jgrafe

I have removed all the bolts in the cover, the crankshaft pulley, the power steering pulley, the alternator, and the lower oil pan. The top part of the chain cover is somewhat loose. What's still holding the cover at the bottom? Are there bolts inside the upper oil pan that connect to the bottom of the cover? The engine is in the car. This is a 96 with 95K miles.

Here are some pictures to jog memories, or nightmares...

MDeezy

iTrader: (27)

the the bolts in the old pan hold the outter timing case in place also. It should seperate pretty easily, if its giving your a hard time there must be a bolt still in place.

get all the outer timing case bolts, plus those two in the oil pan ( the ones towards the front in image 2) and it should come off. they are 12mm bolts.

sky jumper

you're supposed to remove the upper oil pan first. it is sealed to the TC cover. once you remove those 2 bolts you should be able to get it with a bit of prying -- be careful not to damage the mating surfaces, and be sure to use Permatex grey or black to seal the thing up again.

just curious, why are you removing it on such a low mileage engine?

KRRZ350

iTrader: (29)

well I saw that you saw my reply in the newbie thread, as everyone else said, yes just those two forward most bolts, one of them is way up in there. Don't forget that comment I made about the upper oil-pan c-shaped seal also.

He's replacing the tensioner AND guide, along with the water-pump.......

MDeezy

iTrader: (27)

you dont have to remove the upper oil pan first. those two 12mm bolts in the oil pan will set the outer case free.

sky jumper

yes I understand that, but there's a gasket and FIG sealant gluing the two pieces together. you can pry it off (like I said) but the proper way to do it is to remove the upper pan -- so you can apply proper torque to the pan bolts when setting the new gasket material to prevent leaks. I pretty sure the FSM describes exactly this.

or, like I said, you can shmear a bunch of sealant around the thing and hope it doesn't leak. a bit shoddy if you ask me, but it is less work.

jgrafe

I added arrows to the second and third images in the OP to indicate where the two bolts are. After I removed them the cover came off fairly easily. I replaced the tensioner, guide, and water pump. The piston on the old tensioner felt pretty stiff to compress. After all the sludge came out, the piston moved freely. However, I noticed that the piston tends to get hung up when it is about 3/4 of the way depressed. This catching and the sludge build-up seem to be the problem. The new guide and tensioner move very freely. I'm sure it wont make the death rattle when I get it all together tomorrow.

Here's the new and old guides, the new and old tensioner, and the new and old water pump. No noticable differences really.

MDeezy

iTrader: (27)

yea they say they have the new style/version but there appears to be next to no difference....

sky jumper

this is interesting. there has been some confusion about when the tensioner changes hit production, and when the physical size changed. to my knowledge, you're the first person to post pics of the OEM '99 tensioner.

The first change was made in '97, and the first version (95 & 96) was shorter & subbier than the newer versions. that is why your old one looks the same as the new one.

I think your photos confirm that the newest version (3rd, I think) did not involve size/fitment changes - just internal stuff (unless, of course, the '99 came stock with the 3rd version - which according to my dealer, it did not).

in any case, it looks like you could've gotten away without removing the TC cover (unless that guide was gunked up and not moving freely on the pin).

Please update this thread with your results. my '99 gets the cold start rattle with certain oils, and I may try this fix myself.

jgrafe

This is on someone else's 96 with 95k miles, not my 99. My 99 is as quiet as a kitten. This 96 has been making a terrible racket for some time and I’m sure has not received much maintenance. Undoubtedly the wrong oil, oil filter and the wrong amount of oil contributed to its condition. Thanks Jerky Lube!

I took the cover off to see if there were any other issues that required attention. Actually, the old guide looked fine. You’re right sky jumper. I could have gotten away with not removing the cover. But I didn’t know that going in.

Another mystery, the power steering pulley was out of round. This car has been wrecked, so that might have been caused by the wreck.

I'll post my results after my ASE certified son and I get her back together today or tomorrow. With some Permatex ULTRA GREY, it should go back together nicely.

sky jumper

this is a 96?? it must've had the tensioner TSB performed at some point, because that is not the original tensioner design. I think nissan was doing the TSB free for customers who complained about it under warranty. there used to be pics on here comparing the two designs, and they are clearly different and required different guides.

if there was sludge in the tensioner, no doubt that was causing the problem. your friend owes you a huge favor!!

sky jumper

here's the TSB...
http://www.jatan.net/tsbs/047941.pdf

looks like the old tensioner was installed pre 1/96, depending on the production line (now that is sloppy QC). perhaps your '96 was on one of the "good lines"...

jgrafe

We got it back together, but it runs very poorly. It must be misfiring, although the CEL did not come on. We're stumpted once again! It idles rough, smells of gas etc. How do I diagnose and fix it without a code?

Also, I checked the car's VIN against those in the TSB. This max was built after the ones impacted by the TSB. Oh well.

andrei3333

Sorry i dont have an answer to ur post, but these pictures are amazing. So this is what the famous Timing chain that never needs to be replaced looks like. Thanks for the great images.

MDeezy

iTrader: (27)

is timing set properly? did you remove the timing chain? did the chain skip a link?

jgrafe

I don't think it skipped a tooth. I just pushed the chain out of the way to get the new water pump in place.

Is there a way to mess up the timing if the chain does not skip teeth?

KRRZ350

iTrader: (29)

a vacuum reading at idle would be helpful

MDeezy

iTrader: (27)

no, not really, because essentially the chain doesnt move, the links are still in the same place, but it might be possible to happen.

did you hear any odd noises at first start up?

worse come to worse, you'll have to tear back into the timing case, and check the timing.

jgrafe

When first starting it, I heard the loud chain noise for about five minutes. After that, the chain was quiet. It idles rough and then very rough when I put it in gear (automatic).

matty

iTrader: (54)

I would guess you messed up the timing a bit. Check your vaccum at idle.

-matt

jgrafe

Well, I have made no progress since reporting that the idle is funny. I just can't believe that the chain skipped a tooth. I was very careful to avoid that. I also have not checked the vacuum, although the vacuum sounds a little strange near the intake manifold.

I prefer to think that one of the crankshaft position sensors (particularly the REF, but possibly the POS), or the camshaft position sensor is not communicating properly with the PCM. Still no codes though.

I'm going to shine a timing light down there and probably check the resistance at the sensors. Failing a diagnosis from that, I may have to drag the car to the dealer.

Is there a good software application that I could use with an OBD II converter to diagnose the timing? Any recommendations?

sky jumper

you can borrow an OBDII scanner from murray's (or a CSK store) and view live ignition timing. but I think you want valve timing, and I don't know of any way to check that without taking the TC cover off and lining up the timing marks. a vac reading should also give you some clues, so you might try that before going to a dealer. does it sound like a vac leak at the IM?? if so, that will cause your symptoms. find the leak.

I have not messed around with the TC on these engines, but I just don't think it's possible to skip a tooth unless you take one of the sprockets off.
just to confirm -- you didn't remove the water pump until you had the TC cover off, right? you had to turn the crank to transfer slack to the WP side, and while doing so you had a clear view of everything -- was there enough chain slack at the bottom to turn the crank without moving the chain?? that's the only way you could've messed up the valve timing.

someone else might be able to confirm/deny, but I'm betting your problem is elsewhere.

jgrafe

Thanks for sticking with me sky jumper.

No. I removed the TC cover before removing the water pump. To create slack (there was already slack because the old tensioner was not really pushing on the guide), I removed the slack-side guide and tensioner. I then pushed the chain away from the water pump. I suppose the crankshaft sprocket rotated when I pushed the chain out of the way, but I'm sure the teeth stayed where they were.

After installing the new water pump, I installed the guide and finally the new tensioner.

sky jumper

hmm. I'm thinking the crank didn't rotate when you pushed the chain -- that would take a lot of force. it's possible the cams turned though, i don't know how hard they turn.

the other possibility is that removing the guide did in fact create enough slack to slide the chain over the crank sprocket without you noticing it. if so, that screwed up the timing.

the FSM describes turning the crank counter clockwise (with the guide still installed) to transfer slack to the WP side, so you can remove the water pump. but you didn't have to turn the crank -- so that's what has me scratching my head.

I think a vacuum check is definitely in order. that intake noise may be caused by valve timing issues.

KRRZ350

iTrader: (29)

Yeah screw taking it the dealer, they'll probably tell you it's the maf anyways, lol. Besides, do you know how much they'd want to remove the tc!! Also, double check that everything is ok with the front pulley key,. if for some reason it sheered, or didn't seat properly, you could have problems with the ref cps, though you'r not getting any codes which leades me to beleive the chain jumped a tooth. Just hook up a vacuum gauge to the IM, that will tell you if the timing jumped a tooth......

jgrafe

I performed a vacuum test and a timing light test. Here are the results. At idle (700 rpm), the vacuum stayed steady at 17.5 in Hg. Taking it to 2000 rpms, the needle swept down then up and settled at a steady 18 in Hg.

At idle, the timing pointer on the cheater hole cover points way to the right (forward) of the timing marks on the crankshaft.

What does this mean?

BluFlame

iTrader: (2)

How did you remove P/S pulley without taking out the pump?

jgrafe

The power steering pulley is held by the big nut on the spindle. Remove it and the pulley slides off.

jgrafe

Can someone help me diagnose this? Does the timing light test confirm that I must have skipped a tooth when I had the TC cover off?

sky jumper

the correct ignition timing is 15deg BTDC. I cannot tell from your diagram if you are in spec. usually there is a scale with #s. in any case, I don't believe ignition timing will tell you if you skipped a tooth. I think it's based on the crank pos sensor, not camshaft. but I could be wrong.

I looked in the FSM but could not find a vacuum spec. you might call a dealer, or do some searching online.

still no codes??

sky jumper

reading through the FSM a bit more, I do think cam position does factor into ignition timing. so if your cam is out of sync with the crank (from skipping a tooth) the measured ignition timing will indeed be out of spec.

try to verify what the ignition timing is. in your diagram, I'm not sure if the arrow is supposed to be the spec, and the double vertical line represents the timing line on the crank pulley? if so, I believe they should align, and they clearly do not.

jgrafe

Nope. Still no codes. In the diagram, the left-most mark of the pair of marks to the right of TDC is 15 degrees BTDC. The Haynes manual does not say where the pointer should be. Haynes says the vacuum reading should be between 17 and 22. So, steady at 17.5 is OK at my elevation above sea level.

I asked a service writer at my local dealer what the timing should look like. They couldn't (wouldn't, or wouldn't bother to) tell me.

I'm still confused.

sky jumper

hmm. now I'm more confused about your diagram.

when measuring timing you typically have a line on the crank pulley, and a fixed scale off to the side. when the timing light flashes you can visually compare the line to the scale and read your timing.

so do the vertical lines represent marks on the crank pulley, or marks on the fixed scale??

what then is the arrow?

it may be that nissan does it backward -- there's a single fixed pointer, and multiple lines on the pulley.

in any case, I think the arrow needs to align with the 15deg mark at idle when the car is warmed up -- and it doesn't. so I'd say your timing is off. and this implies a skipped tooth, I'm afraid.

jgrafe

I updated the diagram. The arrow is the steel pointer welded to the water pump cheater hole cover. The three vertical lines are marks on the crankshaft pulley. This is how it looks looking down the side of the engine. The pointer is way to the right (forward) of the 15 degree mark at warmed-up idle.

Why is the vacuum fine?

Anyway, I must have skipped a tooth. Oh well. Another teardown is in the car's future.

nismology

iTrader: (8)

The vacuum is a little bit low. It should be closer to 18 or 19 in-hg on a healthy motor from what I've seen/experienced. Also, the fact that your arrow is pointed to the right of the 15* mark tells me the timing is off (which you already know). It's VERY important that all the slack be on the slack side. Priming a brand new tensioner with oil before installing it is also recommended. Good luck.

jgrafe

We got it back together after having to take the cover off the second time. This time we made sure the two dark colored links lined up with the marks on the valve sprockets and the yellow colored link lined up with the notch in the crankshaft. Back in business!

sky jumper

good work.

can you confirm that removing the guide creates enough slack to skip the chain over the crank sprocket?

how does it run now?

jgrafe

We removed both the guide and tensioner. This created enough slack to move the chain. Also, the sprocket on the crankshaft simply pulls off. It's all pretty easy.

We also put on a Warpspeed y pipe (the cheapest replacement for a defective OEM pipe), the correct NGK plugs, and transmission filter and fluid. It had a frozen caliper, shot rotors, non-existant pads, nasty looking brake fluid in the reservoir. A real sad story.

All fixed.

It runs, and stops better than my 99. Shifts smoothly. Steady acceleration. I'm jealous.

nate71

why should the upper oil pan be removed on a vq engine to remove the timing cover?

usablue53

Why do jgrafe's pics not show, is it me or the site?