3126 running temp

steveinak

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Buddy of mine had a similar problem, it turned out when he turned on the gauge lights the temp gauge would go up 10 degrees ???
Have you cleaned out the aftercooler and turbo lately ? Clean bottom? I had a pyrometer on my old boat and when it started to grow grass and slime up on the bottom the pyro would go up 10-15 degrees. The old boat had a 41 volvo in it and when the raw water pump was worn/bad impellor the temp would climb. Maybe you have some broken off impellor pieces blocking the raw water flow ??
 

joelucci33

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Buddy of mine had a similar problem, it turned out when he turned on the gauge lights the temp gauge would go up 10 degrees ???
Have you cleaned out the aftercooler and turbo lately ? Clean bottom? I had a pyrometer on my old boat and when it started to grow grass and slime up on the bottom the pyro would go up 10-15 degrees. The old boat had a 41 volvo in it and when the raw water pump was worn/bad impellor the temp would climb. Maybe you have some broken off impellor pieces blocking the raw water flow ??

Steve,

Brandy new Impeler...Brandy new CAT turbo...after cooler cleaned boiled etc..

I havent jumped in the water to check the strainer yet...but Im getting awesome water pressure..50 PSI under load.
 

traditions

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have you had any old impellers chewed up in the past?Those pieces of the impeller usually go some where and stay,as do old zincs.I would want to check with a mechenical gauge first,could be a sending unit,of faulty gauge.I had one that when you tapped on it,it would drop 10 degrees
 

steveinak

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Steve,

Brandy new Impeler...Brandy new CAT turbo...after cooler cleaned boiled etc..

I havent jumped in the water to check the strainer yet...but Im getting awesome water pressure..50 PSI under load.

You have a gauge for water pressure ?
 

Blitzen

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Has your heat exchanger been cleaned? It may look clean but a film of zinc and calcium will decrease the efficiency of the cooler enough to raise your temps. I had this problem on my 300hp 3116. Cleaned the cooler, new thermostat and it was running 195 all day long.
 

Blitzen

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Also what coolant are you using and are you sure it is at the proper dilution if not using ELC from Cat?
 

Nighthawk

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It's always good to know the real temperature versus indicated by a voltmeter at the dash. Once you determine that you really are above spec then I would follow Blitzen's advice and clean coolers. A Rydlyme flush for example will most definately drop your temps back if any coolers are coated with highly insullating mineral scale. It has amazed me several times that a seemingly clean cooler can become much more efficient with a descaler treatment like Rydlyme, Barnacle Buster etc. Punching out a cooler is fine for shell pieces and general debris but it's the coating that you can't really see that typically causes the problem.
 

captainlarry84

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I think the key is to run the boat at WOT. If the temps creep up then the heat exchanger is not doing it job and it needs to be clean. I just did my 370 Yanmar with a reverse flush. Rydlyme. It was quick & easy to do. The results were amazing… plus no dismantling of motor parts.
I always run my boat @ WOT and the beginning & end of every trip. That is how I picked up on the thermal creeping of the motor. After the cleaning WOT and the temp stays @ 180 degrees with zero gauge movement. I also did remove the exchange end cap and found some broken zincs.

kristen 045.jpg
 

pointblank1

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I have 3126 with 385HP. My temp creep was due to dirty/barnacled up Heat exchanger. Muriatic acid flush several times in a 5 gal bucket works great.

I also have a alternate set of mechanical gauges that are more reliable than electrical.
 

joelucci33

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So quick run down for everyone..

3 weeks ago headed out..about 1 mile from the destination notice waterpressure guage jumping up and down...being cautious turn her around head back in...(we were due for an oil change and a good cleaning so we figured good day to get that done and investigate the issue)

Half way in..engine quits..steam out the exhaust.."ohh Fuck" common phrase used about that time!...take a looksey...water coming out the dip stick tube...close the Seacock...Call Towboat.

Get it in..do some research...either a failer after cooler or the seal around the shaft for the water pump...Removed both units. Seal was on the water pump shaft was toast. brought the after cooler down to thermoflo in watertown...had it cleaned tested etc...checked out perfect. Replaced the seal on the water pump..put her all back together...few oil changes to flush out the system...she was eatin up oil...called around ask some questions..."check your turbo..might have seen some damage when that seal let the water into the oil system"...yanked the turbo off...what a bitch!..yup turbos toast...Get a brandy new on from CAT..slap it back in...fresh oil..fire it up...Honestly runs great sounds great...bruning no oil at all.

Take her out for a run...idling up river..steady temp of 175...get past the no wakes put her under a load...I run it at 2500 for cruising...temp climbs to about 208...Just under the 210 mark on my gauge. Holds steady at 208....brought it up to 2600...still holding steady at 208.

I run all the CAT recommended fluids...Cat 30W SAEO...CAT ELC...We are anal about maintenance on the boat..

So thats were we stand now..
 

WoundUpMarine

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Rearmount

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Come to think of it, I ran a boat that had triple 3406's in her. Because of new design / regulations, the run temp was supposed to be over 200 degrees.
 

reelsportfishing

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50lbs seems like alot of pressure for a raw water system that is an open loop . I would start pulling apart your raw water system starting right after the pump discharge. You may have chunks of old impeller, zincs or weed. You may have lost your sea strainer screen on the outside of the hull. It happened to me before. The whole raw water side was plugged with seaweed. If there is a blockage the first place to look would be your first cooler after the pump discharge. On mine it was the gear/fuel cooler. Good luck. Good exercise in learning your new engine.
 

GLA

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my 3176 shows 201 on the electric dash read out.

there is a plug in temp guage on the block that reads 193 to 195

so I believe there is a problem with the electric gauge, maybe you have the same problem.
 
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