25 replies to this topic

[Drew McCrae]

I've searched the forum using seized as a term but can't find anything so apologies if this is repeating a lot of previous posts. I ask on behalf of my son as I'm helping out with his 1967 850.

Background us car was running and he started working on the mechanicals with a view to getting bodywork welded afterwards. Circumstances changed and it has been left for 3 years outside under a cover. He is now trying to get it back ready to weld and paint but noticed an issue in that he can't turn it over to do static timing and it seems seized. It contained oil and water while waiting.

Spark Plugs are out and ATF has been in the cylinders about 5 days.
We jacked up one side and tried rotating the front wheel in 4thbgear.
We tried rocking in 4th gear.
We tried prising the flywheel as starter motor is off.
We tried draining and putting boiling water in through the thermostat port to heat the block. Nothing comes out the drain and nothing goes in the thermostat port.
Lucky I think the battery is out as we'd be tempted to use the starter motor and risk cracking a piston ring.

We're pretty despondent at this stage, confused as to if it's really seized,why the port won't drain, why it's like that after less than 3 years. What can we do next?

I'd really appreciate some advice, I'm home all day so can try out ideas. We have not put a socket on the crankshaft nut as it's so hard to get to and we'd like to avoid the radiator removal scenario. We also don't have a 1 5/16 open ended spanner.

Thanks everyone
Andrew

Edited by Drew McCrae, 31 August 2026 - 04:40 PM.

[Spider]

Might have been better to put diesel (fuel) in to the cylinders, if you can drain the ATF out, put that in there for a few days and try again.

[68+86auto]

Don't worry about the coolant side for now. That won't stop the engine turning.

You mention using the starter, that won't work. You'll just burn out the starter but you won't damage the rings. It doesn't do anything that manually turning the engine won't do.

 

Was the air filter on it while it was stored?

 

 

People have all different mixtures of oils and chemicals that they use to try and unseize engines.

 

It may be worth buying a cheap borescope to see if any of the cylinders have filled with water for some reason.

[MiniMadRacer]

Might be a long shot, but if the alternator and fan belt is still installed, it may be a seized alternator rather than the engine. Try disconnecting the fan belt to at least rule out a seized alternator and the water pump. 

[Drew McCrae]

For some reason I can't see my previous reply??

Thanks everyone
1. Diesel sounds like a better plan or some other solvent. ATF is basically oil I think.
2. Coolant is not the problem I know but we thought if we could get boiling water into the block, thermal expansion may help shift it.
3. Starter we feel would give direct torque to the crank. But we still don't want the lack of feel and potential to cause ring damage.
4. Air filter was in. Plugs were in while stored. Looking at stuff on YouTube it seems a bit rough that not even three years and she's stuck.
5. No alternator on this car but dynamo can be turned easily

[Ethel]

I wouldn't use the starter. stalled motors have little resistance so you're more likely melt the wiring before moving anything. The most force you're likely to get will be from rocking the car in gear - clutch permitting.

 

It's a big lump of iron, so water heating will take more water than the engine holds. Short of plumbing it in to your central heating I doubt you'd get much affect.

 

Has anyone ever converted a spark plug in to a hydraulic fitting so they can try pumping directly into the cylinders???

[Quinlan minor]

Has anyone ever converted a spark plug in to a hydraulic fitting so the can try pumping directly into the cylinders???

Only someone who wanted to bend a conrod.

[sonscar]

Take the head off,relatively cheap and easy and will reveal a lot.Steve..

[Drew McCrae]

Has anyone ever converted a spark plug in to a hydraulic fitting so the can try pumping directly into the cylinders???

We'd thought if this too. On another forum somewhere when browsing somebody had suggested screwing a grease nipple in. Bearing in mind that your conrod would be probably ok if you chose the most seized cylinder. But that's a 25% chance. Head off seems very radical, great view but what then?

[68+86auto]

If it doesn't come free relatively easily, you will need to remove the head to find out why (or use a borescope). Most likely it will require a rebuild.

 

If you aren't in a hurry, let it soak and keep trying to turn it a bit each day.

[Ethel]

 

Has anyone ever converted a spark plug in to a hydraulic fitting so the can try pumping directly into the cylinders???

Only someone who wanted to bend a conrod.

 

If you didn't want to you'd have more control. Back off the tappets & you could work 2 cylinders together, alternating with the other 2. You'd also be forcing fluid directly round the seized rings.

 

200psi could be seen just on a compression stroke, that'll be around 800lbs of shove on a 998. Without drawing vector diagrams that's 200ft/lb of torque from just the crank throw.

[Ethel]

 

Has anyone ever converted a spark plug in to a hydraulic fitting so the can try pumping directly into the cylinders???

We'd thought if this too. On another forum somewhere when browsing somebody had suggested screwing a grease nipple in. Bearing in mind that your conrod would be probably ok if you chose the most seized cylinder. But that's a 25% chance. Head off seems very radical, great view but what then?

 

 

An air compressor should get you 100psi easily. That's 390 lbs of shove on an 850 piston, equivalent to 87ft/lb of torque  - translated by wherever the conrods are. Applied to 2 cylinders it would defo be a useful assist.

 

I know grease guns have been adapted to pump up hydro suspension to over 400psi.

[sonscar]

You could have siezed valves,bent pushrods,siezed lifters,stuck dissy.Removing the head is simple and gives you a cheap visual which could reveal a yes or definitely no situation.If nothing else you can hit the pistons with a lump of wood.Steve..

[stuart bowes]

 

Has anyone ever converted a spark plug in to a hydraulic fitting so the can try pumping directly into the cylinders???

We'd thought if this too. On another forum somewhere when browsing somebody had suggested screwing a grease nipple in. Bearing in mind that your conrod would be probably ok if you chose the most seized cylinder. But that's a 25% chance. Head off seems very radical, great view but what then?

 

 

also it takes the pushrods / rockers / valves out of the equation, they should all be moving correctly as you attempt to rotate but do you know that for sure, maybe somehow the timing is out far enough for a valve to be causing the jam?    although, you did say it was working previously..  and it's usually non-inteference ?  assuming standard.. but either way, it's not a huge job to remove it

 

on the same lines (again working previously so probably not..) but I seem to recall reading previously there is the possibility of wrong bolts in flywheel/clutch housing that can cause a jam, mabe borescope in through the starter hole wouldn't be a bad idea as well ?

Edited by stuart bowes, 02 September 2026 - 11:31 AM.

[Drew McCrae]

Thanks everyone. I think we'll keep putting the juice into the cylinders and see what happens in a week. I'll put a breaker on the wheel nut and put a bag of sand leaning on it to just keep pressure on.

Just to confirm
Engine did not seize. Drove it onto driveway, turned the key and left her two years so nothing out of timing, no pistons hit valves, starter out, dynamo spins, water pump spins, flywheel does not spin. Currently soaking with no improvement yet.

I'll get an old plug and see if a grease nipple (zerk) will fit or an old tyre valve. But.. I think the only way I should do that is if I knew which cylinder is stuck rather than pushing a free piston and transferring the force back through the crank. Final think will be everything off to get at the head.