This thread will be a good guide to those who need to deal with chain replacement. This thread will become a sticky.
 
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