1) I am a long time rotary owner. I have owned an Rx-2, an FB, and have an S5 FC.
2) Yes I have searched this forum about 3 times looking for similar issues.
3) Rebuild two rotaries to date with good results.
4) The Rx-8 engine will be my third rebuild.

Just bought this 2005 Rx8 GT, 120K miles not sure if original engine. Previous owner sayes he was driving on highway, got hotter and hotter, stopped put coolant in, coolant instantly blown out on startup. Towed to dealership, they say block is cracked. I purchase and have towed home, thanks AAA, remove spark plugs from both housings and all are coated with coolant. I can understand a coolant seal blowing and coating the plugs in one rotor housing but not both housings. Cracked center housing?

Anyone experienced this?

 

ive witnessed coolant blow out of a fc like that after overheating and motor was not cracked but coolant seals were toast.

 

what happened is likely the engine got hot enough to compress the rotor housings at the compression side. this thickness variation allows compression to blow out the coolant seals.

both housings will probably need to be replaced.

i also doubt there is any "cracks" in the block. spec the irons to be sure they didn't warp beyond spec during the overheat. this is basically what happens to aluminum heads when a boinger is overheated, except you can't mill the housings flat again.

you will also have to see if there is a root cause for the initial overheating issue.

 

Thanks for the instant replys. Engine coming out

 

dealership ... seriously ?

 

What difference does it make? You know it has to come out and either be replaced or torn down and inspected in detail regardless. Not sure I'd want to reuse any of the irons or rotor housings on a known overheated engine. I'd be looking for a low mileage original replacement engine and sell that one off for whatever anyone else would be willing to give for it instead.

 

if an iron specs out it specs out, regardless if it was previously overheated or not.

 

Found the inner coolant seals of the rotor housings in the combustion chamber area to be very crispy and deteriorated. Measuring things this week to see what else needs replacing. Found out this is the original engine that has done 123,000 miles.

 

Also never seen so much deposits built up on the rotors of an engine. I know the previous owner used premix and all the internet hyped rotarty oils etc. But maybe he was using too much premix?

 

Maybe he never rev it high, never drive it the way its meant to be driven, used crap gas, used crap oil, so many possiblities.

and seriously, who would just drive it till hot, just pull over to the side and start adding coolant ? no wonder it blew. the previous owner must be some sort of smart ***.

 

Every one knows Dealer ships are really honest and forth coming right. Who gives rats *** , it was broke when he bought it>