Scooper
Well-Known Member
Another possibility could have always just been a bad bearing.
Ideas on what's causing my click/tick/rattle noise?
- Thread starter halfafish
- Start date
-
The analogue timing lights are notorious for being off.
The pistons, rings, and lands are all good and have been cleaned up. The block got a quick kiss with the hone and we are one step closer to assemly.
The definition of experience is getting the test before the lesson. Tough way to go to school but whata ya gonna do?It's time for an update. I tried every suggestion for tracking down the noise and checking EVERYTHING under the hood and under the truck that could have been loose/rattling/vibrating. I came up empty handed. I put the truck in the air and held another session with two different friends that have good hearing. They both said the noise was coming from the oil pan, towards the rear. I did a listening session and I agreed. So I started the painful process of pulling the engine.
View attachment 1715863789
Much to my surprise, this beeyotch came out pretty easy using a standard cherry picker. I used a forklift last time and wasn't sure a picker would have enough reach but with the trans removed first it came out easy-peasy. Yay for me. The good news is after pulling the pan I checked the torque on the rods and mains, they were good. So at least the assembly was good and I didn't leave any bolts loose. However, the bad news is the #4 rod bearing was pretty well thrashed. No wonder this was making a lot of noise.
View attachment 1715863791
View attachment 1715863792
Oh, and lotsa flakes and crap in the bottom of the pan.
View attachment 1715863790
A trip to the machine shop shows I got lucky and shut this down at the right time. I only had to polish the crank and do the teeniest clean up work on two rods. Otherwise no serious damage done. Consensus at the MS was too much timing for detonation. Lots of things to get right the second time around, to be revisited in Mission Creep on a D-150. Sadly, sometimes I learn by thinking I know what I'm doing, only to find out the hard way, I don't.
No joke. If I was an idiot and went blindly charging into things this would make more sense, but I research a lot and try to get things right. Sadly, lacking a mentor, I'm stuck teaching myself the finer details of wrenching.
Can You post a pic of the piston tops, particularly the cyl. that had the most rod brg. damage? If detonation was the cause, there should be pitting in the crowns to witness that,.... any?
On my/6 build I bought all my bearings from ebay. I ended up buying a 2nd set of mains and put the 1st set back into the box, will probably chuck them. They had a full silver coating on them that was flaking and peeled off. I was afraid of taking the chance with them.
Sorry for the show response. I've been buried at work lately, it's hard to get in much shop time. Here are the two pistons that were in the worst shape. I don't see anything on the crowns but to me, they look like there's a lot of carbon buildup for just 700 miles.
my68barracuda
Well-Known Member
I would have your machinest or someone with a lot of engine experience look at those pistons before re using them.
Let them know the engine ate rod bearings due to detonation.
I have better photos, below. They are in order from 1-6. Visually they do look rough, but by touch they are smooth. Just ugly looking.
Thanks - the machine shop guys are the ones that pointed to detonation, and they did inspect the rods and pistons saying they were OK to run.
In my mind, these pistons look pretty crusty with lots of carbon on them for only 700 miles on them. I'll get them cleaned up before they go back in the block.
When that carbon is cleaned off the surface should still appear as newly machined, other than marks from cleaning, if normal combustion is taking place. I'm with Charrlie_S, detonation will leave pits/pock-marks on the piston where it originates, esp. when it's severe enough to wipeout the bearings. Keep Us updated!
I got the pistons cleaned up last night using the parts washer, a toothbrush sized wire brush, and LOTS of elbow grease. I ran out of elbow grease before I ran out of crud, but they are way cleaner. Here are the "after" photos, in order from 1-6. There is no pitting at all on the tops, just the factory machining marks.
The next question is why so much carbon buildup? It looks like quite a bit for only 700 miles use. The head looks pretty cruddy too, here are photos before I clean that up. Keep in mind, I'm probably the world's worst engine tuner so there is no end to the possibilities for what I could have screwed up to get into this mess. The photos are for 1-2, 3-4, and 5-6 chambers.
my68barracuda
Well-Known Member
Agree looks way rich, the exhaust valves in the head should be white. What did the plugs look like?
Concerning being too rich:
1) is the choke adjusted properly or is it staying closed?
2) is the float adjusted properly or is it keeping the carb bowl over full
3) are the idle air mixture screws adjusted properly or are they set too rich
4) was your slant a Lean Burn and if so are you using the Lean Burn carb with wires going to the float bowl?
Did you notice the tailpipe huffing black smoke?
Did you ever check fuel mileage?
It is an expense, but a wide band AF gauge is a nice tuning tool even on a carbureted engine. I have one on the 83D150 and it is a carbed slant six
If you are going to add one I personally like the AEM units, but there are others.
Last edited:
j par
Well-hung Member
I'm not seeing the signs of this detonation problem you speak of...
I think you had a thread talking about cheap easy gains and all that carbon was helping compression LOL...
I think you had a thread talking about cheap easy gains and all that carbon was helping compression LOL...
Timing and detonation didn't do that to those bearings. I really have a difficult time buying into that, especially since there's zero evidence of detonation on the piston tops. I think it was a simple assembly error (no offense) or a possible part failure, or maybe some trash in the engine in the oiling system. If that engine detonated enough to beat bearings out of it, you'd see evidence of it. There is none.
Id bet your issue with the bearings is what I "would have had" had I not gotten another set while it is apart.
j par
Well-hung Member
I wish I would have said that...
My next question is; why is it difficult to see the locating tabs on those shells, & why do they appear sheared and transferred across the parting line? If they didn't spin in the rods, they should never look like that. If they did, I am skeptical the rods are A-OK.
Agree looks way rich, the exhaust valves in the head should be white. What did the plugs look like
The plugs looked like crap. Here they are, 1-6 from left to right. Several of them had a LOT of oil on the threads which makes no sense to me. I did have some minor leaks from the valve cover but I wouldn't think it enough to make this kind of a mess.
Concerning being too rich:
1) is the choke adjusted properly or is it staying closed?
No, it's OK - it's a manual choke and opens fully when I return the cable knob to the dash.
2) is the float adjusted properly or is it keeping the carb bowl over full
No clue, I will have to find out. The carb is a brand new Edelbrock AVS2 500. I ran it OOTB.
3) are the idle air mixture screws adjusted properly or are they set too rich
I set them according to the fairly skimpy instructions that came with the carb.
4) was your slant a Lean Burn and if so are you using the Lean Burn carb with wires going to the float bowl?
It is indeed a lean burn engine, but all that crap has been removed.
Did you notice the tailpipe huffing black smoke?
Nope, not at all. However, it did seem to have a lot of vapor coming from it. When idling for a while when I was working on setting the valve lash or tuning, the tailpipe would actually drip some on the floor. I had no head gasket or other water leaks to explain this.
Did you ever check fuel mileage?
No. I had bigger fish to fry from the get-go, so a mileage check wasn't in the cards. Just going by the seat of the pants, I'd say it wasn't horrible.
It is an expense, but a wide band AF gauge is a nice tuning tool even on a carbureted engine. I have one on the 83D150 and it is a carbed slant six
If you are going to add one I personally like the AEM units, but there are others.
I had a bung welded into the exhaust, and I have a friend with a gauge that I can borrow to set things up. That's on the agenda moving forwards.
RRR - no offense taken. I am well aware I am at best reasonably capable at taking things apart and putting them back together. However, what bites me in the *** all the time is just plain not knowing all the ins-and-outs of this stuff. Operator error on assembly is a distinct possibility. I followed Doug Dutra's book and double checked everything but still, I'm not voting for halfafish getting it right and the problem lies elsewhere. Some new parts do indeed fail, that's certainly possible. Maybe I got some crap bearings. Before assembly I gave the entire engine a complete bath with hot soapy water and multiple scrub brushes, a hot water rinse, and an air blow-dry, followed by oiling down the machined surfaces to stop flash rust. I don't think there was any crud in there but who knows?
As info to all, the whole business of detonation came from the machine shop when I took my pistons and plugs in to see why the rod bearings went south. This is a highly reputable shop that I trust, and two local slant gurus use them all the time. Yet I can't explain why they thought it was detonation and many here have said that isn't supported by the condition of the parts. I do know what pinging sounds like and I didn't have any.
Agreed, the tabs look like they are not there. I wish I'd saved the bearings so I'd have a better idea for clues as to what happened. Unfortunately, I tossed them when I got the photos I have. The machine shop did do a tiny cleanup on two rods, the rest were OK. Looking at the rods when I was working on it the last two days, they do look good. Everything is clear, clean, and sharp.
And the final thought for tonight. Many thanks to all who are helping with this. Sadly, I just don't have the experience to be able to say for sure what happened or didn't happen. I shall continue to pursue this. Meanwhile, I'm putting this back together for round two. Fun fun fun, tomorrow is cam degreeing day, another adventure into the unknown. YouTube, here I come...
Comments about post #114.
- carbon; looks like oil getting into the chamber. Piston ring failure, worn v/guides &/or seals. Also most important: check the wear of the ring grooves, up/down, in the pistons. Worn grooves make excellent oil pumps....
- looks like a tremendous amount of coolant/crud around for just 700 miles.
- carbon; looks like oil getting into the chamber. Piston ring failure, worn v/guides &/or seals. Also most important: check the wear of the ring grooves, up/down, in the pistons. Worn grooves make excellent oil pumps....
- looks like a tremendous amount of coolant/crud around for just 700 miles.
Just a question.....you know there are cast crank and forged crank engines, I am sure. Unlike the V8s, the slant 6 uses different bearings in each engine. Forged crank engines have their respective blocks, cranks and rods that are all different than that of a cast crank engine. They also use different bearings. Is it possible "any of that" got mixed up?
To me RIGHT NOW, the most important issue is the physical damage and finding out what happened there. The carbon and sooty richness is clearly an unrelated tuning issue and can be ironed out after the fact. I would try to concentrate on the physical engine failure FIRST.
-
