1997 350 TBI white steam...and temp warm...?

Port engine 'alarmed' and went into safety mode the other trip while cruising at 3250. I saw the temp gauge spike hot when this happened. Slow cruise back at 1500 temp ok. no more spike.

Serviced new impellers went in. Strainers checked and intake pick up appears clear.

Went fishing, port ran warmer about 200/205 peak after running for a while on temp gauge. Noticed new white steam or smoke from same port exhaust.

I would say it was steam not smoke, this is recent,historically these engines do not steam or smoke white. I had another alarm today but brief at low RPM and cruised back at 3250 after the temp dropped back down. The temp did not spike this time but normally these engines run under 200.

Risers are 3 years old.

What is most likely going on here...? Im not very mechanical....but higher temp, alarm, white steam...?

Thanks.

riser or elbows or both are three years old?

If you can see thru the cloud coming from the exhaust, it is likely steam.....if you can't, that's usually smoke and typically comes from the hose burning due to insufficient water flow.....

are the raw water pumps original? have they ever received a 'major' service kit ( more than the impeller and gasket)?

guessing based on what you provided, I'd suspect there's a restriction in the raw water line, an air leak on the suction side of the raw water system, or the pump is worn out and isn't provided full flow.....The other scenario is the replacement riser was Chinese in origin and has rusted enough to start flaking which is clogging the outlet holes into the exhaust passage....

Elevated steam levels often mean reduced raw water flow. In my case, the culprit was a clogged oil cooler.
FL Panhandle

makomark said:

riser or elbows or both are three years old?

If you can see thru the cloud coming from the exhaust, it is likely steam.....if you can't, that's usually smoke and typically comes from the hose burning due to insufficient water flow.....

are the raw water pumps original? have they ever received a 'major' service kit ( more than the impeller and gasket)?

guessing based on what you provided, I'd suspect there's a restriction in the raw water line, an air leak on the suction side of the raw water system, or the pump is worn out and isn't provided full flow.....The other scenario is the replacement riser was Chinese in origin and has rusted enough to start flaking which is clogging the outlet holes into the exhaust passage....

Click to expand...

The raw water pumps are 'unknown' vintage. The riser kit was as American as we could locate. I avoid Chinese whenever possible.

Do you think a Barnacle Buster soak would be a good idea before I go any further ?

Thanks as always.

Good regarding your parts' origins.....

Have you ever put a cam in the pump? Ever measured the pump's output?

I doubt the soaking will resolve your issue(s)....but I doubt it will hurt anything but your wallet....

I guess in retrospect I should have done the whole pump assembly.

Gonna soak and see....maybe I get lucky.

I would say the pump should have been disassembled and the whole thing inspected.....sadly, these procedures aren't in the owner's manuals and rarely have enough detail in the factory manual to let a mechanically inclined DIYer to know what to look at and what is essential for good performance.....welcome to the first rung of the learning ladder...

For me it was scoring on the inside and cover plate of the water pump. Cost me several hundred to chase the problem but that was it.

Update: After some trail and error had new HeatX installed on both engines, they were original looking and date of last service unknown.
Went with SeaKamps, made in USA,not an exact fit however.

Temps now steady at 180/185*. Still have some slight white steaming port side.

Blackfin27 said:

Update: After some trail and error had new HeatX installed on both engines, they were original looking and date of last service unknown.
Went with SeaKamps, made in USA,not an exact fit however.

Temps now steady at 180/185*. Still have some slight white steaming port side.

Click to expand...

Try RydLyme or Barnacle Buster. RydLyme got my steam to go away. Your temp readings should be that of your thermostats!