8.1S Heat Exchangers and Coolers on 04 340DA

[bajaalex]

Last Fall, one of the transmissions failed. Upon inspection, the trans oil resembled strawberry milk. The trans cooler had failed. I did notice, what I thought, was a gasoline sheen on the water at the exhaust but thought it was related to running rich. Painful lesson. I'll be replacing these ever 5 years.
My question is, what is the expected maintenance for the main heat exchangers and has anyone had these fail? These are the 3-5/8" diameter and cost $1,100 each (4" diameter are $550, not sure why). Mine are 11 years old, not sure if the previous owner did any maintenance on them. Just to note, every single other item on the engines that touch sea water has been replaced.

 

[onthejob]

We had some recent conversation about this very topic. It is DEFINITELY on my list this off season.

http://clubsearay.com/showthread.php/11242-8-1s-(L)-Transmission-cooler-replacement/page2

http://clubsearay.com/showthread.ph...mission-cooler?p=865341&highlight=#post865341

 

[Jimmy Buoy]

Yep, had one fail but it was probably the previous owner not properly winterizing. A few of the tubes were split and although two repairs were made, it continued to leak once up to operating temps. Replaced it for about $850. Some of these coolers can be re-cored, but this one seems to have crimped ends which seem to make it next to impossible to remove the tubes.