Valve Adjusting

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gbestwick

Guest
#1
Hello everyone!

Now, to start off with, I'm asking about a Canadian version of the Micra K10 with the MA12 engine in it. I believe the engines are identical enough for you fine fellows to answer these questions.

Now, I haven't had the valve cover off my engine yet, but, I know there is some serious valve work/adjustment needed. The tick is driving me bonkers. Now, are the valves adjustable on the MA12. Do I use shims? Set Screw? More to the point, should I even bother to take off my valve cover.

Any info/pics would be very helpful.

Cheers!
 
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G

gbestwick

Guest
#2
Ok, too late.

Alright, as no one managed to answer this, I dove in and found out for myself!
:glare:

So, for those out there that *haven't* opened up their engines, heres the goods.

The Canadian K10 has the MA12 engine in it with Adjustable Tappets on the valves. Actual clearance required, don't know, don't have the book. However for those thinking the *tick* *tick* *tick* is enough to drive you nuts, here is a guide.

Quick instructions are as follows...
-1. Go for a burn around the block, and/or the store, beach, or some place. Make sure the engine is warm. Go park.
0. Put the car in Neutral (MANDATORY), Set the E-Brake, and block the wheels.
1. Remove the plugs, and remove the coil wire from the coil to the distributor.
2. Remove the air cleaner cover via the thumb screw, and remove the filter.
3. Remove the 2 10mm bolts securing the air cleaner to the valve cover
4. Disconnect the various hoses from the air cleaner, making note of where they go. You may require a Philips screwdriver to do this.
5. Remove the 2 14mm nuts securing the Valve Cover to the
6. Jiggle the Valve Cover, making sure not to hurt it, but enough to loosen the seals on the securing bolts.
7. Remove the cover, ensuring to flip upside down rather promptly to make sure you don't get oil everywhere!
8. Starting at one end of the engine, rotate the engine by some means till you get the cam positioned so that it is not actuating the valve, preferably 180deg from the lobe of the cam. Because the plugs are out, this'll be a piece of cake.
9. Set the valve to the appropriate distance by putting a Flat head screw driver into the set screw, backing off the 10mm nut, unscrewing the set screw *just enough* to slip the feeler in easily, then tightening the screw down till it makes contact with the feeler. The feeler should still come out without much resistance. With this all in place, tighten the nut. Repeat 7 more times until you are satisfied, or at least until they are in spec.
10. Clean the valve cover mating surface. Ensure it's clear of oil. Clean the valve cover gasket. It'll be covered in oil. Clean with a clean rag, and put a *THIN!!* coating of RTV on it. Preferablly black, as it looks the nicest!
11. Put the rubber washer doodads back on the retaining bolts.
12. Torque the 2-14mm nuts down to ???? (Tight enough to secure, not to bend your cover!)
13. Put the air cleaner back in place, Reattach the hoses to your air cleaner.
14. Put the 2-10mm bolts back to retain the air cleaner.
15. Put your air filter back in, and the air filter lid back on, securing with the wing nut.
16. Put the plugs back in, and their associated plug wired.
17. Reattach the coil to distributor wire.
18. Start your engine and make sure you didn't make matters worse!


Now, can anyone fill in a few bits of info.

1. Torque specs on the Air Cleaner to valve cover bolts.
2. Torque specs on the Valve Cover to Cylinder head bolts.
3. Hot Clearance of the tappets to valves.

Cheers
 
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G

gbestwick

Guest
#4
Thanks

Thanks Paul!

If there is a "how to" section in this website (that I haven't found) I'll add your info and add my article to that area.

Cheers
 
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M

mrmaz

Guest
#6
Hi good post:wow: , just thought i'd give some feedback/comments which you may find useful?o_O

1. Remove the plugs, and remove the coil wire from the coil to the distributor.
I alway find these engines cool down rather quickly, so by the time you get to the last few valves, I'm questioning if the engine is still 'hot' enough for the adjustments to be accurate!! So I tend to leave the plugs in:grinning: . But you right about step 8. Don't see the point in removing the coil wire?


8. Starting at one end of the engine, rotate the engine by some means till you get the cam positioned so that it is not actuating the valve, preferably 180deg from the lobe of the cam. Because the plugs are out, this'll be a piece of cake.
If you rotate the crankshaft clockwise to TDC (pulley notch aligns with the O mark). Don't rotate it the otherway, nor from the camshaft as the timing belt may slip!

You can then adjust four valves in one go:

If No 1 is on compression stroke (No 1 inlet valve just opened and closed)
No. 1 - Inlet
No. 1 - Exhaust
No. 2 - Inlet
No. 3 - Exhaust

or if No 4 is on compression stroke (No 4 inlet valve just opened and closed)
No. 2 - Exhaust
No. 3 - Inlet
No. 4 - Inlet
No. 4 - Exhaust

Once you adjusted 4 valves, rotate the crankshaft 360 degs and adjust the other 4.

9. Set the valve to the appropriate distance by putting a Flat head screw driver into the set screw, backing off the 10mm nut, unscrewing the set screw *just enough* to slip the feeler in easily, then tightening the screw down till it makes contact with the feeler. The feeler should still come out without much resistance. With this all in place, tighten the nut. Repeat 7 more times until you are satisfied, or at least until they are in spec.
Torque Settings for Valve locking nuts are 8 to 11 lbf ft, don't know how important this is?

10. Clean the valve cover mating surface. Ensure it's clear of oil. Clean the valve cover gasket. It'll be covered in oil. Clean with a clean rag, and put a *THIN!!* coating of RTV on it. Preferablly black, as it looks the nicest!
I tend to skip this, never had any leaks!! But good practice.

12. Torque the 2-14mm nuts down to ???? (Tight enough to secure, not to bend your cover!)
Nuts are domed so you shouldn't do too much damage, but as a torque is specified, use it!

Laters...
 

Micra Jim

Ex. Club Member
#8
thanks for this, sorry to bump an old thread, but i have a question. My friend told me i need to replace the rocker cover rubber gasket and seals? Is this right i f i just want to adjust my valve clearances? Where would i get these parts from? Thanks for any info.

ref: k10 94k.
 

SammoHung

Ex. Club Member
#9
usually its not necessary to replace these everytime the cover comes off

Ive had mine on and off about 4 times with the original seals & gasket (109k miles) and there are NO leaks (or potatoes) anywhere,

Just make sure tha gaskets, seals and mating surface are clean and lubed with a bit of fresh engine oil when replacing the cover


Eventually the rocker cover will compress the gasket too much and the cover fixing dome nuts will bottom out before sealing the cover properly...in this case you can get a replacement from Nissan for around 6 quid IIR
 
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R

RTLkyuubi54

Guest
#10
gonna have to do this tomorrow :D

After adjusting, rotate the engine by hand twice just incase you have droped a massive ball and a valve clashes a piston.

Ryan.
 
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