DIY: Check your valve clearances

[Chris Crash]

Today I noticed on the warranty for my engine, it says

Valve adjustment is considered tune-up. Therefore it is CUSTOMERS RESPONSIBILITY.

So I went out to check the valves to see how off they were, and was pleasantly surprised. All my valves were within 2 thousandths of an inch of the lowest clearance, so I figure it'll be ok.

TOOLS NEEDED:
-30 mm socket
-19 mm socket
-Breaker bar
-Big screwdriver
-Feeler gauges

TIME REQUIRED:
-10 minutes

BIG RED DISCLAIMER: This is to be used a guide ONLY. Neither TN nor the author of this guide are to be held responsible due to any damages, injuries or death caused by the use of this guide.

That being said, let's get to work. Do this on a cold engine.

1) Remove the spark plug wires.
2) Remove the PCV valve and the hose going to the intake manifold.
3) Remove the PCV hose going to the intake tube.
4) Remove the four 30 mm nuts on the spark plug tubes.
5) Using a screwdriver, carefully pry up the valve cover. Avoid damaging the gasket.
6) You may need to finesse the cover out of there, but it can come out, trust me.
7) By turning the crankshaft, set the #1 piston to TDC. With the #1 cylinders valves loose and the #4 cylinders valves tight, it should look like this:

8) Take your feeler gauge and start shoving them between the buckets and the lifters. For the first time, check ONLY the intake valves of cylinders 1 and 2 and check ONLY the exhaust valves of cylinders 1 and 3. The clearances for the intake side should be 0.19mm-0.29mm (0.007in-0.011in) and for the exhaust side should be 0.28mm-0.38mm (0.011in-0.015in). If they are too loose (you can fit a feeler BIGGER than the highest clearance), then you shouldn't worry too much. It's when they are too tight and you can't fit ANY of the accepted clearance feelers in that you have a problem and might want to change your shims to smaller ones.

9) Once you have checked all the valves listed in step 8, rotate the crankshaft 360 degrees, making sure to align the notch to 0 again for TDC.
10) Now, check intake side of cylinders 3 and 4 and the exhaust side of cylinders 2 and 4. Same clearances.
11) Record any out of spec valves, they will be used for calculating the correct shims later if needed.
12) Put everything back together in reverse order, make sure to torque the valve cover nuts to 33 ft-lbs in multiple passes.


EDIT: Can't get the pics up right now. Will edit and post pictures tomorrow!

[peshwa]

[Pvt-Public]

Why would you NEED pics? Have you never seen a valve cover or rocker arms? If you haven't you shouldn't be checking valve specs!!

[jtex2717]

[pmx007PL]

There should be sticker somewhere inside engine room - sticker with valve clearances.

For V6 a bit smaller (intake 0,15-0,25 mm or 0,006-0,010" and exhaust 0,25-0,35 mm or 0,010-0,014").

[LynchburgCSI]

Originally Posted by Pvt-Public

Why would you NEED pics? Have you never seen a valve cover or rocker arms? If you haven't you shouldn't be checking valve specs!!

BIG +1. And with that... sticky time.

[fenixus]

nice, you did it man
I was too lazy to replace any shims haha even though at least 4 valves almost require new shims already ... but I will wait a while before I touch this, it's a PITA. the whole process of measuring is time consuming and exhausting a tad.

edit:
have you actually replaced at least one shim?

[mr1114]

How often should this be checked?

[fenixus]

Originally Posted by mr1114

How often should this be checked?

Haynes says every 60k miles, but in practice every 100k should be fine on most engines without other trouble (like sludging).

[mr1114]

Is it pretty common for the clearances to go out of spec? I've honestly never done it on any car I've owned. Didnt see it as critical and they always ran fine

[fenixus]

Originally Posted by mr1114

Is it pretty common for the clearances to go out of spec? I've honestly never done it on any car I've owned. Didnt see it as critical and they always ran fine

I'd say if you are into engine tune up and trying to keep the car at top notch then do it.
If you feel the car runs fine and engine runs quiet (and no other unexplained trouble present) then forget it.

It's hard to say for me why some engines need this service more than others, but yeah they eventually do fall out of spec (get tightened, not loosened).

[Chris Crash]

Nope I have not replaced a single shim. I'm not worried about it. Will re-check in 20 or 30k miles though, as it's as simple as pulling the VC off..

[fenixus]

Originally Posted by Chris Crash

Nope I have not replaced a single shim. I'm not worried about it. Will re-check in 20 or 30k miles though, as it's as simple as pulling the VC off..

so what were your numbers?

the most time i spent on bending over the engine bay and taking measurement and then notes... way more than 10 minutes for me. took me a good hour total and cause strong pain in my back the day after hehe.

[Chris Crash]

My engine's on the ground

Intakes were between .006 and .009
Exhaust between .009 and .012

So...good enough for me!

[fenixus]

Originally Posted by Chris Crash

My engine's on the ground

Intakes were between .006 and .009
Exhaust between .009 and .012

So...good enough for me!

hmmmm .... if norm (at cold) is 0.007-.011in for intakes and 0.011-0.015in for exhaust then some valves may be out of specs (too tight) ... just saying ...

man, I wish I could pull the engine (no tools, no garage makes it impossible) and do it off car ... it's such a pain to do on car...