I've been a lurker here for a very long time. Now I need some help with my base 5spd 5th gen. It has a H22A4 w/ 160k km (100k mi) that when it's really cold outside (less than 0 oC, 32 oF) ticks pretty loudly. When it's warmer outside, or when the engine warms up, the ticking quiets down quite a bit, but it's still there. Here's what was done to the engine:

- full tune-up (spark plugs, wires, cap) less than 10k km ago
- timing belt, water pump, etc change roughly 30k km ago
- valve adjustment 3k km ago

I checked the compression, and all cylinders have 185PSI after 4 cranks, 210PSI after 10 cranks. It burns about 1l of 5w30 synthetic every 2k km.

Now for the videos of the engine:

1. 5 oC outside, engine dead cold:
http://www.youtube.com/watch?v=srFwty1wThI

2. 15 oC outside, engine dead cold:
http://www.youtube.com/watch?v=O52v1Llc-Hk

3. 15 oC outside, engine warmed up at idle (this clip is still processing, should be viewable very soon)
http://www.youtube.com/watch?v=N0kX7Ghtoho

What do you guys think? Does the engine sound ok? I'm a bit worried because some people suggested it's a rod knock, but when I went to my mechanic and the engine was warm he said it sounds normal. I am a bit weary of trusting mechanics, because I've had one tell me everything is perfect on my old car, while my head gasket was toast with coolant going into the oil, knowing full well they'd make money off me later.

So... Please help. I love my Prelude, had it for 6 years and I'd like to keep it for another 6. But not if my engine is going...

 

Did you double check your valve lash ? Make sure you set it while the engine is cold. Has it been making this sound since the adjustment because you said it was done 3k kms ago ?

I believe its technically supposed to be around 70 degrees F ambient temp or something, correct me if I am wrong.

 

If a valve adjustment does not cover the valve lash, then no, I did not have it done. I honestly can't remember it ticking this loudly before the adjustment, but then I may not have heard it. I'm really not driving a lot, so although the adjustment was done 3k km ago, it was done in the fall when it was still warm outside.

 

I had the valve adjustment done again, and this time I made absolutely sure the engine was stone cold. Edit: I also went to another mechanic, because the first one wanted to charge me for the second valve adjustment, even though I only drove about 1-2k miles since the first adjustment.

It turns out that the intake valves were all loose, while the exhaust valves were all too tight. Overall they weren't too far off the mark, except for a couple that were really tight. So as the engine would warm up, the exhaust valves would loosen up and get back within spec, reducing the ticking.

So now I am pretty happy with this engine. Compression is perfect, cam shafts, vales, etc are NOT worn out, sounds good, pulls hard. I won't post another clip, but the engine sounds a LOT quieter now. I also learned a couple of other things, most important being if you have a good mechanic, stick with him. Sad thing is both mechanics are affiliated with my local Prelude club, but from now on only one of them will be getting my business.

 

LMAs

 

Don't you mean LMAO? Yes, I know I deserve to be laughed at. But at least I did not decide to do a port and polish by dumping a bag of sand in my air intake. :D I just trusted a mechanic that came highly recommended by other club members.

 

Yeah that's not a rod. When a rod knocks, you'll know it.

 

lol, hey i can uderstand your worries because I also went through that and once you start hearing "oh the motor is bad" ect... then your like **** i ****ed up my engine lol. but im glad you fixed it...

 

LMA's=Lost Motion Assemblies.

They're sometimes little piston like things or springs that apply tension on the vtec rocker while it isn't in use so that it rides the lobe the way it should. When they're bad they don't apply enough tension making the rocker slap the backside of the vtec lobe as it passes on the cams causing a tapping noise. Older style H22a LMA's are known not to last which is why he suggested this but it seems it was valve clearance causing it.