H22 Knocking in head

[00siboy]

I already started a thread on H-T about this, but haven't been getting many hits (in the last 24 hours lol) so I'm posting here as well.

Here it is: 97 prelude base, 5spd, 116k on the clock. It has a knocking sound that sounds like its coming from the head. It doesn't happen on a cold startup, its mostly after it has been driven or running for a short time. Its not like a valve ticking, its louder and less frequent than that. Someone on H-T suggested that I try compressing the LMAs to see if they are sticking. Made sense, so I went out and tried it. They all compressed, some required little effort, some were pretty difficult to compress, but they all sprung up quickly and did not feel like they were sticking.

Can I try anything else before I move on to another component? If anyone has had the same problem and fixed it please let me know. Its my brothers car and he needs it ASAP.

 

[JohnS.]

Bunch of things I found on Google:

- Pull the plugs and check them (one person found metal shavings and a destroyed spark plug)
- Do a compression / leak down test
- Check your valve clearances
- Re-check the LMA's
- If all else fails, get a stethoscope and look into the engine
- Is the engine overheating at all?

Also, there's a fine difference between a tick and a knock. You sure it's a knock? And are you sure it's coming from the head? Apparently a rod knock can sound like it's coming from the head. It appears some people confuse head knock from a block knock as well. Other than LMA's, there really isn't anything else that can "knock" in the head.

 

[00siboy]

Also, there's a fine difference between a tick and a knock. You sure it's a knock? And are you sure it's coming from the head? Apparently a rod knock can sound like it's coming from the head. It appears some people confuse head knock from a block knock as well. Other than LMA's, there really isn't anything else that can "knock" in the head.

Thanks for the response man. I definitely found alot of stuff already from google. If you define ticking as the sound of valve ticking, then its definitely a knock. The reason I don't think its a rod knock is that it doesn't do it all the time, only after it has been revved at idle or driven. I have heard dozens of rod knocks anyway on multiple different types of engines, and this doesn't seem like it. Some of the checks you mentioned I have already planned on doing at work tmrw.

- Pull the plugs and check them - Will do in a minute.
- Do a compression / leak down test - Can do tmrw
- Check your valve clearances - Can do tmrw
- Re-check the LMA's - Already triple-checked
- If all else fails, get a stethoscope and look into the engine - Can do tmrw
- Is the engine overheating at all? - I talked to my dad and brother about this one (its my brothers car). It does overheat if it sits at idle too long. I always thought I just needed to replace the t-stat and go from there. Why do you mention the overheating?

 

[00siboy]

UPDATE: I pulled the plugs. Other than the tube seals allowing oil to leak down the tubes and onto 3 of the plugs, the terminal side of the plugs doesn't look bad at all.

I guess I should give more info on the car. It was purchased from a random guy that buys junk cars and fixes them. He said that the car was going to the junk yard cuz the engine was bad, not quite sure of the details as to what was wrong. Anyway, he had the head checked at a reputable local machine shop. I think he only replaced the valve seals, head gasket, and other upper end gaskets. He didn't say anything about the lower end at all, and it runs fine so I assumed it was ok until I started hearing this noise. It may have been doing it for a while, but I don't really drive the car very often since its my brothers and he hasn't even had it very long, plus he isn't very aware of stuff like that unfortunately. I will update tmrw night after more testing.

CLIFFS: Haven't had the car very long, previous owner did headgasket, etc. before purchasing, will update tmrw night.

 

[JohnS.]

Why do you mention the overheating?

I'm not sure if this can actually be correct but it may be something worth looking into.

http://ht-archive.org/showpost.php?p=43062135&postcount=9

theory 3 - water pump is bad causing it to over heat and could be the knock.

 

[00siboy]

Yep I saw that link, but didnt find any metal shavings on any plugs, and it doesn't run bad at all, so I am assuming a valve isnt bad. The guy in the link was on 12psi of boost, this is a stock h22. I'll update later tonight when I get back over to the shop. Any idea as to why the knock would sound like it was coming from the other end of the engine and not the water pump side? I guess it just kinda resonates throughout the engine possibly.

Anyone else want to chime in?

 

[00siboy]

I did the water pump this weekend hoping it would fix the knocking and overheating. The old water pump didn't seem like it was bad/noisy when I took it off but whatever. Turns out it still slowly overheats, seems like the fans are coming on later than they should. And it still has the same knocking sound. BTW the front balance shaft (the oil pump I think) was off by about two teeth. Its fixed now though and all the timing marks are on.

One thing I did notice when I took the valve cover off was that the cam lobes looked kinda worn. Any idea about that? Maybe irregular oil changes by previous owner?

 

[00siboy]

UPDATE: So I have been looking at a few things recently. I replaced the water pump and crank pulley, they were both original and needed replaced while I had stuff apart to inspect.

Anyway the noise is still there. Today i drained the oil to check for shavings and it was pretty clean, so I did an oil change with MMO, and decided to just keep an eye on it. I will update if there is any progress.

 

[khmernese]

did you check the cams and journals? i had a similar problem with my head. the cams had deep scratches in them and cam journals were milled to remove the deep scratch on them by the previous owner. caused the cam not to seat correctly plus movement since it was milled. the cam were warped or something i dont remember what they told me. although my head was a b series, im sure its the same idea.

 

[00siboy]

I'm hoping the MMO will get rid of the varnish on the cam lobes so that I can get a better look. Seems like the previous owner(s) didn't care for it like I do.

 

[khmernese]

hey i manage to get a hold of the guy who found my problem. he said the cams were minor but also made the noises, but the lost motion assembly was the real cause. it was worn out.. and i looked up what it was and it sounds legit. the symptoms matches.

In the beginning, Honda used to equip all B-series and H-series VTEC with a hydraulic fliud based lost motion assembly. Over time, especially with the use of high-lift camshafts, these wore out and lost(lose?) their tension causing ticking noise similar to a needed valve adjustment.

if this doesnt fix your problem then your SOL

 

[00siboy]

The factory LMAs get worn out because of buildup not allowing them to slide properly, so they start to stick. I have seen the problem cured by taking out the factory LMAs and soaking them in a cleaner, but most people just replace then with the updated spring type. I'm going to have my brother drive it for a while and I will just keep an eye on it.

 

[taluzer45]

^^ are you the guy who actually owns the car, or are you just resateing the fact?....... BTW welcome to CC!

 

[Avant Uprising]

prop need to tear the head off and physically check everything. sound does travel so dont rule out some things

 

[00siboy]

Ok so there has been quite a few posts on here with lots of info so I will sum it all up here:

-Its my brother's 97 prelude, stock.
-It has a knocking sound most noticeable at idle.
-It doesn't knock on a cold startup, has to run for a bit before it starts.
-No shavings in oil, and hard to tell where noise is coming from.
-Its not a terrible knocking, only someone familiar with cars would notice it. (for example, my brother never noticed it...)
-The LMAs all sprung up fine when I tested them, and valves are adjusted.
-Cams have a little but of varnish on the lobes, I did an oil change with MMO and I am keeping an eye on it to see if the noise gets worse or more frequent.

Thats all, I'm not working on it anymore at present. Don't tell me that I shouldn't ignore a sound like that because you can't diagnose it over the internet. I know the limits of cars and their random noises and I am comfortable with where I have left it. Thank you to all who offered helpful input it is appreciated.

 

[khmernese]

oh wait i forgot you already checked the lma... LOL my bads.

LOL thanks taluzer. i thought i remembered him mentioning that he did checked it. and i dont know why i didnt think about it before posting... . i guess i kinda got hyped cause i thought i figured it out.

yeah i am new to the forum. kinda just lurking and getting/ passing info before i make my intro thread.

 

[00siboy]

Go ahead and make your intro. All you need is pics/specs of your car.

 

[Hecz]

Put your ear close to the Cam gear cover. You might hear the knocking noise better. Meaning it could be your timing belt hitting the cam gear cover, meaning your Auto tension-er might not be working correctly.

 

[00siboy]

Already did that, its not it. I had everything apart when I did the water pump and the tensioner is fine. I'm currently looking at getting the parts for the manual tesnioner conversion just to be safe for the future.

 

[Hecz]

i believe a auto tensioner is better then a manual one - specially in h22 . good luck man.