Volvo Penta 5.0 GXIC-P. Catalytic thermostat housing problem

[bluestreak21]

2011 Volvo Penta 5.0 GXIC-P EFI,CAT EXH. Helping a friend out with his boat and having trouble finding much regarding the thermostat housing on the riser of exhaust manifold(Housing is heat control for cat). Engine started with overheat alarm, gauge seemed to be accurate. I went to the lake, started it, temp slowly climbed like normal. When the engine thermostat opened, a unfamiliar sound started coming from the starboard side exhaust manifold. Sounded like a pressured release, it lasted about 6-7 seconds then alarm when off, gauge did not react. Took engine t-stat off, tested fine,everything normal. I have the part on order, as it seems parts inside the housing are not serviceable.
My thought is the t-stat inside the starboard housing has failed and the exhaust is backflowing in the cooling system.

Wondering if anyone was experience with this exhaust thermostat system?
Thanks,
Pat

 

[Nashville]

2011 Volvo Penta 5.0 GXIC-P EFI,CAT EXH. Helping a friend out with his boat and having trouble finding much regarding the thermostat housing on the riser of exhaust manifold(Housing is heat control for cat). Engine started with overheat alarm, gauge seemed to be accurate. I went to the lake, started it, temp slowly climbed like normal. When the engine thermostat opened, a unfamiliar sound started coming from the starboard side exhaust manifold. Sounded like a pressured release, it lasted about 6-7 seconds then alarm when off, gauge did not react. Took engine t-stat off, tested fine,everything normal. I have the part on order, as it seems parts inside the housing are not serviceable.
My thought is the t-stat inside the starboard housing has failed and the exhaust is backflowing in the cooling system.

Wondering if anyone was experience with this exhaust thermostat system?
Thanks,
Pat

Pat, Morning. There’s not enough information posted to say for sure, but it sounds like the alarm is exhaust temperature not engine temperature. If you hook up Diacom or TechMate you’ll see which sensor triggered. Alternatively, post the alarm. Solid tone, intermittent beep and frequency/timing, etc. The “thermostat” on each Cat is not generally serviceable, but gases are not what’s being recirculated unless there’s a breach. Post the serial number, PM a valid email and I’ll forward a PDF of the flow diagram. I’ll try to post it here first, but don’t know if I’m able. It’ll be later today as I’m working on the boathouse today. Regards, Nash

 

[bluestreak21]

Pat, Morning. There’s not enough information posted to say for sure, but it sounds like the alarm is exhaust temperature not engine temperature. If you hook up Diacom or TechMate you’ll see which sensor triggered. Alternatively, post the alarm. Solid tone, intermittent beep and frequency/timing, etc. The “thermostat” on each Cat is not generally serviceable, but gases are not what’s being recirculated unless there’s a breach. Post the serial number, PM a valid email and I’ll forward a PDF of the flow diagram. I’ll try to post it here first, but don’t know if I’m able. It’ll be later today as I’m working on the boathouse today. Regards, Nash

Nash, Thanks for the input- engine info- 5.0GXIC-P 40869138 , 80A172901. Also fresh water cooling, the flow diagram would be great. Also been looking for a manual, do you know if they cover that system with with some depth or is very basic. Out of all the manuals I have nothing covers this, Im sure its a supplement or something due to the cats. thanks again. Ill PM
an email.

 

[Nashville]

Nash, Thanks for the input- engine info- 5.0GXIC-P 40869138 , 80A172901. Also fresh water cooling, the flow diagram would be great. Also been looking for a manual, do you know if they cover that system with with some depth or is very basic. Out of all the manuals I have nothing covers this, Im sure its a supplement or something due to the cats. thanks again. Ill PM
an email.

Pat, For reference, 40869138 is the Product No. and not the Serial No. Not sure what 80A172901 is. I believe I found the engine in question, and will post a PDF of the flow diagram tomorrow. In the meantime, I emailed the EGC Catalyst Manual. The flow diagram is on Page No. 35. Please keep in mind, Volvo Penta has more derivatives than Baskin-Robbins and the famous/infamous 100 flavors. Serial No. is the guiding light. Regards.

 

[rwfloberg]

Did you get this resolved? I am having what appear to be the same issues. Cannot track down the flow diagram