Caterpillar Running Temp issues

Graham Lorimer

Graham Lorimer

Member
Feb 13, 2009
436
Boat in Sant Carles, Spain. I live in Cheltenham,
Boat Info
Sundancer 460 2002
Volvo 480 HP
Raymarine Electronics
Avon 320DL RIB
Yamaha 25HP 4 Stroke
Engines
Volvo 74 TAMD EDC
My 400 1997 Sundancer running 3116 TA Caterpillars, has for the last two years run at 180 degrees when run at full cruise speed of 2200.

Yesterday when out, at 1150 rpm's (my usual cruise speed), temperatures were just below 180, quite normal. When raising the speed to 2200 rpm, the port engine ran at 180 but the starboard ran at about 187 degrees. After ten minutes at that speed, as I dropped back to 1150, the temps both ran at the same at 180.

Should I worry about this, is it a sign of a problem starting to show up?

The raw water filters are clean and the flow seems normal out the exhaust. Water coolant levels are correct when I checked again this morning.

Thanks for any advice

Graham
 
Your engines should have 195 degree thermostats in them, not 180's.

Engine temps that rise with power or rpms usually indicates a lack of heat transfer in the heat exchanger. That can happen with a reduction of cooling water flow......sea water pump impeller needs replacement, grass in the inlet side of the transmission oil cooler or a plugged up heat exchanger. It can also be caused by the coolant side of the heat exchanger being coated with antifreeze silicate from old or non-Cat antifreeze.

Your boat is old enough to need the heat exchangers to be removed and cleaned and if the seawater pumps have not had new impellers in the last 2 years/200 hours, you should consider that as well.

Keep an eye on the temperatures, if your heat exchangers are blocked, this is a problem that will get worse, pretty quickly. These engines.....and diesels in general.....do not tolerate being overheated well. What ever you do, don't let the temps get over about 205 degrees.
 
Thanks for the quick replies......... Frank, are you suggesting that I should be running at 195 degrees normally, if so and a thermostat change is needed, it worries me why the wrong ones have been fitted. Could this have been to correct a problem that was starting three years and 350 hours ago?

I did spend 200 engine hours last summer travelling down the French Canal system at a maximum of 700 RPM.

Thanks guys

Graham
 
Yes. All I know is that Caterpillar determined that the 3116 is a very clean burning and efficient engine if the operating temperature is at 195 degrees. Mine consistantly run 190-195 and my engines deliver slightly more efficient fuel burn numbers that spec.

I have no clue as to why your engines might have 180 degree thermostats in them.
 
FWIW: Both a 180* and a 190* coolant temperature regulator are available for the 3116. As the Frank is pointing out above, the hotter of the two is the preferred. Reason being; for reduction in white smoke emissions and crankcase condensation. This will extend your engine life for sure.

As far as that little temperature spike: I suppose if your normal operating temp was 195* (5* above rated regulator temp) you would have never noticed until your existing problem develops further. At this point who knows what regulators are in your engines or how accurate your instrumentation is. The fact that the starboard temp creeps up with higher load demand, to me is a indicator of something below the surface.

Not knowing your boats maintenance history...I would suggest to you (both engines); that you have your heat exchangers bundles rodded out or replaced (pending how deep your pockets are). Coolant replaced with new. Coolant regulators replaced with 190's. Zincs checked/replaced and sea water pump maintenance brought up to date.
 
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A question for you:

I've been watching this discussion on thermostats with some interest despite having a different pair of motors. My Cummins 6CTA (450) run 160 degree stats. Many of the Cummins owners on BoatDiesel use the 180 degree stats. When I went down to my local Cummins store to change to the 180 ones, the mechanic was there and told me to stay with the 160 stats because in his opinion the factory knows best.

Seems like quite a difference in operating temperature between 3116 and 6CTA.

James
 
You can't make that decision based on thermostat ratings alone. You have to consider the entire cooling system. Caterpillar significantly over specifies cooling capacity on its engines...meaning you can suck up some grass without it affecting your cooling systems ability to transfer adequate heat away from the coolant. Cummins on the other hand tend to specify the minimum acceptable capacity. The Cummins boats around here are a lot less tolerant of any cooling obstruction at all. Many Cat boats go 10 years before heat exchangers need cleaning;most Cummins boats need heat exchanger maintenance by the 4th year.

My view would be to do what Cummins says instead of what you read on some boating forum.......including this one.
 
Thanks again for the advice.

Can someone give me an indication of the hours needed to strip and clean heat exchangers and change raw water impellers on two engines, bearing in mind it is a 400 Sundancer, and room is limited.

I have modified the engine lift so that it can be removed allowing better than normal access. Does the water header tank need removing on both engines in order to get the heat exchangers off?

Secondly, I have noticed some "dry rust residue" under the raw water pump on the Port engine, have never seen it "wet" indicating a leak, just dark brown dust. This engine is running at a normal temperature.

I have asked the local Spainish Cat agents for a price estimate, but always nice to have other experienced opinions of the likely cost involved.

Thanks

Graham
 
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Graham,
Its great to ask questions here, but one should really get familiar with their CAT engine manual. It outlines the service intervals.
 
Dave

Unfortunately I do not have a Service Manual for the engines, and the boat came to me nearly three years ago with virtually no service records at all.

Once I had bought the boat, (and not before) Pantropic in Florida gave me a print out of what was done over the preceeding years, however whenever they worked on the boat, they only entered one engine number into their records for each job call out, and they then did the work on either engine, very strange sytem because it is impossible to tell exactly what has been done to each separate engine, quite a lot of guesswork is involved.

Over the last two years, I have been able to start compiling a service record for the boat, and hope to build on that as time goes on.

I do intend to get hold of a manual sooner rather than later, but no so easy or inexpensive in the UK.

Graham
 
Page-01.jpg
 
Impeller change-outs are somewhat subjective.
The parts are cheap, so if access is easy, change them annually.
On my 3208's, the port impeller requires two mechanics (one of them a skinny guy) to unbolt the pump and remove it in order to change the impeller.
After two years, they still looked brand new, barely a crack in the rubber.

I go with two years barring any symptoms (overheat) that would indicate a possible problem.
 
tobnpr said:
Impeller change-outs are somewhat subjective.
The parts are cheap, so if access is easy, change them annually.
On my 3208's, the port impeller requires two mechanics (one of them a skinny guy) to unbolt the pump and remove it in order to change the impeller.
After two years, they still looked brand new, barely a crack in the rubber.

I go with two years barring any symptoms (overheat) that would indicate a possible problem.
Click to expand...

This is what mine looked like after about 200 hours.

87383dd1.jpg
 
This is what my gunked up aftercooler did after a hard run. Didn't notice any performance problems, I only noticed it when I went to change a zinc on the exhaust elbow. Notice how the turbo got so hot that it discolored the paint. I'm glad I saw this before my big trip

e5540ff1.jpg
 
I had a mechanic take it off and they gave it a sonic bath... After I called frank in a panic.
 
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Graham: To bid that job from afar is a wag to say the least. I think your looking at the Tech pulling the heat exchangers and working on them back at the shop. Most likely 4-6 hrs per engine with sea water pumps. Now add all that goes with working on a boat for a customer and a post test. You could easily spend two service calls and two days labor.

BTW:
Every 60 000 L (16 000 US gal) of Fuel or 2000 Service Hours
Heat Exchanger - Inspect


Every 91 000 L (24 000 US gal) of Fuel or 3000 Service Hours or 2 Years
Cooling System Water Temperature Regulator - Replace
 
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It is extremely comforting to know FrankW is but a phone call away! Frank, We 450 guys really do appreciate your kindness! JC
Turtle, Did you take more before and after pictures? JC
 
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