Nissan Forum banner
1 - 20 of 30 Posts

·
Registered
Joined
·
117 Posts
Discussion Starter · #1 ·
I read in another thread that Nissan has issued a Technical Service Bulletin that no longer recommends removing the cylinder head to change the timing chains on GA16DE engine. I looked up a discription of the bulletin (NTB98107) at Nissan publications and found the following description of the bulletin:

NTB98107 A revised service procedure for the engine front cover/timing chain has been adopted for the GA16DE. It is no longer recommended to remove the cylinder head when removing the timing chain/front cover(s). Utilize the steps in this bulletin when servicing the front cover, timing chain, guides or tensioner(s). See this bulletin for further details."

Has anybody had a look at this bulletin or have any idea of what steps Nissan is now recommending?
 

·
freakish poster
Joined
·
1,236 Posts
I would imagine it's strictly a warranty issue in that the revised procedure
requires less labor and parts; hence Nissan saves money on payouts. In other words, there's more than one way to skin a cat and they've developed a cheaper way.
 

·
Registered
Joined
·
117 Posts
Discussion Starter · #3 ·
Centurion said:
I would imagine it's strictly a warranty issue in that the revised procedure
requires less labor and parts; hence Nissan saves money on payouts. In other words, there's more than one way to skin a cat and they've developed a cheaper way.
It's awful funny they haven't passed the savings in parts and labor back to the customer. It still cost the same to get your timing chain replaced by Nissan as it did when they had to remove the cylinder head.

I'm in the process of changing my own right now, so I'm looking hard to find a way to avoid pulling my cylinder head off. There is a good online-article by one of the folks here on how to do it without removing the head, but I would be curious see how it compares with the official version from Nissan. Who knows maybe they borrowed his method.
 

·
Registered
Joined
·
353 Posts
cactusfarmer said:
It's awful funny they haven't passed the savings in parts and labor back to the customer. It still cost the same to get your timing chain replaced by Nissan as it did when they had to remove the cylinder head.

I'm in the process of changing my own right now, so I'm looking hard to find a way to avoid pulling my cylinder head off. There is a good online-article by one of the folks here on how to do it without removing the head, but I would be curious see how it compares with the official version from Nissan. Who knows maybe they borrowed his method.

Why are you chnaging your chain? :wtf: They should last 200K easy. The guides may not last 200k though. How many miles are on your 97???
 

·
Registered
Joined
·
117 Posts
Discussion Starter · #5 ·
nissannut said:
Why are you chnaging your chain? :wtf: They should last 200K easy. The guides may not last 200k though. How many miles are on your 97???
The guides or something down there in the chain department is blown out. The car died one day when I was driving it. I pulled off the valve cover and the idler sprocket spins but the top chain does not move. It catches every now and then, spins a bit then quits. The car was sounding like a diesel before it died, which of course is the classic sign that something's wrong in the chain area. Your right, the chains maybe ok, but I'll have to tear into to see what's messed up. I'll probably change the chains anyway while I'm doing it unless the chains appear to be in just great shape. I have 108K on my car.
 

·
Registered
Joined
·
353 Posts
cactusfarmer said:
The guides or something down there in the chain department is blown out. The car died one day when I was driving it. I pulled off the valve cover and the idler sprocket spins but the top chain does not move. It catches every now and then, spins a bit then quits. The car was sounding like a diesel before it died, which of course is the classic sign that something's wrong in the chain area. Your right, the chains maybe ok, but I'll have to tear into to see what's messed up. I'll probably change the chains anyway while I'm doing it unless the chains appear to be in just great shape. I have 108K on my car.

Ouch... Sounds bad... I have always had good luck with my chains. I guess I am lucky.
 

·
Registered
Joined
·
466 Posts
I think I may have a copy of the entire TSB. I'll check when I get home tonight.
 

·
Registered
Joined
·
117 Posts
Discussion Starter · #10 ·
tonsters200 said:
Heres a guy who sent me his site to look at when I was going to do mine.
http://b13sentra.netfirms.com/aug03/
The process is the same as listed in the Hayes(I think thats the one I have) Manual.
Tonster
The Haynes manual I have says you have to take the head off to change the timing chains on the GA16DE. Maybe I have an old version of the manual.

I've been to the web site you listed. He's got a great article on changing your timing chain without removing the head. That's why I'm so curious to see what the offical Nissan bulletin says. I want to see if their way matches his. Who knows, maybe they got the idea from his site.
 

·
freakish poster
Joined
·
1,236 Posts
Removal

This procedure is revised by TSB # 98-107 Date: January 15, 1999

Note: A revised service procedure for the engine front cover/timing chain has been adopted for the GA16DE. It is no longer recommended to remove the cylinder head when removing the timing chain/front cover(s). Utilize the following steps when servicing the front cover, timing chain, guides or tensioner(s)

Parts Required






Caution:

After removing the timing chain, do not turn the crankshaft and camshaft separately or the valves will strike the piston heads.
When installing chain tensioners or other sliding parts, lubricate contacting surfaces with new engine oil.
Apply new engine oil to bolt threads and seat surfaces when installing the camshaft sprockets and the crankshaft pulley.
Do not spill engine coolant on the drive belts.
Please use the correct tightening torque.
Set # 1 piston at TDC on its compression stroke.
Remove the spark plug wires.






3. Remove the rocker cover (see figure 1). 4. Remove the coolant reservoir tank with bracket and reposition it for clearance.

Support the engine with a suitable jack.
Remove cylinder head front mounting bracket.
Remove engine front mounting, then the engine front mounting bracket.
Remove cylinder head front cover.






Remove the upper chain tensioner (see figure 2).






Wipe off the links of the upper timing chain next to the timing marks on the sprockets. Put paint marks on the timing chain, matching them with the timing marks on the cam sprockets and idler sprocket (see image 3)
Remove the four (4) front cover to cylinder head bolts.
Remove side and lower engine compartment splash covers.
Remove the accessory drive belts.
Remove the crankshaft pulley.
Drain coolant by removing the cylinder block drain plug and opening the radiator drain cock.
Drain engine oil.
Remove intake manifold support of engine front side.
Remove power steering pump, pump bracket and tension rod. Position pump aside for clearance.






Remove the thermostat housing (See figure 4).






Remove the lower chain tensioner (see figure 5).
Remove the front exhaust tube.
Remove the front and rear engine gussets (if equipped) on either side of the oil pan. NOTE: On A/T models, remove the rear plate cover.






Remove the oil pan (see figure 6).
Insert the tool between the cylinder block and oil pan. CAUTION: Be careful not to damage the aluminum mating face. Do not insert a screwdriver, or the oil pan flange will become damaged.
Slide the tool by tapping it on the side of the tool with a hammer.
Remove the A/C compressor and position it aside for clearance.
Remove the A/C and alternator bracket with the alternator.
Remove the oil pump drive spacer. CAUTION: Be careful not to scratch the drive spacer when removing it.
Remove the front cover bolts and front cover.




CAUTION:
One bolt is located on the water pump (see figure 7).
*1: Located on engine front mounting bracket.
*2: Located on the water pump.
*3: Located on the power steering oil pump adjusting bar.

CAUTION: Be careful not to tear or damage the cylinder head gasket.



Remove the cylinder block to front cover alignment dowels. CAUTION: Do not hit the dowels or the cylinder block will crack.






Wipe off the links of the lower timing chain next to the timing marks on the sprockets. Put paint marks on the timing chain, matching them with the timing marks on the idler sprocket and crankshaft sprocket (see image 8).
Copyright © 2003 ALLDATA LLC
Terms of Use
 

·
Registered
Joined
·
117 Posts
Discussion Starter · #12 ·
Thanks for the post -- very helpful. Did they give any tips on the timing cover back on without messing up the headgasket? Also did they say why you need to remove the cylinder block front cover alignment dowels? Are they located inside the timing cover.
 

·
Registered
Joined
·
805 Posts
Probably the same thing as with Toyo 22r/RE. You can do the timing without removing the head although the book says otherwise.. Part of the headgasket is used to seal the upper portion of the timing cover to the head. None of this area actually sees compression. So thus you carefully remove the front cover and use Silver (Factory) RTV to reseal it.

As for the cost remaining the same...... If the book say 10 hours you get charged for 10 hours.. It doesnt matter if the mechanich knows tricks to save time you STILL pay for 10 hrs.... 95% of Shops and ALL Dealerships charge by the book.... How do I know???? Because I work at shop.. Did a 22RE last week and my 92 sentra about a month or so ago. Different Manufacturer, Different motors but very similar procedures.
 

·
Registered
Joined
·
117 Posts
Discussion Starter · #14 ·
nastynissan said:
So thus you carefully remove the front cover and use Silver (Factory) RTV to reseal it.

Thanks for the insight on how the shops charge. Sorry I was just whining because my car's broke down.

Also thanks for the info on the headgasket. When you put the timing cover back on, do you cut off the part of headgasket that is sticking over the timing cover and use the RTV sealant to replace it, or just use RTV sealant to stick the headgasket back on?
 

·
Registered
Joined
·
466 Posts
cactusfarmer said:
Also thanks for the info on the headgasket. When you put the timing cover back on, do you cut off the part of headgasket that is sticking over the timing cover and use the RTV sealant to replace it, or just use RTV sealant to stick the headgasket back on?
That's what I want to know. I would imagine if you cut off the gasket, you would have to use something in addition to RTV to seal the gap. If you left the gasket alone, I am still not sure how you would get a good seal, as there is nothing compressing the RTV, to get a good seal.
 

·
Registered
Joined
·
476 Posts
With regard to my article that many of you are reading about timing chain guide replacement, I basically did what seemed logical and easier. It didn't really make sense to remove the cylinder head since I was only changing the guides and installing the new guide rail which can be accessed without doing so. I read on Nissan's site about the TSB and that there was another way to do this but I wasn't willing to pay ~$30(perhaps higher) for one day access. I relied on my Haynes and '94 Sentra FSM. I used both at first to cross-reference each other as a lot of things didn't seem to be in the correct order. After I had a better understanding of what I was doing I only used the FSM.
Part of the head gasket is used to seal the upper portion of the timing cover to the head. None of this area actually sees compression. So thus you carefully remove the front cover and use Silver (Factory) RTV to reseal it.
What nastynissan said is what I had planned on doing. The problem was, after several attempts at a dry fit to figure out how to align the front engine cover before I applied the Ultra Grey sealant my head gasket buckled and creased a few times. The center portion wouldn't insert in the small spacing, even when guiding or forcing it in place during install. That's the reason I cut mine off and made a new piece. Even still, it was rather difficult to set in place. I used Ultra Copper(oil and higher heat resistance) sealant mainly in the corners between the cylinder head and block, along with the metal gasket I cut out, to better seal it. That is the biggest problem with any manual and Nissan's TSB, they don't tell you precisely how to put it back together in relation to the head gasket if you don't remove the cylinder head.
I haven't checked lately to see if any substantial amount of oil has leaked out but since my crank seal is still leaking, after replacing it twice myself, not to mention the rear engine seal it was the least of my worries.
 

·
Registered
Joined
·
117 Posts
Discussion Starter · #17 ·
95 SentraB13 said:
What nastynissan said is what I had planned on doing. The problem was, after several attempts at a dry fit to figure out how to align the front engine cover before I applied the Ultra Grey sealant my head gasket buckled and creased a few times. The center portion wouldn't insert in the small spacing, even when guiding or forcing it in place during install. That's the reason I cut mine off and made a new piece. Even still, it was rather difficult to set in place. I used Ultra Copper(oil and higher heat resistance) sealant mainly in the corners between the cylinder head and block, along with the metal gasket I cut out, to better seal it.
I really appreciate the clarification on how you handled your gasket problem -- BIG, BIG help for me! The whole gasket thing is why I was so curious to see what the Nissan TSB said. I wanted to see if they came to the same conclusion as you did, and if their modified procedure was the same as yours. It seemed like to me, I'd just be looking for more trouble down the road by removing my cylinder head just to change the timing chain. Thanks for all your help and the great article.
 

·
Registered
Joined
·
805 Posts
Well the question was anwsered before I got back..... But in addition to what has already been said it REALLY helps if you pull the oil pan. Its and easier job and cheaper than a head gasket. And make installation Much easier. BUT thats my choice..... Yes leave the portion of headgasket in place if possible. If not Silver RTV will seal it but be cautious.. In other aspects I usually use copper silicone but the silver is what Nissan uses from the factory...Note the timing cover "gasket" you remove... Tis also the most expensive RTV.. Copper will do the job But In the shop with a 12mo. 12,000mi warranty thats my responsibility.. I use the BEST...

BTW........ALWAYS replace any seals (front main) or other Routine Maintance items while your in there....Why have to do ALL this Work for some little 10-15 dollar piece???
 

·
Registered
Joined
·
476 Posts
...it REALLY helps if you pull the oil pan. It's an easier job and cheaper than a head gasket.
I might be mistaken but I do believe it's near impossible or much more difficult to remove the front/oil pump housing without removing the oil base pan, even if the cylinder head was removed. Reason being, the housing cover is held in place with the alignment dowels which means you can't haul up until you pull out and the oil pump leg limits horizontal movement until the oil base pan if taken off. Before you can do that the cross-member and header pipe needs to be removed first. That's the reason why this job is so expensive because half of the engine bay needs to be taken apart.

The ONLY place I used Permatex® Ultra Copper® RTV Silicone was on the original metal matting surface, not the face of the engine housing cover, between the cylinder head and top of the housing cover. For metal gasket replacement or in higher heat and oil resistance Ultra Copper is recommended.
For everything else I used Permatex® Ultra Grey®.

As for there being a price difference in Ultra Copper and Grey there isn't, not at WalMart at least or from what I can remember. Both products are equally as good but Ultra Copper has a slightly different usage than what is required here, in most instances.

Nastynissan made a good point though. Once you remove the front engine cover you will need to replace 2 metal o-rings as well which can be found online for $6 each - search Google for "Sentra timing chain parts" and you should find them unless your local dealer has them cheaper. I paid $19 CDN each from Nissan and I would consider that to be rather expensive for such a small part. Since I used the timing chain guide kit I removed off another engine the o-rings were the only thing I never had.
 

·
Registered
Joined
·
117 Posts
Discussion Starter · #20 ·
I really appreciate all the help you guys have given me on this project. I'm pretty much deep in the middle of it now. I'm only able to work on it for a couple of hours at a time, and it never fails, when I get into the middle of something I find myself needing a tool I don't have. And, since I'm out in the boonies it may be a day or two until I can get it.

Right now I'm in the process of tearing down the engine to get to the chains. It seems rather insane to have to do all this just to change the timing chain, but I guess it comes with the job. It sure makes the dealer's price seem much more reasonable after working on this thing a few days. But, I have to admit, I am enjoying it somewhat, and have learned more about my Nissan than I ever thought I would.

I am a little concerned about lining up the timing marks when I put the new chains in. My timing is so screwed up, because the camsafts were not turning, (I think my idler sprocket is screwed up) neither of the chains are lined up, so it's pointless to mark them before taking them off. It looks like to me, the best approach is going to be to start with the crankshaft gear and work my way up from there when putting on the chains.

As I understand it. the keyway on the crankshaft pulley should be at 12 o'clock straight up, then you just line up the chain links on the stamped marks on the other gears as you make your way up. But, what I don't understand is, do I need to remove the crankshafts or can I just turn them in place to line up the chain links with the stamped marks on the camshaft gears?

Again thanks for all the help. I'll keep you posted.
 
1 - 20 of 30 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top