So what happens when a 13B Overheats?
 

I ask this for the reason that I bought an engine from a stateside company who warrantied it.

The motor was Tested and does seem good but it had what looked like a coolant leak that was never cleaned off before shipping. I have been flushing through the motor and... yeah its really dirty rust colored.

I thought I got it then I removed the block drain and it was stopped up... finally got it opened up and have been going through it and more rust colored mess...

This leads me to ask just what happens and what can I look for on this motor? I was planning on running it and its almost cleared up but it has me concerned.

Thanks for any help.

Junk in the coolant passages is somewhat normal.

Does it hold pressure when you run a coolant pressure test?

I don't have the tools for that nor can I seem to find a 54mm socket to put the new clutch and flywheel on.

For a pressure test all you need to do is rent the tester kit from autozone / advance auto parts.

in reference to the original question, what happenes when you overheat any engine that has an aluminum head?

heat and aluminum= bad news.

depends how hot it got, obviously. but like any engine, sometimes you get lucky and sometimes you blow a gasket/coolant seal. i went shopping for an E36 and found rotary engines were just as un-reliable as those engines if they got even a touch too hot. most people in that community were passing off cars with blown head gaskets as good solid runners, it was sad.

Like stated above, junk in coolant passage is some what normal. Especially engine that are imported. depend on how long they sat before someone pick them up.

Just rent a tester kit from Advanced and pressure test your system if you are concern it might've been overheated in the past.

Where was the coolant leak? Have any pics?

Pull the oil pan. If the bottom of the rotor housings have oil burnt onto them it is a good indication if it was overheated.

agreed. heat + old aluminum & iron mixed together has a lot of potential for things failing.

and yeah BMW cooling systems are well known as reliability weak points.

Never knew that... Does discoloration count?

no, because oil varnish is normal from certain types of oil and lack of regular oil changes.

No, badly overheated engines I've seen the bottom of the rotor housings are almost black with cooked oil. That would be on the side of extreme overheating though. Karack is spot on that slight discoloring is normal.

So what happens when a 13B Overheats?
The car usually ends up on 3rd gen part out forum!! LOL!

Tons of rusty junk in the coolant passages = bad news

Those are the engines that make good compression on a bench test but develope an overheating issue shortly after install.

Even after flushing all of the junk you can actually get out..some of it will be trapped inside and can only be removed by taking the engine apart.. you may still end up with a sideplate that breaks away at the O-ring groove..

It can happen right away once the engine gets running or a few hours, days, weeks, months later after the engine has a had a few heat cycles or when normal coolant system heat/pressure puts pressue on the O-ring groove where the failure is bound to happen..

You may have purchased an engine that will soon fail...

You may need that warranty.. sadly, it may fail just after your warranty has expired...and you will be stuck with it...

I would not even bother installing an engine with the coolant passages looking like what you have described.. Way to much work and time $$ to get it installed to find out shortly after its no good...

Contact your Jspec supplier and get one without this issue or get your money back..

Not worth it..

I wanna see pictures of wrecked rotary engines. I'm a sick person, I know.