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YOUR RESEARCHEngine knocking...
Leading reported evidence
Replace the is no way
Performed · outcome unconfirmed
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Performed · outcome unconfirmed
YUP, my guess is that the oill in your lfters is the same oil the car left the factory with no matter how many times its been changed - The is NO WAY for the oil to get out - seriouosly
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Suggestion · Original poster
Having worked as a mechanic in my youth (long enough to decide I didn't want to do that for a living) I decided it sounded more like a valve clattering noise similar to a stuck lifter and after checking the oil level gambled on a restart.
Leading evidence: 'Replace the is no way' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'cause since it sounds like it already happened' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check oil level gambled' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
That engine ran so I bought it for $200 and put it in my car.
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Performed · outcome unconfirmed
Next time I'm out and about for a year besides fuel stabilizer and new oil for the car to sit with I'm using exhaust plugs.
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Performed · outcome unconfirmed
An old friend that was a diesel mechanic in his younger years when I met him told me about a trick he used for freshening up an engine that pisses him off being jacked up.
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Check oil level gambled
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Suggestion · Original poster
Having worked as a mechanic in my youth (long enough to decide I didn't want to do that for a living) I decided it sounded more like a valve clattering noise similar to a stuck lifter and after checking the oil level gambled on a restart.
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Suggestion
I was providing the info because it might be a good compromise for everyone to clean & reuse all acceptable lifters instead of replacing the 1 or 2 that are noisy now.
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Suggestion
If it's a lifter or 2 it would be good to remove all the lifters, submerge them in new engine oil (while keeping track of where they go backh in the head in the same place they came from) and pump the lifter until all the old oil gets purged with clean oil.
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Suggestion
I was providing the info because it might be a good compromise for everyone to clean & reuse all acceptable lifters instead of replacing the 1 or 2 that are noisy now.
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cause since it sounds like it already happened
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Suspected cause
I recommend you don't attempt to do this, but without actually hearing the noise in person this is likely the cause since it sounds like it already happened to your Variocam actuator which works like a tall lifter.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
45 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
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Outcome without a verified action link
Everything will be back to normal after all the bones and fir get spit out
But no one's home. Sorry. I couldn't resist.
My 02 996 C2 has been sitting for a few days (been driving the F150 while remodeling). I went to start it and when it did it made a horrible clattering noise. I killed it immediately and sat there wondering if the IMS bearing had just died (no pun intended). Having worked as a mechanic in my youth (long enough to decide I didn't want to do that for a living) I decided it sounded more like a valve clattering noise similar to a stuck lifter and after checking the oil level gambled on a restart. This time it started without the clatter but it had a definite metallic knock like a rod bearing.
I dug out my 24 mo/24k aftermarket warranty paperwork and found I have approximately 3k miles till it expires. Whew!
So I had it towed to the dealer and am anxiously awaiting a call. I guess if something is going to break, better now than in 3k miles. I've been out of work since June and the oil and gas industry doesn't look to improve before next summer. I certainly can't afford a huge repair bill right now. I just hope the warranty doesn't try to weasle out of any repairs. They were great with the last repair - a failed cam actuator - but one never knows.
did you listen to this thread?
https://rennlist.com/forums/996-foru...ound-clip.html
also could be other things, lifters get stuck/bleed down, cam chain tensioners stick and bleed down, and pulley bearing make noise - lets hope its something simple (or covered)
1st guess is a lifter, same stuff in the oil that can clog a vario-can actuator can clog lifters too. Hopefully you can get a "upgrade" out of this. If it's a lifter or 2 it would be good to remove all the lifters, submerge them in new engine oil (while keeping track of where they go backh in the head in the same place they came from) and pump the lifter until all the old oil gets purged with clean oil.
But you have to see what they want to do.
Uh oh. Horrible clattering is what santa's sleigh is supposed to do on the roof instead of in your engine. Hopefully rod bearings are covered.
Make sure you don't do any reving the engine when its cold. It's the best way to turn a bearing in this world.
lifters sticking is not always curable with "new oil"
the variocam plus motors center section of the lifter can mushroom to the point of sticking a little, them permenantly - wanna see the pics (again)
Hopefully
I
won't be doing any of the repairs, but I remember oiling the lifters when I rebuilt the engine to my first car. It was a 73 Dodge Charger. It was given to me by a cousin who had trashed it. It didn't run so I had it towed to my house (I was 15) and it sat in the backyard for a year. I met a guy who had a 69 Charger with a worn out 318 he was replacing. That engine ran so I bought it for $200 and put it in my car. I drove it for a couple of years till the rings were so bad it smoked like a Peterbuilt. At the time I worked at an Oldsmobile dealership taking care of the used cars. I spent 3 grand rebuilding the engine - 484 lift cam, forged pistons, 9.5:1 compression, ported heads, etc. I loved the sound of that engine idiling...(sigh)
Anyway, now is not a good time for me to have to undertake an engine teardown or rebuild.
Hopefully the warranty will cover all.
seafoam is supposed to clean the lifters well. im on an offroad forum alot and they swear by it. The early Nissan Pathfinders have noisy lifters all the time, and the motors routienly go for 250+ thousand miles.. Im waiting for someone to use it on here...
When I was a teen, I knew a guy who was always blowing head gaskets from rapping the engine out on the freeway onramp before it was fully warmed up. After helping him replace one I asked him why he didn't learn. He said "I just got the urge".
I guess sometimes you just gotta.
I heard a saying a few years ago I really liked and it can be altered a bit to fit
"You gotta be tough if you're gotta be stupid"
change to "you gotta have money....."
Sorry. I've never heard of seafoam. I guess it's some kind of oil treatment... Just googled... Never seen it but I have a bottle of the Bugs-B-Gone in my garage.
I'll check it out for future reference.
While I appreciate the suggestion I have to admit I've always viewed oil additives as "snake oil" - lots of marketing hype. There never seems to be any empirical scientific test data to validate their claims, but there is an over-abundance of anecdotal evidence from everyone and their brother.
I read this on another forum: "I have no empirical evidence to suggest that Seafoam is not a useful treatment. If owners are seeing positive results with their own eyes, who am I to argue? What I do know is that it contains pale oil (a lightweight, highly refined mineral oil), naptha (commonly known as Coleman lantern fuel), and isopropyl alcohol. Solvents, essentially. None of these are magic elixers and all can be found in the other motor flushes on the market. Do they work? If they do, I would expect the manufacturer to be ble to produce evidence from ASTM, SAE or other well-respected testing lab for scrutiny. AMSOIL and other companies do this with some of their additives. I could find nothing of the sort on the seafoam site, though admittedly I didn't dig long."
I guess it's my engineering background but before I buy additives, I want to "see the numbers". In the meantime I'll change my oil regularly.
Perhaps you have seen test data to support Seafoam's claims?
I recommend you don't attempt to do this, but without actually hearing the noise in person this is likely the cause since it sounds like it already happened to your Variocam actuator which works like a tall lifter. I was providing the info because it might be a good compromise for everyone to clean & reuse all acceptable lifters instead of replacing the 1 or 2 that are noisy now. The problem with the lifters is the internal clearances are so tight that trash in the oil goes in but never comes out. If you use Seafoam or other engine flushes it brings trash from the whole engine to park in the lifters.
never used seafoam, but I think you put it in the intake down you ? (like a cleaner?)
maybe they offer multile levels of snake oil protection
actually I have heard a lot of people say its good stuff
directions smerictions....
honestly I have never used it, but I had one of the old pathfinders and they had lifter problems, and I know a ton of people that swear by it and say it completely stopped their noisy lifters. many people do it 2x a year as maintance, and these are people who have clocked 250+k miles on their motors.
But agian, I have never used it. :-)
Dealer just called and said they couldn't find anything wrong. They believe the noise was because it sat for a few days and the oil drained from the lifters causing the clattering and subsequent knocking. Anyway they say it's running fine so I'll go pick it up and listen for the knocking I heard. If all's well, so much the better.
I think I'll pick up a new filter while I'm there...
When I do that kinda' thing, I'll pull the motor and go thru it, upgrade and replace wear items and do a complete inspection. I'd hate to do that sorta' thing thru the rear deck opening.
Like refreshing a race motor after so many hours.
I picked up the car and it sounds fine although the dealer said he had to jump start it this morning. I guess it's about time for a new battery: the old one has been in there about three years. I also picked up a filter so this weekend I'll change the oil.
I got my baby back, baby back, baby back. I got my baby back, baby back...
so here are the lifte pics...
This is a 60k mile 03' C4 (IIRC)
So the lifters have been taken apart to discover what causes them to stick - you can see the gouges in the side of the center (variocam Plus) section - good reason to change your filter more than every other oil change - you can see the top surface is shiny indicating that it has worn - the hardest area is the surface and once it wears a little, the wear rate increases. Once the top begins to "mushroom" it doesnt take much to cause the parts to stick together (I found it to be <0.0005" and found parts with 0.002" interfierance.. so clearly some force is "unsticking them" until the point that is no longer possible)
anyhow... I have taken several of these apart, very cool little assemblies and I have a "working model" that you can go play with if you stop in at my indy shop... it is fun and helps explain how this works because you can actuate it like it is in the car - cool stuff
the lifters wear out prematurly on some cars - my guess is heat from poor oil, poor oil change intervals, using the filter too long, lugging the motor, I dont know.... any number of other factors...maybe they were just not heat treated right at the factory (though that doesnt seem too likely)
soaking them in any magic oil aint gonna fix this, might fix some of the debris....but not this
I've used Seafoam in my intake before. I hear you can add it to your oil and run your car for a bit to clean out all the gunk. I don't think its much different than kerosene...
Interesting pics. Thanks for sharing. Something else that should be closely inspected and probably replaced at a convenient opportunity as a wear item.
Probably just a mouse crawled up the exhaust past an open exhaust port vavle and slept in the piston cylinder. Everything will be back to normal after all the bones and fir get spit out
Next time I'm out and about for a year besides fuel stabilizer and new oil for the car to sit with I'm using exhaust plugs. I still don't like the way the injectors sit with fuel drying up in them gumming things up. The you have a whole fuel rail of gummy stuff to ram past the injectors.
You might try some injector cleaner. It could just be the few days gave the gunk in their a little extra chance to harden more and jam things up. Injectors are more complex than just a needle valve and opening. Some of them are like a maze of channels with all of them easy to foul up.
NO DO NOT DO THIS!!
The M96 engine is a lot different than others that respond well to engine flushes.. Why? Because the valve train is at the end of the secondary oiling system and because the lifters only have one hole in their body to fill with.
This means that when flushing the engine all the debris from elsewhere in the engine goes directly to the lifters!! To make the issue worse the lifters only have one hole in the body, so the debris enters the lifter and can't be removed.
I have experienced this on many occasions with the M96. If the lifters are dirty they must be removed and disassembled to be cleaned correctly. With any engine flush you are just further contaminating the lifters with all the other crap that the flush freed up inside the engine.
YUP, my guess is that the oill in your lfters is the same oil the car left the factory with no matter how many times its been changed - The is NO WAY for the oil to get out - seriouosly
An old friend that was a diesel mechanic in his younger years when I met him told me about a trick he used for freshening up an engine that pisses him off being jacked up. He'd put diesel in the sump and crank the engine through for a while to flush it out. His reasoning was the diesel is a light oil which it is and it cleans while it's at it. Doing this I'd imagine might work old oil out of the lifters. I am not sure if dry cranking the engine would get the lifter to collapse and empty the old out before going to a sump of diesel. That would be the ideal condition to then have diesel enter which would even more flush the lifters of old oil when dry cranking a little after the diesel. Of course when you have the option of a new crate motor in a military shop it helps. I think he was hand cranking the engines with the glow plugs out so that it was easy cranking by hand. I'm sure if I were doing it I'd hand crank with the plugs out flushing and reinstalling the synthetic oil so that the intial start up doesn't have the diesel as the base of lubrication. But we are talking about spending a few hundred in synthetic oil to just flush the diesel out before starting
Pac, I have also heard of that (from my father) but never did it or saw it done...
I have however poured water down the carburator on V6 and V8 motors - the theory there is the water turns to steam in the cumpusion chamber and steam cleans the pictons and carbon build up... I have done that on several of my own older chevy trucks, (pre cat converter years)
