I bought an s4 turbo engine from the junkyard for $250 several months ago and never got a chance to look at it much.

Well today I take a good look into the intake ports and voila-all the apex seals are intact.

The rotors look really black and gummed up but no signs of rust due to a blown coolant seal.

The car the engine is from supposedly had 160k miles on it, was pink, and was only at the junkyard because it was considered total due to hail damage. (That's what the junkyard told me, the engine was removed and the car was crushed long before I picked it up)

So I'm thinking---was it rebuilt at some point? Possibly replaced or swapped?

I want to further investigate and see if I can throw this block in my t2 to save me from having to get a rebuild.

How can I confirm the engine is good while its out beyond a visual inspection?

I'd like to test coolant pressure and engine compression if there is a way.

Here's a pic of the engine.

Is it being outside under my deck on a pallet with a tarp over it okay?



Its the only place I was allowed to put it. Sigh

Rotary >Pistons

 

you can compression test it if you put 12 volts to the starter and roll it over.
As far as the cooling system you can block off all outlets etc and pressure test.

 

I assumr I can do that from the spark plug holes without blocking anything else off?

Problem is its not attached to any transmission , so no starter is attached.

Any other way to crank it fast enough?

An engine test stand to test if it can run would be nice right about now.

Too bad Kevin landers is 7 hours away, I know he has one not that he'd want to test my engine Lol

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Put a drill to the main pulley and spin it that way maybe?

 

I was thinking about that. Lol

Would it give similar results to using a starter though is the question.

I may rent a compression tester and coolant pressure tester and see what I come up with.

How likely is it the engine lasted 160k miles without blowing?

Imho if the engine lasted that long it probably is on low compression.

Edit - a friend informed me that using anything other than the cars starter will not turn the engine fast enough to yield the correct compression numbers. Sigh

Rotary >Pistons

 

It looks like every bit of 160k original miles to me...I sure wouldn't trust it unless your goal was to throw into the car and sell really quick or something.

 

Even a test using the starter and a strong battery won't really give you accurate results.

1) the engine is supposed to be at operating temp. colder engines will give higher compression readings usually.

2) you get some oil drainage from the OMP system and from the rotors when the engine sits longer than a few hours. This oil puddles up in the bottom of the chambers, and if you compression test it that way the puddled oil will fill in gaps between seals and artificially raise compression (kinda like pumping ATF/oil into the engine).

Still, you can at least get an idea if it is blown, decent, etc. Expect to see about 90-100psi out of it based on what you've said.

 

Exactly Kevin.
Just adding that at least with a decent starter and charged battery it will give him an rough idea,one way or another,which is better than just dropping it in and hoping for the best.
Hell,even without the Compression tester you would hear the "whooshes" when it rolls over,and if ONE was missing you know what that means!
With the starter rolling it over with the tester he can get a "reading".(though not 100% totally accurate,but a reading none the less).
I was really surprised at the Torque of the starter when you first hit the darn thing with 12 volts..lol,
Sort of made me jump!..Wasn't expecting that!

 

+1

 

Goal is to have it running and last awhile.

If its a bad idea to run it, it'd be a good candidate for rebuild if everything is usable.

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After 2 cans of degreaser and carb cleaner this is how the engine looks also took some pictures of the apex seals and a video of me turning the engine to show how compression sounds.

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Heres the youtube video of how it sounds being turned by hand.


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Sounds pretty weak to me.

 

That seemed way to easy for you to turn.... Which indicates low compression. I would just pull it apart and save the good parts.

 

Shouldn't it be easy to turn when it's in shortblock ? I was spinning it by holding a peg sticking off the flywheel.

If I get it rebuild I should have all the parts I need seeing as I have another engine that's still in the car.

That engine supposedly ran but was overheating (most likely blown coolant seals).

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Bro you're turning the damn thing backwards.

 

from the little i see of the flywheel, it's moving counterclockwise. which would be correct.

@ 160K miles it's going to be easy to turn w/out the plugs in.

if it has descent compression (doubtful if original apex seals) it's well worth re-assembilng it w/the $180 gasket/O-ring set from Atkins.
much cheaper than dropping it in and then finding out you got some major issue.

 

Oops. I made the video quick , wasn't really thinking. I didn't hurt it by spinning it backwards did I?

Is the engine being outside under my deck under a tarp a bad thing?

I wasnt given an option to put it anywhere else

I could plug up all the holes if necessary.

If necessary I'll make a video of me spinning it in the correct direction,I think it'll sound the same though.

Rotary >Pistons

 

No, he's turning it backwards. Trust me. The engine is supposed to turn clockwise from the front or counterclockwise from the back. You're looking at the flywheel in that picture and he's turning it clockwise. Of course it's not going to make any compression that way.

 

It will definitely sound different, with chugs instead of whistles.

As long as nothing got inside and it hasn't sat too long it might be okay. They are hit or miss...I've seen them sit for a year in a basement and ruin, and I've seen them after sitting for 8 years outside under a tarp and still be perfect inside.

 

Here's the pics of apex seals I took from the exhaust port.

I tried to brighten them up a little to make it more visible.

To me it looks like the rotor is covered in carbon/oil, but other than that everything looks okay.

























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That's actually a normal (or even mild) amount of carbon for a high mile rotary.

The problem with this approach is that you can only see about 70% of the apex seal, the rest is obscured on either side of the port. And the weakest point of the seal that will tend to chip is in that remaining 30%. But, if you can see or feel no damage around the exhaust port then odds are they are all intact.

Even so, it's bound to be a very weak compression engine that's ready to let go at any time if it's original. IF you have time to burn then sure, go on ahead and throw it in and see what it does. IF you are a "do it once and be done for a few years" kind of guy, then there's no way I'd expect to put it in and have it be 100% for a long time.

 

I'm probably going to rebuild it then.

It'll be my first time rebuilding so I'll need to take my time. If I change mind though you'll probably be rebuilding it.

I just wish I could throw it in and put my money into other things on the car that require my attention.

I'm a paranoid person so I'll be doing all I can to make it last.

I.e. - Was told the turbo was making a funny noise so I will have to get that checked out and possibly rebuilt. (This is my first turbo car so I know little about turbos)

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These turbos don't normally "make a funny noise" as a mode of failure. They start smoking and burning oil out the exhaust/turbine side, or maybe pass oil from the compressor via the intake tract and burn it in the engine that way. You can usually tell when a turbo has been burning oil because the turbine outlet to downpipe will be black, while the inlet from the engine will be clean/tan/brown. Of course if the engine itself was burning oil then the entire thing will be black and you won't be able to tell about the turbo because of it.

 

I'll have to check it out when I get it taken off, I don't think the previous owner knew what he was doing or talking about.

I plan on porting the wastegate, I'll try to keep the boost close to stock but with having a 3" exhaust I'm sure it won't stay at 5.5 psi

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