Engine charcoal and spark plug bonks
- Thread starter Korys_thing
- Start date
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naw man, you gotta exercise all the demons before you call for the mechanic in a bottle!
The BIG question not asked yet: How long has the #7 not been firing and wearing out the cylinder wall and rings from not firing. How long has it run to get that much sluge?
Since you bought it? How long? Miles? Did you know it ran on 7 cylinders?
1) Try a shorter plug for #7
2) Clean out the plugged exhaust crossover in intake and heads.
3) Remove sludge with a putty knife, etc.
Now go drive it and see what you've got.
Beyond that, It's a 273. Dump it.
Since you bought it? How long? Miles? Did you know it ran on 7 cylinders?
1) Try a shorter plug for #7
2) Clean out the plugged exhaust crossover in intake and heads.
3) Remove sludge with a putty knife, etc.
Now go drive it and see what you've got.
Beyond that, It's a 273. Dump it.
Korys_thing
Member
Guessing since I bought it back in July. Admittedly, don’t recall if I checked all the plugs or if I hit a handful and thought it looked ok enough. Probably only driven the thing 100-150 miles since then.
Everyone keeps telling me “sounds like it runs good! What a find!” Meanwhile, I was trying to figure out why I could never get consistent oil readings and it felt underpowered.
Compression on all cylinders is 143-155 if that tells anyone anything. 150 on #7. Thought this was all pretty promising until I started taking it apart!
Short term solution might be spacers/shorter plug and the clean out Hail Mary while I look into a replacement and start buying some Black Friday engine removal equipment
that's actually really promising. however... by opening it up you may have let out all the magic...
all kidding aside, you could clean all that out as best you can button it back up and then run some regime of things and stuff to get it all out of the internals... and probably drop the pan and do a pick up... and wind up with a motor that'll give years of reliable service.
or it could suck something up and clog the screen, jam the pump or get lodged and spin a bearing.
so you have compression. i'd borrow or rent the stuff to do a leak down test and get a bigger picture of the overall heath of the engine before making a determination on which direction to take-- nurse that along or replace it wholesale.
but know going in that something is going to need to be done in addressing the plug getting bonked. what exactly that could be is a very broad "TBD" and most of it time consuming and/or costly.
JDMopar
Well-Known Member
Is it the car in your avatar? 64 Valiant? Automatic or straight drive? If you can find a good 5.2 Magnum, that will be your cheapest route to being back on the road reliably. It's pretty much a bolt in except for a few fiddly things. The main thing being, you'd need to get an LA 360 oil pan for a car. All Magnums, 5.2 or 5.9 have to use an LA 360 car pan to fit into our old cars. If your car is an automatic, you will need to get an adapter ring that fits in the register in the back of your crank where the flex plate bolts on, so your existing torque converter will live happily ever after with the Magnum motor. If your car is a manual trans, all of your stuff will bolt right back up and work. You will also need to buy a Chinese air gap intake off Amazon for $135.
Your motor is fixable, but you just have to decide which way is best for you. Whatever is boinking the #7 plug would be my primary focus if I was taking it apart. You can yank the heads and get that far before buying/renting a hoist.
Your motor is fixable, but you just have to decide which way is best for you. Whatever is boinking the #7 plug would be my primary focus if I was taking it apart. You can yank the heads and get that far before buying/renting a hoist.
Get a cylinder head casting number and see what year those heads are. Then see what plugs that head needs compared to what you have in there.
Never know what's going on, they may have an oddball piston in #7 hole. Guys do stuff like that.
Never know what's going on, they may have an oddball piston in #7 hole. Guys do stuff like that.
I've cleaned an Olds 350 many years ago where the intake valley was slam FULL of that mess. On that particular job, I removed the oil pan. When I got all of it out of the intake valley and heads, I taped off the intake ports with duct tape and used a pressure washer and blasted the intake valley and inside of the heads after I let some purple stuff sit in it till the next day. It came VERY clean. Because of the sludge stopping up some of the pushrods, it burned up several of the aluminum rocker arm hold downs and the valve train was very noisy and the engine ran terribly. I also ended up putting a new oil pump and pickup on it, as well as a new timing chain set. When I got done that was one of the smoothest running Olds engine I've ever seen. It was crying for help.
mygasser
Well-Known Member
re 1).... add an extra 2-3 washers/compression rings? to the plug he has to space it out a bit.
JDMopar
Well-Known Member
I've done similar a few times. That's one of them jobs where you just strip down and throw your clothes away when you're finished, and carry a new bottle of Dawn dish soap to the shower with you...lol.
Yup, you're right on the money!
If only You knew how many 'teeners were running around that look just like that, "runs like crap when it's cold out, & doesn't want to 'kick down' off fast idle", chances are 50/50 or higher over 85K.......I've punch & chiseled bunches of intakes, then sent them to get 'boiled out' while I worked on the heads, usually timed-out good......when the parts/gaskets & clean intake came back, I had everything opened & cleaned ready for them.
Lol, that's the 1st thing that popped into My head....
Better get 3 or 4 cans for that one !
I've never seen Pennzoil do that, Quaker State, yes, but having said. I worked at an automotive machine shop for awhile when I was 21, we called them Valvoline engines. Some of us forget that we used to have non detergent oil. I have seen carbon build up like that and carbon wax build up like that. I certainly wouldn't waste my time trying to clean that up, it wouldn't even cross my mind. I would overhaul it, not 318 it.
Paraffin based oils and short trip driving does that.
I always blocked off the crossovers anyway on my cars but I have aftermarket carbs on all my junk except the slants. I saw a guy once pour water down the carb with the engine revved up to break up the carbon from off the piston tops. He would rev it up and pour in water until it almost died then repeat several times. There was a whole lot of black junk coming out of the tailpipe so maybe it worked.
Been there, done that.
You left out a couple steps. First, trickle a pint or quart of ATF down the carb while it is running. Rev the engine to keep it running when adding ATF or water. Second, drive around the block to loosen up the carbon. Then you trickle 10 to 16 oz (coke bottle) of water down the carb while it is running. We had to do that to a couple /6s that just got putted around town.
JDMopar
Well-Known Member
Dan, thanks for jogging my memory on how to do that. I knew there was ATF involved someway, but couldn't remember what, so now I know until I forget it again...lol. The old guy who I saw do that 40 years ago had a saying, "Kill the skeeter's first, then drown the carbon." When I saw him do it, the car smoked like a Tar Kiln while the ATF was being dripped in....lol.
The sharpest guy I worked for did that to maybe 2 or 3 slant 6s when I worked with him back in the mid 70's.
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