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So, i have a project 1984 f150 with the inline-6 300. The other day i went to drive the truck to work, and noticed that my oil pressure dropped. On the way back home, i added 1/2 Quart of oil to the engine. By the time i got home, i lost that much.
I opened the hood, and oil is coming out of 3 places. The top valve cover breather, and the two spark plug holes (assuming 5 & 6).
I pulled the first spark plug out (#1 or closest to the grill) and this is what it looks like.
then i pulled #5 or the second closet to the cab, one of the ones that is leaking out of the spark plug hole. it was drenched in wet oil both on the firing end, the threads, and on the outside.
While a rebuild is not out of the question, to make sure, is it the rings that are bad? Cylinder walls? or something with my valves? Ideas? If a rebuild isn't necessary, i'd like to wait about it, but if it is, so be it. NOTE that the PCV valve and the valve cover breather is both brand new. sorry about the huge images too.
This happened all of a sudden? I don't see how rings could wear out all of a sudden. But the 300-six, for all its somewhat questionable reputation for reliability, is notable for piston breakage, which can happen all of a sudden. Machine shops often find broken pistons in 300s they tear down.
But while the 300 has a couple of weak links from the factory, when you rebuild one with better pistons (forged or high-silicon) and add an aftermarket cam gear, THEN you have a very tough engine (and of course there are several other functional improvements you can make to have a tough engine that also makes good street power and is fuel-efficient).
This happened all of a sudden? I don't see how rings could wear out all of a sudden. But the 300-six, for all its somewhat questionable reputation for reliability, is notable for piston breakage, which can happen all of a sudden. Machine shops often find broken pistons in 300s they tear down.
But while the 300 has a couple of weak links from the factory, when you rebuild one with better pistons (forged or high-silicon) and add an aftermarket cam gear, THEN you have a very tough engine (and of course there are several other functional improvements you can make to have a tough engine that also makes good street power and is fuel-efficient).
No, it didn't happen suddenly, it was just so slow that I didn't really think of it. It was only till the other day it lost that much at a time though.
Running platinum plugs?? Time to switch back to plain ol' copper plugs.
Be sure the PCV valve and emission/vacuum hose is connected and working properly. I'd run some rotella 15w-40 and some MMO for a few hundred miles or a 1000+ and do an oill change. Could just be trash and sludge causing the oil burning problem. That rotella will help to remove a lot of the sludge and perhaps restore the valve guide seals if they aren't to far deteriorated.
This isn't "One size fits all" fix. Just a thought. Hopefully I won't get flamed.
I can't see running platinum plugs on the vintage engine, and also burning oil.
By no means not trying to argue there is nothing wrong with platinum plugs in an engine that was designed for them, but seems it just isn't needed in this engine.
I just noticed they were and was addressing it. I respect all you have to say and give Frenchtown Flyer. Wasnt trying to give bad advice.
Running platinum plugs?? Time to switch back to plain ol' copper plugs.
Be sure the PCV valve and emission/vacuum hose is connected and working properly. I'd run some rotella 15w-40 and some MMO for a few hundred miles or a 1000+ and do an oill change. Could just be trash and sludge causing the oil burning problem. That rotella will help to remove a lot of the sludge and perhaps restore the valve guide seals if they aren't to far deteriorated.
This isn't "One size fits all" fix. Just a thought. Hopefully I won't get flamed.
what do you mean by MMO? Well, as i said earlier, i replaced the pcv valve, but i'll also check the lines. But, could sludge really cause oil being forced into the cylinder, and force out the spark plug?
Okay, AB, I've been asking this for years: What is the mystery in Marvel Mystery Oil? By this I mean, what is in it that makes so many people swear by it, which they have been doing since I was a kid in the Fifties, and before? Everybody is willing to guess about this, but I've never seen a formula. What's that modern analogue of MMO, oh yeah, Sea Foam; what's in that? Something like urban legends grow up around this kind of thing; when I was a kid, we all "knew" that the then-popular Rislone was "just kerosene" (whether true or not). We had our cheap substitutes as well, such as putting a can of condensed milk in a leaky radiator if you didn't have any Bars-Leak. Somebody online asserted that the Air Force buys cases of milk of magnesia for the aero-mechanics to use as a high-temp anti-seize.
(I better quit this; I just got chewed out for going off-topic on another thread here. Personally, I think that's part of the fun, but it's not my thread.)
Heh, that's the mystery. Honestly, I have no idea. It was recommended to me, and when I've used it, it's done the trick. Cleaned up lifter tick, removed varnish, etc.
Another one that's been suggested, and works well, is to swap out a quart of oil for a quart of automatic transmission fluid. That stuff has some serious detergents in it.
So everybody is thinking that changing the oil could help, but I'm a little lost on that part. If it is just a seal or something that could be the problem I'd assume just to fix it.
It definitely looks like there could be more going on. But for starters, being sure your engine is cleaned out, some varnish, buildup, or blocked passage somewhere isn't making problems, etc. is a very inexpensive fix to try. If that doesn't help, then move on to the more expensive things.
What I like to use is some stuff called "Auto RX". It's not cheap but it works great. It slowly cleans out sludge from your engine.
If it was me I'd do a compression test.
If you are having a bad blow by issue, you've got either worn rings/cylinders, stuck rings ( that's where the Auto RX, MMO or other additives might help ) or a cracked or otherwise damaged piston.
If it's worn rings/cylinders or a damaged piston then it's rebuild or replacement engine time.
If it's stuck rings then an oil & filter change and some additive might clean the sludge/carbon out of the ring land grooves. That could free up the rings and improve the issue.
But start with the compression test. That will tell you a lot.
What I like to use is some stuff called "Auto RX". It's not cheap but it works great. It slowly cleans out sludge from your engine.
If it was me I'd do a compression test.
If you are having a bad blow by issue, you've got either worn rings/cylinders, stuck rings ( that's where the Auto RX, MMO or other additives might help ) or a cracked or otherwise damaged piston.
If it's worn rings/cylinders or a damaged piston then it's rebuild or replacement engine time.
If it's stuck rings then an oil & filter change and some additive might clean the sludge/carbon out of the ring land grooves. That could free up the rings and improve the issue.
But start with the compression test. That will tell you a lot.
Well, i must have read your mind, i bought a compression tester on my way home today, and ran it before i read this
considering, those are some pretty consistent numbers, which would lead me to believe that it isn't the rings, but something else. What does everybody else think? what should be my next test? the valves?
considering, those are some pretty consistent numbers, which would lead me to believe that it isn't the rings, but something else. What does everybody else think? what should be my next test? the valves?
It could still be the rings. I think if it was me I'd try the oil change with the additive next.
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Inline 300 Worn Rings or Something Else?
Honestly, I have no idea. It was recommended to me, and when I've used it, it's done the trick. Cleaned up lifter tick, removed varnish, etc.
