I am going to be looking at a JDM engine on Saturday for my girls s4 t2. Hers has 250,000 miles. With no warantee, and this car going to be her daily driver, I want to ensure that it is a healthy motor that will last. Engines are garanteed to have less than 65,000 miles and have been compression tested- but he doesn't know the results. Ya, okay. My t2 engine has 67,000 miles at 60psi. I think its because the previous idiot had no tune on a 3in full exhaust with one muffler, and a 3" Honda civic intake with a autozone truck filter and a straight rubber coupler that ruptured trying to fit it to the tiny turbo inlet. I don't want a crap engine.

Engine will include transmission, wiring and ecu. I assume all sensors and accessories are included as well.

How would one go about safely checking the compression on an engine outside of the car?

Is it possible to start the engine without the body harness and ignition, or would I have to perform a cold compression test?

Should I apply some two stroke oil to each housing for lubrication? What about the turbo bearing?

If I have to cold test it, would I just jump my battery to the starter?

Thank you very much!

 

You should rebuild the motor despite what the compression test says if this is the case.

 

Budget and time. That's the reason we are looking into a low milage engine to begin with. Otherwise we would buy two new rotor housings and rebuild her current streetport engine.

 

Stock Tii engine at 250k?

 

All you need to do is bring your self a 12v battery and hook it up to the starter if it has one or (bring your own) try a dry test first then a wet (with very small amount of oil inthe housing) and voila compression numbers.

 

Agreed, Who knows for sure what a Rotary's life has been like. Especially one thats been sitting.

Yah, how the hell did you get so many miles out of a turbo rotary?!?!?! Amazing stuff

 

Fixed.

 

/\ Haha, thanks

 

I got 17k miles out of my last jdm imported turbo engine.

Build your own if you want more then 20k miles

 

Bolt the bellhousing to the engine, and bolt on the starter. Apply voltage. Not hard to figure out


The ****? How does one start a gasoline engine without ignition????

 

+1 on rebuild current motor if it hasnt been totally destroyed internally.
Putting unknown used engines in a daily driver without rebuilding them first ... hmmm

I would do it this way if I were into situation to buy or not buy a used engine.
Spray WD40 or other stuff of your choice into the plug holes or exhaust ports.
Turn the engine over (19 socket, remove pully if needed) with a ratchet and make sure rotors and seals get a bit lubrication.

Turn it over again and listen for even nice pulses. This way you dont get compression numbers but
you will be able to tell if the engine is junk or has "potential".

If you can look into the exhaust ports you will be able to see roughly in what condition the rotor housings are.
Make sure you study reference pictures. For example: http://www.rotaryresurrection.com/2n...ear_guide.html

Borescope would be the tool of your choice if you still have manifold & turbo attached.
Put it in to the Leading plugs (lower) and check it out.

If you want an engine that lasts long, rebuild it. Regardless what the seller says dont trust them if you are not 100% sure.
Many (not all !) JDM importers (especially if they arent rotary specialists) will sell you the funniest things as they have no clue what they are looking at.
I havend had any experience myself on this topic but on this forum you will find enough input.

 

If the transmission and starter are bolted to the engine you can turn it over with a freshly charged 12v battery and get numbers. But they wont be super accurate as the whole mess is not near operating temp.

But at least you can find out if it is blown or not...

 

There is nothing budget or time related about daily driving a 20+ year old turbocharged sports car. Have you even opened up the broken engine and determined what needs to be replaced?

 

is it safe to say that if the block turns by hand and shows good compression that the engine is perfectly rebuildable? will not have any issues with rotors/housings/irons that will necessitate purchasing new replacements???

 

It could be good...or bad. Many old, worn out engines lose compression when the seal clearances grow too large or the housings flake around the edges. Don't try to guess what parts you need for the rebuild until the engine is apart and you inspect the wear/damage.

 

no. if it spins and compresses, this means nothing is BROKEN, which is good. however it can be totally worn out.

 

+1.