Due to cam lobe wear, i have decided to embark on its replacement as a more permanent solution to filling.

I have a PDF file of 2003-7 Service manual. I have not seen a particular process of this job but have seen related processes. I have put together a process of my own. However i am at lost to skip or not to skip one vital step that can make the job easier or complicated. That relates to either removing timing chain tensioner, locking it or none. My aim is to finish the job without having to open timing chain cover and resetting the timing chain, it will be tedious if i have to do that due to lack of space.

Step 1: Remove Valve cover
Step 2: Loosen the exhaust cam pulley bolt
Step 3: Loosen the Camshaft position sensor pulse plate at the other end of the camshaft (this is required because i envisage the pulse plate isnt exactly same with the source camshaft)
Step 4: Loosen all camshaft holders
Step 5: Bind by means of a wire the exhaust pulley to the chain (this is to prevent jumping)
Step 6: The next step is where it gets tricky because once camshaft goes out the pulley will be pulled down by the chain auto tensioner and we may not be able to pull it back up and slot in the new camshaft. 2 ways i have in mind. 1 is to open the chain auto tensioner hole (Pic 1 item 2) and locking it (the procedure is in the service manual option 2 simply fixing a support screw driver below the camshaft before removing the shaft.
Step 7: Remove the pulley bolt and pull out the old shaft and insert the new one (they have a guide that will automatically put it in correct position as show on pic 2 which shows the replacement shaft)
Step 8: Work back in reverse order and check valve clearances before closing the cover.

My other concern is that the shaft which i have seen to have a different pattern only on the sensor plate may not have been sourced from a K24 engine. The service manual has exhaust cam lobe height the same for 2003-7.

I just hit a wall.

The the sourced camshaft isnt exactly same. The sourced one has another set of 4 contact points for something that obviously my exhaust cam system doesnt have. The lobe is wider and height i am yet to find out.

I am not willing to remove my in own to have compared to every millimeter. Meanwhile a sub has been ordered but in this location, am not hopeful. I may have to abort.

Pic 1 is lobe 2 of new
Pic 2 is lobe 2 of mine
Pic 3 is lobe 1 of mine

Lobe 3 and 4 of mine look exactly like 1 in pic 3 but even worst.

No 3

Interesting. That's some wear. Following the thread.

9icetoo:
Interesting. That's some wear. Following the thread.

It got me scared. I have not seen such wear before.

Anyways, the job was aborted. As a temporary measure, i reguaged the exhaust valves to accomodate the lobe wear.

K24 engines like mine mostly have 0.28-0.32mm as exhaust valve clearance. I had when i discovered the lobe wear set all exhaust valves with a 0.30mm valve feeler guage. That led to more noise.

So as a compensative measure, i reset the valves according to level of wear though not with specifics. One instrument that would have been helpful if i had was a venier calliper. So instead of 0.30mm for all valves, i varied it as follows.

Cylinder no 2 - 0.30mm standard (wear signs only)
Cylinder no 1 - 0.26mm with 0.02mm estimated as wear (lesser wear compared to 3 and 4)
Cylinder no 3,4 - 0.23mm with 0.05mm estimated as wear (worst wear)

The result was impressive. I have never heard my engine this quiet. I only fear that my estimations could go wrong and lead me to burnt valves. I envisaged that the wear of my cam lobes is worst than 0.05mm as estimated.

Nice work. Will be doing wifeys city sometime next year. It should be due for a valve adjustment then.

I finally got to change the camshaft yesterday. It was an easy job that i had no courage to embark on my own so i asked my mechanic to do for me. It was schedule for early in the morning so that we dont have to let the car cool. So the job was done at my house.

Am sorry, i didnt take any pictures.

A bit of background on the subject. I did some research and found out this is a serious problem affecting most Honda K24A4 engine and others. My mechanic confirmed that some few days ago, he worked on a similar car and mine was small compared to the other car. Research did mention that most people changed the exhaust camshaft and rocker arms. The last time i opened the cover i didnt see any wearing of the rollers on the rocker arms that make contact with the camshaft. So i decided i will be fine with only the camshaft. Besides, since the engine is prone to such wear, most camshafts i hav seen at the Apo mechanic village Abj had either worn or showing initial signs. So getting a complete one was difficult.

Anyways, after installing, we had to readjust the valves back to stock as i used smaller guage last time to take care of the worn lobes. The specs were
Intake 23+- 2mm
Exh 30+-2mm

Valve guage available to me this time had only 20, 25 and 30mm. So i used 25mm for intake and 30mm for exhaust.

Result was very bad as the valves became noisier than before the work started. I was confused why but only thought my mechanic probably did do the settings well. So i decided to reguage the valves myself with great care and time.

I worked on the guage this morning which took me several hours. The result wasnt much different.

Now my thoughts are that the rollers of the rocker arms that male contact with the lobe might have worn too. Valve noise is anoyying so i have scheduled to open the cover again tomorrow. There was one rocker arm that had too much play which i reguaged a number of times but wont stop the noise.

This time i have no 28mm to make it tighter. The only thing i can do is use 25mm but with more play then check with 30mm to make sure am in the range.

Another problem i encountered of recent was a pinging sound. Even after this job, its still there especially with driving with. My suspicion is carbon deposites

Happening right now.

Find pics attached

Interesting. Following

Nigeria's first auto only forum- www.partboyz.com/forum

Out of desperation for a quiet engine I rechecked all valves and adjusted were necessary. I found the 25mm too free on some intake valves which i adjusted such that the drag on the guage was very much to probably achieve 23 or 24mm. On the exhaust side, i adjusted all with the same 25mm but having too little drag to achieve 28mm.

This morning's DIY was a huge success. The engine is quiet but with just 1 valve set probably a little too loose. It can barely be heard and ok its for me.

I arrived my mechanic's workshop and stopped next to him. I left the engine running and he actually thought it was turned off not until i asked him to make a comment he asked 'on what'. I said on my running engine!