Valve Clearance Adjustment on 2003 – 2007 Accord
This is the procedure for a valve clearance check/adjustment on the 4cyl. 7th generation i.e. 2003 – 2007 Honda Accord. As per the owners manual, this procedure is recommended every 110,000 miles or if the valves become noisy. Intake valves let the air-fuel mix into the combustion chambers whilst the exhaust valves vent the burnt gases into the exhaust system. It’s widely said that exhaust valves tighten while the intake ones loosen over time (for solid valves though). The valve clearance for this model is:
Intake: 0.21mm – 0.25mm (0.008inch – 0.010inch)
Exhaust: 0.28mm – 0.32mm (0.011inch – 0.013inch)
Materials:
Feeler gauges; curved feelers gauges are better (I used; intake-0.22mm, exhaust-0.30mm), torque wrench, 10mm jam nut tool (recommended but a 10mm ring spanner & flat screwdriver will do. The jam nut tool makes the process easier), 19mm socket, wrench & extension, and 16mm spark plug socket.
Steps:
NB: The firing order for this engine is 1-3-4-2 and as such, the valve clearance check/adjustment will follow this order. Cylinder 1 is the one closest to the power steering pump.
Valve clearance check and adjustment should only be done on this model with the engine temperature at 38°C or less. Best done first thing in the morning!
1. Remove the front right wheel: This is to gain access to the 19mm crankshaft bolt that would be turned to achieve top-dead-centre (TDC) position for the different pistons. Attach the 19mm socket to the crankshaft bolt but do not turn.
19 mm socket with extension attached to the crankshaft bolt
2. Remove the negative battery terminal: For safety purposes.
3. Remove the valve cover: The steps for this have been covered in this previous post; Valve cover gasket replacement on 2003 -2007 Accord
4. Remove the spark plugs: Remove using the 16 mm spark plug socket and set aside. I usually keep the plugs such that I know which one came out of which cylinder.
Image showing the camshafts and rocker arms
Above is an image showing the exhaust and intake camshafts and their respective sprockets. The red circle also shows the locking screw which overlies the valve lash.
5. Check and adjust valve clearance: valve clearance check and adjustment should only be done at TDC positions. Set the piston in cylinder 1 to TDC (TDC is the position of the piston at which it is farthest from the crankshaft). To do this, there are punch marks and TDC dashes on both intake and exhaust camshaft sprockets. The punch marks on this model are highlighted by Honda in orange ink. At TDC the punch marks and TDC dashes would be at certain distinctly related positions. By turning the crankshaft bolt clockwise the exhaust and intake camshaft sprockets will turn clockwise as well to achieve a TDC position. A 180° degree turn of the crankshaft will turn each sprocket 90º.
At TDC in cylinder 1, the TDC dashes on the sprockets will be aligned to each other i.e. exhaust TDC dash will be at 3 o’clock position while that on the intake sprocket will be at 9 o’clock position. Both punch marks will be at 12 o’clock position. Because of the ABS lines and pump are in the way, getting pictures of the TDC marks is difficult. However, I produced a diagram showing the positions of the both marks at TDC on the different cylinders.
Punch mark on exhaust camshaft sprocket highlighted in orange and at 12 o’clock position at TDC on cylinder 1
Position of punch mark on intake sprocket at TDC position on cylinder 1
So to achieve TDC on cylinder 1, turn the crankshaft clockwise until the marks on the sprockets align to those shown above for cylinder 1. Then check the valve clearance at the intake valves using the set feeler gauge.
Checking the valve clearance on cylinder 1 intake valves
If the valve clearance or lash is out of spec, use the jam nut tool to slightly loosen the locknut and with the included flat screwdriver loosen or tighten the adjusting screw accordingly. Tighten the locknut and then recheck the clearance to ensure it is within spec. Torque for locknut is: intake – 20Nm & exhaust 14Nm.
Adjusting the intake valves on cylinder 1
After this do same for the exhaust valves with the right feeler gauge. Next, turn the crankshaft bolt 180° clockwise to attain TDC on cylinder 3 (Refer to position of TDC marks for cylinder 3 in the diagram above). Check and adjust valve clearances if necessary. Turn the crankshaft another 180° for TDC on cylinder 4 and after doing the needful, turn the crankshaft another 180° for TDC at cylinder 2.
In the end, the valves needing adjustment on mine were intake valves on cylinders 1 and 3 and the exhaust valves on cylinder 2.
Adjusting exhaust valves on cylinder 2
All said and done, replace the valve cover replacing the valve cover gasket if worn. The steps for this can be found here. Cheers!
We all know a major problem that can happen is stripping the valve cover stud bolt. NOTE: 8.7 lb ft torque for the nuts.
The part is 90011-PNA-003 called the head cover bolt/ stud bolt. It usually needs to be replaced if stripping or breakage occurs.
I believe according to a repair manual the bolt is torqued to 16 lb ft. But again I am not 100% sure so someone please verify.
Thanks for the good write up!
I don’t understand why you removed the spark plugs? I also don’t understand why anybody would remove the wheel (some suggestions on here). You can fully lock the wheel or, just turn the cam shaft with a spanner, Think it’s 27mm but that’s from memory.
Removing the plugs makes it much easier to turn over the engine – no compression to ‘fight’.
Hi, i did the adjustment within spec on my 03 accord Nd it now has ticking. Drives normal though. Should i re adjust or what? I adjusted as stated making sure to have correct tdc.
Hi Ray,
My thinking is that the valve lashes could be a tad wider. What clearance values did you use?
I would recommend a readjustment using the lower limits of the clearance values especially for the intake valves. You know depending on the way you hold the feeler gauges you may experience some drag even if the clearance is out of range. The feeler gauge has to be pependicular to the valve lash for best results. I hope the engine was cold and you did the adjustment under a shade.
Finally know you are not alone! Had to do mine twice to get the desired result.
I did the job with the car cold. I used intake .229 and exhaust .305 mm. It was the middle range for the range given under my 03 lx 4 cyl accord sedan. I probably should use .205mm for intake and slightly lower for exhaust? The guages were perpendicular and had slight drag when adjusting. Triple/ quadruple checked for accuracy. I think i will use lower range for the redo.
By the way, should the rockers move up/down while in tdc for a cylinder. I remember that i jiggled them a bit to check clearances. I know they are supposed to click when you jiggle them but the movement range should be within the guage setting right??
No need for replacing the gasket again? Should just remove honda bond and re apply in those 4 spots?
Thanks again
I would use the gauges that are closest to the lower clearance limit for the redo. That was what I did in my own case.
The rocker arms would move a bit and at TDC for the cylinder. Its an additional way to confirm TDC. It is logical to think that the range of movement should be within clearance of the valve, I do concure but not 100% sure. Will look up.
No need to change the gasket, just reapply HondaBond at the 4 points and you are good.
Final point is that level of drag is subjective and in time with repeated exposure we get what feels just about right. However, you could use same amount of drag as at first since you are moving to lower gauges.
Do let me know how it goes.
I also stripped the rear bolt that bolts into the valve area and sticks out of the valve cover in order to hold the cover. I ordered a new one and i would like to know if there is a proper way of installing that. I.e. Locktite/ threadlocker? Btw I will redo the lash adjustment in a few days and let you know of the results. Thank you for replying!
Hi Ray,
So sorry for taking a long to reply, was caught up with work JJ
I guess a thread locking compound will be appropriate for the part of the bolt that shouldn’t loosen while loosening the nut on the valvecover.
Not sure if there’s any special procedure to it, but I’ll just see if I can find the torque specs on the service manual. I’ll update in a bit
The firing order he has up here is incorrect. The correct firing order goes (1,3,4,2)
Hello D fresh,
1,3,4,2 is exactly the firing order I have in the post. You may want to look through again as there is no error in the firing order written.
Do both front wheels have to be jacked up? Do you have to put it into Neutral to turn the crankshaft bolt?
Thanks for the great write up.
Hi Blue,
Great to have you.
Only the right front side of the vehicle would require to be jacked up. The position of the gear does not affect turning the crankshaft bolt. You can leave the transmission in Park.
if it is a standard you will need to have it in neutral. i almost dropped mine off the jack stands
Fist,let me say thank you.this is the best information that i have found for what i was looking for…every other info ived looked at was just getting me confused. And your info is the best one that explained evrything step,by step without confusion…thank you again. ..sincerely, ,rafael.
You are welcome Rafael. Glad to hear you found the info useful. All the best.