Logo
FULL SITE MENU

engine over heats at high rpms

9

90seaswirl

New member
Good day fellow mariners. I have a 1990 Seaswirl Sable Cuddy with an OMC 5.0 stern drive. Runs like a top. Problem is
at 3000 - 4000 rpms the temp pegs in the red. I have done all the obvious tasks ; i.e. installed new impeller kit , changed thermostat , installed new temp sender and checked risers for blockage , which was minimal. My mechanic let me borrow his infrared temp sensor to check manifold and risers under load. I ran at 3500 rpms for about 10 mins and gauge creeped up near red. I back off the throttle and took readings , 119 stbd , 103 port. told him of the readings. he said with a 160 thermostat those are good numbers and water is circulating thru block and that I have a bad temp gauge. I did a diagnostic following steps from my Seloc manual and gauge checked out good.


  • :confused:

I'm confused and bewildered. Any ideas or suggestions ?
 
My mechanic let me borrow his infrared temp sensor to check manifold and risers under load. I ran at 3500 rpms for about 10 mins and gauge creeped up near red.
Click to expand...

Ayuh,... Ya checked the exhaust manifolds, but how 'bout the intake manifold,..??

Does the heat of the intake, just aft of the t-stat housin', match yer dash temp gauge,..??
 
Have you serviced the oil cooler and is the raw water intake screen nice and clean? Just sounds like a restriction in the supply to the motor. Disconnect both water hoses to the oil cooler and plug one end and fill it with oven cleaner. Let it sit overnight and the flush it with high pressure water. If it springs a oil leak it needed to be replaced anyways!
 
Last edited:
Back
Top