Jammed engine
04-22-2018 | 03:39 PM
#1
Thread Starter
Intermediate
Joined: Feb 2017
Posts: 47
Likes: 0
Jammed engine
Hi Folks
Just bought a project car with a 'jammed' engine
It moves freely just a 1/4 turn using the crank bolt and then stops.
There is oil in the sump, water in the system and evidence of compression on turning.
Before I remove the motor and strip does anyone have any idea what it is likely to be.
The 1/4 turn is I believe the clue,
I have no other information
Thanks in anticipation.
Trevor
Just bought a project car with a 'jammed' engine
It moves freely just a 1/4 turn using the crank bolt and then stops.
There is oil in the sump, water in the system and evidence of compression on turning.
Before I remove the motor and strip does anyone have any idea what it is likely to be.
The 1/4 turn is I believe the clue,
I have no other information
Thanks in anticipation.
Trevor
04-22-2018 | 05:06 PM
#2
Rennlist Member
Joined: Oct 2014
Posts: 6,795
Likes: 1,169
From: L.I. NY
Hi Folks
Just bought a project car with a 'jammed' engine
It moves freely just a 1/4 turn using the crank bolt and then stops.
There is oil in the sump, water in the system and evidence of compression on turning.
Before I remove the motor and strip does anyone have any idea what it is likely to be.
The 1/4 turn is I believe the clue,
I have no other information
Thanks in anticipation.
Trevor
Just bought a project car with a 'jammed' engine
It moves freely just a 1/4 turn using the crank bolt and then stops.
There is oil in the sump, water in the system and evidence of compression on turning.
Before I remove the motor and strip does anyone have any idea what it is likely to be.
The 1/4 turn is I believe the clue,
I have no other information
Thanks in anticipation.
Trevor
04-22-2018 | 05:18 PM
#4
Burning Brakes
Joined: Feb 2013
Posts: 774
Likes: 59
You should be able to turn it over even with compression, if it stops dead and feels mechanically solid, the piston is hitting a valve , could be a snapped cam chain, be careful not to force anything and cause extra damage ok
04-22-2018 | 05:32 PM
#5
Rennlist Member
Joined: Aug 2006
Posts: 9,051
Likes: 1,781
From: Chicago, IL
Most likely a broken rod. If a piston was hitting a valve, you might get more than 1/4-turn, although it’s possible that all pistons could hit valves in each cylinder if the timing is off.
If there was a single broken spark plug in a single cylinder, you’d be able to move more than 1/4-turn.
An unlikely cause: a faulty transmission. Try pushing the clutch all the way in by wedging something that pins the clutch all the way in and try again. It’s highly unlikely this is the problem, but technically possible. Yes, the transmission turns the gears even when in neutral.
I would remove the serpentine belt to make sure it’s not some weird thing with the belt or pulleys or a jammed and stuck-on AC pump.
If there was a single broken spark plug in a single cylinder, you’d be able to move more than 1/4-turn.
An unlikely cause: a faulty transmission. Try pushing the clutch all the way in by wedging something that pins the clutch all the way in and try again. It’s highly unlikely this is the problem, but technically possible. Yes, the transmission turns the gears even when in neutral.
I would remove the serpentine belt to make sure it’s not some weird thing with the belt or pulleys or a jammed and stuck-on AC pump.
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04-23-2018 | 06:29 PM
#10
Race Car
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From: Melbourne, Australia
04-24-2018 | 04:18 PM
#13
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Joined: May 2008
Posts: 5,541
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From: Northern NJ
Remove the accessory drive belt and make sure all pulleys turn. Couple years ago someone brought a failed engine to Flat Six and one of the idlers was seized. It stopped the engine from turning.
04-24-2018 | 04:25 PM
#14
Rennlist Member
Joined: May 2008
Posts: 5,541
Likes: 96
From: Northern NJ
Not uncommon for seized pulley to cause no turn condition.
https://grassrootsmotorsports.com/fo.../126145/page1/
https://grassrootsmotorsports.com/fo.../126145/page1/
04-24-2018 | 06:02 PM
#15
Thread Starter
Intermediate
Joined: Feb 2017
Posts: 47
Likes: 0
Hi Guys
Thanks for all the suggestions still working on them in turn
I have no other background on this car
I bought it from a guy who bought it from an auction the previous owner was significantly absent
So I do not know the lead up to the demise of the engine sadly
The rest of the car has been neglected but is remarkably sound
All the pulleys turn even just the 1/4 turn is enough to see that although there may still be an issue further round the turn so I will remove the belts next
I will post all results as they happen
Trevor
Thanks for all the suggestions still working on them in turn
I have no other background on this car
I bought it from a guy who bought it from an auction the previous owner was significantly absent
So I do not know the lead up to the demise of the engine sadly
The rest of the car has been neglected but is remarkably sound
All the pulleys turn even just the 1/4 turn is enough to see that although there may still be an issue further round the turn so I will remove the belts next
I will post all results as they happen
Trevor