FMC80
SILVER Star
I’m dying here!!!
misfire shake down trip work (250K) (1 Viewer)
- Thread starter landcruiser3DP
- Start date
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Why don't you start by testing whether or not there's exhaust gas in your radiator (and write down the result!), then do a basic tune-up before digging deeper?
If you have a blown head gasket, there's no point in doing anything other than addressing the blown head gasket.
If you *don't* have a blown head gasket, then the most logical thing to do is a basic tune-up (plugs, cap & rotor, wires). There's no reason to be digging into the valve cover yet.
Regarding your theory about "oil-fouling" at high RPM and load, I think you've got it backwards. High RPM and high load are likely burning out all the carbon you've built up from putting around town with leaking valve stem seals.
If you have a blown head gasket, there's no point in doing anything other than addressing the blown head gasket.
If you *don't* have a blown head gasket, then the most logical thing to do is a basic tune-up (plugs, cap & rotor, wires). There's no reason to be digging into the valve cover yet.
Regarding your theory about "oil-fouling" at high RPM and load, I think you've got it backwards. High RPM and high load are likely burning out all the carbon you've built up from putting around town with leaking valve stem seals.
- Thread starter
- #44
yeah. thanks. seems odd it only happens after a full day of driving and really, really running it hard though. so i suppose colder plugs can't hurt.
also if replacing the plug and clearing the code makes it go away - and it hasn't come back in "regular driving" - i'm wondering if there is any harm in just replacing plugs and coils and driving it back. basically.
i mean, well i suppose if i get someone to do a compression and leak down it could show an underlying issue? or if i test the radiator for oil it could show an underlying issue?
but if it is running really strong i am starting to think i could just change the plugs and coils and drive it back with extra plugs. or if i have access to cheap OEM parts and someone to put it in i could do the radiator now too.
both of these would be pretty straightforward.
but also if i find the right guy up here i could buy employee priced parts and have him do valve cover gasket and spark plug tube seals while i am up here. and if he'll let me wrench i can just add in some extra time on this end.
one question: can you inspect rings and cylinder bores when you do a valve cover gasket and spark plug tube seals? i guess that's a part i'm still not tracking.
This is the thing with all the advice you get on your posts. You're not reading the answers.
People have driven with a blown head gasket. Do a compression test. Do it before posting anything else. Post the numbers.
If you have leaky valve seals, you can drive all the way home. If you have to carry around a box of spark plugs to do a road trip, you have an underlying condition.
If you can't do your own radiator, you're not ready to do the head gasket yourself.
You can inspect the cylinder walls with a borescope camera. But if you get a compression test done, it will tell you what you (likely) need to know.
The engine order is valve cover, cylinder head, head gasket, engine block. The block is where the pistons are. You can't physically see the cylinders with the naked eye with the valve cover off, because the cams and head are in the way.
I forgot about this, "seems odd it only happens after a full day of driving and really, really running it hard though. so i suppose colder plugs can't hurt."
Yes, colder plugs can absolutely hurt. You have a stock engine. Use stock plugs. You run the risk of fouling the plugs quickly when you're just driving around because you won't get them hot enough to burn off deposits. If you were running a turbo, sure. If you're running lean, a colder plug could help, but that's an underlying issue. If you have advanced the timing, you could run a colder plug. What's your timing set at?
I believe the stock plug is Denso heat range 16, which corelates to an NGK 5. You're only going one plug colder. That might help if you are doing high RPM, high speed interstate driving in hot weather.....but is not going to work well for around town or short trips.
Yes, colder plugs can absolutely hurt. You have a stock engine. Use stock plugs. You run the risk of fouling the plugs quickly when you're just driving around because you won't get them hot enough to burn off deposits. If you were running a turbo, sure. If you're running lean, a colder plug could help, but that's an underlying issue. If you have advanced the timing, you could run a colder plug. What's your timing set at?
I believe the stock plug is Denso heat range 16, which corelates to an NGK 5. You're only going one plug colder. That might help if you are doing high RPM, high speed interstate driving in hot weather.....but is not going to work well for around town or short trips.
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@landcruiser3DP this video literally shows you everything you are asking about, step by step.
The FSM also has procedures for doing all of this, great resource, go read that too. Start at EM-12 and read from there.
Everyone is trying to help you but at some point you have to get off the keyboard and go do something. Either turn a wrench or pay someone.
If your next post isn't "Here are my compression test results" you might start getting a bunch of ted mosby memes...
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- Thread starter
- #49
thanks. it's always tricky learning something.
it's not so much not be able to do a radiator it's just doing it for the first time, having the time to do it, and whether it is worthwhile for various reasons for me to just have someone do it while i am here. if the price is right i may as well have someone do it here. does that make sense?
the other thing i was trying to do was to to decide how much /other work to do up here (again if the price works) and whether it made sense to do a valve cover and tube seals now instead of a just a tune up. chances are very good i need tube seals obviously.
so one thing i was hoping to figure out was if i could try to get some insight into whether doing valve cover up here was /not/ a good idea for some reason such as not being able to inspect the cylinder walls or the the rings. and conversely if it would not be a good idea because by the time you are that far in - if they say you need machine work then it is already open and "on the table" and i would get either hung up up here or i would have to ask them to "button it back up" and not do the head work when i really should do it if i am that far.
does that make sense?
so why not do that work when i get back where i will stay and have time to not be driving it with a backup vehicle.
for instance
A. if i ask them to borescope the engine can they only do that when the valve cover is off? or does the ?
B. the engine has 225K and i can report back on compression and leak down if/when i can get it done obviously. but from the sounds of your response i can drive it home after just doing plugs and wires and looking to see if the distributor cap is clean?
i do get it is frustrating answering technical questions on a forum like this so apologies. i'm usually troubleshooting things like this on the phone.
anyway if i am talking to mechanics about them doing the work it's easier to get these noob questions out of the way now first which will make things easier.
- Thread starter
- #50
thanks man. i haven't had a chance to check my timing unfortunately. i've just been trying to slowly sort it and haven't gotten to it. i do have the code reader here so this has helped because engine codes far from home is a but of trial by fire for me.
You put the scope down the spark plug holes (with the plugs removed). You don't have to take the VC off to do it.
A compression test will give you one idea if you should drive it, and that's if you have a bad head gasket. It doesn't mean you have no other problems. Ideally, your cylinder numbers should be within 10 percent of one another. If the first five cylinders are between 175 and 195 and the sixth cylinder is below, say 120, you have an issue.
A leakdown test will give you a better idea of what the mechanical issue is with the engine (worn rings, bad head gasket, bent valves/worn seats).
I am absolutely not saying you can just drive it home after doing plugs and wires. I am saying you need to do some basic tests to narrow down the issue or see if you're at the precipice of a catastrophic failure.
A compression test will give you one idea if you should drive it, and that's if you have a bad head gasket. It doesn't mean you have no other problems. Ideally, your cylinder numbers should be within 10 percent of one another. If the first five cylinders are between 175 and 195 and the sixth cylinder is below, say 120, you have an issue.
A leakdown test will give you a better idea of what the mechanical issue is with the engine (worn rings, bad head gasket, bent valves/worn seats).
I am absolutely not saying you can just drive it home after doing plugs and wires. I am saying you need to do some basic tests to narrow down the issue or see if you're at the precipice of a catastrophic failure.
I eagerly await the new post where we explain how to check your timing, what it means, what it should be, and how it impacts the price of tea in the southern hemisphere.
But really, here's your first mosby meme:
In all seriousness, we all gotta learn and start somewhere... this is me trying to motivate you to dive in with a wrench and stop pontificating. You have the steps, you have the info, go give it a try. If you were in my town i'd even come help you! Until you get in there and start actually doing it, you won't learn. If you saw the long long list of stupid stuff i've done working on things, I promise you would laugh.
As long as you don't do this, you'll be fine:
- Thread starter
- #53
thanks. trying to get my notes together here.
so compression/leak down test?
borescope if feasible to inspect cylinder walls and rings?
FSM seems to say compression in each cylinder is 171psi > 128 psi and they don't want a variance larger than 14 psi.
the radiator doesn't leak and i tested it once before but here is a pic. there is some weird distortion in the image but it's clean aside from some kind of small film thing.
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can i just ask if compression/leak down comes back hood and if i am doing s new radiator anyway it's basically an "elective" in terms of doing a tune up with plugs and wires versus going ahead and doing valve cover gasket and spark plug tube seals?
meaning if the price is right and i have the one is there a downside to doing valve cover gasket and spark plug tube seals now?
meaning barring further info if the numbers come back OK i am either doing that to alleviate a plug foiling problem or i am doing plugs and wires and dealing with it back in texas?
here is FSM on plug gap (0.81mm) and compression numbers but not sure if i should have anything else handy?
Why do you refuse to simply start with the basics?
You're endlessly pontificating and theorizing instead of getting productive work done.
You're endlessly pontificating and theorizing instead of getting productive work done.
Why do you refuse to simply start with the basics?
Bingo
FMC80
SILVER Star
So I can be sure to avoid this 80 like the motherfucking plague if it ever comes up for sale.
