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1969 Opel Gt 1.9 Automatic
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Discussion Starter · #1 ·
Hi guys my grandpa and I are going to turn over the engine in the GT on Easter. We don't want to use the starter motor in case one of the valves are stuck. Do you just turn the fan or do you get a ratchet and socket? We want to do it manually.

Thanks Sam
 

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Can Opeler
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Personally I’d use the starter. It’s going to turn (or not) either way.

But a 19mm socket on the crankshaft will turn it.
 
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Since it's an automatic, you can't rock the car in gear to see if the engine is seized. You might want to pull the plugs and inject some Mystery Oil or other light oil into the cylinders to soak the rings before you try to move them.
 

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Opeler
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Useful / Critical / Helpful Information:
Firing her up after 20 years
Priming oil pump on new rebuilt
 

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1969 Opel Gt 1.9 Automatic
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Discussion Starter · #5 ·
Since it's an automatic, you can't rock the car in gear to see if the engine is seized. You might want to pull the plugs and inject some Mystery Oil or other light oil into the cylinders to soak the rings before you try to move them.
We have already put some oil in it.
 

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1969 Opel Gt 1.9 Automatic
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Discussion Starter · #6 ·
Is it had to turn it over with a ratchet?
 

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Depends on whether it is stuck.
If it is not stuck, you will have no trouble turning it over with a ratchet and socket. As has been noted, remove spark plugs and squirt some oil. MM oil is good for that. Just don't over do it.

Wishing you luck. I have had this particular exercise go both ways. Sadly, the last stuck engine I worked on was a 57 Chevy 283 from my nephew's car. Only one piston was stuck. That's all it takes. Had to disassemble the engine and remove everything else before getting that one piston out.... with a baby sledge hammer. That cylinder was so rusted, it was like the two metals had fused.

A lot depends on where and how it was stored. I have also fired up engines that have sat for 40 years or more with very little trouble.
 

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1969 Opel Gt 1.9 Automatic
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Discussion Starter · #10 ·
We removed the spark plugs to put the oil in the engine about 2-3 days ago. We have no idea if it is stuck. We are just making sure we put oil in there just in case. I had a kohler k241 that was sitting for 30+ yrs outside. It had one stuck valve we took it out and the engine ran very good. We also might try to start it if it turns over good.
 

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I would also pull the valve cover, and squirt good motor oil on everything you can get to. Those rockers are dry as can be after the long slumber.
Plus that way, you can watch to make sure valves are moving up and down. In fact, since they are so easy to get to, I would probably pull the rockers, then pull out each lifter, lube it with some cam lube and put it back in.
 

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Just Some Dude in Jersey
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I would just use the starter, as said, it will either turn over or it won't and you'll have to take it apart. Using a wrench or grabbing the fan might get a little "stuckage" broken free.

It is best practice to regasket the engine at the very least before you entertain the thought of driving it. Freeing the engine up to do a compression test and maybe see if the engine will fire up and run for no more than one minute will give you an idea of where you are at with the engine.

Opel engines have a chronic problem with vacuum leaks at the intake manifold-to-head gasket, the carb-to-intake manifold, and the hoses going to the intake manifold and this is the reason that many perfectly fine Opels end up in a barn with 70K miles on them: One day they just won't start, even though they have plenty of spark and fuel and everything else about the engine is just fine. The six bolts that hold the intake/exhaust manifolds to the engine are "shared" between the 2 manifolds and they are torqued slightly less(33 ft/lbs) than bolts that size are normally torqued to. Normally, bolts that size would get torqued to 45-50 ft/lbs elsewhere on the car. This is because the exhaust manifold gets red hot and expands, but the intake manifold will be much cooler with fresh air flowing through it and it doesn't hardly expand at all. This creates a thickness differential at the bolting flanges of the manifolds. Those 4 middle bolts are simultaneously holding the intake/exhaust on. If you tighten those bolts to 45-50 the exhaust manifold expansion, when it gets red hot, will snap the heads of the bolts off, so they are torqued to 33 ft/lbs. But this is a fraction too loose to stand the test of time and those bolts slowly unscrew over time and one day your car won't start. Long time Opelers know to check the tightness of those bolts once a year or whenever the car gets finicky to start. It's darn near impossible to fit a torque wrench on those 4 middle bolts, so torquing them is often done by "feel".
 

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1969 Opel Gt 1.9 Automatic
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Discussion Starter · #16 ·
I would just use the starter, as said, it will either turn over or it won't and you'll have to take it apart. Using a wrench or grabbing the fan might get a little "stuckage" broken free.

It is best practice to regasket the engine at the very least before you entertain the thought of driving it. Freeing the engine up to do a compression test and maybe see if the engine will fire up and run for no more than one minute will give you an idea of where you are at with the engine.

Opel engines have a chronic problem with vacuum leaks at the intake manifold-to-head gasket, the carb-to-intake manifold, and the hoses going to the intake manifold and this is the reason that many perfectly fine Opels end up in a barn with 70K miles on them: One day they just won't start, even though they have plenty of spark and fuel and everything else about the engine is just fine. The six bolts that hold the intake/exhaust manifolds to the engine are "shared" between the 2 manifolds and they are torqued slightly less(33 ft/lbs) than bolts that size are normally torqued to. Normally, bolts that size would get torqued to 45-50 ft/lbs elsewhere on the car. This is because the exhaust manifold gets red hot and expands, but the intake manifold will be much cooler with fresh air flowing through it and it doesn't hardly expand at all. This creates a thickness differential atthe bolting flanges of the manifolds. Those 4 middle bolts are simultaneously holding the intake/exhaust on. If you tighten those bolts to 45-50 the exhaust manifold expansion, when it gets red hot, will snap the heads of the bolts off, so they are torqued to 33 ft/lbs. But this is a fraction too loose to stand the test of time and those bolts slowly unscrew over time and one day your car won't start. Long time Opelers know to check the tightness of those bolts once a year or whenever the car gets finicky to start. It's darn near impossible to fit a torque wrench on those 4 middle bolts, so torquing them is often done by "feel".
That makes sense because the Opel only has 77,000 miles on it. It looked like my great uncle was fiddling with the fuel pump. Maybe it wasn't starting for him.
 

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Just Some Dude in Jersey
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It has been my observation that almost every decent condition GT that someone finds in a barn, with nothing apparently wrong with it, has mileage somewhere in the 70K's.

Even better, your car has an automatic, which I prefer, and that means that you will probably discover that the engine will actually run and the rear axle will be healthy. Stick shifts create a direct link from your tires to your piston rings and every time you take your foot off the gas your piston rings now become your brakes. As a consequence, it has been observed that automatics have less wear on the entire drivetrain. The automatics are Chevy TH180's and are virtually indestructible and will outlive the car, so the rear axle and tranny probably will be in excellent condition and there's a good chance that your engine is servicable. Remember that our cars have flat tappet lifters and require that zinc(ZDDP) be added to the oil. You will also have to have hardened exhaust seats installed in the head, when you can afford it, because of modern unleaded gas.
 

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Discussion Starter · #18 ·
It has been my observation that almost every decent condition GT that someone finds in a barn, with nothing apparently wrong with it, has mileage somewhere in the 70K's.

Even better, your car has an automatic, which I prefer, and that means that you will probably discover that the engine will actually run and the rear axle will be healthy. Stick shifts create a direct link from your tires to your piston rings and every time you take your foot off the gas your piston rings now become your brakes. As a consequence, it has been observed that automatics have less wear on the entire drivetrain. The automatics are Chevy TH180's and are virtually indestructible and will outlive the car, so the rear axle and tranny probably will be in excellent condition and there's a good chance that your engine is servicable. Remember that our cars have flat tappet lifters and require that zinc(ZDDP) be added to the oil. You will also have to have hardened exhaust seats installed in the head, when you can afford it, because of modern unleaded gas.
Do you think the automatic is hard to work on or fix? My grandpa has only work on stick shifts and not autos.
 

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Just Some Dude in Jersey
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You won't have to do anything to it, internally they are pretty much last forever indestructible. The only thing you need to do is put new front and rear main seals on it, replace the o-ring on the fill tube, replace the flying saucer-shaped modulator on the back, and put a new pan gasket on it. All that stuff is CHEAP and just ensures against leaks, except for the modulator, which is what makes the tranny shift.

Tips: Buy the "deluxe" oil pan gasket, not the cork kind, they work much better. Do NOT put sealer on the gasket. Make sure the pan isn't dented/warped where the bolts are. Don't overtighten the bolts, only torque them to the ridiculously low spec of 7-9 ft/lbs. When you unscrew the modulator there will be a 1/4" diameter x 1" long tube inside the hole, DON'T LOSE IT! That tube is what the diaphragm inside the modulator pushes on to make the tranny shift. The fill tube is very difficult to install and get seated into the tranny when the engine is in the car, try to reinstall the engine/tranny with the tube already inserted. It MUST be pushed in until the bulge/ring on the tube is tight against the tranny. DO NOT hammer on the tube to try to get it in. If it isn't all the way in it will leak and the tranny will suck air when you go around turns and slip out of gear. A 1/4" ID rubber hose goes from the modulator to the intake manifold, the suction from the manifold is what makes the tranny shift. Put a new hose on to assure no leaks, if it leaks the tranny won't shift. There is an "on demand gear kick down function" that drops the tranny one gear when you squash the pedal to the floor. There is a "kick down cable" that gets yanked that does this. They are often broken where they attach to the gas pedal. You adjust them to only get pulled just before your gas pedal hits the floor, adjust them to get pulled before that and the ball on the cable gets ripped off. They aren't really necessary, your car will most likely downshift on it's own without that cable being pulled. Make sure to unbolt the tranny gear selector lever from the tranny when you drop your engine! People forget to disconnect it and the pivot ball gets snapped off.

There is no need to rebuild these trannies. Most people take them out and install 4-5 speeds, so there's lots of used ones out there that people will give you for free if for some reason you need a new one. I have NEVER heard of one of these trannies breaking or wearing out in the 40 years I've been driving GT's. I have owned and heard of HUNDREDS of 4-5 speeds that were worn out. It's your first car, I take it, so keep it simple and keep the auto tranny and check tranny problems off the list.

Often, you don't need to replace ANY of the stuff I just mentioned, no matter how old the tranny is, it will work just fine.
 

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Discussion Starter · #20 ·
You won't have to do anything to it, internally they are pretty much last forever indestructible. The only thing you need to do is put new front and rear main seals on it, replace the o-ring on the fill tube, replace the flying saucer-shaped modulator on the back, and put a new pan gasket on it. All that stuff is CHEAP and just ensures against leaks, except for the modulator, which is what makes the tranny shift.

Tips: Buy the "deluxe" oil pan gasket, not the cork kind, they work much better. Do NOT put sealer on the gasket. Make sure the pan isn't dented/warped where the bolts are. Don't overtighten the bolts, only torque them to the ridiculously low spec of 7-9 ft/lbs. When you unscrew the modulator there will be a 1/4" diameter x 1" long tube inside the hole, DON'T LOSE IT! That tube is what the diaphragm inside the modulator pushes on to make the tranny shift. The fill tube is very difficult to install and get seated into the tranny when the engine is in the car, try to reinstall the engine/tranny with the tube already inserted. It MUST be pushed in until the bulge/ring on the tube is tight against the tranny. DO NOT hammer on the tube to try to get it in. If it isn't all the way in it will leak and the tranny will suck air when you go around turns and slip out of gear. A 1/4" ID rubber hose goes from the modulator to the intake manifold, the suction from the manifold is what makes the tranny shift. Put a new hose on to assure no leaks, if it leaks the tranny won't shift. There is an "on demand gear kick down function" that drops the tranny one gear when you squash the pedal to the floor. There is a "kick down cable" that gets yanked that does this. They are often broken where they attach to the gas pedal. You adjust them to only get pulled just before your gas pedal hits the floor, adjust them to get pulled before that and the ball on the cable gets ripped off. They aren't really necessary, your car will most likely downshift on it's own without that cable being pulled. Make sure to unbolt the tranny gear selector lever from the tranny when you drop your engine! People forget to disconnect it and the pivot ball gets snapped off.

There is no need to rebuild these trannies. Most people take them out and install 4-5 speeds, so there's lots of used ones out there that people will give you for free if for some reason you need a new one. I have NEVER heard of one of these trannies breaking or wearing out in the 40 years I've been driving GT's. I have owned and heard of HUNDREDS of 4-5 speeds that were worn out. It's your first car, I take it, so keep it simple and keep the auto tranny and check tranny problems off the list.

Often, you don't need to replace ANY of the stuff I just mentioned, no matter how old the tranny is, it will work just fine.
Cool, That just made my life easier. My grandpa and I were worried we would have to rebuild it. Thanks for the info!

Sam
 
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