cactusfarmer

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?

 

Centurion

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.

cactusfarmer

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.

nissannut

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

__________________
Barry
1993 King Cab SE 4wd- SAS, 35s + stuff
1992 Pathfinder SE 4wd - SAS 33s + stuff
2004 Quest SE

cactusfarmer

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.

 

nissannut

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

__________________
Barry
1993 King Cab SE 4wd- SAS, 35s + stuff
1992 Pathfinder SE 4wd - SAS 33s + stuff
2004 Quest SE

tonsters200

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

johnand

I think I may have a copy of the entire TSB. I'll check when I get home tonight.

__________________
1991 Sentra SE - Auto to Manual swap, 15" Rota Subzero's, 205/50 Kuhmo 712's, Tsuru headlight conversion, SE-R front and rear disc brakes, SE-R front and rear swaybars, SE-R throttle body, SE-R rear inner taillights, HS CAI and Header, H&R springs, Koni shortened struts, ES Hyperflex kit, B&M Short Shifter, Autometer gauges.

cactusfarmer

Thanks. I'd sure be curious to see how they say go about changing the timing chain without taking the cylinder head off.

cactusfarmer

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.

 

Centurion

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
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cactusfarmer

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.

nastynissan

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.

__________________
****Nothing worth saying or showing****

cactusfarmer

[quote=nastynissan]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?

johnand

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.

__________________
1991 Sentra SE - Auto to Manual swap, 15" Rota Subzero's, 205/50 Kuhmo 712's, Tsuru headlight conversion, SE-R front and rear disc brakes, SE-R front and rear swaybars, SE-R throttle body, SE-R rear inner taillights, HS CAI and Header, H&R springs, Koni shortened struts, ES Hyperflex kit, B&M Short Shifter, Autometer gauges.