I have been experiencing white smoke and for the first time in 3 years slight overheating. I have an 89 cat 30 with a Universal M25XP with around 850 hours (salt water). I have been running at 160 degrees and twice this year without any reason I have been hitting 175 degrees. The raw water strainer is not clogged. I overhauled the entire cooling system over the winter, including: boiling out the heat exchanger and pressure testing, new thermostat, new raw water pump and every cooling hose was replaced. My reward for all of this preventive maintenance is occasional borderline overheats. The white smoke is another issue, I believe the problem is in the mixing elbow. Has anyone changed the exhaust elbow riser to the nre Westerbeke part number 200266? Also, does anyone know the internal diameter of the inlet on the original waterlift muffler that came with a 89 Cat 30.The Westerbeke outlet is 2" and I plan on changing the muffler over the winter, if I can get the old parts to match up it may salvage my short sailing season. I had a sailing vacation planned, however without a dependable engine the wife does not want to take a chance. Actually I can't blame her. Around half of the people I spoke with think I could get away with the current condition, others do not think it is worth taking a chance.
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J
John
165o not so bad
My M25xp is runing a little hot and i think its becouse the lake water has warmed up to 75o and its been in the 90s if i run at 2200rpms i stay around 165o My mixing elbow cracked becouse it was not lined up with the muffler.The part looked new after 17 years it was cast iron welded to black pipe nipples so we welded it with nickle and proof tested it in a vice with arm power.I was blowing white smoke becouse the water tube was pushed in and the cooling water was runing down one side of the pipe and was not cooling the exhost gas. The white smoke is steam there could be a small peace of stuff in the mixing tube or if you dident lube your new impeler it mite burn up before water hit it.There should be good water comeing out of the rear tube at 1000 rpms I think you could get a nice stainless pipe from a muffler shop and weld stainless steam fittings on that would line up with all the old parts on the moter. The muffler shops make all kinds of funny pipes for turbo cars and they can weld it two Ive never tryed this but i will next time. John
My M25xp is runing a little hot and i think its becouse the lake water has warmed up to 75o and its been in the 90s if i run at 2200rpms i stay around 165o My mixing elbow cracked becouse it was not lined up with the muffler.The part looked new after 17 years it was cast iron welded to black pipe nipples so we welded it with nickle and proof tested it in a vice with arm power.I was blowing white smoke becouse the water tube was pushed in and the cooling water was runing down one side of the pipe and was not cooling the exhost gas. The white smoke is steam there could be a small peace of stuff in the mixing tube or if you dident lube your new impeler it mite burn up before water hit it.There should be good water comeing out of the rear tube at 1000 rpms I think you could get a nice stainless pipe from a muffler shop and weld stainless steam fittings on that would line up with all the old parts on the moter. The muffler shops make all kinds of funny pipes for turbo cars and they can weld it two Ive never tryed this but i will next time. John
W
Will
Sounds like to your on the right track
Warren John sounds like your on it. The most common place for this to start is at the through hull especially if it has a screen.Though dont you east coast folk haul you boats for the winter ? meaning that got checked. Do Well Will.
Warren John sounds like your on it. The most common place for this to start is at the through hull especially if it has a screen.Though dont you east coast folk haul you boats for the winter ? meaning that got checked. Do Well Will.
D
Don Guillette
White smoke
Warren: That white smoke is actually partially steam. I had the same problem with my 25XP and I did everything you did with one exception - I did not go far enough in the system. My boat did not have the black pipe exhaust setup which Catalina slaps on boats to save a few bucks. What I had was the original Universal setup, which consisted of an exhaust riser (I can send you a picture of it) that connects to the exhaust manifold. The obstruction was at the elbow of exhaust riser where the heat exchanger hose comes in. I never bothered going past the heat exchanger. I decided to replace the riser because I felt it was probably loaded with junk and a new one was only about $150. Everytime you waste an impellor that is where all the piece you can't find end up. When I took the old one off I found that it weighed more than the new one!! I did have an awful time mating up the new riser to the old hoses. It took a couple of trips to a marine store to get the parts I needed. The connectors are simple but there is not a lot of room to work with so I had to be creative. Once I completed the job, the temp was back to about 165, which actually is a little cold for that engine but I'd rather err on the side of cold than hot. When it starts to get up to 185 I start to get concerned. If you want a picture of the setup send me your email at yankee3223@juno.com
Warren: That white smoke is actually partially steam. I had the same problem with my 25XP and I did everything you did with one exception - I did not go far enough in the system. My boat did not have the black pipe exhaust setup which Catalina slaps on boats to save a few bucks. What I had was the original Universal setup, which consisted of an exhaust riser (I can send you a picture of it) that connects to the exhaust manifold. The obstruction was at the elbow of exhaust riser where the heat exchanger hose comes in. I never bothered going past the heat exchanger. I decided to replace the riser because I felt it was probably loaded with junk and a new one was only about $150. Everytime you waste an impellor that is where all the piece you can't find end up. When I took the old one off I found that it weighed more than the new one!! I did have an awful time mating up the new riser to the old hoses. It took a couple of trips to a marine store to get the parts I needed. The connectors are simple but there is not a lot of room to work with so I had to be creative. Once I completed the job, the temp was back to about 165, which actually is a little cold for that engine but I'd rather err on the side of cold than hot. When it starts to get up to 185 I start to get concerned. If you want a picture of the setup send me your email at yankee3223@juno.com
B
Bill
maybe it's your gauge and not the engine
Have you verified your engine temp gauge is correct and not inaccurate/sporadically acting-up? Might there be corrosion on the temp sensor wire or other wires behind the engine panel, or at the sensor, or either of the two rubber plugs/terminal strips? Remember the gauge gets its power at the panel so if the gauge's power or sensor wires are loose or have corrosion, it might explain the 'sudden' temp increase. I recently heard of a 1985 cat 30 with a broken brown wire at the sensor which was thought to be a dead gauge. Just last week I was checking my engine for a slight increase in temp (10 degrees) over the past 2-3 years. Found out the gauge was reading 10-15 degrees hotter than the radiator temp gauge I placed in the engine's anti-freeze within the 'radiator' (where radiator cap goes). That sent me off looking for why the difference. After noticing corrosion on the terminal strip behind the cockpit panel, I cleaned the wires and replaced the terminal strip and then noticed a slight decrease in the gauge (3-5 degrees). I now am considering replacement of the temp sensor and the gauge to get a more accurate reading (noticed teleflex instruments only have a 2 year warranty, so since mine is over 17 years old, figure it might be time). regarding the 'white smoke', does it dissipate like steam (instead of leaving a yellowish/white color -- i.e. burning oil)? Does it happened when the temp spikes? Assuming it is steam, how is the quantity of water coming out of the exhaust, does it suddenly seem reduced too? Does it happen when you are on a starboard tack (port rail in the water)? If the answers are 'yes', then my guess is the water quantity from your raw water cooling/pump is being reduced due to some air getting into the pump's suction side. Are the hoses the correct size to the hose barbs and are all the clamps very tight? Might the strainer cap/cover have a crack in it that doesn't leak but does allow air to be sucked in? Did you use wire reinforced hose which will not collapse due to suction, from the strainer to the pump? Also, regarding the mixing elbow/exhaust pipe. My 88 M25XP also runs in salt water all it's life. I pulled the raw water hose off to inspect and the pipe looked like new (assuming it was stainless -- had heard Catalina changed to stainless) and there was NO corrosion or salt build-up inside it. Hope this helps..
Have you verified your engine temp gauge is correct and not inaccurate/sporadically acting-up? Might there be corrosion on the temp sensor wire or other wires behind the engine panel, or at the sensor, or either of the two rubber plugs/terminal strips? Remember the gauge gets its power at the panel so if the gauge's power or sensor wires are loose or have corrosion, it might explain the 'sudden' temp increase. I recently heard of a 1985 cat 30 with a broken brown wire at the sensor which was thought to be a dead gauge. Just last week I was checking my engine for a slight increase in temp (10 degrees) over the past 2-3 years. Found out the gauge was reading 10-15 degrees hotter than the radiator temp gauge I placed in the engine's anti-freeze within the 'radiator' (where radiator cap goes). That sent me off looking for why the difference. After noticing corrosion on the terminal strip behind the cockpit panel, I cleaned the wires and replaced the terminal strip and then noticed a slight decrease in the gauge (3-5 degrees). I now am considering replacement of the temp sensor and the gauge to get a more accurate reading (noticed teleflex instruments only have a 2 year warranty, so since mine is over 17 years old, figure it might be time). regarding the 'white smoke', does it dissipate like steam (instead of leaving a yellowish/white color -- i.e. burning oil)? Does it happened when the temp spikes? Assuming it is steam, how is the quantity of water coming out of the exhaust, does it suddenly seem reduced too? Does it happen when you are on a starboard tack (port rail in the water)? If the answers are 'yes', then my guess is the water quantity from your raw water cooling/pump is being reduced due to some air getting into the pump's suction side. Are the hoses the correct size to the hose barbs and are all the clamps very tight? Might the strainer cap/cover have a crack in it that doesn't leak but does allow air to be sucked in? Did you use wire reinforced hose which will not collapse due to suction, from the strainer to the pump? Also, regarding the mixing elbow/exhaust pipe. My 88 M25XP also runs in salt water all it's life. I pulled the raw water hose off to inspect and the pipe looked like new (assuming it was stainless -- had heard Catalina changed to stainless) and there was NO corrosion or salt build-up inside it. Hope this helps..
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