Steam out the exhaust? 87 mkII Universal MX25XP
- Thread starter jonelli
- Start date
We went thru that last year. Could be several things, but most likely the heat exchanger is beginning to become plugged. You'll begin to see less water coming out the exhaust and the engine temp gauge will start running hotter. Simple fix, we had the exchanger boiled out at a radiator shop. Engine now runs cool and no steam. But as long as your down there start fresh with a new impeller also. One less thing to check in the process of elimination. Check the Catalina 34 site for tons of information on how to's and info.
I kept my eye on the temp guage, and it was pretty consistent.
If I ran it close to 2KRPM, it would sit at about 175 degrees.
If I ran it 1200 RPM it would stay about 160 degrees.
Part of it is that I don't know yet what is normal and I don't have a mechanic yet to talk to.
It wasn't a ton of steam, but it was constant. Water was still coming out too.
If I ran it close to 2KRPM, it would sit at about 175 degrees.
If I ran it 1200 RPM it would stay about 160 degrees.
Part of it is that I don't know yet what is normal and I don't have a mechanic yet to talk to.
It wasn't a ton of steam, but it was constant. Water was still coming out too.
I don't normally see steam coming out of mine. On the few occasions that mine has started to steam and engine temps climb to 180, I shut the engine down and check the intake filter right above the seacock. That gets filled with weeds and restricts the flow. To empty it, first shut off the seacock, unscrew the filter, remove the screen and dump it out, I then like to open the seacock to make sure I'm getting good flow. On a couple of occasions I've had to remove the filter housing, open the seacock and push a piece of wire down and out the bottom of the boat to clear lodged seaweed. It's possible to suck other debris up there as well, like plastic bags.
Also as Fortitude stated, check the impeller while you're down there.
Also as Fortitude stated, check the impeller while you're down there.
Jon,
Your temperature readings look fine. Do you see steam when first starting? If you look at a car when first started, if the ambient outside temperature is on the cold side, you will see steam from the exhaust. I have been on friend's boats in cool weather & have seen some steam when first started.
I liked what Fortitude advised on heat exchanger & impellor check. I had Sen-Dure make a larger H/E for my 3M20A. I believe they made them for Catalina. I can take off the end plates to inspect the tubes & shell, hopefully you can. I believe in ten years, I did this twice to be on the safe side, luckily, it has stayed clean.
If you do see anything in the tubes, you can take it to a radiator shop for cleaning.
CR
Your temperature readings look fine. Do you see steam when first starting? If you look at a car when first started, if the ambient outside temperature is on the cold side, you will see steam from the exhaust. I have been on friend's boats in cool weather & have seen some steam when first started.
I liked what Fortitude advised on heat exchanger & impellor check. I had Sen-Dure make a larger H/E for my 3M20A. I believe they made them for Catalina. I can take off the end plates to inspect the tubes & shell, hopefully you can. I believe in ten years, I did this twice to be on the safe side, luckily, it has stayed clean.
If you do see anything in the tubes, you can take it to a radiator shop for cleaning.
CR
HI: I'm another newbie to the Cat 30. I had hot running until I learned about the 3" heat exchanger. I also had steam. After the change, she runs at 160-165 at any RPM. It was 190 and even more if I pushed it when I first acquired the boat. You can buy the replacement at Catalina Direct, or you can buy direct from the manufacturer (whose name I just forgot, but perhaps someone can fill that in.) It was $300 or so, if my memory is correct. You might as well also do the alternator bracket changeover, and the wiring harness, ammeter elimination if you have an early model 30.
I have not examined anything further, as I don't trust myself to know what I'm doing yet. I will find a mechanic first that i can ask questions and get help from. But I verified yesterday, that there is not any discernible steam at first. After running for about 15 minutes or so, I'll have a little bit of steam. The temp seems to be fairly stable around 160 degrees.
I showed it to another person who I was sailing with, and they thought it could be a normal amount of steam.
I suspect that you all are correct that either intake or heat exchanger needs some looking at, but I also think that it's not urgent, so I'll wait till I find a motor guy before i worry too much about it.
I showed it to another person who I was sailing with, and they thought it could be a normal amount of steam.
I suspect that you all are correct that either intake or heat exchanger needs some looking at, but I also think that it's not urgent, so I'll wait till I find a motor guy before i worry too much about it.
Update:
I had a mechanic come out and check everything. He showed me how to change the impeller which needed changing badly. Then we inspected the heat exchanger and zinc. Zinc was totally gone and the exchanger looked a bit clogged up. Needs to be serviced. But we ran the motor to normal temp and he was okay with it for now. Temp guage runs about 10 deg hotter than actual thermostat and there's enough water flow to keep everything happy.
He recommended that I service it over the winter.
So I'll keep an eye out on temps for now and schedule service in January probably.
Something else baffling though. Whenever I check the oil dipstick, the first time I pull it out, there's almost no oil indicated. Then I stick it back in and pill it back out and it shows full. It's only ever the first time I pull the dipstick.
Any idea why?
I had a mechanic come out and check everything. He showed me how to change the impeller which needed changing badly. Then we inspected the heat exchanger and zinc. Zinc was totally gone and the exchanger looked a bit clogged up. Needs to be serviced. But we ran the motor to normal temp and he was okay with it for now. Temp guage runs about 10 deg hotter than actual thermostat and there's enough water flow to keep everything happy.
He recommended that I service it over the winter.
So I'll keep an eye out on temps for now and schedule service in January probably.
Something else baffling though. Whenever I check the oil dipstick, the first time I pull it out, there's almost no oil indicated. Then I stick it back in and pill it back out and it shows full. It's only ever the first time I pull the dipstick.
Any idea why?
This is completely normal. There is a seal at the top of the dipstick that makes it air tight and doesn't allow the oil to come up into the tube until after you pull it out.
To check the oil you should always pull the stick, wipe it clean and the reinsert it. Then when you pull it the second time you will get the accurate reading.
HX sources:
http://c34.org/bbs/index.php/topic,6920.0.html
M25 series engine info:
http://www.c34.org/wiki/index.php?title=Diesel_Engine
Good luck, you're learning, which is the key.
http://c34.org/bbs/index.php/topic,6920.0.html
M25 series engine info:
http://www.c34.org/wiki/index.php?title=Diesel_Engine
Good luck, you're learning, which is the key.
when the engine is not running the oil eventually settles low in the sump, when the engine is running the oil is circulating so the dipstick will show a higher oil level which is why the method hayden suggested is universal - no pun intended.
You can clean the heat exchanger yourself very cheaply. Get some pool acid (Muratic acid). If you don't have a pool it's $12 @ Home Depot. Get two buckets and some kitchen gloves. I didn't have any and used long Bar-B-Q tongs. Take it out of the boat, take end caps off. Fill one bucket with water as a safety measure,hold the exchanger on end in the empty bucket and gently pour the acid into the exchanger. It took less than half a gallon for mine. Turn the exchanger over and pour from other side. Pour slowly allow it it sit for a few minutes. The acid won't eat metal but will the salts in the exchanger. It will eat concrete too so don't spill it on your driveway. To dispose of it turn on the faucet full and pour it down the drain. It will clean it out too, or pour it into your pool. Rinse the exchanger with a hose reassemble, reinstall and you're done. Add paint if it needs some.
UPDATE again...
So I was getting ready for an island trip yesterday and motored to the gas dock. I noticed on the way almost no water coming out and the temp getting too hot way too fast.
Long story short, spent about 4 hours trying different things and finally found the clog at the impeller housing exit elbow. Must have been almost flogged already and after changing the impeller, got some more loose crud the we cleaned fr the housing stuck in there.
There's now 10 times more water flow coming out the exhaust then ever before, no more steam, and temp stays right on 160.
Leave it to say that I now know every hose around the engine.
So I was getting ready for an island trip yesterday and motored to the gas dock. I noticed on the way almost no water coming out and the temp getting too hot way too fast.
Long story short, spent about 4 hours trying different things and finally found the clog at the impeller housing exit elbow. Must have been almost flogged already and after changing the impeller, got some more loose crud the we cleaned fr the housing stuck in there.
There's now 10 times more water flow coming out the exhaust then ever before, no more steam, and temp stays right on 160.
Leave it to say that I now know every hose around the engine.
I think I'll just pay the $30-50 for the radiator guys to make it nice.
So far we motor-sailed the 27 miles on Friday morning and I found that I could run up to 2300 RPM and the motor would stay cool. 160-170.
But at 2500+ it would get a little higher so we stayed with 2300.
I think this is normal.
So far we motor-sailed the 27 miles on Friday morning and I found that I could run up to 2300 RPM and the motor would stay cool. 160-170.
But at 2500+ it would get a little higher so we stayed with 2300.
I think this is normal.
My mechanic, who has three of M25XPs in his garage, says don't run it over 185 to keep from blowing a head gasket. My heat exchanger looked clean, but when I took off the hoses I found the salt water exit port was plugged except a small pin hole. Wondered how it stayed so cool with that small amount of water flow. Cleaned it out, see above post, and it now stays below the 180 mark at full throttle now.
Did you see a significant change in water coming out the exhaust? Did you have any steam before? How high RPM and for how long can you run it and still stay below 180?
I should probably check my exit port/hose too. I haven't done that yet.
I have lots of water coming out now, but still a small amount of steam when it's running 165.
I should probably check my exit port/hose too. I haven't done that yet.
I have lots of water coming out now, but still a small amount of steam when it's running 165.
Yes I always had some steam but water too. I could run it at around 2k RPM all day and it would stay at 165. But I was only doing 5.5 kts too. Full throttle for just under 5 min and I was at 185. A throttle back to below 2000 it would cool down in 3 min. After I cleaned it at 2500 I still get some steam but lots of water. But I get 6.5 knots and my exhaust is below the water so it is hard to tell steam from diesel smoke. I have the two blade prop too. At 2800 it will heat up to 180 but I can run it all day and it doesn't overheat. I can get 7 kts but I got better milage at 2200. (.5 gal/hr). I have the 2" heat exchanger. The 3" would be better but don't have the money now.