Sitting motor

[DWBOX2000]

I got a motor from a junk yard. I want to soak cylinders before I turn over by hand. What do I use for that. It’s a Miata 1.8L motor. Thanks.

[2.7RS]

I've seen people loosening farm engines with.....

Marvel mystery oil
Brake fluid
Tranny fluid red

Filling the cylinders let them soak for days and then gently turning the crank.

I've done 2 engines, cast iron, in the past with brake fluid and I was successful

Wondering if alloy blocks v/s iron make a difference

[1990C4S]

Any of the three above...or any mix of those three.

[JackDidley]

Id stick a scope in the spark plug holes and see what it look like in there. I have one but you can rent one from the auto parts store for free.

[Shaun @ Tru6]

I used Marvel in my Fiat that sat for over a decade.

[Zeke]

Originally Posted by 2.7RS

I've seen people loosening farm engines with.....

Marvel mystery oil
Brake fluid
Tranny fluid red

Filling the cylinders let them soak for days and then gently turning the crank.

I've done 2 engines, cast iron, in the past with brake fluid and I was successful

Wondering if alloy blocks v/s iron make a difference

Agree and I could add a few. If you have any of those types of chemicals, it's worth a shot. Kind of expensive to be pouring Kroil in the cylinders. But old used motor oil with some solvent would not be my first choice but not my last either. Just needs a catalyst.

[unclebilly]

Originally Posted by JackDidley

Id stick a scope in the spark plug holes and see what it look like in there. I have one but you can rent one from the auto parts store for free.

Buy a wifi one from Amazon for $30. They are awesome.


https://www.amazon.com/NIDAGE-Automotive-Inspection-Semi-Rigid-Smartphones/dp/B07C9C6P5D/ref=sr_1_4?crid=3W4NOQYDYFR11&dib=eyJ2IjoiMSJ9.HLj6cw2OYCSxhFSPY0FpmsLiLiWjAo4M9 Rrl2rSZZJKB2cncpKTWDKe5U5QNy_TAwW3URHwWFG6xALovIx-hErvtC3dwV68qBud-5Ah_9AFXABqP2iWdgIocPUiqJ8_vAb74X7yPh7uoaORdIAXfUv TxO4BxArWZRrQm4gB3lCPCIS0xjf3TOBaWcImXUOhf7NQ0hHUD Vc9UCq4GCNdYDLsrZhNkdb_akq2O7OcBaDs.wXw7q7Nq2WhFUp UJmM7hgXqaFM_YbohlvcJ0D2OuOeM&dib_tag=se&keywords=borescope+wifi&qid=1715253258&sprefix=borescope+wifi%2Caps%2C174&sr=8-4

[LWJ]

I have never heard of anyone doing this, but I use this concoction for anything that needs penetrating oil. Which, is essentially what you need for a frozen engine.

50% acetone 50% ATF.

I think I am on a personal mission to spread the word as this stuff has saved the day so many times for me.

Good luck! Let's see your Miata.

[id10t]

Originally Posted by LWJ

I have never heard of anyone doing this, but I use this concoction for anything that needs penetrating oil. Which, is essentially what you need for a frozen engine.

50% acetone 50% ATF.

I think I am on a personal mission to spread the word as this stuff has saved the day so many times for me.

Good luck! Let's see your Miata.

Sounds similar to Ed's Red - https://www.hensleygibbs.com/edharris/articles/EdsRedRecipe.htm

[DWBOX2000]

My son’s car. I’m just helping.

[1990C4S]

Since you have not said the engine is 'stuck' I would not go crazy with concoctions. Throw some ATF, oil, or MMO etc. down the hole and turn it over by hands. Odds are it is not frozen.

No need to complicate things before things are known to be complicated.

[DWBOX2000]

Agree, it’s probably fine but figured on the side of caution. I’ll get some mystery oil, pour in tonight and get back at it over the weekend. I think the engine was recently rebuilt. Seems to have a ton of paint markings on various bolts. The engine came out a wreck supposedly. I guess we will find out.
Thanks everyone for the help.

[fanaudical]

My opinion - I'd avoid brake fluid. It tends to be corrosive when it picks up moisture and you don't need that in an engine. Displace any water you mind find with WD-40 first. My go-to's to soak a motor to free it up (in order) are:

Marvel Mystery Oil
Acetone/ATF mixture
PB-Blaster for the stubborn stuff - spray/soak

[LWJ]

As I re-read and see that it isn't stuck?

Pour atf or any oil down there. Turn the crank. This is easy.

I may be jonesing for a Miata...

[cockerpunk]

if you have a miata engine on the stand, any reason you dont just open it up? its like 16 bolts, and most of them are the cam cover.

open it up, take a look, make sure everything is good, and close it back up.

[Zeke]

I've used ATF and acetone before many years ago. It didn't do anything for me. The right product for the right job has always performed much better. For instance, on stuck rusty nuts ATF just ran all over the place. Heat and wax is much better. That's only one example. Heating and then cooling with Kroil, PB and LW have always worked.
If I were freeing an engine {I guess yours is not stuck), I would use an impact back and forth on a soft setting after the soak.

[DWBOX2000]

I think I will be removing the head eventually and putting on the car in picture. My son thinks his valves are his compression issue. The motor in picture has great compression numbers, the one in picture, not so much. Figured we would try. Worse case it does nothing but I learned a little. I look at it as a little time with the kid and it gets me wrenching versus just watching it on tv all the time. More questions will be coming.

[Rusty Heap]

LED illuminated bore scopes you hook up to your phone are stupid cheap and work fantastic.

[JackDidley]

Originally Posted by Rusty Heap

LED illuminated bore scopes you hook up to your phone are stupid cheap and work fantastic.

Yep. A buddy had one and could not get it to work for some reason. Gave it to me so it was free. Works great.

[cockerpunk]

Originally Posted by DWBOX2000

I think I will be removing the head eventually and putting on the car in picture. My son thinks his valves are his compression issue. The motor in picture has great compression numbers, the one in picture, not so much. Figured we would try. Worse case it does nothing but I learned a little. I look at it as a little time with the kid and it gets me wrenching versus just watching it on tv all the time. More questions will be coming.

taking the whole engine out of a miata is not that much harder than taking the head off.

Id take the spare out of car engine, replace the seals, open it up, do the headgakset etc, and then swap the whole thing in.