Author Topic: Terrible Engine Vibration  (Read 989 times)

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5816nick

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Re: Terrible Engine Vibration
« Reply #15 on: May 29, 2019, 10:28:23 PM »
Well, Today i replaced the - Points / Condensor / Leads / Plugs / Carb Stripped / Rebuilt / Valve clearances Checked / Compressions checked and 110 PSI on One Cylinder and 95 on the other..... and still the engine vibrates terribly....at 1700 - 2200 RPM.... I don't know what else to do?

Does anyone have any ideas?

Pete126

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Re: Terrible Engine Vibration
« Reply #16 on: May 30, 2019, 12:15:21 AM »
I’ve run out of ideas what carb is on the car?
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michaelodonnell500

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Re: Terrible Engine Vibration
« Reply #17 on: May 30, 2019, 11:47:18 AM »
It is always a good idea to check through all the standard items first. However large vibration issues are rarely fixed by swapping small parts.

I would suspect that your engine has been stripped and rebuilt incorrectly. I purchased a second hand engine from someone who had given up on it because it was vibrating so badly. The vibrations were so bad the tinware had split in several places which he repair welded a few times before giving up on the engine.

When I took the engine apart there was about 2mm of end to end crankshaft float. Another second had engine might be a good idea if you want to get it running again quickly
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1973/126

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Re: Terrible Engine Vibration
« Reply #18 on: May 30, 2019, 06:19:10 PM »
 Have you got any photos of the engine mount. If it is assembled incorrectly it could cause vibration. Also the Blitz buggy is much lighter which probably makes the vibration more noticeable.
 If everything else is ruled out on the outside of the engine, the next thing would be to check the internals.
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Bar Vitelli

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Re: Terrible Engine Vibration
« Reply #19 on: May 30, 2019, 08:19:27 PM »
I recently had a crankshaft issue on one of my cars, when it idled there was no vibration/rattle, when it revved it made a loud vibration rattle. The only thing that does not match with your description is that you say your car does not vibrate at higher revs.

When the car vibrates does it feel like the vibration is coming from the engine or is the engine causing another part of the car to vibrate?  If its not coming directly from the engine it might be worth checking the gearbox mounts and the gearbox cradle. If the cradle is fitted too tightly that could cause a vibration.
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Gadge

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Re: Terrible Engine Vibration
« Reply #20 on: May 30, 2019, 09:57:58 PM »
I'm still putting money on the flywheel area. If the spigot is worn or perhaps the input shaft bush then the input shaft (on which the clutch plate is on) can oscillate around so what happens is that the clutch doesn't sit squarely in the centre between the pressure plate and flywheel and so tries to spin the gearbox in an eccentric manner. Obviously the gearbox can't move independently to the engine because it's attached to it so the whole thing starts to move around. Having a spring for an engine mount doesn't help either making the vibration worse.

Years ago I had an almost identical problem except I had the vibration as I tried to take up drive in first but the vibration was so vicious that it felt like the engine was climbing out the car! A new spigot bush cured it completely. It of course may not be this, but to cause that much vibration it must be a mechanical imbalance rather than poor running.
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5816nick

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Re: Terrible Engine Vibration
« Reply #21 on: June 02, 2019, 07:43:18 PM »
Hey Guys Thanks for all the Replies, i found an exploded view of the Engine mounting on the very helpful subscribers area on here.... Thanks!

I am waiting for the top hat top washer and bush (Which are both missing....) Hopefully they will come tomorrow.... although as it was still vibrating badly with the main engine mounting taken  off - i don't think it's this....

I took the starter motor off yesterday and see that the flywheel moves very very very slightly, maybe that is loose?
I  am preparing myself to take the engine out next weekend....

The engine Vibrates at 1700-2200 RPM  but then it resonates extremely badly through the rest of the car....

I've tried uploading photos on here but it keeps saying the file is too large.....

Does anyone have a spare 604cc engine they want to sell, i'm imagining worst case scenario.....
I found out the 126 was originally a 1977 model, although i'm still waiting for the logbook.... it's now reay to hit the road, apart from the vibration and logbook issues.....

michaelodonnell500

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Re: Terrible Engine Vibration
« Reply #22 on: June 03, 2019, 09:29:26 AM »
When you say the flywheel moves very slightly, can you be more specific?
Is it rotating? moving end to end? moving side to side?

If you're lucky, maybe the flywheel is loose. If you take the sump off you can check if the crank is moving as well.
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5816nick

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Re: Terrible Engine Vibration
« Reply #23 on: June 09, 2019, 09:29:29 PM »
Thanks to all the replies Guys!

The problem turned out to be, the bottom rubber to the Engine mounting was put on upside down by the previous owner and one spacer washer was missing!

The 126 Buggy was originally made in 1977 and is MOT/Tax Exempt and  has been driven on the road for the first time since 1996 today!

michaelodonnell500

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Re: Terrible Engine Vibration
« Reply #24 on: June 10, 2019, 09:23:28 AM »
That's must be a big relief!
Good work getting to the bottom of it!
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Ricksy1121

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Re: Terrible Engine Vibration
« Reply #25 on: June 12, 2019, 09:13:18 PM »
Good info here, have a mid range vibration in mine though not as bad as yours sounded but the engine has been out before so will try adjusting the engine mount before digging any further 👍🏻

5816nick

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Re: Terrible Engine Vibration
« Reply #26 on: June 13, 2019, 10:47:18 AM »
Thanks Mike! it is a relief! i'm looking forward to driving it, when it stops raining!

Ricksy, do you have your engine mount lower / upper rubbers on the right way around and the plastic bush/ spacer and 2 metal  washers in the right order? This was the problem with mine, the lower rubber was not present initially, as i had bought it off the previous owner who had put it together wrong ( I thouht it was right / and it looked right - double check the one manual on the subscribers page, there is an accurate and clear picture)

Kind regards Nick

Ricksy1121

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Re: Terrible Engine Vibration
« Reply #27 on: June 13, 2019, 08:34:53 PM »
Thanks, it’s away getting a few rust issues sorted at the moment so when I get it back I will get onto it 👍🏻

Ricksy1121

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Re: Terrible Engine Vibration
« Reply #28 on: June 22, 2019, 03:58:33 PM »
So with the engine running and the inspection cover off the flywheel you can see the flywheel isn’t running perfectly true, there’s a slight wobble in it I’m going to assume this could be the problem, the engine is out and it looks like the holes are towards the head when the pully is at tdc, it’s difficult to determine if the rattle is from the bottom end or the flywheel area of the gearbox. The noise isn’t there at idol and the engine sounds nice it’s once it’s in the mid range it develops the vibration, does anyone know if the bottom end has gone would it sound ok at idol or not. Many thanks 🙏🏼

DEYAN IYI

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Re: Terrible Engine Vibration
« Reply #29 on: June 22, 2019, 04:32:43 PM »
Are the moving parts original or modified and in both cases are they balanced and dynamicaly together?