Back2Back

I managed to upload a HD video for anyone to listen to. I'm looking for some solid clue as to what is causing this sound. I'm hoping it will be unmistakable to someone here or knows someone who can identify the cause of the sound. I figured I'd reach out before I ordered a bunch of parts and went gun-ho on the engine. A close friend of mines believes it may be a spun rod bearing and told me I might be on "new engine status". I'll decide that after I can collect enough information.. I'll be updating this thread as I go along with pictures if requested or need be.

Back story on the car - 97 Honda Prelude SH with a USDM H22A4. Put a cold air intake and bolted on a 2 1/2" cat-back exhaust. Bought her three months ago and changed the thermostat/cooling fan switch and replaced the knock sensor to clear the CEL and to get the radiator fans to run correctly. I also cleaned the IACV which had a lot of carbon and crud in it in and on its own. Who knows what the inside of the manifold looks like.. Besides that I did all the necessary fluid changes as would be expected when buying a car you know close to nothing about.

Without further ado, the HD video I took. Also, I forgot to mention. The sound that sounds like a handful or thin metal rings being clinked together is something different. That has been there since I bought it, so honestly, there are two sounds going on here, but I'm mainly concerned about the other sound. I've done some research to no avail on this sound. -

holmesnmanny

That sounds like some serious rod knock.

Compression test it.

98vtec

pull a plug wire off the spark plug just enough for it to come off the plug on each cylinder. if the noise goes away, its likely a bearing issue. if it doesnt go away, pull the valve cover off and check the timing belt.

Back2Back

You aren't too far off. Why would I compression test when I know which cylinder it's coming from?

holmesnmanny

Depends on if the spark plug wire pull does the trick however that can also blow your coil so it's safe to compression test, unless you don't have a kit, then you can do the dirty test.

98vtec

Yea you don't want to do it over and over but if there is a noticeable change and the sound weakens, it tells you it's internal

To me it sounds like the timing belt slapping which is why if it were me, I would pull the valve cover off first to be sure it's safe enough to run.

Back2Back

I'll be report back with my findings.

friutoftheLude

sounds like the timing belt to me too, the sound has no pattern, like if the belt was rattling and randomly scraping along the inside of the cover

Back2Back

Alright, gentlemen, I've found the issue. It is the timing belt. Thank you 98vtech and fruitofthelude, your consideration and input were spot on and correct.. The timing belt is indeed loose, as you'll see in the second video I'm going to link. The first video is just a look at my valves.. if you care to review it and see anything, please let me know. So it looks like it jumped a tooth somehow. I've never abused this engine since I've bought it, I've never pegged and bounced off redline, just did a couple good pulls up to third gear and from what I've been told by my close buddy, it doesn't matter and can happen anyways.

What would cause a jumped timing belt tooth? From what I understand, it could be a stretched belt, or a malfunctioning timing belt tensioner pulley. What would cause either to go bad? Does this definitively call for a new timing belt tensioner pulley?

Here are the HD videos I took, and thank you again for all and any help. I'll be reporting back with pictures and video and updates of the work that is done.

holmesnmanny

Those auto tensioners are prone to going bad. The pulley wouldnt have anything to do with it.

98vtec

the tensioner failed. all you can do now is one of two things: replace the tensioner with a NEW honda unit (they apparently made an updated tensioner), or you can replace it with the KStuned manual tensioner.

Put the engine back in time and start it up, then pray it idles smooth.

Back2Back

Gotcha fellas. As soon as I get everything together and start conducting maintenance, I'll report back with the happenings from day to day with video and pictures I suppose. I've been busy keeping up with helping with my parents house repairs. I'm finishing up tomorrow and then hitting the range for a good bit of Thursday to shoot with a close buddy, after that then it's guns-ho. I wouldn't expect an update from me until Saturday but I will be checking in until then. I'll let you know 98vtec.

Raitoningu

Good luck with that, hopefully nothing too major.

Back2Back

Alright. First and foremost, I apologize for not getting back sooner. I really am sorry. I'm hoping I can make up for it with any questions that anybody will have about what needs to be done to theirs, so forth and so on on the parameters of the job I just did.

The auto tensioner did fail and my timing belt had a tear on it that almost almost went halfway through. This job took me four days considering it was my first time, and I was back and forth from the HELMS manual making sure everything was properly torqued and installed correctly. After everything was buttoned up on the third night I started her up and she purred like a kitten. She seemed to be idling better and the power steering had me turning the wheel with such minimum effort. It was glorious and I was all smiles... I turned the car off because the alternator/AC compressor belt seemed to be deflecting too much and I wanted to check the specs once more to confirm the tension. I walked to the back of the car to say something to a buddy for a second and walked back to the front of the car and noticed a huge oil puddle underneath my driver's side door. The car had dumped all 5QTs of oil on the ground. The next day I unbuttoned everything only to put my hands on the rear balance shaft gear box to find all three bolts weren't torqued at all. A full day and twenty four dollar waste but no damage done.

Replaced - Valve cover gasket, cam seals, timing belt, updated auto tensioner, forward balance shaft seal, real balance shaft gear box o-ring, balance belt, balance belt tensioner arm spring, and the forward crank shaft seal.

This job was super fun. I can now do this same job in a single day, no doubt about it. The Prelude is a car I've always had an eye for, so, this is great going about my repairs and maintenance gaining knowledge about the car knowing that I'm working on a car that I love. My end goal in the near future is to get this car road worthy for long distance driving. The front right (passenger side) wheel has play on it when I jack it up from left to right as does the rear left (driver side) wheel. My next project looks like it's the ball joints from what I can tell now. Is there anything else I should be aware or look out for?

Again, thank you 98vtec and holmesnmanny.