front iron damage
 

I have torn apart many REW engines and have never seen this happen. It appears that the coolant seal failed due to the iron breaking at the jacket. I have seen it on 2nd gen 13Bs but never a REW.

Just figured I would share it with you guys. Anyone else see this happen?

i had a guy bring in an engine with this issue on the red seal .. middle iron toward s the bottom on the rear facing plate .... i always wondered what exactly causes such damage ?

You also have to check new plates very carefully for consistency in this area. There can be considerable difference in thickness. On last rebuilt my builder sent two brand new plates back before getting a good one!

We see coolant seal retaining wall failure quite often on all series S4-S6. I believe that the main culprit is people not flushing there coolant system often enough, this allows the iron to rust out and then cave in, as you have pictured. We see it on low and high mileage engines, and have seen it on the front, middle and rear plates.

Very well put. That's been our experience as well. It's essential to flush your block and rad coolant often, preferably annually. Rotary people change their oil and spark plugs often, but somehow the coolant gets neglected.

I'm sure you're right, but how does replacing coolant with coolant help prevent this from happening?
Also, how often would you suggest flushing the system? Once a year?

Thanks

Ceylon

Here is a quick way to determine condition of your coolant.

With engine cold, use a voltmeter set to 2V resolution. The black probe goes into the filler neck contacting liquid coolant (don't touch the metal neck), the red probe goes to battery ground. More than 2V means your iron plate and rotor housing with coolant are acting like a battery. Coolant should be replaced if more than 2V.

Mine consistently read 2V or higher within a year of changing conventional green coolant (car sits around alot). Losing 2 engines due to coolant induced seal failure I switched over to Evans NPG+. I have not changed coolant in 6 years, NPG+ only reads 0.18V.

Thanks for the info, I'll check mine later :)

Coolant testers are available at auto parts stores, it is a hydrometer that test the pH level of the coolant. If the pH level is too high the coolant becomes acidic.

Another issue besides the old coolant is the use of tap water. You should always use distilled water in the coolant system. The minerals and iron in normal tap water form deposits inside the engine, which lead to internal rust and retaining wall failure.

yeah I have....

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/found-culprit-causing-all-my-coolant-pains-868822/

Sorry to thread jack, I've been searching for the last 30-45 mins for the best quantities to use regarding coolant/water wetter/distilled water ratios, I've found 3 answers that are pretty different. Whats would you advise? As I haven't changed mine in just over a year.

Thanks

Ceylon.

So all the engines with coolant seals on the rotor housings (S1-S3, Rx-8) have much less retaining wall failure?