engine vibration

wbedwards

wbedwards

Senior Member
1959 Edsel 361V8. I've owned this car for over 2 years. It has run well all this time and has a smooth quiet idle, uses very little oil. The engine has never felt smooth to me like newer cars. It gets busy right off of idle all the way up to about 2000 rpm then seems smoother over that.
No apparent play in crankshaft or signs or sounds of other major problems. My question: can motor mounts get stiff over the years and need replacing or do I need to fish deeper like flex plate bolts?
 
Motor mounts do wear out so I would certainly look into that. They're pretty easy to replace and not very expensive. Flex plate bolts would be maybe 2nd on the list. Has the transmission ever been out of the car?
 
I don't know if it has been out, but the engine trans both look very original. I did a pan drop and it does not look rebuilt. I had to put a rear seal in it too. That old fluid smells different than today's. Not burnt, just different.
 
When I hear the term "engine vibration", it doesn't make me think of flex-plate bolts. If your flexplate bolts are loose and you run it for a long time like that, it can cause the bolt holes to become slotted or oval shaped which will throw your converter out of balance, but you won't notice it until you get up to a certain speed.
Engine vibration makes me think of a misfiring plug or one plug wire leaking to ground. valve lash adjustment too tight, distributor shaft badly worn. All these are pretty easy to check.
 
Ok, I will go that route then. You can take it out of gear and coast and is smooth as silk, but drop it in gear and the hash is back.
 
Performing a cranking compression check on the engine will rule out an unbalance related to the firing of the cylinders. More than a 10% difference from the lowest to the highest compression reading will require looking deeper into the engine. Ted Eaton.
 
wbedwards said:
You can take it out of gear and coast and is smooth as silk, but drop it in gear and the hash is back.
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In that case, I would say possibly two avenues to investigate. First; sounds like there is only a problem if engine is "loaded" which would make me want to check operation of the vacuum advance and make sure the little wire pin didn't fall out of the vac advange actuator rod where it connects to the breaker plate.
Second, maybe some kind of transmission problem, if you can take it out of gear and coast and the vibration goes away, the converter is rotating at engine idle speed (in which you also do not have a vibration). That could very well mean that you could have a converter imbalance.
 
wbedwards said:
I had to put a rear seal in it too. That old fluid smells different than today's. Not burnt, just different.
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You put a new engine crankshaft seal in ??? or transmission rear seal ?

The trans is probably of a Cruisomatic variety. I believe those require Mercon/Dextron type trans fluid. If you used something else, that could be a problem. Some people make the mistake of using type F fluid and get a rougher riding transmission.
 
Get an infrared temp reader ($19 at Lowes) and read the temperature of each the exhaust ports. Easy to do on the FEs. Mine come in around the 400* area. Easy to tell which cylinder in being bad.
 
I've got the thermometer. I haven't have the energy to go home after work and do it. Will try to get on it today or this weekend. I have a new vacuum advance.I put in a new trans seal last year. The trans is the 2 speed Mile-O-Matic and it calls for type F. I'm going to jack it up and get the inspection plate off and see what it looks like in there. My compression is not near what it should be but it has been over a year since I checked it though.
I appreciate all the suggestions.
 
Well, here is what I found. Converter looks new, was gold in color and had 3 loose converter bolts. Motor mounts look new but they were loose also. The transmission mount looks original and it was loose. Warmed it up and the exhaust temps idling in the shop were from 315 up to 331 depending on where you shot them. While it is smoother, it is not as smooth as newer engines.
I will check the compression this weekend when I can get some help. I haven't checked it in a couple years but when I first got it, the compression was all running about 75% of what it should be. It sat for many years and I was hoping driving it might bring them up.
Am I expecting too much of an engine that is tired and a little over 100000 miles?
 
wbedwards said:
......
Am I expecting too much of an engine that is tired and a little over 100000 miles?
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It seems to me that back in those olden days having 100k miles on a car was pretty much the usual max life expectancy. More than that you drove with your fingers crossed for good luck.
Cars weren't built to last for longer than 10 yrs or 100k mi, I guess so they could sell you another one, and the technology wasn't really there yet either.
 
It runs well, idles well, pulls well, just low on compression. It doesn't even have much blow by. I'm going to check that this weekend.
 
wbedwards said:
... You can take it out of gear and coast and is smooth as silk, but drop it in gear and the hash is back.
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It won't hurt to double check the driveshaft u-joints.
If they're worn they can go off-center when loaded and re-center when unloaded.


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I will, I put one in it last year. The torque converter, flex plate and front of the transmission were very clean. I didn't think the transmission had been out of it but now I wonder.
 
I have a 351W that I rebuilt and also had it balanced. Before I put it back in the car I sent the transmission to a big name shop. When done and installed it has a small vibration. Thought it was something with the balance job as I had driven the car since it was new. Turned out the rebuilder of the converters had a run of out of balance ones and it was my lucky day.
 
dmsfrr said:
It seems to me that back in those olden days having 100k miles on a car was pretty much the usual max life expectancy. More than that you drove with your fingers crossed for good luck.
Cars weren't built to last for longer than 10 yrs or 100k mi, I guess so they could sell you another one, and the technology wasn't really there yet either.
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I agree on the technology thing too. Better control on everything that is made, better fits and clearances, better lubricants and coatings.

I had an oil spewing 352 in a '64 Ford with over 100k miles on it. Oil out the exhaust, out the breather. I had a shop rag tied around the breather. Anti-foulers on the spark plugs, but it was quiet and smooth.
 
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