Ok so I will make this simple. Since I have had my car built and tuned I get this weird noise around 2k to 2500 on decell and it sounds like rod knock. Fast forward to Monday I put a fresh tank of pump gas in the car and drove it to my buddy shop to change the oil being it has been a long while and it hasn't been done since last time we were on the dyno on e85. Long story short car developed a problem and didn't have the funds to fix it and now its fixed here is the problem.

We changed the oil, put a fresh Schaeffers 15w40 race oil in the car with the Schaeffers molly and decided hey lets put my uc-10 in the car. So we fart around for a few hrs and we finally start the car. Car fires up fine no noises that say somethings wrong, but once we backed the car off the lift and out the door we heard what we thought was a rod knock. Oh **** how?

Fast forward to last night he pulls the pan and finds nothing wrong with the rods. In fact this is the worse bearing out of what he found.



So as you see there is isn't really anything to be concerned about. These bearings have about 17k miles on them, no oil squirters in the engine which I found out and I am not happy about being I was told they were putting them in the new motor. So now I hate to do it but main bearings are going to be next. It is odd that I have heard rod knock 10000s of times in all my years of dsms and evos and I was sure that was the noise. So with that says and showing all the bearings and this was the worse out of the 4 I am not sure what the noise was. I thought it may have been the windage tray hitting the rod botls as well but that seems to have plenty of clearance as well so idk what else to think.

Does anyone have any idea what it is I am hearing? I am going to think the mains are fine but we are going to pull them anyways because why not do both while the pan is off. I have been looking around and I can assure its not spark knock, piston slap being I had my skirts coated to fit the cylinders, cracked exhaust manifold, and anything out of the normal I can rule out.

Spark knock is the only thing I can think it may be but it would be all the time and this noise has done it since the engine was built and I just figured it was a normal noise. I am thinking maybe it could be this being that the e content went from my last tank to this tank went from 16% to 10% but honestly shat shouldn't matter and if it was spark knock it would do it more often rather then just at those rpm ranges. I am at a loss what do you guys think?

 

So my main bearings showed up at the shop and we are going to be taking the mains out and inspect them as well. I am highly certain the main bearings didn't spin or anything like that, but this is for insurance and maybe just maybe the freak ok maybe it did start to spin a bearing. I am afraid though that if I redo all the bearings this noise will come back then idk wtf to do. Maybe I should ask has anyone had any strange noises or anything since they put the moroso oil pan on their car with the windage tray and the scraper maybe clinging together or something to those effects. I know we are going to tack weld the windage tray and the scraper to make them one unit just to eliminate this noise. We tried hard to move both of them around to see if possibly the rod bolt is hitting maybe the scraper but there is plenty of clearance so idk what else to do. If anyone has any ideas please let me know. Thanks in advance..

 

you 100% sure its in the motor? I had a scary "knock" a few years back that ended up being my exhaust tapping on the pan I think it was that happened only on decel. I would have guessed it was rod knock as well when it happened but I think that might have been me just expecting the worst lol.

 

I am 100% positive nothing is hitting. The noise I heard got bad after an oil change and the car warmed up. As you see in the pic above, that is the worse bearing out of the 4 rods. The rest of them looked like they had 0 wear on them. But back to the noise, it happened while backing out of the bay. Car ran 5 mins or so to warm up the oil and no noise what so ever. Back it out and rod knock sound as it was backing out of the bay. I have clearance for my exhaust everywhere being along with what you said I figured maybe something is hitting. But this noise is very distinct, and being I have heard plenty of rod knocks in my time I was sure thats what it was and the bearings tell me different. Idk

 

Yea, thats weird man. The bearing looks fine? I don't know what you could be hearing. It will be interesting to see if the mains look good though I'd expect them to.

Its interesting you have had this the whole time. I'd be doing the same thing you are, making sure there is clearance around the scraper and windage tray, and looking at the bearings.

Could always try and back off the tune a bit to check if its tune related but idk, really doesn't seem that way.

 

Def not tune related being it's done it since I got it back from sm. But the thing is it wasn't as loud. It was like hmm I hear something and now it's like rod begging to get out of the block difference.

 

That's so weird man. That really makes it sound like its a rod knock but it really doesn't look like it?

I'll be curious to see how it reacts to the new bearings.

 

Yeah me too I'm just afraid once they go in there and there's noise reappears now what you know. Right now I'm in no shape money-wise or health-wise to be taken this motor apart.

 

I feel that but it will be what it is. I think you are making the right moves to try and get it sorted man. I don't have any other ideas.

 

Thanks brother, I always appreciate your help when you throw in useful info to help. We will see I will keep you updated.

 

Wish I was more helpful in this instance but I try lol. I'll be watching for the update, I am definitely curious.

 

Make sure the flywheel isnt loose. Just had a similar issue. Odd random knock at idle and on decel between 2-3000rpms's

 

I don't have it at idle at all just at 2500 to 3000 rpms only on decel, but good idea I will have him check that. Are you thinking that maybe its wobbling on idle and decel or at those loads?