Sudden onset of engine clacking/knocking noise while driving uphill

[I-4]

Running any car with a bad bearing is a risk. (I personally would take that risk and run it for 2-3 minutes to turn it around) Try not to put any load on it. It could go on knocking for another 100 or 1000 miles. Or it could fail and turn your block into junk. You could send an oil sample to Blackstone Labs, or another oil analysis lab. But that will not cure anything, just tell you if you have metals in the oil and what they are. No real way to tell what went wrong, without a teardown.

[steinfel]

Thank you for your ideas. I'll try the thicker oil test, but I have to get out to the store and get some first.

I'll turn the car around in the driveway, under minimal rpm/engine load which will probably take only a minute to do. Just a three-point turn to get the car oriented favorably. That will hopefully be enough running time to stir up the oil in the pan and get a somewhat suspended mix of whatever may possibly be in there.

I'll use that as an opportunity to drain the existing oil into a clear container so to look for glitter. Glitter/metal shavings should be a positive diagnosis for damaged bearings, yeah?

Also, before draining, I can record the engine sound/video with the existing 5w30 oil in place. I'll drain it, and replace it with straight 30 weight oil. I can do another recording to observe any difference in sounds. If thicker oil quiets the clacking sound, then that would be a positive for bearing damage/rod knock, again. Do you think straight 30 would be adequate for this test, or should I go higher?

Both positive results should be indicators for me to have solid enough ground on which to take apart the lower end, and bring it back to the shop that built it for me. I could show the recordings as evidence, as well as the oil samples, if necessary.

Does that sound like a decent strategy?

[I-4]

Originally Posted by steinfel

Thank you for your ideas. I'll try the thicker oil test, but I have to get out to the store and get some first.

I'll turn the car around in the driveway, under minimal rpm/engine load which will probably take only a minute to do. Just a three-point turn to get the car oriented favorably. That will hopefully be enough running time to stir up the oil in the pan and get a somewhat suspended mix of whatever may possibly be in there.

I'll use that as an opportunity to drain the existing oil into a clear container so to look for glitter. Glitter/metal shavings should be a positive diagnosis for damaged bearings, yeah?

Also, before draining, I can record the engine sound/video with the existing 5w30 oil in place. I'll drain it, and replace it with straight 30 weight oil. I can do another recording to observe any difference in sounds. If thicker oil quiets the clacking sound, then that would be a positive for bearing damage/rod knock, again. Do you think straight 30 would be adequate for this test, or should I go higher?

Both positive results should be indicators for me to have solid enough ground on which to take apart the lower end, and bring it back to the shop that built it for me. I could show the recordings as evidence, as well as the oil samples, if necessary.

Does that sound like a decent strategy?

Looking for glitter in the drained oil is the least expensive way to check for internal damage. Removing and then Cutting open the oil filter and looking is another way. Without a tool to cut the filter can open, it will be a pain, and if you use a hacksaw, it is messy and the metal filings from the filter can skew what you are looking at.

For a heavier oil, try a 20w-50. Castrol or Valvoline racing. A straight 30 weight will most likely not sound any different than the 5w-30 you are using now.

If you want to send a used oil sample to Blackstone Laboratories, you would have to go to their website and ask for a kit. The sample kits are no charge. Their standard analysis cost is $30 last time I checked. If you are/have spent all this money on a rebuild, it may be a good idea to send a sample in, IMHO. I have no affiliation with Blackstone, there are other oil analysis companies out there, my direct experience is with them, for various engines.

Good luck

[steinfel]

So I was able to take a listen to the running engine with my doctor friend's stethoscope and the noise was loudest at the top of the engine, specifically by the #4 intake valves. Both she and I agreed on that assessment. The sound can be heard at any contact point on the engine, but it is most deferred at the bottom, under the exhaust manifold. Even with the air gap at the cover, the noise was loudest up top.

I ran the engine for a few minutes to stir up the oil pan, as well as turn the car around so it faces the other way. That's the first time I drove the car since parking it that night, only to reposition it in the driveway. It drove fine; the low rpms I used didn't make much of the noise while moving the car. I then drained all of the oil (until it was just a bit of dripping from the plug hole) and collected it into a clear tub. The oil was then strained through a piece of pillow cloth into a clean container, in case it was still good [20,000 mile Mobil1 Ext oil, with less than 2.5k on it]. There was not a spec of glitter at the bottom of the tub, nor on the pillow material. Filtering took forever. The oil was very clean and still had an amber color on the stick.

I put in 4 quarts of straight 40 and ran the engine for a few minutes. At first it seemed quieter, but as it warmed up, it seemed to make the same amount of noise as with the 5w30. The valvetrain seemed noisier with the straight 40 in it. I did take a listen again when the car was turned around before draining the 5w30 oil.

I wish that cylinder 4 wasn't wet with oil, because I don't know what the compression value is dry, like the others.

Does a lack of metal bits/glitter suggest that the bearings are ok?

Are there any other recommended tests that I should do while the engine is still in one piece?

I think it is time to inspect the valve components, especially at #4. I'm contemplating taking the head off, unless there is/are inspection(s) I should do without disturbing the head bolts/gasket.

I won't be able to do the next steps until I return in two weeks; I'm flying back to Chicago on Wednesday to check on my mom.

Thanks again for your time and input.

[steinfel]

This is long overdue, but somebody might be wondering how the tale came to an end, or perhaps gain from this report. It's been a trial, so here goes.

After a lot of time spent over that summer investigating various possibilities, the clacking/knocking noise was identified after taking the oil pan off and discovering a wrist pin circlip in the oil. Also, there was the presence of forbidden glitter. It turned out that the wrist pin came loose and was grinding away at the side of cylinder number 4, the oily piston/fouled plug cylinder previously mentioned. Discovered was a deep groove in the side of the cylinder wall where the loose pin was contacting the vertical metal. I contacted the shop that did the block work and they agreed to make it right. Apparently, the then owner of that shop, who actually did the work, was deteriorating in health while working on my engine. He ended up passing away a few months after completing my block. The shop owner's protege became the new owner. I ended up taking the block out again and delivering it back to him. Turns out they did not have the means to resleeve the scraped bore, so they tracked down and provided me with another block. They rebored that block's cylinders to .5 over, per the original order, installed the same Silvolite pistons with new rings, and the crankshaft for that one proved to be within spec, so they just polished and replaced the bearings--no need to grind down to the next size. They assembled the internals and I went down to them to pick it up. I installed that block late last fall with my original cylinder head, which I had re-inspected at the same closer-located shop that did the valve job/replacement at the beginning of this rebuild.

At the start of the last winter season I drove the car regularly, once all was complete and the break in was finished. The car drove well for about 3500 miles but never stopped consuming oil, which had me concerned about problems with break in. I eventually noticed a fouled plug at cylinder 4, but compression was good. Cleaning the fouled plug brought the cylinder 4 back to life when the fouling deactivated it. This happened more than once. We received a ton of snow that season, so I was unable to do much other than wait for better weather and more time to plan an investigation into the oil consumption. In March of this year, the familiar oil-related misfire symptoms presented during a climb up a mountain pass near me, I made it home, and I cleaned the plug per the familiarized practice I had done before. That instance, however, proved unfruitful, as the cylinder remained nonfunctional with the cleaned plug, and with a set of new plugs. Inspection with a borescope revealed a burnt valve at number 4. Ultimately, I would take the cylinder head off and bring it to the shop that did the inspection and valve work. They agreed to make it right and replaced the second burnt valve. They could not find the cause of the burnt valve, though. I asked them to replace the valve guides and thoroughly inspect everything. The owner of this shop showed me everything as he did the work in front of me. The exhaust valves were tired, starting to cup, so we replaced all eight of those. The intake valves were still good. The valve guide installation led to the discovery of two bad valve stem seals on cylinder number 4. Apparently, the guy who had done the inspection prior to my second rebuild missed that fault.

I got everything back together this past July. I filled the oil to the "FU" on the "Full" stamping on the dipstick, per OldNuc's, may he rest in peace, protocol. I have been driving the car normally. Since only the cylinder head was worked on, no break in was needed. In addition to local driving, I recently drove the car on a 1600 mile road trip and have not had to add any oil--this is after 2000+ miles. The oil is still at the "F". This is a first for me, not having to add oil at gas station fill ups. I am still in distrust/disbelief.

On this road trip I had one engine code show up at lower elevation/sea level after resting the car at my destination a few days, a code 26, which later accumulated a code 34 on the return drive, also at a sea level zone. The codes didn't show up again after that #34 showed up. Some noticeable stuttering at low rpm was felt. Oddly, the higher elevation parts of the drive did not summon this stuttering. Upon arriving home where the elevation is 6200, I replaced the MAP sensor and the car appears to be stronger and smoother. Gas mileage seems to have improved, too. Still no codes.

I am currently about to replace my AC hoses, as the high pressure one developed many microcracks that allowed the refrigerant to escape. I guess there was too much flexing/bending of the old hoses while moving the compressor out of the way while rebuilding/removing the engine so many times in the past 20 or so months. The hardest thing to find is the refrigerant mineral oil for the o-rings at the hose junctions. I have the dryer can, the PAG 100, the two AC hoses, but am still unsuccessful in obtaining the mineral R12 oil. People/shops are saying to use PAG oil for this function but this site says otherwise.

More on the second/third rebuild here:
https://www.saturnfans.com/forums/sh...=183725&page=2

[TomM96]

very gratified to hear of an eventual positive outcome

Happy Motoring !

[steinfel]

Originally Posted by TomM96

very gratified to hear of an eventual positive outcome

Happy Motoring !

Yeah, I am happy to have a successful project, after all of the hardships and problems. Thanks again for the help! The engine is still running well. Just gotta find a teaspoon of the R12 mineral oil for the AC component o-rings and I can restore my AC system, too. That stuff us hard to track down! Still no success there, so suggestions are appreciated.

[billr]

I usually stick to the "Tech" forum, but saw your name on this post and took a peek.

Why are you reluctant to use PAG for the O-rings, if PAG is what will be in the running system??? That makes no sense to me.

If you still want to use MO, it is readily and cheaply available labeled for non-refrigerant purposes. Yes, "mineral oil" is not a precise spec and they will vary; but they are all similar enough to be fine for just the little bit you will use to lube O-rings. And anything pure enough to ingest should surely be pure enough for the A/C system.

[steinfel]

Originally Posted by billr

I usually stick to the "Tech" forum, but saw your name on this post and took a peek.

Why are you reluctant to use PAG for the O-rings, if PAG is what will be in the running system??? That makes no sense to me.

If you still want to use MO, it is readily and cheaply available labeled for non-refrigerant purposes. Yes, "mineral oil" is not a precise spec and they will vary; but they are all similar enough to be fine for just the little bit you will use to lube O-rings. And anything pure enough to ingest should surely be pure enough for the A/C system.

According to more than one search on this forum, I saw that PAG oil should only be used for the compressor and other components, but not used for the o-rings. Perhaps they are isolated from the circulating lubricant when tightly secured at the connections. Apparently, PAG reacts with the o-rings and breaks them down. I saw that R12 refrigerant mineral oil needs to be used for the rings, despite the rest of the oil on a R134 system being PAG.

I'd love it if I can indeed use PAG for this, as I already have some. I just want to do what is right here. I am having trouble finding the AC mineral oil. Thoughts?

"9. O-rings, seal washers and seats must be in perfect condition. A burr or piece of dirt may cause a refrigerant leak.
When replacing the O-ring, first coat it with clean R-12 Refrigerant oil (mineral) and position on line as shown.

Notice

Use only Polyalkylene Glycol Synthetic Refrigerant Oil (PAG) for internal circulation through the R-134a A/C
system and only 525 viscosity mineral oil on fitting threads and O-rings. If lubricants other than those specified are
used, compressor failure and/or fitting seizure may result."

[billr]

"Perhaps they are isolated from the circulating lubricant when tightly secured at the connections."

You are working hard too justify ignoring common-sense. The O-rings are going to get exposed to whatever oil is in the A/C system very soon after it is in operation. Not using PAG on them at install only delays the inevitable for a short time.

The only rationale I have come across for not using the PAG for O-ring install is that PAG is hydroscopic, so "free-range" PAG may have some moisture in it that may corrode the metal parts the O-ring is sealing. It is a pretty long stretch of imagination to believe that is a real problem, but it has become a myth that persists.

As to attacking the O-ring material, the info I have found indicates PAG is compatible with all common O-ring materials. But does it matter, do you have any clue as to what your O-rings are made of; other than that they are intended for use in a system using PAG?

[steinfel]

Originally Posted by billr

"Perhaps they are isolated from the circulating lubricant when tightly secured at the connections."

You are working hard too justify ignoring common-sense. The O-rings are going to get exposed to whatever oil is in the A/C system very soon after it is in operation. Not using PAG on them at install only delays the inevitable for a short time.

The only rationale I have come across for not using the PAG for O-ring install is that PAG is hydroscopic, so "free-range" PAG may have some moisture in it that may corrode the metal parts the O-ring is sealing. It is a pretty long stretch of imagination to believe that is a real problem, but it has become a myth that persists.

As to attacking the O-ring material, the info I have found indicates PAG is compatible with all common O-ring materials. But does it matter, do you have any clue as to what your O-rings are made of; other than that they are intended for use in a system using PAG?

I am going strictly by what I have read on the forum here, heeding what others have already discussed. I thought the same thing about the common sense, but the counterpoint is significantly present on here, and I am simply looking for the correct move in this application. Personally, I do not have a desire to continue tracking down the mineral oil called for in this application--I've been unsuccessful for too long and am tired of the search. I would love to use the PAG oil I already have to lubricate the o-rings, but according to several posts on here, I would be making a mistake in doing so. It sounds like you have been substituting the R12/mineral oil with PAG oil and have not had problems.


Here are some of my references:

Post #3
https://www.saturnfans.com/forums/sh...d.php?t=117581

Post #6
https://www.saturnfans.com/forums/sh...d.php?t=234821

Post #3
https://www.saturnfans.com/forums/sh...d.php?t=237419

Post #8
https://www.saturnfans.com/forums/sh....php?p=2344437

Post #16
https://www.saturnfans.com/forums/sh...d.php?t=237354

[billr]

Thanks for posting the references so neatly. It saved me from having to scroll through those threads thoroughly.

Did you notice that all those references were relying on the opinion of the same one person? I feel that person is mistaken in this case. Note that the only reason cited was the same I mentioned before, that moisture in the PAG may corrode metal fittings. How much moisture do you think can be in a drop or two of PAG? How fast/badly would aluminum or steel corrode with the nano-grams of water that may be in those few drops of PAG???

Your car, your choice. Oh, and also not that those references suggest using common drug-store mineral oil, same as I did earlier.

[steinfel]

Originally Posted by billr

Thanks for posting the references so neatly. It saved me from having to scroll through those threads thoroughly.

Did you notice that all those references were relying on the opinion of the same one person? I feel that person is mistaken in this case. Note that the only reason cited was the same I mentioned before, that moisture in the PAG may corrode metal fittings. How much moisture do you think can be in a drop or two of PAG? How fast/badly would aluminum or steel corrode with the nano-grams of water that may be in those few drops of PAG???

Your car, your choice. Oh, and also not that those references suggest using common drug-store mineral oil, same as I did earlier.

I did notice that about the responses, being by that frequent poster, but others have said the same throughout my search. Also, the .pdfs ripped from some manual that were uploaded stated the same. Other sites I have found also mention to use refrigerant mineral oil.

https://www.city-data.com/forum/auto...y-mineral.html

https://www.delphiautoparts.com/reso...134a%20systems.

The ripped .pdfs were posted at the bottom of this thread: https://www.saturnfans.com/forums/sh...d.php?t=234821

I hear you about the subtle amounts of moisture carried in the miniscule amounts of PAG. I have been thinking the same thing, that it must be negligible. I bring up this question/concern because, despite this thinking, I still see so many sources, not just opinions of one poster, here and elsewhere, saying not to use PAG for this purpose. I figure there must be some important reason for it, given the the high frequency of found instructions to use mineral oil.

Yeah, I remember your mention of non-refrigerant mineral oil. It's the *non-* part that had me wondering. I saw that others have been in my shoes in looking for the elusive R12 mineral oil without success, and in posting those links, I saw that baby oil was used as an alternative, which seems to have worked for some folks. Looks like I want to find some relatively pure drug store product. I went to Ace Hardware and they had cutting board mineral oil, but it had additives in it (vitamin E, etc). Looks like I'll try finding a different (baby/household) mineral oil that is additive-free.

I have the hoses, the PAG, and the dryer can. Those parts have the o-rings included. However, the cold line kit I have looks like it does not include the compressor's flat seal washer (the aluminum one with the integrated rubber inner ring--the one seal that does not get lubricated). I feel I should replace that seal while I am doing this work. Do you know if I need to get a specific size for this car, or if Oreilly's off-the-shelf selection will do the job? Is it a common size? I figure I could just take the existing one off and bring it with me, but perhaps I should minimize atmosphere/moisture exposure to the AC system's "lumen" while driving the car to and from the place unsealed.

Thanks for sharing your thoughts!