Anything I should do to engine while I have it out on a stand?

[avid]

Today I pulled the rebuilt 4.0 OHV from my Ranger to put in a Mazda I got with a good transmission. The engine has maybe 35K miles on it. I'm fixing an exhaust manifold bolt thread that has been messed up since I got it, and also swapping the Oil Pan since the one on the rebuilt has a helicoiled drain plug.

Is there anything I should check or do maintenance-wise while it's out?

 

[Brain75]

any motor, "good", junkyard, reman, unknown I run a compression and leakdown before I go to the effort of putting it in - reveals issues before you put it in...

 

[RobbieD]

Look at all of the freeze plugs real close for evidence of coolant/rust "tracks" from weeping pin holes in the plugs. If the coolant passages look really nasty, from peeking into the radiator and heater hoses' inlet/outlets, I'd be tempted to replace all of the freeze plugs anyway as preventative maintenance.

And look at the rear main seal on the crank. Not hard to replace, and much easier to do while the motor's out.

 

[avid]

any motor, "good", junkyard, reman, unknown I run a compression and leakdown before I go to the effort of putting it in - reveals issues before you put it in...

That's a great idea, but how do you run a compression test with it on a stand already? How would you do so at a junkyard- do you take in a battery or one of those jumper units?

 

[avid]

Look at all of the freeze plugs real close for evidence of coolant/rust "tracks" from weeping pin holes in the plugs. If the coolant passages look really nasty, from peeking into the radiator and heater hoses' inlet/outlets, I'd be tempted to replace all of the freeze plugs anyway as preventative maintenance.

And look at the rear main seal on the crank. Not hard to replace, and much easier to do while the motor's out.

Thanks. Both excellent ideas.

 

[lil_Blue_Ford]

That's a great idea, but how do you run a compression test with it on a stand already? How would you do so at a junkyard- do you take in a battery or one of those jumper units?

You need a stand that allows you to bolt the flywheel on and spin it.

Alternatively you could potentially try a leak down test since you rotate the motor to where the valves are closed for a particular cylinder and inject compressed air into the cylinder with a gauge and see how fast it leaks out on the gauge. I have a tester somewhere that I bought awhile ago for that but haven’t really used it. Only time I used it was on my dump truck and the valve guides and seats are so bad the air came out as fast as I put it in…

 

[Uncle Gump]

35k on a rebuilt...

If it was a runner... I'd seal up anything that's leaking and send it.

 

[19Walt93]

If you had it running in the Ranger for those 35,000 miles with no problems I wouldn't worry about the compression unless it's been badly overheated. Things like freeze plugs and the front and rear seals will never be easier to replace, though.

 

[avid]

35k on a rebuilt...

If it was a runner... I'd seal up anything that's leaking and send it.

If you had it running in the Ranger for those 35,000 miles with no problems I wouldn't worry about the compression unless it's been badly overheated. Things like freeze plugs and the front and rear seals will never be easier to replace, though.

Yes, it was running good. I mean it's a clattery 4.0 but no problems and no obvious leaks. I already looked at the rear main seal and it's good- I installed a new one when I put the rebuilt in.

I marked the flex plate and torque converter on the Mazda and was thinking I would use the Mazda Flex Plate assuming it's undamaged when I get that engine out as it was previously married to that torque converter with no problems. I don't know if that will make a difference but that's my plan unless anyone sees a potential problem with it.

Also wondering about swapping the oil pans: is there any good way get all the coolant out so I can flip the engine over? Both oil and coolant were drained and I could remove the pan from below easily enough but installing the new would be a lot easier if I flipped it. Is there a good DIY way to evacuate all the coolant from engine? Or does it even matter? Just turn it over slowly and catch fluid from the water pump openings? Or just do it from below?

 

[alwaysFlOoReD]

I would probably find a cheap kiddie pool to put under the engine. Or large commercial baking sheets work too.

 

[Curious Hound]

Thoroughly clean and degrease the engine bay of the recipient chassis. Check for and repair any damaged wiring in engine bay or on engine harness. Much easier with all the open access.

 

[avid]

Thoroughly clean and degrease the engine bay of the recipient chassis. Check for and repair any damaged wiring in engine bay or on engine harness. Much easier with all the open access.

Yeah, great idea. I was originally thinking about doing this and then I've sorta forgotten with everything else going on so thanks for reminding me. I'm pretty sure I have a jug of Simple Green to use with my pressure washer. I'll have to make sure it has a low-pressure setting and cover up the electrical components/connectors.

 

[SenorNoob]

Cleaning was probably 2/3 of my engine swap. And I still missed some stuff.

 

[19Walt93]

Yes, it was running good. I mean it's a clattery 4.0 but no problems and no obvious leaks. I already looked at the rear main seal and it's good- I installed a new one when I put the rebuilt in.

I marked the flex plate and torque converter on the Mazda and was thinking I would use the Mazda Flex Plate assuming it's undamaged when I get that engine out as it was previously married to that torque converter with no problems. I don't know if that will make a difference but that's my plan unless anyone sees a potential problem with it.

Also wondering about swapping the oil pans: is there any good way get all the coolant out so I can flip the engine over? Both oil and coolant were drained and I could remove the pan from below easily enough but installing the new would be a lot easier if I flipped it. Is there a good DIY way to evacuate all the coolant from engine? Or does it even matter? Just turn it over slowly and catch fluid from the water pump openings? Or just do it from below?

I'd replace the rear seal again, you'll never be closer to it and it'll never be easier to do. I bought a drip tray from Summit that slips onto my engine stand. Even after pulling both block drains, coolant is going to drip when you invert it. A torque convertor isn't married to a flex plate, they're bolted together.

 

[Curious Hound]

A torque convertor isn't married to a flex plate, they're bolted together.

If that’s not married. I don’t know what is.