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qr25de cam timing without marking chain?

39K views 23 replies 6 participants last post by  drich06 
#1 ·
Hi Guys, I recently pulled the head off my girls 02 sentra ser, and didnt mark the chain on the cam sprockets.
Now I am trying to set the timing back up, and I have no marks to go by on the chain.
The factory yellow paint marks don't line up when the crank is at tdc, spun it a full 360 deg and rechecked.

So how can I set the timing without first marking the chain on removal?
I can't believe nissan would rely on the tech to mark the chain, any other engine I've set timing on has defined marks.

Thanks
-Dan
 
#5 ·
Code:
INSTALLATION
NOTE:
 There may be two color variations of the link marks (link colors) on the timing chain. 
 There are 26 links between the gold/yellow mating marks on the timing chain; and 64  links between the
camshaft sprocket gold/yellow link and the crankshaft sprocket orange/blue link, on the timing chain side
without the tensioner.
1. Make sure the crankshaft key points straight up.
2. Install  the  balancer  unit  and  tighten  the mounting  bolts  in  the
numerical order shown with the following procedure:
CAUTION:
When  reusing  a  mounting  bolt,  check  its  outer  diameter
before  installation. Refer to EM-125, "Balancer Unit Mounting
 Bolt Outer Diameter" .
a. Apply new engine oil to threads and seating surfaces of mounting
 bolts.
b. Tighten them to 45.2 - 51.0 N·m (4.6 - 5.2 kg-m, 34 - 37 ft-lb).
c. Turn them another 90° - 95° degrees (Target: 90° degrees).
d. Fully loosen in the reverse order of tightening to 0 N·m (0 kg-m,
0 ft-lb).
e. Tighten them to 45.2 - 51.0 N·m (4.6 - 5.2 kg-m, 34 - 37 ft-lb).
f. Turn them another 90° - 95° degrees (Target: 90° degrees).
CAUTION:
Check  tightening angle with an angle wrench or a protractor.
 Do not make judgment by visual check alone.
3. Install the crankshaft sprocket and timing chain for the balancer
unit.
 Make sure that the crankshaft sprocket is positioned with mating
 marks on the block and sprocket meeting at the top.
 Install it by lining up mating marks on each sprocket and timing
 chain. 
Limit  : 0.15 mm (0. 0059 in) or more
KBIA0126E
KBIA0122E
KBIA0080E
KBIA0123E
EM-126
[QR25DE]
TIMING CHAIN
4. Install timing chain tensioner for balancer unit.
NOTE:
Chain guide and  tensioner move freely with the caulking  pin as
the  axle. Therefore, bolt  hole position  of  the  three points could
be changed during removal. If points change, temporarily fix the
two mounting bolts on the chain guide and move the tensioner to
match the bolt holes.
 Be careful not to let mating marks of each sprocket and timing
chain slip.
 After  installation,  make  sure  the  mating  marks  have  not
slipped, then remove stopper pin and release tensioner.
5. Install timing chain and related parts.
 Install by lining up mating marks on each sprocket and timing
chain as shown.
NOTE:
Before  installing chain  tensioner,  it  is possible  to change  the
position  of  mating  mark  on  timing  chain  for  that  of  each
sprocket for alignment. 
CAUTION:
After the mating marks are aligned, keep them aligned by
holding them with a hand. 
 Before  and  after  installing  chain  tensioner,  check  again  to
make sure that mating marks have not slipped.
 After installing chain tensioner, remove stopper pin, and make
sure the tensioner moves freely.
 To avoid skipped teeth, do not move crankshaft and camshaft
until front cover is installed.
Pulled that from the Engine Mechanical section of the 2000-2006 Nissan Sentra FSM. Hope it helps you with your problem.
 
#6 · (Edited)
notbinks said:
Code:
INSTALLATION
NOTE:
 There may be two color variations of the link marks (link colors) on the timing chain. 
 There are 26 links between the gold/yellow mating marks on the timing chain; and 64  links between the
camshaft sprocket gold/yellow link and the crankshaft sprocket orange/blue link, on the timing chain side
without the tensioner.
1. Make sure the crankshaft key points straight up.
2. Install  the  balancer  unit  and  tighten  the mounting  bolts  in  the
numerical order shown with the following procedure:
CAUTION:
When  reusing  a  mounting  bolt,  check  its  outer  diameter
before  installation. Refer to EM-125, "Balancer Unit Mounting
 Bolt Outer Diameter" .
a. Apply new engine oil to threads and seating surfaces of mounting
 bolts.
b. Tighten them to 45.2 - 51.0 N·m (4.6 - 5.2 kg-m, 34 - 37 ft-lb).
c. Turn them another 90° - 95° degrees (Target: 90° degrees).
d. Fully loosen in the reverse order of tightening to 0 N·m (0 kg-m,
0 ft-lb).
e. Tighten them to 45.2 - 51.0 N·m (4.6 - 5.2 kg-m, 34 - 37 ft-lb).
f. Turn them another 90° - 95° degrees (Target: 90° degrees).
CAUTION:
Check  tightening angle with an angle wrench or a protractor.
 Do not make judgment by visual check alone.
3. Install the crankshaft sprocket and timing chain for the balancer
unit.
 Make sure that the crankshaft sprocket is positioned with mating
 marks on the block and sprocket meeting at the top.
 Install it by lining up mating marks on each sprocket and timing
 chain. 
Limit  : 0.15 mm (0. 0059 in) or more
KBIA0126E
KBIA0122E
KBIA0080E
KBIA0123E
EM-126
[QR25DE]
TIMING CHAIN
4. Install timing chain tensioner for balancer unit.
NOTE:
Chain guide and  tensioner move freely with the caulking  pin as
the  axle. Therefore, bolt  hole position  of  the  three points could
be changed during removal. If points change, temporarily fix the
two mounting bolts on the chain guide and move the tensioner to
match the bolt holes.
 Be careful not to let mating marks of each sprocket and timing
chain slip.
 After  installation,  make  sure  the  mating  marks  have  not
slipped, then remove stopper pin and release tensioner.
5. Install timing chain and related parts.
 Install by lining up mating marks on each sprocket and timing
chain as shown.
NOTE:
Before  installing chain  tensioner,  it  is possible  to change  the
position  of  mating  mark  on  timing  chain  for  that  of  each
sprocket for alignment. 
CAUTION:
After the mating marks are aligned, keep them aligned by
holding them with a hand. 
 Before  and  after  installing  chain  tensioner,  check  again  to
make sure that mating marks have not slipped.
 After installing chain tensioner, remove stopper pin, and make
sure the tensioner moves freely.
 To avoid skipped teeth, do not move crankshaft and camshaft
until front cover is installed.
Pulled that from the Engine Mechanical section of the 2000-2006 Nissan Sentra FSM. Hope it helps you with your problem.
Thanks for the effort, are you able to get the pictures?
I still don't see which marks I am lining up if the yellow paint marks on the chain dont line up with anything when the crank is at tdc.
Turning it around and around will not make a difference, the marks will always be in the same place when It comes back around.
I'm a bmw tech, and used to a set of cam blocks that set the cams in the right position, or marks on the cyl head that line up with the cam sprockets.
Not feelin nissans timing design.
 
#7 ·
#8 ·
The best way to know for sure that your cam timing is set correctly is to pull the front cover off the engine. There will be an orange paint mark that lines up with a mark on the crank gear, and then line up the two yellow marks with the two marks on the cam gears.
 
#9 ·
Thanks man.
I wonder if when the the orange mark on upper the timing chain is lined up with the mark under the cover, is the balancer tdc mark lined up with the pointer on the cover?

At the factory, they must set up the timing away from tdc.
I suppose I could just line up the paint marks with the cam sprocket marks, and turn it by hand to see where the crank and cams end up.
Trying to avoid removing the complete front cover.

-Dan
 
#10 ·
Do you have any reason to believe that the timing chain slipped on the crank gear? If not, you line up the TDC mark on the crank pulley with the mark on the front cover. Then line up the mark on the cam gears with the yellow marks on the timing chain. If you have it set correctly, the lobes for the #1 cylinder should be flat and pointing away from each other when at TDC.
 
#11 ·
Syhnthetik said:
Do you have any reason to believe that the timing chain slipped on the crank gear? If not, you line up the TDC mark on the crank pulley with the mark on the front cover. Then line up the mark on the cam gears with the yellow marks on the timing chain. If you have it set correctly, the lobes for the #1 cylinder should be flat and pointing away from each other when at TDC.

I don't believe the chain has slipped on the crank gear. Looking at pictures, and reading the instuctions, there is not enough room for it to skip a tooth due to clearance between the gear and front cover. I havent removed the front cover, so It should be good.
But with the tdc mark lined up with the pointer, and the #1 cyl cam lobes pointed out (exh towards front, intake towards rear), the paint marks aren't Are 5- 10 links away from the marks on the gears. This engine is weird.
 
#12 ·
Well I noticed that you said that turning the crank over would not change how the marks match up, that's not true. The marks only match up every other revolution. So turn the crank over until you get the yellow marks back up to the top and see if they line up after that. Good luck
 
#17 ·
dansciol said:
Right you are, I was refering to the comment maked by jarrett2k above.
I've tried turning the crank 360deg a few times, they still dont line up.
Turning the crank 360 deg will only move the timing chain a little bit. Turn the whole timing chain 360* and see if it lines up after that.
 
#19 ·
Ok I got her running again.
What I did was: with the cam sprockets removed, and spark plugs out, I spun the engine over by hand at the crank pulley, until the 2 yellow paint marks lined up with the corresponding bolt head/hole in the picture here:
Pic provided by nightrider, Thanks!
The service manual pic doesn't show the paint marks on the chain.
Once the paint marks line up, and the crank is at tdc, pointer is lined up.
I can slip the cam gears back on, and check that the #1 lobes are equally pointed outwards.

Thanks guys
 
#23 ·
Ok I got her running again.
What I did was: with the cam sprockets removed, and spark plugs out, I spun the engine over by hand at the crank pulley, until the 2 yellow paint marks lined up with the corresponding bolt head/hole in the picture here:
Pic provided by nightrider, Thanks!
The service manual pic doesn't show the paint marks on the chain.
Once the paint marks line up, and the crank is at tdc, pointer is lined up.
I can slip the cam gears back on, and check that the #1 lobes are equally pointed outwards.

Thanks guys
i pray youre still active, PLEASE HELP
 
#22 ·
nightrider46 said:
np. glad u got it running. I actually edit that picture so ppl can see the yellow markings and stuff. I dont use the service manual, it sucks ***.
Yea thats what the service manual pictures are lacking.
I cant belive they wouldnt just make a knotch for each cam gear on the timing cover. That would make things alot easier.
Thanks
-Dan
 
#24 ·
Soooo this is for my 04 altima, not sentra, but still the same qr25, i removed the cylinder head to do a headgasket job, but like a dummy i didnt mark the cams. Is there anyway i can retime my engine without pulling off the front engine cover? Ive looked at other threads and they arent seeming to help. Fixing this is an emergency as its my daily, and only vehicle. If someone could email me text me video chat me whatever to help that would be amazinf. This is a bad situation.
 
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