Running Temp Differs Port to Starboard-gctid341067

[kwb]

Port runs 150F all day long Starboard runs 175F and did all year (first year I had the boat). Same readings on bridge and lower station. Intentionally pushing the port engine harder by 50-100 RPM for a few minutes and everything stays the same.

Engines are 175 Hinos - I just redid the manicoolers including ceramic coating the internals, the system was flushed, fresh fleetguard coolant, both have the accessory items shut off (Heater, Water heater), Both cooling bundles were acid dipped and had similar level of crud on them both cleaned up nicely.

I haven't replaced Port Impeller yet but have done the starboard both show similar water flow out the exhaust.

Any ideas? My next move is to IR gun to same components all the way through the system and then possibly swap the sender.

[mmichellich]

Risers

Strainers

Thermostat

Temp Guages

Partially collapsed pick up hose to raw water pump

Impeller

Raw water pump internals

[iceclimber]

I'd reorganize that list above in order of the least amount of work Swapping the senders #1.

[smitty477]

Yes - senders and gages first would be nice (both for accuracy).

If that is confirmed good - it may just be the port thermostat.

And if not that is it possible that the stb is burning much more fuel?

No, I dont think so - it is much more likely one of the 1st two.

Hope this helps

[cosmo777]

Is your water heater plumbed from the port engine?

If you're starting with a cold water heater, it will act as a heat sink and keep your engine temp at 150 deg.

Only once the water heater is up to 150 deg, then both the engine and the water heater will slowly rise together.

Yet any use of hot water while cruising will only delay the engine and water heater temps from rising together past 150.

[kwb]

smitty477 wrote:
Yes - senders and gages first would be nice (both for accuracy).

If that is confirmed good - it may just be the port thermostat.

And if not that is it possible that the stb is burning much more fuel?

No, I dont think so - it is much more likely one of the 1st two.

Hope this helps

Fuel burn is nearly the same so far as I have seen - given variable genset use/fuel stops

cosmo777 wrote:
Is your water heater plumbed from the port engine?

If you're starting with a cold water heater, it will act as a heat sink and keep your engine temp at 150 deg.

Only once the water heater is up to 150 deg, then both the engine and the water heater will slowly rise together.

Yet any use of hot water while cruising will only delay the engine and water heater temps from rising together past 150.

Water heater has a valve to it and that loop is currently shut off even when it has been open I have made 4hr runs and still the 150/175 split between the two.

Both risers (SST version) are cool to the touch when running. Strainers are both clean, hoses are not crushed, flow out the exhaust is the same by eyeballing the stream.

I am hoping it is just gauges/sender at this point but it might be a while before I have a chance to swap wires around to see if that is the deal.

[dmcb]

150 is to cold for your engines so that is the problem engine. I have never noticed my water heater side being enough different to notice.

Sending units would be the easy choice to be sure the gauges are correct but I suspect the thermostat is stuck open.

Doug

[smitty477]

"I am hoping it is just gauges/sender at this point but it might be a while before I have a chance to swap wires around to see if that is the deal."

FWIW - I always carry 2 long wires approx. 18 gauge with alligator clips on both ends. For a quick temporary check you can just undo the gage attachments and run these 'test' wires back to each others side.

Hope this helps

[Guest]

I would suggest getting a good quality infra red temperature scanner and shoot the area around the temperature gauge senders, both engines. This will tell you if they are the same or not and whether the gauges are reading relatively accurately.

I had a similar problem on our '32, Faria instruments. I replaced the sender that was reading low. It lasted about 10 running hours so I replaced it with a Stewart Warner sender. So far, so good.

BTW. If you replace a sender make sure it is for a dual gauge set up.

[LTCret]

My 2 cents

1-Start with the IR thermometer. Probably the T stat is open

2-I've seen little about temp sender issues on this forum, but that would also be easy to check.

Good Luck

[Guest]

cosmo777 wrote:
Is your water heater plumbed from the port engine?

If you're starting with a cold water heater, it will act as a heat sink and keep your engine temp at 150 deg.

Only once the water heater is up to 150 deg, then both the engine and the water heater will slowly rise together.

Yet any use of hot water while cruising will only delay the engine and water heater temps from rising together past 150.

Shouldn't this be overcome by the thermostat?

[WhiteRockMike]

smitty477 wrote:


FWIW - I always carry 2 long wires approx. 18 gauge with alligator clips on both ends. For a quick temporary check you can just undo the gage attachments and run these 'test' wires back to each others side.

Hope this helps

Great idea! I'm going to make a set of those up.

[capt._ron]

WhiteRockMike wrote:
Great idea! I'm going to make a set of those up.

Radio Shack sells a sells a set that has 4 color coded pairs, they have them in 2 different lengths.

[Guest]

Do the easy things first, skip the first if you want:

1. Check with an IR meter as mentioned above. check the top of the thermostat housing.

2. Swap temp senders.

3. Replace stats, they do go half bad. You can also pull the stats and test them for opening and closing in a pan of water on a stove with a thermometer.