What up ... as some of you may know, I've been asking abou valve adjustments for a while. I finally did my own today after 30k miles on my car. Nothing was really out of whack and I only adjust one valve, but here's a little writeup for anyone else that hasn't done it. I would have pictures and step by step instructions, but my olympus is dead ... for all you that wanted pictures, blame Olympus or buy me a new camera. =)
Note: this was done on my 98 Base Prelude
Tools Needed:
8, 10, 17, 19 mm socket
17 mm wrench
Torque Wrench
Tappet Adjuster - Part# 07MAA-PR70110 ($20.81)
Tappet Locknut - Part# 07MAA-PR70120 ($32.88)
Honda Bond - Part#08718-0001 ($10.57)
Valve Cover Gasket - Part#12341-P13-000 ($7.93)
Feeler Gauges - Got mine from Sears ... made by Craftsman ($5.99 I think)
Instructions:
1. Loosen the drivers side wheel, jack up the front end of the car and put it on jackstands. Take the drivers side wheel off. I left my car in 4th gear, but I think any gear will work.
2. In order to do this, you need to take off the valve cover. In order to do this, you have to take off all the connecting parts first. First step is to take off the spark plug cover then remove the spark plug wires by just pulling them out. Set these wires aside.
3. Take off the ignition coil by first disconnecting it from the alternator (one plug you just pull, the other you need an 8mm socket). Then undo the plastic gray zip tie thingy by pulling up on the tab. Next, unscrew the bolt holding it to the valve cover (10mm). you should now be able to pull it diagonally out enough to swing it to the back of the car.
4. Remove the grounding wire connected to the valve cover near the cam gears (10mm).
5. Take off the air hose that leads to the intake by pushing the clamp off the valve cover. I have an aem and when I replaced this tube, the stock one was really hard to get off. It took a lot of prying and I eventually got it off with one of those hook like tools.
6. Take off the PCV hose which you can just pull out .. it's on the right side towards the back near the cam gears. Just pull up.
7. Unscrew all 8 bolts holding the valve cover in place (10mm). Notice there are 2 that are located underneath the ignition coil (or where it was).
8. I loosened my oil cap, but I dunno if I really needed to ... next use a flathead screwdriver to pry the valve cover off. Wrap the screwdriver with something so you don't scratch things up. If you're valve cover has never been taken off, concentrate on the ends of the valve cover where the cam gears/cams are. This is where Honda puts a lot of Honda Bond. The rest should come off easily. Voila ... valve cover removed.
Valve Adjustment:
9. Get your 19mm socket and look in your drivers side wheel well ... there should be a star like hole in the wheel well towards the engine. This is your access to the crank pulley. Stick your socket in there and make sure you're on the bolt.
10. Take a look at your cam gears ... if you don't know what they are, they're the gears on the far right side (when standing in front of the car) that were once covered, but are now naked. Look on the side and you should be able to see either an arrow or a dash mark on the gears. If you don't see the arrows on the gears, turn the 19mm socket on the crank pulley counter clockwise (ie direction of the rotation of the tires when moving forward). It may take a lot to do this, but if it's giving you some hastle, get a pipe and put it on the end of the wrench. Turning the crank will turn the engine and do so until the arrows are pointing straight up and one of the dashes is lined up along the plastic.
11. Use your feeler gauges and see if the intake and exhaust valves at the #1 piston are ok. Here are the correct ranges ...
Some people say you don't need to use the tappet screw adjuster, but I think it's just nice to buy it to make life easier. A flashlight is really useful if you don't know what you're doing, but bacisally use feeler gauages on one side and the tappet screw adjuster on the other. If you need to adjust the valves, loosen the nut, then adjust the screw, then retorque the bolt with a 17 mm wrench/socket (20 Nm / 14 ftlb). Double check clearance cause when you tighten down the bolt, sometimes the screw will turn also. Play around with things before you adjust ... I did.
12. Turn the crank pulley bolt counter clockwise until the cam gears turn 90 degrees and the arrows are aligned on the left side of the plastic belt cover. Adjust valves at piston #3.
13. Repeat 12. and adjust valves at piston #4.
14. Repeat 12. and adjust valves at piston #2.
15. Double check all your valves ... then you're done.
Reinstallation
16. Take a look at the gasket that lines the valve cover .. you'll notice some gray stuff around the semicircles where the cams are located. you can either use a whole new gasket, but I just reused mine. apply some Honda Bond in the same places and pop that sucka back on. Screw the valve cover back on just like you would a wheel ... take 2 or 3 steps to tighten them down and go in this order ... (I hope this makes sense):
Originally posted by jtown 1. Loosen the drivers side wheel, jack up the front end of the car and put it on jackstands. Take the drivers side wheel off. I left my car in 4th gear, but I think any gear will work.
Valve Adjustment:
9. Get your 19mm socket and look in your drivers side wheel well ... there should be a star like hole in the wheel well towards the engine. This is your access to the crank pulley. Stick your socket in there and make sure you're on the bolt.
Why leave it in gear if you are using the crank pulley to rotate the engine? You should be in neutral. If you are using your wheel to rotate the engine (instead of the crank pulley)...then you leave it in gear. Or maybe I misunderstood you.
Originally posted by Vamz I think he did that, so the car wouldn't roll away, parking brake is kinda whimpy, instead of blocks
The transmission actually doesn't have a whole lot to do with the rear wheels. At least it doesn't on my Prelude . . . .
Instead of using the crank pulley, isn't it possible to rotate the engine by leaving it in 5th & turning the wheels?
From a performance standpoint, would it be better to adjust the valves towards the larger end of the range? I mean, would making sure the intake valves are set all the way to .19mm, and the exhaust to .21mm help breathing in the top end? Kind of like a (very) mild poor-man's cam upgrade.
And it's also worth mentioning, this is supposed to be done with the engine stone cold. Most people recommend letting it sit overnight.
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Originally posted by Daemione Instead of using the crank pulley, isn't it possible to rotate the engine by leaving it in 5th & turning the wheels?
Yes... and easier to rotate into the exact position you want. The front wheel provides leverage.
Quote:
Originally posted by Daemione From a performance standpoint, would it be better to adjust the valves towards the larger end of the range? I mean, would making sure the intake valves are set all the way to .19mm, and the exhaust to .21mm help breathing in the top end? Kind of like a (very) mild poor-man's cam upgrade.
Other way around...you want them a bit tighter. But it's hard enough just to get them into the spec "range" unless you're more experienced at it...which I am not.
...I use a SnapOn 10mm value adjustment wrench to adjust the valves.
It's about $24.00 and contains a socket with a handle attached to it, and a screw driver in the center to keep the valve adjustment in place when you tighten the nut.
And it's also worth mentioning, this is supposed to be done with the engine stone cold. Most people recommend letting it sit overnight.
It's important to also note that the dealer will not be able to adjust your vavles while completely cold. They have to get the car into the service bay, and the unually means running the engine....
It's important to also note that the dealer will not be able to adjust your vavles while completely cold. They have to get the car into the service bay, and the unually means running the engine....
-Gerhard
unless they leave it in the service bay overnight.
ya, I couldn't find the snap on tool for cheaper than the honda one for some reason. plus I was ordering **** from hparts anyway.
Originally posted by Lostboy7500 I thought it was better for the valves to be loose if anything than tight....Im pretty sure Im right but someone please clarify.
Too loose or too tight is bad. To be safe, you should just follow the Honda specs and stay "within" the range.
Here's a comment from Darth Luder that is good advice...
Quote:
Thats if you can differentiate between the extra thousandth. Most of you guys reading this, be careful, because it is a fine line if you do it yourself. Staying within spec is just fine. And always remember, a well maintained engine will run better than one that hasnt been adjusted, oil changed, tuned, etc...
Below are some past discussions that should claify things...the first one is in the Prelude FAQs. thread 1 thread 2 thread 3
I must say, very good write up. I am glad I did a search on my name. Cool to see I still get quoted after so long. I am only a few thousand away from my next valve adjustment also so this will be a good print out to have with my service manual.
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If you only knew the power of the Lude...
'94 Porsche 968 - National PCA HPDE Instructor
'98 Red Base Prelude - 02 & 03 DSP Champion - Sold
"Straights are for fast cars. Turns are for fast drivers." - SCCA Solo2
its really easy to do if u ahve the helms manual. i did it last weekend and its not very hard at all. most of my valves were still in stock specs just on the loose end of the stock spec so i tightend them to the minimum end of the stock specs. my intake valves seemed more loose then my exhause valves, not real sure why, but anwyayz, i would say anyone who has some mechanical knoweledge can do this
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I can drive a stick, but why do i own an SS you ask? Well a poor college student will usually take anything his parents buy him, and i my friend am a poor college kid indeed.
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I am only a few thousand away from my next valve adjustment also so this will be a good print out to have with my service manual. 
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