Lots and Lots of Missfires

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directsource

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:confused:So, Today driving at around 35mph I had to accelerate hard to pass a vehicle... and got up to 55mph and then the strangest noises started to appear and my dash light up (my Check Engine light was flashing yellow). What I mean a CRAP ton of misfires I swear i'm either running on two or three cylinders... A LOUD clanking noise can be heard from the engine now the exhaust smells like unburned gasoline(Poor quality gasoline?) or light diesel fumes(No i did not buy diesel) , not to mention the amount of misfires are causing my entire exhaust to shake so violently that my hangers and joints are rattling! I stopped and tried to restart the car and it barely, barely started... Weirdly I don't have any hydraulic brakes(No vacuum pressure due to underpowered engine?), that means I have to push extremely hard on them to function, scary in the Icy roads of the Midwest Now I have a few ideas what exactly may have happened one of them is the Worst Case scenario timing chain, Coil Pack or rod knock. But, about a 1/2 a year ago my relatives cadillac (4.2L V8 Northstar) had almost the same symptoms we thought it was a timing chain, but we were wrong. Bad gasoline was the culprit, out of nowhere this problem occurred and sounds exactly like my shortstar(3.5l V6). He filled the tank full added fuel injector cleaner and fuel stabilizer which seems to have fixed the problem. Could it be some bad gas at the bottom of my tank that the engine is running off of since i'm at 1/8 of a tank? Or my worse case scenario... Now in future reference I just replaced my spark plugs they are at the right gap, and this was done about 1-2 K miles ago. I will not be driving this car until I have diagnosed this problem and either way this weekend I was planning on replace my wheel hubs due to wear and my little incident with the curb and yes the curb won... :thumbsdow
BTW I can get a video of the noise if needed and my OBD2 Bluetooth dongle will be coming tomorrow so i can check the misfires and codes!
So any Help would be awesome, I would like ANY suggestions for a problem like this
 
Another theory that has come to mind is that my timing chain has skipped(a tooth or two), which is entirely possible I guess which could potentially cause my engine to misfire like this... The weekend is going to be dreadfull... What should my approach be in a senerio like this? How long does it take to pull the valve cover off to check timing?
 
Go back to basics. Air, fuel, spark. Pull air filter and make sure it's clean. Pull fuel filter and might as well replace. Pull coil packs and make sure no carbon tracking on plugs and that plugs were properly installed. Do compression test.

Miles? Year? How long have you had it? And paragraphs are not your enemies, and increase the likelihood that someone is going to understand what you wrote and give you a correct answer.
 
Miles: 139,800 Miles on the engine and body, 5 Years of ownership in my family. It's a 1999 3.5L LX5 GLS. A key note is that this car has had no major engine problems minus the fact it burns oil like any other LX5
 
If your talking about spark plug gap I hope your using copper, and really copper should not be in these cars. Platinum, Iridium and whatever else is on the market are factory gapped, and if you gap them yourself you could very easily damage the plug. Had this happen a few times with an AutoZone employee who was writing gap specs on platinum plugs, then the customer would call saying we sold them bad plugs after they "gapped" them.
You could also have a few bad coil on plug boots. Since these act as a transport for the energy created by the coil to the plug if they are bad, it will cause issues. When I first picked mine up I didn't notice one of the boots had fallen off as I was putting the rear coil pack back in place, turned it on and had a slight knock and it was missing like crazy, that was the reason-no plug boot.
As a side note these engines don't burn oil so to speak, if you buy a cam cover gasket set that will stop oil consumption assuming it's not coming from your pan, or any where else. I did mine and don't have to add oil at all anymore, and it stopped the oil pooling down in the spark plug seats too.
 
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I personally didn't gap them I just pulled out the old ones put in the new ones and torqued them down to spec. I bought some Bosch Platinum +4 spark plugs about 4 months ago, they have four tips didn't have to be gaped is what I should have said. Thanks for the input I will try to keep everybody posted as I try and figure out this mess.
 
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After a few hours of tinkering changing plugs to the originals, yes I managed to keep them :) No difference . Sea foam and mid grade gas to 3/4 still no difference I'm beginning to think it's a mechanical problem... Really loud slapping/ticking noise coming from cylinder 5. I suspect either no compression, piston ring broke possible a broken valve spring or bent valve. I'm running out of ideas what it could be that wouldn't require me dropping the engine. I'm getting a compression test, all electrical being tested and possibly a verdict of what could be broken.
 
Problem possibly diagnosed

Well I talked it over with my dad and we came up with this that my valve spring has cracked and broke. The sound my engine makes is IDENTICAL to this 3.8 with a broken valve spring, so tomorrow I will have a second opinion on this issue. Now my question could I pull valve cover off the engine which is towards the back of the engine cylinders 1,3,5 and change out a valve spring, without dropping the engine? Or would that be a nessisty? Please reply I need some guidance.

Sound of the 3.8 that makes the same noise https://www.youtube.com/watch?v=Wx2fNCBOhLM
 
Do you have a shop manual? The 3.5l is a COMPLETELY different animal than the 3800 series dinosour...push rod motor compard to a quad v-6... you need a shop manual.
P.S the 3.5 doesn't have a valve cover, it's a "cam cover" when you go to get gaskets for it.
 
I just bought a factory service manual for the engine today, so a mechanic I had look at it said the my piston is slapping my head which I find hard to believe. Either way a turn for the worse has actually proved my theory right of a broken valve spring... Why might you ask? Well driving home on the broken valve spring, seriously 1 block away stop sign all the noises from the engine just escalated so fast within that 100 feet(sounded like a belt shredding) and last thing i head was a pop, bang, smoke open the hood and smoke came up near the top of the intake manifold. I tried cranking it, dead silent so I pushed the damn thing home and now for sure something is going to have to be replaced. I think that a valve dropped into my cylinder and BAM goodbye piston and head. Well, now this weekend i'm pulling off the heads for sure. Now I know I can take off the front head cylinders 2,4,6 but what about the rear head cylinders 1,3,5 would i be able to take it off without lowering the engine?
 
You "could" get to it, but it'd be a royal PITA. Your going to have to take the timing chain off to get the heads off, and although you'd spend some hours just prepping the motor for removal, it would be much easier to do what you need to with the motor out of the car.
One last thought, you didn't get sold wrong plugs by chance? I myself find it hard to beleive your piston was slapping the head. The piston was probably hitting a valve, then the valve became bent and started to weaken until it broke and dropped, or though not likely since it's just one piston, it could have been making contact with a spark plug that was too long.
While you have your motor torn apart you should consider replacing the coolant crossover gaskets, usually they are hard to get to, but you'll have to take both exhaust manifolds off, so it wouldn't be much work really, and they are notorious for springing small leaks.
 
That engine sounds pretty far gone. :( Maybe time to think about getting a crate engine and replace it all.

Or bid on Copart.com or IAAI. Buy a rear-ended Intrigue, and swap the motors.
 
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Well, I find it rather a small chance I got sold the wrong plugs, because this is the first time in three months that this engine had a problem. These plugs were looked up by an O'riely auto parts store employee which looked up the engine 3.5l. Now I know I will have to set up the timing again. Should I focus on that while tearing it down or not I honestly cannot crank the engine it's "stuck" for some reason or another. I think it couldn't be that big of a pain to set up the timing again if I sat down and spent an hour or two just for timing. Thanks for the suggestions guys! I will be taking pictures for the disassembly of all of the stuff since I find it useful for myself(probably won't remember:)) and the LX5 community. Anything I should lookout for when pulling the heads such as breaking bolts, safety precautions, etc..
 
I can understand being curious what happened, but that's probably the worst sounding engine failure anyone has described on this forum. The 3.5L is known for developing gasket leaks, but internal damage is very rare.
 
My 3800 Series 2 did the same exact thing. That's why I think a valve dropped in yours. My valve started knockin, I took it on a high speed run, heard the valve drop, motor stopped and would not rotate at all, just made a loud click. Then I pushed it in the front yard and sold it for $500.
The reason I said what I did about the plugs is because you mentioned them as being tinkered with recently. Parts store employees aren't required to know much about cars, components of a charging system, what's this (insert picture of a muffler) it's a joke how little mechanical knowledge is required.
Make sure to buy the cam tool, or impovise a way to hold the cams in place once the chain is off.
Good luck, look forward to seeing your progress.
 
haha, yeah no kidding I was heartbroken when it died:( But, worst comes to worst I can part out the remainder of the engine and try to acquire a used one. Although, I seriously want to REBUILD it, it's the first car love :cool:. By any chance do any of you guys know if im crazy but my cam cover is painted black for cylinders 1,3,5 the rear one(maybe not Factory Stock). And it's peeling which is driving me crazy since that paint could easily flake off and fall into the cylinder.
 
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