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Relevant Details : 2000 NB, BP4W, Eagle rods + FM pistons, ACL Race Bearings (rod and main)
Boundary oil pump, ARP mains + heads, Reused the stock oil warmer/cooler
Engine was running when pulled, although very varnished inside. Bored to 84mm
I recently finished up my first engine build. I reinstalled the engine, seated the rings and did about 25 miles of driving around (55 MPH roads, lots of accel/decel), and not much idling.
I went out to run the car around some more, but my idle had been hunting and lean so I wanted to dial that in before. While I was sitting there trying to get the idle dialed in I started hearing a ticking/clacking noise.
Pulled into the garage, drained the oil (for the second time so far, first time after seating the rings). There was some metal grit in the oil both times I drained it. I cut the second oil filter open and did not see any large chunks.
My magnetic drain plug came out with some black material on it which was super fine.
The noise sounds like it is coming from the top end to me. I did lap the valves and reshimmed them when rebuilding the engine and was able to get all the lashes within OE spec.
I will be getting a mechanics stethoscope tomorrow to pinpoint where the noise is coming from.
At this point, I expect to pull the motor, but want to do my due diligence to avoid that if possible.
Things that I think are clues at this point are...
The limited idling I've done with the car was very hunty. I was able to get it to idle smoothly, but the idle AFRs had to be around 12.0. If I leaned it out much more than that it would start oscillating. I'm curious if that could be caused by a leaky intake valve? With a very lightly tuned VE map my AFRs while driving look within a few tenths of my targets.
Full disclosure, I did change out my injectors from stock to FF640s when reinstalling the engine, but did update my tune to reflect that.
I do not hear the clicking noise when driving the car. I can rev smoothly through the rev range up to around 5500 and do not hear any noise. I hear it if I rev the car while stationary, and the sound is tied to RPM.
It did look like some of the metal in the oil was golden and non-magnetic, which leads me to think it's a bearing failure of some sort, or possibly wrist pin bushings. I did have to have my wrist pin bushings on my rods honed.
I went to ARP Main Studs when rebuilding. Machine shop checked and said a line (align?) bore was not necessary. When I plastigauged my mains, as best as I can tell, the measurements were at the tightest end of OEM spec, if not tighter. I opted to switch to ACL's HX line of bearings, which got all the clearances to 0.002, if not very slightly looser
When I went to do the first start I had an incorrect trigger angle setup in my tune after swapping to the FM 36-2. I was using 80 degrees (Hydra setting), however it should have been closer to 210 (speeduino). I cranked the engine for quite a while before figuring this out thinking it was an incorrect air/fuel mix. My oil pressure gauge is connected to a switched power, so I wasn't able to look at it while cranking, but I was seeing oil pressure (sometimes as much as 20 PSI) when I stopped cranking. Once I updated the setting the engine fired immediately
Oil pressure has seemed reasonable to me throughout my measly 26 miles of driving.
My plan is to check valve lashes tomorrow, along with pinpointing where the noise is coming from (top or bottom). I would be happy to find out this is just an issue with the valve shims, but I'm not expecting that to be the case.
Like I said, I am prepared to pull the engine, but figured I'd throw this up as a Hail Mary. Any thoughts or feedback is welcomed.
When I read posts like this, it's pretty much always to late. If you visually see glitter in your oil, this thing has to be pulled and inspected further.
Arp mains do not just tighten the clearance overall, they push the bore out of round, so there can be a pretty drastic difference depending on where you take your measurements. Better having a little bit of a loose engine than tight.
I'm interested in what happened here, seems like you did your homework. I feel sorry for you, this sucks big time, hope I'm wrong
Right, I was thinking about that as well with the ARP mains. It seems like they would be more likely to turn the bore into clamshell shape than a () shape. My thinking there is that maybe the horizontal bore was very loose, although I'm not sure that would cause a failure unless it was very far out.
Thanks for commiserating, I figure that's part of the reason I posted here. I'm certainly not the most precise/---- person on here, but I did try to do my research and build things to a level of quality that I was comfortable with. Thankfully I've been able to borrow any/all specialty tools from friends so I could try to do everything properly.
Ironically I was commenting on another thread about how much metal was normal for a new engine's oil, which was making me feel better. Oh well, we'll see what the diagnosis is after looking at it tomorrow. On the upside, if (when) the engine comes back out there are some smaller things I can tidy up while its out.
Anecdotal evidence here. Not an expert compared to the others here by any means.
When I built my motor the first time, I got the block line bored with the OEM main bolts, but ended up building it with ARP mains. My motor ended up spinning a rod bearing at 2,700 miles (seemingly from oil starvation) and I had to rebuild it. With a reman'd crank and .010" over bearings, my main clearances this time around were still within spec. 3,200 miles and four track days in and everything's still good so far. My buddy did the same thing with his built VVT/EFR6758 motor and it's been pushing 350-400whp for 20k miles without a problem yet. While it's worked for the two of us, I definitely don't think it's the way it should be done. We're both probably just lucky. As DV said, the bore deforms in more ways than you'd think.
On a lighter note, my buddy that I mentioned above had an issue with a ticking noise that occurred only at idle right after building his VVT motor. It ended up being the woodruff key. He replaced the key and crank bolt and it never came back. Given the golden oil hue, though, this may not be your concern.
I appreciate the input Z. The oil didn't look great, but with assembly lube and everything else circulating I'm not sure exactly what it should look like.
The engine bay is relatively full (AC, PS, turbo bits, etc...) but the noise sounded like it was coming from the engine itself.
The few miles I have put on it felt great, if anything it's more motivation for me to fix the issue and get it back on the road.
Well I'm glad it's felt great so far at least. I feel you, after running a freshly built engine (especially one you put together with your own hands), it's hard to wanna go back to anything else. I remember starting my built motor for the first time and thinking: "Wtf, this thing is so smooth now" lol.
Stethoscope-ing the motor while the noise is present will definitely be the next necessary diagnostic step. Just for sh*ts and giggles, though, do you have a photo or video of the recent oil you drained? And a video of the noise occurring? Oil qualities aren't going to tell you as much at this point as they would later on, but between that and a video of the noise, the others on here may be able to guide you a little bit.
What oil are you running? Another anecdotal piece, I'm running Rotella T4 in my engine and basically any metal dust in the oil turns it gold. Currently running OEM bearings and in all my early oil changes after rebuilding my engine, the metallic sheen was gold, or a slightly lighter shade of brown. Used blue assembly goo and my first oil change came out super dark.
I'm planning to grab some video of the engine sound tomorrow. I figure there isn't much use running the engine more than needed right now, so I'll do that when I have the stethoscope in hand (and after I take a break from thinking about it for an evening).
I'm also running Rotella T4 (the conventional version, not the synthetic blend). First start was using Lucas break in oil. SAE 30 and while the garage was warmer than ambient, it's also pretty cold here (just a bit above freezing) right now. I was curious if that could cause issues but I didn't find much definitive information about it. I figured if it was a big deal I would have found more info saying, "DON'T DO THIS!". That's another reason I'm hesitant to call out the color of the particulate, because the oil is certainly contributing to the color.
I wouldn't be surprised if a tiny bit of the crud is from the subframe, as I was wiping that down to avoid getting some of the spilled oil from the filter onto the floor. I am operating under the assumption that the vast majority of the particulate (and all the metal) is from the engine. Oil drain pan after the majority of the oil was dumped off. 13mm spanner for reference
The photo below is the oil that I dumped out of the filter after cutting it open. I'll look closer at the filter tomorrow and get some photos of that as well. Lot's of dark particulate, but surprisingly little glitter. Oil left in the filter once it was cut open.
When replacing main bolts with studs the cap can shift across the parting line. This is caused by the elimination of the eccentric action of the bolts as they are tightened. The process to re-align them would be align honing and very rarely would it require boring & honing. Usually boring is only required when installing different caps. Measurement at the parting line is important when installing studs. Vertical oil clearance is still paramount.
Valve lapping was a possibility and somewhat common for shade tree mech’s before the seats were hardened. This would be before unleaded gas, today it should not be used to recondition the sealing surfaces. It is sometimes used lightly for inspecting the valve to seat location.
There should be no metal to metal contact of the wet components in an engine. It’s not ideal to have metal particles in an engine after the first few oil changes. There are reasons for some to show up on a new build but if it’s a long term issue something will eventually fail. It will either be the components that are causing the particulates or from the effect of them on other components.
Engines that have complex wet cam drive systems as in chains and tensioners etc, are very prone to have metal particle contamination early in life. This is one of the benefits of a belt drive system. It is always best to pull an engine and disassemble it early when there are issues to avoid catastrophic failure. Parts for these engines are getting more difficult to find.
I appreciate the feedback Leo. When checking the oil clearance I did check it vertically.
If lapping valves is no longer relevant, I assume a machine shop would recondition the seats to the valves?
I've only changed my oil twice so far, but again, I'm trying to be realistic. In my mind, the likelihood that the engine is coming back out is very high. Hopefully it will be with minimal damage to the crank.
The valve seats are cut or ground. The valves need to be ground. If they are new valves they can be checked with a runout checker. I recommend grinding new valves. Valve’s that are out will eventually break from cycling.
Went out and fired up the car with a couple buddies. I believe the rich idle is coming from an issue with the FM 36-2 wheel and my fueling setup (running sequential, although it's unclear if Speeduino has the proper cam profile to support this).
We didn't end up concluding anything. The noise wasn't as apparent, if present at all. I did capture some video, checked valve lash, cam timing and ECU trigger angle. I looked more closely at the second filter and there were no large chunks of metal, just a few tiny specs throughout the filter.
The car idled decently, still super rich (think 12.0 AFR, Edit, checked my log and it was closer to 13.5 after warming up).
Tunerstudio is deleting my logs for some reason. I took two, but only one of them saved, and of course its the less useful one.
This was about as bad as the filter got. No large chunks of metal, a few pinhead sized specs. Plenty of black crud Warm measurements of the lash
Here are the video's. It seems like the noise is more noticeable in the cabin, although I didn't notice it as much today, if at all. My friend who owns a BP Escort thought there was a sound similar to lifter tick (solid lifters, not the case, but gives an idea of the sound).
Also, the car isn't quite fully warmed up when I'm in the cabin. The oil pressure is sitting around 35 when warm with a Boundary stage 3 pump and oil squirters deleted on fresh T4 15-40 conventional.
There wasn't any obvious noise, IE we weren't able to come to a conclusion. At one point when warming up I revved the car and there was a tiny bit of chatter as the revs were dropping.
At this point I'm thinking I'll sort out the tune and see if I notice anything concerning. Thoughts?
I can’t view the video, but is the noise the same frequency as a lifter tick would be? Bottom end issue would tick twice as fast as a valvetrain issue since the crank spins twice for every cam rotation.
Some of your cam lobes don’t look like they’re in great shape…
I wasn't able to replicate the sound yesterday. I thought I heard it very briefly but it was not obvious or apparent.
I'm also learning that my trigger setup was incorrect, so I've likely been running half sync. I'm planning on correcting that in my tune today. I haven't found any large chunks or shavings in the oil filter. I think I'm going to drive it and monitor for any sounds.
I don't want to lose more sleep over this, so I'm hoping to come to a definitive answer soon, however that ends up happening.
Yeah, I probably should have spent more time cleaning the cams, I figured any place that made contact would stay clean. The journals on the cams were all clean. For context this is what the head looked like when I pulled it.
I took the car back out and put ~45 miles on it, taking it from 25 up to ~70. The noise I've been hearing was present once the car was fully up to temp and the oil pressure dropped to what I assume is it's normal range. This is my first time having an actual oil pressure gauge and I'm very glad I installed it at this point.
I just dropped the oil and cut the filter, fully prepared to confirm a kill on the engine. I would say the oil looked similar, if not a bit better than the last change.
The filter medium was similar to the last one as well, if not a bit cleaner. No large metal chunks or shavings, just a few tiny metallic specs.
I'm realizing that with the flourescent light and the oil, these photos don't really communicate much, but for those interested
I've linked a video of the noise from the cabin of the car here. It's somewhat hard to hear, but I've found that the cabin seems to filter out a lot of the other engine noises. https://photos.app.goo.gl/CfaVQWEeiR3GdJFH8
The noise is pretty apparent when I stop at a stop sign, but is harder to hear when I pull into the garage and idle there for a minute. I'm not sure if that's a clue, but it seems to be the case to me.
It is definitely tied to RPM. I'm starting to wonder if it could be an accessory pulley or my crank pulley. I'm also guessing that this noise has been there the whole time, although the first time I took the car out it was idling terribly and I was rolling through stop signs, so it's possible I didn't notice it.
I haven't been able to pinpoint the noise with the stethoscope, like I said it's harder to reproduce in the garage.
If anyone has ideas of things to check, or recognizes that noise please chime in. I'll probably start looking into it again tomorrow after work to see what I can find.
When my car had oil starvation and developed a rod knock, I still drove it home and that is why the crank needs to be turned. The place to look is in the oil filler cap with a good flashlight. Pictures don't show up very well, but if you have a bearing problem. There will be copper glitter in the oil filler hole, **** tons, in every pocket, the tops of the cam bearing cap bolts, the Allen key holes on top of the studs, every little pocket in the head. It will be obvious, not some little glitter that isn't copper colored from breaking in the fresh hone on your cylinder walls.
At least, that's been my experience.
Last edited by sonofthehill; 01-28-2024 at 10:17 PM.
Reason: dang autocorrect
Also, the sound was only during the transition from coast to power. Drive, zooooooom, knock knock knock, coast... Knock knock knock zooooooom, knock knock knock coast. Like that.
I don't have much to add, but on the coattails of sonofthehill's post, my rod knock noise didn't show up at all during idle, and would only show up above 2k rpm, regardless of load. This was after fully spinning a bearing though.
How many miles do you have in total on the thing now? My engine seemed to be shedding metal at a similar rate to yours. That's not to say mine couldn't blow on the way to work tomorrow.
Edit: I take back that last part. Don't wanna jinx myself.
My car has a bunch of 11.5 second 1/4 miles on it since I changed the bearings and crank, after the first oil starvation problem. Which I imagine is due to inadequate cleaning of the block after machining. My car rips and could actually do much quicker if I actually have a crap.
I'm only at 70 miles, and 45 of those were on the filter I posted above. I'm starting to think I'm being overly paranoid. To be fair, there's another thread on here with a similar story from a friend of mine, and he just got a new crank in the mail.
I drained the oil today and didn't have any to fill it back up, because I expected to find large chunks in the filter. When I saw that wasn't the case I went back to the drawing board.
I can't run the car any more until tomorrow because I don't have oil to fill it back up, but I'm starting to think the sound is my injectors. I swapped to some FF640's that were used for a while in my roommates car.
I've got a couple tuning issues right now (Speeduino doesn't seem to support the 36-2 wheel with the Miata cam trigger), so although my car's running, my idle is super rich right now and a bit lopey.
I've found some anecdotal evidence on here and other places where people describe something similar to me, especially that the sound is easier to here in the cabin. Found some video's as well that sound pretty close.
My roommate who sold me the injectors also had top end noise, but assumed it was due to an adjustable cam gear that failed and caused piston to valve contact (high compression motor, I promise we're somewhat competent with cars). I'm starting to suspect it was the injectors, at least partially.
Son, when I first heard the noise I thought it might have been improper valve lash so I took the valve cover off. Lash was in spec or within a thousandth and I did not see any metal.
Z, I actually had rod knock in my subaru about a year ago and I remember recognizing it immediately the first time I started the car. This sound wasn't definitive for me, so maybe that's a good sign.
Once my oil shows up tomorrow I'll fire the car up and see what the injectors sound like with the stethoscope. Apparently it isn't uncommon for these to be pretty loud as they age based on some forum posts.
If I confirm it I'll try to get some more focused video of the noise.