940 Engine locked

hessam69 · 07-01-2021, 02:14 AM

Beat-up neglected 940 got towed in to me, I know nothing about it's history, other than it died one day and no one could work out why.

The first thing I tried was to see if the cam belt had broken, tried turning the vibration damper by hand and see if the cam turns, crank will not turn. It is possibly seized. OR

Could the AW71 be stuck? Auto oil pump seized? I did witness another 940 some years ago that had this same problem, mechanic could not turn the crank, swapped in a junkyard AW71 and off they went.

How to tell for sure without taking it off?

Janspeed · 07-01-2021, 05:32 AM

Is there any oil in the engine? what level?
any oil leak on the engine?
If there is no oil in the engine the case for a locked up engine is stronger.
if there is oil in it it is very unlikely that the block has seized.

any oil leak on the trans? what is the ATF level?
any ATF mixed in with coolant?

Maybe remove the starter and use the hole to inspect the flexplate to see if the torque convertor bolts are still there, if you can see cracks or score marks.
Same for the plate closing off the underside of the bell housing. It's easily removeable for inspection

90volvo · 07-01-2021, 06:56 AM

Id try a socket on the crank, I know I cant turn my engine over by hand. I think its a 15/16 deep well and 1/2 in drive rachet. Then if it wont budge, Id say engine is seized.

linuxman51 · 07-01-2021, 08:31 AM

put a breaker bar and socket on the crank as suggested above, and work forward from there.

it is unlikely that a running car would seize up the pump in the automatic, anything is possible for sure, but that is fairly unlikely.. the car would have stopped driving first as the fluid level would have to be low (or the filter completely clogged in the trans) for the gears to start to build up that kind of heat. more likely that it'd rust from sitting and getting water incursion, but this was said to be running and driving.

when you put the socket on there, try easing it both ways (Without putting enough ass on it to break the bolt loose). If it's truly locked up and went from running to dead stop, it's probably partout/new engine time.

so, as others have suggested: check oil level, maybe drain the oil if the stick comes up dry, put a wrench or breaker bar on the crank bolt and try to spin it over, pop the valve cover off, and between those things (which should total to less than 20 minutes give or take tool availability) you should be able to develop a pretty clear picture of the state of engine affairs.

Also, if it rolls backwards from current position but stops before making a complete revolution, some kind of foreign object may have fallen down in the engine and gotten stuck (think bolt, nut, that sort of thing).

hessam69 · 07-01-2021, 05:34 PM

Sorry everyone, when I tried turning the engine, it was with a socket on the bolt, with an extra long breaker bar. It would not move at all either right or left. There is oil in the engine and transmission but of course the ATF is dark.

Still, can something in the AW71 oil pump break or seize enough to lock itself up to the point the crank won't turn? Some significant force would be needed to stop a driving B230

dl242gt · 07-01-2021, 06:10 PM

Take off the valve cover and see if anything broke. It may have dropped the head of a valve into a cylinder which would prevent any movement if it's a large enough chunk.

hessam69 · 07-01-2021, 10:07 PM

Thanks, I'll try that.

If all checks out there, I'll have to pull the AW71 out (leaving the torque converter on the flexplate) so I can at least get the engine started

2manyturbos · 07-02-2021, 03:54 AM

Don’t do that. You can damage the converter or stator pulling a transmission that way. All you need is the flex plate in place in order to start the engine.

hessam69 · 07-02-2021, 04:01 AM

Unfortunately, without the ability to turn the engine, there is no way to remove the transmission with the torque converter still attached; there is no access to remove the torque converter retaining bolts

2manyturbos · 07-02-2021, 02:29 PM

Quote:

Originally Posted by hessam69

Unfortunately, without the ability to turn the engine, there is no way to remove the transmission with the torque converter still attached; there is no access to remove the torque converter retaining bolts

True. I had to do the same on an 87 740 T that broke a rod and sent the intermediate shaft out through the back of the block. It was locked rock solid. Just make sure you slide the transmission straight back using a transmission jack. Don't let it hang on the converter.

Harry Tuttle · 07-03-2021, 12:42 AM

Somebody correct me if I am wrong here. In order for a locked up tranny to prevent the engine from turning, wouldn't the torque converter have to be locked up also?

MasterBlaster · 07-03-2021, 12:50 AM

Quote:

Originally Posted by Harry Tuttle

Somebody correct me if I am wrong here. In order for a locked up tranny to prevent the engine from turning, wouldn't the torque converter have to be locked up also?

The TC's shell is bolted to the flex plate.
The TC's snout turns the transmission's oil pump.
If the pump is seized/damaged, it can stop the TC (and the engine) from turning.

Harry Tuttle · 07-03-2021, 12:53 AM

Thanks. Shows what I know about those things...

hessam69 · 07-03-2021, 01:40 AM

I think that is what's happened, but how? What causes an autotragic oil pump to seize?

As mentioned I did witness another 940 with this problem, crank would refuse to turn, they had the AW71 replaced and all was well. I wonder if there are any warning signs this would be about to happen.

Strange

dalek · 07-03-2021, 04:59 AM

Wouldn't if be some funny smell/bits in the tranny fluid as hint?
How to remove the transmission then? I have not taken an automatic off a car in ages. Does the troque converter just sits on the transmission shaft so it can stay attached to the engine as you pull the tranny out? If so, would you have to tilt the entire assembly down on the rear so to slide it out, or take drivetrain out and separate on the ground?

nel621 · 07-03-2021, 11:24 AM

If this is for a customer then just say no. Too much time and going to cost too much money. If you're doing it to "know" what happened and have spare time , then just remove the engine and transmission as one. There is a good chance you'll be needing both.

hessam69 · 07-09-2021, 03:08 AM

PO reckons the transmission was working well. Had it serviced recently, but he did say there was a coolant problem with the engine. When I got the car, there was no coolant in it. He says he had the engine cranking, trying to start, it sounded funny like a lack of compression perhaps (head gasket)

So why won't it turn now? Can an engine seize up hard after sitting for 6 months with a possible blown head gasket? I want to get it running before taking the head off. How best I unseize it?

Janspeed · 07-09-2021, 03:40 AM

Maybe the engine had a blown HG from coolant passage to combustion chamber causing coolant to leak into the cylinder which could cause a hydro lock in that cylinder. Maybe remove the spark plugs and hand crank the engine to see is it moves with the coolant having a way out?

Otto Mattik · 07-09-2021, 05:30 AM

Quote:

Originally Posted by nel621

If this is for a customer then just say no. Too much time and going to cost too much money. If you're doing it to "know" what happened and have spare time , then just remove the engine and transmission as one. There is a good chance you'll be needing both.

a) ^^ this

b) Coolant in any cylinders, or in the oil ?

dalek · 07-09-2021, 08:27 AM

Look for a cheap USB borecam on amazon/ebay. Most come with lights built around the camera and little mirrors (which you should tie to the camera's shaft so if it falls off you can still retrieve) that are clipped in a very precarious way to said camera. Contrary to what the name implies, it is not only BDSM applications. Remove the spark plugs and then look at the cylinders, pistons, and valves.

FreeEMSFred · 07-09-2021, 09:05 AM

Blown HG with water for coolant (cause of blow, perhaps) and 6 months could mean pistons rusted solid in bores, yes. Plugs should tell you a story, though.

hessam69 · 07-09-2021, 06:31 PM

I'll try that.

Any ideas how to unseize it so I can get the engine turning?

TestPoint · 07-09-2021, 08:40 PM

I wish you find a easy solution but you are running out of easy alternatives.

My brother brought me a 20 year old Jeep with an overheated seized engine not run in 6 months. Pulled the head, blown head gasket, coolant in cylinders with rusted rings to walls.

Pull the plugs!

Not enough info to make a best guess. Worst case is a new engine. Hope for better.

hessam69 · 07-09-2021, 11:44 PM

I think you're right.

What else can cause an engine to lock up besides water leaking in.

What should I pour down the spark plug holes to unseize the pistons? I just want to see if I can get it to run again as a curiousity project.

fastcomet · 07-10-2021, 12:57 AM

Ive heard of guys using transmission fluid.

07-01-2021, 02:14 AM	#1
hessam69 Board Member Join Date: Jun 2009 Location: Sydney, Australia	Engine locked Beat-up neglected 940 got towed in to me, I know nothing about it's history, other than it died one day and no one could work out why. The first thing I tried was to see if the cam belt had broken, tried turning the vibration damper by hand and see if the cam turns, crank will not turn. It is possibly seized. OR Could the AW71 be stuck? Auto oil pump seized? I did witness another 940 some years ago that had this same problem, mechanic could not turn the crank, swapped in a junkyard AW71 and off they went. How to tell for sure without taking it off?

07-01-2021, 06:56 AM	#3
90volvo Board Member Join Date: May 2017 Location: Eldorado Springs Mo.	Id try a socket on the crank, I know I cant turn my engine over by hand. I think its a 15/16 deep well and 1/2 in drive rachet. Then if it wont budge, Id say engine is seized. __________________ 90 Volvo 240-my current setup. B230ft rebuilt -MS-Turbo-E85 1985 240 Work in progress. sons car- 93 240-15g turbo-chipped-95,000 miles. Slick car Leave feedback- http://forums.turbobricks.com/showthread.php?t=355413

07-01-2021, 08:31 AM	#4
linuxman51 BRANDSCHUTZVORSCHRIFTEN! Join Date: Dec 2002 Location: mont, AL	put a breaker bar and socket on the crank as suggested above, and work forward from there. it is unlikely that a running car would seize up the pump in the automatic, anything is possible for sure, but that is fairly unlikely.. the car would have stopped driving first as the fluid level would have to be low (or the filter completely clogged in the trans) for the gears to start to build up that kind of heat. more likely that it'd rust from sitting and getting water incursion, but this was said to be running and driving. when you put the socket on there, try easing it both ways (Without putting enough ass on it to break the bolt loose). If it's truly locked up and went from running to dead stop, it's probably partout/new engine time. so, as others have suggested: check oil level, maybe drain the oil if the stick comes up dry, put a wrench or breaker bar on the crank bolt and try to spin it over, pop the valve cover off, and between those things (which should total to less than 20 minutes give or take tool availability) you should be able to develop a pretty clear picture of the state of engine affairs. Also, if it rolls backwards from current position but stops before making a complete revolution, some kind of foreign object may have fallen down in the engine and gotten stuck (think bolt, nut, that sort of thing). __________________ "They bum rushed them in their own crib, they drank all their beer, they partied with their ladies and they left with the trophy" Now with in-house Dyno tuning! Megasquirt Tuning!

07-01-2021, 06:10 PM	#6
dl242gt Old and boxy but good. Join Date: Jun 2002 Location: S NJ, a suburb of Phila.	Take off the valve cover and see if anything broke. It may have dropped the head of a valve into a cylinder which would prevent any movement if it's a large enough chunk. __________________ Dave, 1982 242 turbo. 338k miles. MVP coilovers and 3" exhaust. Flowed 405 with a V15. Cossie turbine housing with upgraded compressor housing. 90+, IPD remote oil filter. Some other goodness, too. Been lots of fun over 25 years. Restored in 2k. Now ready for a 2nd restoration. 1993 245 Classic, 435k miles, enem V15. IPD bars and chassis braces. Simons sport exhaust from Scandix. sbabbs ezk chip. Been a good road warrior. Genuine Volvo rebuilt leaky M47.

07-03-2021, 04:59 AM	#15
dalek Benchracer Tribe Join Date: Oct 2005 Location: Orange Alert, NC	Wouldn't if be some funny smell/bits in the tranny fluid as hint? How to remove the transmission then? I have not taken an automatic off a car in ages. Does the troque converter just sits on the transmission shaft so it can stay attached to the engine as you pull the tranny out? If so, would you have to tilt the entire assembly down on the rear so to slide it out, or take drivetrain out and separate on the ground? __________________ "you can't leave your thingy hanging in public... you can get arrested." "What's Arkansas supposed to be, Kansas for pirates?" Forg "I think I can touch the tire. Damn! I can touch the tire! That hurts!" 240Psycho (on the back seat of my 94 Jetta while I was driving to a J/Y) "Use the barbed adapter like what I use to inflate the air camping mattresses and my dates." FTF Engineering i am inspired. i will replace my windsheild... with an intercooler.swedishK Feedback!

07-01-2021, 05:32 AM	#2
Janspeed Board Member Join Date: Sep 2005	Is there any oil in the engine? what level? any oil leak on the engine? If there is no oil in the engine the case for a locked up engine is stronger. if there is oil in it it is very unlikely that the block has seized. any oil leak on the trans? what is the ATF level? any ATF mixed in with coolant? Maybe remove the starter and use the hole to inspect the flexplate to see if the torque convertor bolts are still there, if you can see cracks or score marks. Same for the plate closing off the underside of the bell housing. It's easily removeable for inspection

07-01-2021, 05:34 PM	#5
hessam69 Board Member Join Date: Jun 2009 Location: Sydney, Australia	Sorry everyone, when I tried turning the engine, it was with a socket on the bolt, with an extra long breaker bar. It would not move at all either right or left. There is oil in the engine and transmission but of course the ATF is dark. Still, can something in the AW71 oil pump break or seize enough to lock itself up to the point the crank won't turn? Some significant force would be needed to stop a driving B230

07-01-2021, 10:07 PM	#7
hessam69 Board Member Join Date: Jun 2009 Location: Sydney, Australia	Thanks, I'll try that. If all checks out there, I'll have to pull the AW71 out (leaving the torque converter on the flexplate) so I can at least get the engine started

07-02-2021, 03:54 AM	#8
2manyturbos Moderator Join Date: Mar 2003 Location: Monroe, OR USA	Don’t do that. You can damage the converter or stator pulling a transmission that way. All you need is the flex plate in place in order to start the engine.

07-02-2021, 04:01 AM	#9
hessam69 Board Member Join Date: Jun 2009 Location: Sydney, Australia	Unfortunately, without the ability to turn the engine, there is no way to remove the transmission with the torque converter still attached; there is no access to remove the torque converter retaining bolts

07-03-2021, 12:53 AM	#13
Harry Tuttle Board Member Join Date: Jun 2006 Location: in your ducts	Thanks. Shows what I know about those things...

07-03-2021, 01:40 AM	#14
hessam69 Board Member Join Date: Jun 2009 Location: Sydney, Australia	I think that is what's happened, but how? What causes an autotragic oil pump to seize? As mentioned I did witness another 940 with this problem, crank would refuse to turn, they had the AW71 replaced and all was well. I wonder if there are any warning signs this would be about to happen. Strange

07-03-2021, 11:24 AM	#16
nel621 Board Member Join Date: Apr 2009	If this is for a customer then just say no. Too much time and going to cost too much money. If you're doing it to "know" what happened and have spare time , then just remove the engine and transmission as one. There is a good chance you'll be needing both.

07-09-2021, 03:08 AM	#17
hessam69 Board Member Join Date: Jun 2009 Location: Sydney, Australia	PO reckons the transmission was working well. Had it serviced recently, but he did say there was a coolant problem with the engine. When I got the car, there was no coolant in it. He says he had the engine cranking, trying to start, it sounded funny like a lack of compression perhaps (head gasket) So why won't it turn now? Can an engine seize up hard after sitting for 6 months with a possible blown head gasket? I want to get it running before taking the head off. How best I unseize it?

07-09-2021, 03:40 AM	#18
Janspeed Board Member Join Date: Sep 2005	Maybe the engine had a blown HG from coolant passage to combustion chamber causing coolant to leak into the cylinder which could cause a hydro lock in that cylinder. Maybe remove the spark plugs and hand crank the engine to see is it moves with the coolant having a way out?

07-09-2021, 08:27 AM	#20
dalek Benchracer Tribe Join Date: Oct 2005 Location: Orange Alert, NC	Look for a cheap USB borecam on amazon/ebay. Most come with lights built around the camera and little mirrors (which you should tie to the camera's shaft so if it falls off you can still retrieve) that are clipped in a very precarious way to said camera. Contrary to what the name implies, it is not only BDSM applications. Remove the spark plugs and then look at the cylinders, pistons, and valves. Last edited by dalek; 07-09-2021 at 10:23 AM..

07-09-2021, 09:05 AM	#21
FreeEMSFred Board Member Join Date: Nov 2009 Location: Kiwiland	Blown HG with water for coolant (cause of blow, perhaps) and 6 months could mean pistons rusted solid in bores, yes. Plugs should tell you a story, though. __________________ FreeEMS.org - the open source engine management system My Volvo Adventure (No 56k). My non-Volvo turbo truck. My gold 1991 240 wagon! My blue 1990 740 16v sedan!

07-09-2021, 06:31 PM	#22
hessam69 Board Member Join Date: Jun 2009 Location: Sydney, Australia	I'll try that. Any ideas how to unseize it so I can get the engine turning?

07-09-2021, 08:40 PM	#23
TestPoint Board Member Join Date: Jul 2009 Location: Ellijay	I wish you find a easy solution but you are running out of easy alternatives. My brother brought me a 20 year old Jeep with an overheated seized engine not run in 6 months. Pulled the head, blown head gasket, coolant in cylinders with rusted rings to walls. Pull the plugs! Not enough info to make a best guess. Worst case is a new engine. Hope for better. __________________ 1982 Volvo 245 with a Ford 302 V8 Ford V8 Conversion Manual - http://forums.turbobricks.com/showthread.php?t=250257 Bertone Restoration - http://forums.turbobricks.com/showthread.php?t=256460

07-09-2021, 11:44 PM	#24
hessam69 Board Member Join Date: Jun 2009 Location: Sydney, Australia	I think you're right. What else can cause an engine to lock up besides water leaking in. What should I pour down the spark plug holes to unseize the pistons? I just want to see if I can get it to run again as a curiousity project.

07-10-2021, 12:57 AM	#25
fastcomet Board Member Join Date: Oct 2016	Ive heard of guys using transmission fluid.

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