B12 Sentra GA16i timing chain job - Nissan Forum
E/CA-Series & GA16i Engines Engine Discussion: 1982-1990 Sentra/Pulsar

Reply
 
LinkBack Thread Tools Display Modes
#1 Old May 19th, 2013, 10:27 PM
Nissan Enthusiast
 
Join Date: May 2013
Posts: 52
B12 Sentra GA16i timing chain job

Here with more questions about the timing chain and guides replacement job I need to do on a 1989 Sentra, GA16i engine, B12 chassis.

Looking at the suckiness that is both Chilton's and Haynes, they tell you to remove the motor mount at the pulley (and front cover) end, which, looking things over, looks necessary. They say, support the front of the engine from overhead for this. (Since the oil pan has to come off too.)

Question one; considering that I don't have an engine hoist or something to use, what bright ideas might somebody have about dealing with this?

Next.

Question two; doing my homework, in the course of the work steps in Chilton's, they tell you to torque the crank pulley to crank bolt to 69-76 ft-lbs.

Elsewhere, Chilton's says, in the actual torque specs, that it's 132-152 ft-lbs.

Oh yeah? This is getting interesting. (Incidentally, looking more, I notice that Chilton's specs the torque for the flywheel bolts as 69-76 ft-lbs, which makes an obvious suspect for an oops source.)

So, I check Haynes... they say 98-112 ft-lbs.

Swell.

What is it really?


JLE
Sponsored Links
Advertisement
 
#2 Old May 19th, 2013, 10:45 PM
jdg
The Judge!
 
Join Date: Aug 2009
Location: ND, USA
Posts: 2,671
Going off my experience with my B14's, but should be close enough...

Engine support - take off the crank pulley, jack up the engine a bit (I used a big block of wood under the oil pan to spread out the load), and support the engine at the crank itself sitting on a block of wood. Not the best option, but it worked for me.

Torque spec's - I'd be inclined to believe the higher ft-lbs numbers. Unless you're using an 8ft breaker bar or something like that, I'd think you'd be hard pressed to get much more than 150 ft-lbs anyways without some sort of mechanical advantage assisting you.

99% of the questions that are "STRANGE" have a dirt simple answer...usually answered by a dirt simple search.

NISSAN GOOGLE

Is it just me, or does the majority overlook the obvious?

Somebody ate a whole bag of dumbass for breakfast.

Why do people continue to run a vehicle when a warning light comes on or starts flashing? Isn't that a clue that something is wrong and you probably should NOT drive it?
Is this whole car driving thing really freekin' brain surgery?

Here's something new for the crowd/clowns...
"A little bit of Google goes a long way!"

Ever notice the one post wonders for info on turbo'ing a GA16 are never heard from again after they figure out the cost???

And if you can read this, you don't need glasses! :)

And yes, I am diggin' it...
#3 Old May 19th, 2013, 10:50 PM
NF Mod
 
smj999smj's Avatar
 
Join Date: Jan 2006
Location: Prospect, VA
Posts: 6,212
It would be best to have an engine hoist (or "hanger"). You might be able to get one through your local parts store's "tool loaner program," if they have one. Otherwise, you would use a floor jack with a wooden board to support under the trans. The problem with this method is that without that mount, the engine will likely move a little closer to the right, inner fender, which means you'll have even less room to work with in an area where there's not a whole lot of room to begin with to remove the front cover. You could also get a wooden board to run across the engine compartment and use a chain to support the engine. Sometimes you just have to get inventive!
#4 Old May 19th, 2013, 10:52 PM
NF Mod
 
smj999smj's Avatar
 
Join Date: Jan 2006
Location: Prospect, VA
Posts: 6,212
Per ALLDATA, the crank bolt spec is 98-112 ft/lbs....if you believe ALLDATA. I usually just gun the bolt on with an impact air gun. Not accurate, I know, but I never had one fall off or break...knock on wood!
#5 Old May 19th, 2013, 11:29 PM
Nissan Enthusiast
 
Join Date: May 2013
Posts: 52
Thanks for the quick replies, guys.


Quote:
Originally Posted by smj999smj View Post
It would be best to have an engine hoist (or "hanger").
Yes it would. Wouldn't that be nice?

Quote:
Otherwise, you would use a floor jack with a wooden board to support under the trans. The problem with this method is that without that mount, the engine will likely move a little closer to the right, inner fender, which means you'll have even less room to work with in an area where there's not a whole lot of room to begin with to remove the front cover.
Yeah. That's one thing I keep looking at. How much will it move, and where; and like you said, the last thing I need is this bastard moving any closer to the right side of the car. Just a couple weeks ago I changed the water pump, thinking that was the source of the noise that turned out to be a disintegrating timing chain guide, and what should be one of the easiest jobs there is was a royal pain in the ass because it was so tight. (And afterwards, I realized that if I had just bothered to take out the splash guards so I could get in underneath through the RF wheel well, it would have been ridiculously easier.)

Quote:
You could also get a wooden board to run across the engine compartment and use a chain to support the engine. Sometimes you just have to get inventive!
I was actually considering that, carefully pondering how I could paint myself into a corner and having to back up again because I found that got in the way of what I was doing in the first place.

I also consider the idea of getting the oil pan off first before the motor mount on the pulley end/RF of the car, and rigging up some woodblock arrangement under the bolts on crank bearing caps.

That gets me to another question, though. That damned frame member piece has to come off first to drop the pan. But looking at that has me wondering. I looked at it, and it looks like the back end of the frame member is actually fastened on the the bottom of the back motor mount (i.e., block and transaxle case to firewall area), but, looking at the thing, I'm not quite sure if that member actually partially supports the motor mount there, and if I just unbolt the member without added motor support, stuff will suddenly shift and cause real problems.

This is where I'd like to know from people who have been down this road already.


JLE
#6 Old May 19th, 2013, 11:43 PM
jdg
The Judge!
 
Join Date: Aug 2009
Location: ND, USA
Posts: 2,671
I'm not 100%, but I think it still applies.
The noise you're talking about might be the upper chain tensioner that's shot. Kinda makes the motor sound like a diesel. The things are bad for going out after X hundred thousand miles.
Jist of the story...you might not have to swap out the whole timing chain and everything. The problem might just be that upper tensioner.

99% of the questions that are "STRANGE" have a dirt simple answer...usually answered by a dirt simple search.

NISSAN GOOGLE

Is it just me, or does the majority overlook the obvious?

Somebody ate a whole bag of dumbass for breakfast.

Why do people continue to run a vehicle when a warning light comes on or starts flashing? Isn't that a clue that something is wrong and you probably should NOT drive it?
Is this whole car driving thing really freekin' brain surgery?

Here's something new for the crowd/clowns...
"A little bit of Google goes a long way!"

Ever notice the one post wonders for info on turbo'ing a GA16 are never heard from again after they figure out the cost???

And if you can read this, you don't need glasses! :)

And yes, I am diggin' it...
#7 Old May 19th, 2013, 11:47 PM
NF Mod
 
smj999smj's Avatar
 
Join Date: Jan 2006
Location: Prospect, VA
Posts: 6,212
Yes, you have to remove the crossmember before you remove the oil pan. Yes, I would remove the oil pan before you remove the front mount. Ultimately, the only supporting mount will be the tran mount (which is why they instruct to use an engine hanger attached to the front of the engine. You can support using a board and a floor jack under the main caps, but IIRC, the GA16i uses individual main caps instead of a main bearing cradle like the KA24DE engine. The difference being is that the cradle type gives you a flat surface to jack on, whereas the individual caps gives you a round surface, making it less stable when it's resting on your board. I've done quite a few timing chains on the GA16i's, but it's been a lot of years since I did one. It used to be a common job at the Nissan dealer back in the early-mid '90's. I probably haven't done a GA16i in at least 15 years! Also, make sure you get a new gasket for the oil pickup tube as you'll need to replace the old one.
#8 Old May 19th, 2013, 11:50 PM
Nissan Enthusiast
 
Join Date: May 2013
Posts: 52
Quote:
Originally Posted by jdg View Post
The noise you're talking about might be the upper chain tensioner that's shot. Kinda makes the motor sound like a diesel. The things are bad for going out after X hundred thousand miles.
Jist of the story...you might not have to swap out the whole timing chain and everything. The problem might just be that upper tensioner.
No.

Not a bad thought, in fact, I went and bought just a new tensioner with the thought of putting that in (easier and cheaper) to see if that malfunctioning might be making for chain slack in that area.

Then I pulled off the valve cover to peek down in and see what I could see, and that settled this.

Let's put it this way... the chain guide on the tension side of the chain was so far gone that I knew it was toast just from what I could see (and feel, carefully poking around) from up top looking down in.


JLE
#9 Old May 20th, 2013, 12:06 AM
Nissan Enthusiast
 
Join Date: May 2013
Posts: 52
Quote:
Originally Posted by smj999smj View Post
You can support using a board and a floor jack under the main caps, but IIRC, the GA16i uses individual main caps instead of a main bearing cradle like the KA24DE engine. The difference being is that the cradle type gives you a flat surface to jack on, whereas the individual caps gives you a round surface, making it less stable when it's resting on your board.
I've never seen the bottom end of this thing naked, but I figured that whatever the exact shape of the bearing caps, that the bolt heads would provide something of a stable base to rest square and solid on the end of a chunk of 2x4... my thinking was, get the thing up on the stands, measure the distance, get a couple of 2x4 scraps cut to length so they'll wedge in there with maybe just a little mallet encouragement, do that on a couple of them, and then stabilize it by cutting another short 2x4 to lay on the floor flat slid in between those (maybe a couple stacked), and wood screw them together to keep it stable.

Dunno.

Quote:
Also, make sure you get a new gasket for the oil pickup tube as you'll need to replace the old one.
Aw, shit.

I didn't even think about that.


JLE
#10 Old May 20th, 2013, 02:19 AM
jdg
The Judge!
 
Join Date: Aug 2009
Location: ND, USA
Posts: 2,671
May as well do that rectangular baffle gasket on the valve cover while you've got it apart. While I haven't had trouble with either of mine, others have had problems with oil consumption/burning/etc when their "baffle gasket" goes dry.

As far as jacking up the block, you might even be able to get the 2x4 to sit decently on the edge of the block where the oil pan bolts up.
Million different ways to do it. Some better than others obviously, but whatever works, and if it doesn't fall on you, then that whatever method was the best.

99% of the questions that are "STRANGE" have a dirt simple answer...usually answered by a dirt simple search.

NISSAN GOOGLE

Is it just me, or does the majority overlook the obvious?

Somebody ate a whole bag of dumbass for breakfast.

Why do people continue to run a vehicle when a warning light comes on or starts flashing? Isn't that a clue that something is wrong and you probably should NOT drive it?
Is this whole car driving thing really freekin' brain surgery?

Here's something new for the crowd/clowns...
"A little bit of Google goes a long way!"

Ever notice the one post wonders for info on turbo'ing a GA16 are never heard from again after they figure out the cost???

And if you can read this, you don't need glasses! :)

And yes, I am diggin' it...
#11 Old May 20th, 2013, 11:11 AM
Nissan Enthusiast
 
Join Date: May 2013
Posts: 52
Rectangular baffled gasket on the valve cover? You talking about that baffle plate inside the valve cover on the top that's pinned in?


Anyway. I thought about it a while last night after reading here. All things considered (including the thought that whatever I do, I want to make sure I don't rig up something that I then find is in my way and some point, kind of painted into a corner)... I thought about putting together some sort of temporary stand of a sort out of scrounged bits of 4x4 and 2x4 screwed together.

I think that might work out, and after I thought about it some more, I started thinking that instead of sticking something under a crank bearing cap/bolts like I was thinking, I might do something with a pair of upright pieces screwed to a horizontal piece on the floor, with the uprights wedged under the block on the sides so that the mating surfaces where the oil pan attaches are resting on blocks of wood. That might take a bit of time of measuring sawing and fiddling, but I'm thinking that might get me what I need in terms of the combined criteria of solid support, stability, and staying out of the way of the work at hand.


JLE
#12 Old May 20th, 2013, 03:37 PM
NF Mod
 
smj999smj's Avatar
 
Join Date: Jan 2006
Location: Prospect, VA
Posts: 6,212
There is no upper chain tensioner nor the small, rectangular gasket on the bottom of the valve cover on a GA16i engine. Those were on the B13 and later GA16DE engines. The GA16i has a single timing chain and a single chain tensioner.
#13 Old May 20th, 2013, 03:52 PM
jdg
The Judge!
 
Join Date: Aug 2009
Location: ND, USA
Posts: 2,671
Quote:
Originally Posted by smj999smj View Post
There is no upper chain tensioner nor the small, rectangular gasket on the bottom of the valve cover on a GA16i engine. Those were on the B13 and later GA16DE engines. The GA16i has a single timing chain and a single chain tensioner.
Totally different animal then eh?

99% of the questions that are "STRANGE" have a dirt simple answer...usually answered by a dirt simple search.

NISSAN GOOGLE

Is it just me, or does the majority overlook the obvious?

Somebody ate a whole bag of dumbass for breakfast.

Why do people continue to run a vehicle when a warning light comes on or starts flashing? Isn't that a clue that something is wrong and you probably should NOT drive it?
Is this whole car driving thing really freekin' brain surgery?

Here's something new for the crowd/clowns...
"A little bit of Google goes a long way!"

Ever notice the one post wonders for info on turbo'ing a GA16 are never heard from again after they figure out the cost???

And if you can read this, you don't need glasses! :)

And yes, I am diggin' it...
#14 Old May 20th, 2013, 03:57 PM
NF Mod
 
smj999smj's Avatar
 
Join Date: Jan 2006
Location: Prospect, VA
Posts: 6,212
Yeah, the GA16i is a single cam, 12-valve engine whereas the GA16DE is a twin-cammer. The GA16i is to the GA16DE as is the KA24E is to the KA24DE. Same engine family and block, but different head and valvetrain.
#15 Old May 20th, 2013, 05:06 PM
Post Freak
 
ahardb0dy's Avatar
 
Join Date: Nov 2003
Location: orlando,FL
Posts: 1,235
The torque specs for the crank bolt are as follows this is from the 89 FSM for a Pulsar, same engine:

132-152 NEWTON meter
98 - 112 foot lbs

page from FSM below:




I come on these forums to help if I can, if I say something wrong and someone corrects me I also learn something.

Current Nissan:
93 Hardbody king cab, 2wd, KA24E with the 5 speed



Previously owned:
90 Nissan Sentra
94 Nissan Pathfinder
05 Nissan Titan 2wd
94 Infiniti Q45t
87 Nissan Hardbody SE-V6 4WD
80 Datsun 310GX (first Datsun/Nissan)

Last edited by ahardb0dy; May 20th, 2013 at 05:09 PM.
Reply

  Nissan Forum > Sentra, Pulsar, NX, B14 200SX > E/CA-Series & GA16i Engines

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Nissan Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On