318 Poly Vibration

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matthon

matthon

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Replaced motor with another 318 with low miles. New MSD and everything else except carb, used battery, alternator, and could not find a new trans mount. I painted engine, had valve covers and pan off, extremely clean.

Ran really good, but had a slight hesitation above 50 so I rebuilt the carb.

With a few adjustments it was running great and driven daily.

Alternator went, replaced, charged battery, drove fine for many hours on a parts run, left it idling for 30 minutes or so. Got home, shut it off, battery spent.

Next day replaced battery, drove to gas station, halfway there wouldn't move, wanted to stall, felt a vibration. Made it, needed gas to get back. Ran better by the time I got home. Checked all plugs, pulled wires apart, re-crimped a few to be sure. Checked firing order, started, ran the same, realized I forgot to plug 1 wire in, ran the same.

Starts right up, idles nice, but has a vibration, not water pump, disconnected alternator, not alt, not power steering, no knocking noise, no oil in radiator, no metal in oil, pulled valve covers, all pushrods in place, checked lash but not by the book, just to see if one was way off. Used long screwdriver to ear trick all over engine, nothing detected. Put phone under car, in and out of reverse and drive, trans doesn't budge, mount doesn't move, engine moves a little, rubber mounts new, look fine, bolts tight.

Today I checked the oil, a little bit of milky, been sitting over a month, ran it, looks fine. Water comes out the tailpipe at startup, seems excessive, but not green, not sure if it would be, no sweet smell, exhaust looks white-ish but it's cold right now. TTI headers/exhaust if it matters. Water comes out since I put this all together in mid July, but radiator has been the same level since.

Vibration can be felt best on tops of fenders in front, and really well on top of air cleaner.

Any input is appreciated.

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Start by doing this: Devise a way to short the spark on individual plugs. Some guys pull off plug wires, DO NOT do that, as an "open" plug wire can cause cross-fire to adjacent "holes."

Sometimes you can ground a clip / alligator lead to a small screwdriver. "Loosen" all the wires at the distro so they are just sitting in the towers. Use insulated fuse pullers to pull out a wire with one hand and slide your grounding probe in with the other.

Use a tach if at all possible and listen. One cylinder that does not "drop" the same as the others indicates a "dead" hole for whatever reason.

Compression test? Cylinder leak down?

Somebody mentioned distributor. I've seen distributors worn in such a way that the points would sort of "accidently" open on some cylinders and not others, as the shaft was that badly worn/ bent. The oppposite can be true, sometimes they won't CLOSE on some holes
 
Thank you, I had heard of leak down but never did it, I'll look into that and comp.

Distributor is new MSD from day one.
 
could there be a crankshaft to converter mismatch?
 
I was thinking bad converter, or bad balancer.
Maybe pull the pan and if everything ok change filter/fluid.
Balancer might have slipped, I believe it has the rubber insert, have to check, but with no timing mark I won't be able to tell. I googled 318 poly balancer and some don't have a mark, saw a pic where one had a single 0 but I can't locate anything on mine.

Crank to converter mismatch- I checked both engines over, only differences were the oil pan, pick up, and one valve cover, original was a 64, replacement is a 66. Would a mismatch be fine for 2 months?
 
matthon said:
Thank you, I had heard of leak down but never did it, I'll look into that and comp.

Distributor is new MSD from day one.
Click to expand...
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I still say it again check the distributor. Doesn't matter if it's new or not do as 67darts273 said for starters.
 
You can use, what I use is an everyday run of the mill test light to short the cylinders one at a time. Just attach the clamp on anything that is a ground. The pointed probe will slide in the spark plug boot very easy, and you will not get shocked.

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I will definitely check distributor to see if I can locate a dead cylinder.

Not sure if the pick up would cause this, or the distributor itself.

Just getting ideas, at work right now.
 
Drove home, ran worse, checked oil, definitely water in oil, dipstick covered in milk, wiped, put in again, straight up water on it, breather full of milk.
Radiator still free of any oil, clear and clean.
Had to go back out, couldn't go any farther.
 
There probably isn't a rule book for water in oil but no oil in water, but I was thinking start by pulling the intake and hoping it's the guilty party. Then a compression test/leak down which would hopefully indicate if I need to go further.
 
Drained some oil into a glass jar, don't see water.
Started grounding each cylinder and there was no change. Recalled in my first post when I mentioned I had left a wire off in error, plugged it back in, no change.
Went to change cap for the heck of it, sent wrong replacement cap, cleaned up one on car, started, thought it was same or slightly better.
Started grounding on other side, no change, pulled wire apart w/o noticing. Went to put back together, thought this wire looks pretty dam cheap!
Wire on left extra from another set, strands packed, wire on right on car now, strand spread out under some back covering, destroyed on end. Rubbed my fingers on it and the strands were visible.
Think this could be the cause?

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Have had zero time to spend on this.
Last thing I did was ground each cylinder and it idled the same for all, so I ordered new plug wires.
I needed to move it today, so I had to put the new plug wires on it.
Checked oil, looked clean.
Changed wires.
Fired right up first try, it's been cold too.
Let it warm up, moved it, left it to idle. Still felt that damn vibration. Pulled dipstick, milky, moved it back, pulled dipstick again to take a pic, went back oil spitting from tube, that's a first!
Turned it off, pulled valve covers, oil on heads looks fine. Flipped valve cover over, covered in water droplets.
Checked radiator, clean, no oil.

Did a quick online search- bad rings, valve guides, pcv.

I realized I never replaced the pcv. It's part of the metal cap on that valve cover, and I can't find a replacement.

I need to get a leak down tester, any recommendations on a reasonably priced brand?

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That's normal condensation on the dipstick and in the valve cover. Why not actually try some diagnosis instead of just throwing parts at it? You said you made no difference grounding plug wires. Guess what? You didn't ground them successfully! Had you done so, each time you grounded a wire, you would have gotten a dead skip.

Run a standard compression test first. You can do that for FREE! Go to your local big box auto parts store and rent a compression tester. You get all of your money back when you return the tool. If it has a compression problem, that will pick it up. Screw a leak down tester. That's more for testing percentage of leak down when comparing cylinders. Not necessarily what you need here.

Do the compression test.........or keep chasing your tail. It's your choice.
 
Did you watch all the rockers while it was running? A pushrod could be bent and still look ok from the top on those polys. Usually you can tell if its a dead hole just by driving it or by using the methods mentioned above, if that isn't it its something else, lol.
 
water looks normal in engine for cooler temps did you adjust the valves too tight? has it had many miles of reg. unleaded fuel thru it causing sinking exhaust valves? are the two cylinders not firing on the same intake runners (vacuum leak) intake valve not sealing tight from carbon build up on valve? none of these things take money to check just a little time.
 
I'll do a compression test asap, and check the pushrods while running. I never adjusted the valves.

I appreciate all of the advice. I noticed when I do online searches when trying to figure things out there's always multiple links to fabo. Even non car related stuff.

I'm trying to educate myself and eliminate simple things, unfortunately with little time lately I find myself picking up a few steps ahead of where I left off. Add in new developments, oil out the dipstick tube, and I loose track.

When I initially forgot to plug in one plug wire, in my first post, and plugged it back in there was no change in how it ran, zero. This was the night it first happened and it would barely move.

When I was grounding wires there was no change from cylinder to cylinder, meaning all of them had the same effect on the engine, none had no effect. I was expecting the one cylinder where I forgot to put the wire back on initially to have no effect, if that makes sense.

Say hello to George.

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if your going to pull a wire off you should bring the idle speed up to 1200 rpm and with a tach hooked up that cylinder should droop 50 rpm ,some times it hard to hear /feel and if one should smooth out the vibration there a problem with a intake valve on the shared runners
 
I would check/adjust the valves for sure if you haven't done that, most all those polys had solid cams and over time things can get out of whack.
 
Bad plug. Or plugs.
The loose wire may have fouled the plug.
On a side note i had a bad plug (champion)
The electrode was floating free inside plug. Pulled it out and looked at it, looked fine. But i held it upside down. When i pointed plug down, electrode closed the gap. I caught it when i tried measuring the gap.
 
I have always pulled plug wires off and never had an issue, BUT, Del (67Dart273) is absolutely right. It is best to ground them out. I've known that ever since auto shop class in high school, but never done it. I've just been lucky I guess.
 
Got it on the tach, I definitely need one to see the actual rpms.

Spark plugs I'll look at again, and check my notes, I believe I changed recently.

Adjusting valves, I read a manual on adjusting poly valves, and I'll have to double check, but I recall it states to do it while warm and running. The problem is the 4 dips in the poly heads are perfect for funneling oil onto the headers.
I think the alternative was do it cold, not warm and off, but I will check.
If it needs to be done running I have another set of covers I can cut the tops off.

It's electronic ignition, and I thought grounding at the distributor would easily jump to another post, so I was pulling the wires from the plug and grounding them using a wire with an alligator clip on the other end.

Realistically, I probably won't have time until next week, and freezing cold tools suck! Insulating and heating garage are #1 priority in the warmer months.

I bought this in February with a seized engine and a shot interior, did everything myself, including the upholstery, and was driving it 5 months later.

I'll keep a detailed list of what I've done with results.

This thread will not go unanswered.

Thank you again.

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You might warm it up before checking the valves but doing it while running isn’t nessesary. Just making sure nothing is sloppy loose or too tight causing a miss is the most important thing at this point. I’ve always just pulled wires without grounding them to find where a problem is, I think I will try the grounding thing next time.
 
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