i've never seen a rotor come out of a rebuilt engine with rust on it without lots of water intrusion so that's totally new to me. seems to me other factors were at play here that led up to this. sure you didn't drive through a "puddle of water"? as my customers would tell me.

my partner tried to submarine his RX8 in our flooded driveway with a cold air intake behind the front bumper, the results were similar to this, that engine had less than 5k since i rebuilt it.

the sides of your rotors also have a lot of rust on them, that engine has dealt with a traumatic event, whether you know about it or not it occurred. in the other thread i can't recall how long you had the car before this occurred but to me this looks like flood damage followed by forced return to labor and eventual failure.

If i sound a little annoyed it is because i am, you stated the builders name in both threads but this isn't a fault of build quality. maybe that wasn't the intent but i do gather tiny hints at it. only other time i saw a near spun rotor bearing was in an engine built by some random mazda shop, they bead blasted the engine during rebuilding it and a lot of sand media was left inside the engine resulting in it eating itself alive. the friction alone left me struggling to get the engine to idle properly until we drained the oil and it looked like glitter paint. that engine only had a few hundred miles on it, at which i'm surprised it even made it that far. luckily for the owner he got it for a good deal due to the idle issue.

sucks it happened but half of the job of rebuilding an engine is figuring out what caused it to prevent further failures. sometimes it's impossible to know but that rust is concerning.

 

I see what you are informing me about the amount of rust on my rotor.
Since this is the first engine I ever took to pieces as a do-it-yourself backyard mechanic, I know very little.

I think I ordered this engine in 2004, and it sat in its box for a couple years. I did not have the time to install it.

I finally put it in during the Great Recession as I was laid off.
It fired right up, and I drove it as my daily driver until it seized in April of 2018. 75k miles I put on it.

I had to add coolant to the overflow tank from day one! About a cup every week or so. Did not think much of it.
In hindsight, it appears that I had a small coolant leak into the rotor housing. Needed the car running, so I just keep the cooling system full. Along with keeping the oil level full.

It had been sitting for six years in storage before I found a fresh rebuilt engine that fit my pocketbook.
I was never in a flood or submerged by a deep puddle. It just sat with the fluids still in it for the six years.
As I purchased the car new off the showroom floor as a leftover 1988 in February 1989 and put all of the 150k miles on it. I'm pretty sure it never got water flooded into the air intake.

Here is the kicker, after sitting in its crate for two years, I was wondering if the core charge was still valid along with the prepaid shipping.
So, I called to see if it was valid to ship my original engine back (prepaid!) and get the $450 core charge refunded.

My questions were answered by a woman who said "yes, ship it back (after a two-year delay) and we will refund the $450."
I called the shipper listed on my paperwork and he came and picked it up.

After a month or so I called back to see where my refund was.
Same woman answered, when I explained what I was looking for she started screaming at me!
How I was responsible for the shipping charge. I had the feeling that she had done this before!
It is not like I didn't call beforehand to make sure it was OK!

I could see her bullying young customers into forfeiting their core charge!
It did not seem likely that I would see my money any time soon.

I opened a small claim lawsuit; I had my paperwork from the purchase.
They sent in an inch high stack of papers for their side.
It went in my favor, and I received a check for the $450 from the middleman I went through for the purchase.

I purchased something from an eBay listing from them and gave neutral feedback.
The owner called me to find out why the less than stellar feedback.
I explained about the lawsuit, and he blew up on me, stating how he had to change some of his paperwork because of me.
To this day, I cannot order anything from them, I have to do it through a straw buyer.

Yes, there is a hint of bias against these two people.
I'm just a customer; they run the company!

Anyway, what do you think of my reasoning about a small coolant leak causing the rust on the rotor?

 

it's hard to say where the rust formed from, i just observed it in the pictures and it looks to be a bit more than just surface rust from humidity but if the engine sat untouched for 2 years it's possible if you live in a rather salty humid climate from just sitting that it formed over time. i personally have never seen rust pitting that much from just the atmosphere though, so it may have had a coolant leak internally.

 

Ahh,
I moved the engine still mounted to the engine stand along with the engine hoist out to the car. This is happening outside in the neighbor's driveway!

I attached the transmission to the engine and removed them from the stand to the hoist.
There was a storm coming so I threw a tarp over everything and called it a day.
A couple of hours later while it was raining, I thought that I should see if the tarp was still in place.
Of course, it had blown off, so I went out into the rain and tied it down.

The next day was my granddaughter's college graduation, so I had to wait until the next day to go over to the car.
The tied down tarp had slipped and exposed the lower intake manifold to the rain; I could not have positioned the tarp any better to allow the maximum amount of rain to get into the manifold!

When I stuffed paper towels into the openings I was thinking of stopping a stray nut or bolt from getting into the ports!
It never crossed my mind about it raining. Of course, the rain soaked through the paper towels and made its way into the engine!
I looked into the ports after removing the paper towels and could see them full of water!

I pushed paper towels into the ports to soak up the water until they came out dry.
Today I tilted the engine and drained another cup or so out of the intake.
I can feel the side seals rusting into their grooves right now!

So, before you do anything, tape off all the ports with a double application of 2" masking tape!
Hindsight is 20/20.

My plan going forward is to install the engine ASAP and start it.
Hoping that the damage is just some surface rust and everything will free up and function normally.

Also, tie the tarp to the hoist and engine, that will stop the wind from blowing it off.


Do not use paper towels to block the intake ports!

 

spray a liberal amount of WD40 in there and rotate the engine over by hand to work the water out and the water displacer(WD40) into the engine. i tend to always tape up intake ports, though water intrusion also isn't the first reason for doing so.

 

Any updates?

 

Hi everyone,
I sprayed a quarter of a can of WD40 into the intake ports and rotated the engine by hand. I rotate the engine every time I work on the car. Today I noticed when I rotate the engine, on one turn I do not hear the sound of the exhaust cycle! I think I have a rusted apex seal that does not hold compression!

I am going to proceed with the installation and hope for the best if it starts. I am now trying to attach the wiring harnesses and I'm having some problems. You know where you are supposed to label EVERY connection on the harness when you disconnect it, I didn't!

I am now missing the round connector for the coolant sensor that is located close to the oil pressure sensor!? At my age things go missing!

Is there a thread here that shows where every connection on the harness goes? I might be making connections that are wrong.