F22a1 Engine Knock Only When Rpms Are Climbing

[Kev1990]

Hello I posted about this before but I'd really love to figure this out. Only when slowly climbing rpm's I get a knock in the valves around 2.5k rpm's if I hold the rpm's steady at 2.5k there are no knocks or if I go at a steady pace past 2.5k rpms there is no knocks I don't think it happens when the engine is cold ether here is the video of the sound you can only hear it when the rpms are slowly climbing. This same exact problem started recently on a F22A6 a friend of mine has and another friend's F22A1 175k but the F22A6 has it at 2k rpm's 190k on it we all would love to figure this out thank you in advanced to any helpers lol. BTW valve adjustment has already been done to my car but not the other two engines.

Here is a video : https://www.youtube.com/watch?v=db3e15EL5tI

[H311RA151N]

A knock only when accelerating and/or under a load? I wish you would have revved it a bit harder in the lower RPM's in the video.

My 1993 LX with 374,000 miles started doing something similar. It ended up being two rod bearings. This is what rod knock sounds like.

[Kev1990]

Every time you hear that knocking sound when the rpm's are raising is about 2.5k-3k rpms I can take another video how high do you think I should rev it? Because the higher I rev it sounds a lot better lol. And dam I don't think I have that type of knocking. I can be sitting in PARK-DRIVE any of them and the valve knock will happen. It especially happens when I am accelerating slow when I hit the gas I little bit harder I just bypass it and hear no knocking like shifting around 2.8k-3k. If I put the car under load like up hill I don't hear it. If i'm doing like 55-60 I keep the rpm's stable I don't hear it but if I slow down a little then re-accelerate you can hear the knocking it that rpm range. BTW I will specifically listen for it on a cold engine today when I go out and I will get back to you if it happens when it's cold too.

[H311RA151N]

That's exactly where mine would knock the loudest. I'm not suggesting that's the issue with yours I'm just explaining what mine did.

Quick small jabs to 3500 rpm or so from an idle. That's where I noticed mine the most.

[H311RA151N]

I see you added the part about a cold engine. Mine was 100% for sure rod knock (when I disassembled the engine I found two messed up rod bearings and two screwed up journals on the crank) but when the engine was cold it would not knock. Not even a little. Once it warmed up it would knock again.

[Kev1990]

Dam. My knock happens exactly around 2.4k-2.6k rpms that's about it. Truthfully it's happened since I owned the car. If it was some type of serious knock though wouldn't it of done some detrimental damage to the engine by now? I've put 35k-40k miles on the car just since purchasing it. Did you ever notice the knock ahead of time on your engine? Or did it just appear? If you held the RPM'S steady on that one with the knock would it still knock or would it go away? I have to take off a bit slow to actually hear the knock. Any other symptoms of the same problem you went through?

[thumping_accord]

IMO That sounds like to me the begining stages of rod bearing failure. The more you drive it like that the more it will sound like H311RA151N's. My old F22a1 made the exact same noise at about the same RPM, it would not make it at higher RPM's either. When I replaced my bearings one them was cracked.

[Kev1990]

Boo! Bad answer LOL. But thanks for your reply man.. How long did you drive your car for after you first noticed it? Was it nearly as bad as mine when you noticed it? What symptoms did you have when it started anything or did you have any symptoms when it got worse? So anyways you think there's any way to prolong the life of the engine if this is the case? Like going easy on it? Using heavier weight oil?

[H311RA151N]

IMO That sounds like to me the begining stages of rod bearing failure. The more you drive it like that the more it will sound like H311RA151N's. My old F22a1 made the exact same noise at about the same RPM, it would not make it at higher RPM's either. When I replaced my bearings one them was cracked.

^^^ This. Glad to hear of someone else having the same thing happen. Well, not glad but at least I can be more certain with what that noise is if I happen to run into it again in the future.

[Kev1990]

Hmm Josh what symptoms did you have before and currently with the rod knock? Did yours happen all of a sudden or could you hear it when it originally started with a minor knock?

[H311RA151N]

Hmm Josh what symptoms did you have before and currently with the rod knock? Did yours happen all of a sudden or could you hear it when it originally started with a minor knock?

No symptoms other than that sound. I noticed it after a night of about 7 runs at Ozark Raceway Park. 374K with me behind the wheel is what happened. Actually is started at about 370K and I just babied it until it was hit and totaled sitting in a parking lot. My friends started to do it and lasted maybe 300 miles before making serious noise and losing power.

[Kev1990]

Dam I don't go easy on my engine ether it hasn't gotten worse in the past 10k-15k miles so in that case and it's not full range rpm dependent do you still think it's a rod knock? Just in the past month I've put about 2,500 miles on the car and it hasn't changed. This has been happening since I bought the car and hasn't seemed to change in the past 35k-40k miles ether if it was a rod of some sort wouldn't it of blew through my engine by now? BTW I have no loss of power ether.

[thumping_accord]

Boo! Bad answer LOL. But thanks for your reply man.. How long did you drive your car for after you first noticed it? Was it nearly as bad as mine when you noticed it? What symptoms did you have when it started anything or did you have any symptoms when it got worse? So anyways you think there's any way to prolong the life of the engine if this is the case? Like going easy on it? Using heavier weight oil?

The only reason I noticed it was because every now and then I like to just drive without radio to just listen to the car, its kinda peaceful lol. I probably drove it a couple months, 10k-15k, after I first heard it, mainly because I didnt know what it was lol. I did take it pretty easy on it during that time though. The noise was the only "symptom" I ever really had. When I brought it to the mechanic he told me what it was and I had it fixed asap after that, the mechanic said I was extremely lucky it didn't turn on the crank or it would've had to have been replaced. All this being said, the new bearings fixed the issue, temporarily, about 3 months later the knock came back, I tried driving around with it like that for a while, bout 10k, but this time I was so lucky, wound up slinging a rod and locking up the motor. Turns out the journal that the bearing sat in went bad during it all, which caused my motor failure.

So just from my experience, I would not recommend driving around on a knocking motor, and I would bring it to the mechanic asap to have him give a proper diagnostic. As far as heavier wieght oil, I wouldnt know how much that would help cause I never tried it lol.

[BreckAConner]

I have the same issue, and I was told it could be piston slap. Cloud that also be this issue to what's going on with our cars? I've been hard on my car to see if the issue has gotten worst, and I haven't noticed anything.

[H311RA151N]

I have the same issue, and I was told it could be piston slap. Cloud that also be this issue to what's going on with our cars? I've been hard on my car to see if the issue has gotten worst, and I haven't noticed anything.

I did the same thing. Just to see if it would get worse. And it only seemed to get worse over time.

As for piston slap, since I rebuilt the engine (it's not been worked on in about 6 or 7 months now but all it needs is the head put on the block and a couple gaskets) I can say that when I tore it down the pistons were within spec. But the oil pump was not within spec and the rings had a ton of carbon build up. Which was why it smoked.