2010 Challenger 255 Overheating

[gazzaskirepair]

Replaced head gasket
Installed 180F thermostat
Replaced Engine temp switch

Still overheating when going above 5000rpm

Any ideas

 

[JPass]

Have you checked the water pump? Have you pressure tested the system? Is your overheat engine related or is it exhaust related? Which notification are you getting?

Have you tried an IR gun to test the temps throughout the cooling systems to see where the blockage may be or the temp difference?

 

[gazzaskirepair]

Water pump impeller is intact and not cracked
Is there a measurement of the impeller blades that indicates it’s worn
I have used a IR gun and found the thermostat was opening and the drive plate was reducing temp by about 20 C
The boat ran great after changing thermostat then the next day it started overheating
I used a SBT 180F Thermostat kit and wondering if it’s not opening
The difference between engine water outlet next to temp switch to water entering ride plate was about 10C
I would appreciate if anybody has temp matrix of engine location temps and radiator inlet

 

[gazzaskirepair]

The customer was pulling a banana with 2 teenagers and an adult on it which I thought might be a but too much. Our sea temperatures right now are 38C which doesn’t help

 

[gazzaskirepair]

Oh sorry it’s engine giving the alarm and this time gave PO116 so will do the resistance check at ECU connector for the temp switch

 

[JPass]

The 4tec is a closed loop system, and you've stated it's the engine overheat and not the exhaust, so that leaves out the pump.

You replaced the temp sensor, thermostat and head gasket. I'm assuming this was done after the overheat due to damage? Have you pressure tested the cooling system? The 4tec has a traditional water pump in it, similar to a car or motorcycle, to pump the coolant around the motor and through the heat exchangers. I'm wondering if you're having circulation problems?

Does it overheat with one person when going over 5000 rpm?

Cooling System Flow

 

[gazzaskirepair]

Great video
I believe it is a circulating problem too
I did a pressure check before doing head gasket and wasn’t even holding 5 psi
After head gasket change and thermostat I haven’t done a pressure check
The boat is a 2 hours drive from me so only get there once a week
Are the cylinders prone to cracking ?
No external leaks either hence suspecting cracked cylinder

 

[gazzaskirepair]

I am going to remove thermostat housing and do a reverse flush with hose pipe from top of cylinder head big hose then from cylinder block outlet up to cylinder head outlet to confirm water flow is clear
Do the resistance check at ECU connectors

 

[gazzaskirepair]

Just to close this off of how I fixed this problem
The thermostat I got from
SBT was not the same size physically as the Seadoo
After installing it and ran the boat for an hour two without problem I got the overtemp again. I opened up thermostat housing and found the SBT Thermostat had fallen apart and the large washer from it went into the water pump impeller and destroying it
SBT refused the the claim for damage after I provided photos with measurements showing the different size

I installed a Riva thermostat and new impeller and boat runs great

 

[JPass]

Just to close this off of how I fixed this problem
The thermostat I got from
SBT was not the same size physically as the Seadoo
After installing it and ran the boat for an hour two without problem I got the overtemp again. I opened up thermostat housing and found the SBT Thermostat had fallen apart and the large washer from it went into the water pump impeller and destroying it
SBT refused the the claim for damage after I provided photos with measurements showing the different size

I installed a Riva thermostat and new impeller and boat runs great

Thanks for the update. It's always nice when people post the solution to the problem.