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Overheating issues

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carverjeff

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I've tried everything but unable to resolve an overheating issue with my Crusaders. Over 2800 RPM, the temp goes from 180 to 200+ and shuts down. I've replaced many parts but still no luck. Does anyone know a good Crusader mechanic I can pay to consult with me?
Thanks, Jeff.
 
wanna elaborate on "...tried everything..."?

where is the boat located?

which engines do you have?

how many hours on them?

RWC or FWC?

Do you have any service history?
 
Thanks for reaching out. Here's what's been done... Impellers, sea strainers, heat exchangers (new), risers, thermostats, raw water pump, clean water pumps, coolant. That's all I can think of... boat is in SoCal, salt water. I'm willing to pay for consulting from Crusader knowledgeable mechanics. Crusader 454's, 35' Carver
 
Follow up info.
I wasn't sure if this forum was active.
Here's what's been done... Impellers, sea strainers, heat exchangers (new), risers, thermostats, raw water pump, clean water pumps, coolant. That's all I can think of... boat is in SoCal, salt water. It runs well at the dock, but under a load at 2800+ it goes from 180 to about 210 and shuts down. Someone mentioned timing or Risers put in wrong. I believe it's a fuel injected so shouldn't we be able to connect a computer and read some error codes?? I'm obviously not the mechanic.

I'm willing to pay for consulting from Crusader knowledgeable mechanics to see if you can help my mechanic solve the issue. Crusader 454's, 35' Carver
 
Have you confirmed overheat with thermo gun ?
Could be erroneous sensors with auto shut down ......running up to the helm temp gauges .
 
willow said:
Have you confirmed overheat with thermo gun ?
Could be erroneous sensors with auto shut down ......running up to the helm temp gauges .
Click to expand...
I know my mechanic uses a heat gun, but not sure if we are fully synchronized when it shuts down. I'll have to discuss and maybe try again. I think it's something other than just water flow...gauges, sensors, etc., so thank you Don for thinking outside the box.
 
any maintenance done before the problem occurred? a lean running engine is very hard to cool, especially under load...

how long have you had the boat?

if the bottom clean with the thru hull scoops open?

If the engines are fuel injected, you can scan the ECU but that rarely tells you what the root cause is. the detail also varies by ECU version.

When you say "risers" are you referring to the exhaust elbows or the exhaust risers?
 
Was this issue ever solved? I'm having the identical problem with my port side 454/7.4 TBi. Somewhere between 2500 and 3000 temp will climb to 200+. I pull back throttle to idle to get immediate drop in temp and return to 2000/2300. Have done all the same diagnostics as you have. Had a couple of codes show up on ECM that indicated a timing issue that we corrected. Saw some improvement that will allow me to run constantly at hull speed at 2200. Pressure tested FWC system - OK, Checked raw water pump - OK, Inspected elbows and risers - OK Inspected/tested heat exchanger - OK, Removed thermostat - took longer to come up to temp but still overheated above 3000. Replaced with New T-stat - No change. What have I missed:
 
So you know about the oil coolers - that good.

My guess is an air leak on the raw water side...strainer gaskets/cap not being tight are viable sources. you can use a piece of clear hose at the inlet of the oil cooler's raw water passge to see if the water is clear (solid stream) or aerated (bubbles)...

how many hours on the engines?
 
Last edited:
makomark said:
So you know about the oil coolers - that good.

My guess is an air leak on the raw water side...strainer gaskets/cap not being tight are viable sources. you can use a piece of clear hose at the inlet of the oil cooler's raw water passge to see if the water is clear (solid stream) or aerated (bubbles)...

how many hours on the engines?
Click to expand...
Thank you! We had bubbles in strainer and opened it up, cleaned and sealed and still overheats.
 
so solid stream of water going to the raw water pump...

Based on the data you have offerred, I'd say the problem is on the raw water side...

I'd be inclined to check the raw water output to make sure the pump isn't aerating the water. You said you checked the raw water pump - can you provide details on what was done/checked? same for risers & elbows. How old are the risers/elbows?
 
Steady stream of water coming through intake and strainer, no air. Elbows and risers were new in 2023. Will have to talk to mechanic about what he actually did to strainers. I know he replaced gasket.
 
many owners learn to change the impellers after their first overheat experience...that usually works for a few cycles...there are other wear items that need to be replaced in the water pumps. The frequency for those additional parts is driven by the operating environment the boat exists in. Infrequent use can limit the impeller's service life...operating in silt or sand laden water can cause a good bit of wear in a short period of time..

Would also be prudent to measure the raw water pump's output...usual process is to pull the output hose with the engine running at a fixed value and divert the stream into a bucket for 15 or 30 seconds and then to measure that volume of water. Eyeballing the product volume usually is far from accurate.
 
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