OK folks, I'm finally frustrated. I had a VERY large amount of white smoke (cloud) which smelled strongly of anti-freeze come from the exhaust as soon as we left the marina in the earlier part of the season.(first cruise)...Crept back in at idle, and diagnosed (with supposed weekend mechanics, of which I'm one) that the head gasket had blown......3 weeks to get it!...along with all of the other upper end gaskets, etc.
Replaced the head gasket, checked valves (they look new), installed new seals, gaskets, etc. on intake, exhaust...had a shop check for warpage, and they stated the obvious, it looked almost new and was in good shape (aside from a little outside rust)....Also rebuild the salt water Oberdorfer pump and used the run-dry impeller.... Replaced thermostat...Checked water flow to the heat exchanger, it was good.... Bypassed the through-hull fitting, (to monitor the fact that the raw water pump was working consistently, with a 5 gallon bucket....
Ran the engine for a 15 minute warm-up, then under load (in gear)....and...the water vapor returned, and gradually got worse! ......What the H--- am I looking at?
We did run the boat for an hour initially, to season the head gasket, and re-torqued the bolts...
There has never been any water in the oil...
Temperature is about 180 once it warms up...
Why else would I be getting a vapor trail after doing all of these seemingly obvious repairs?
Have you considered the heat exchanger? Fresh water (coolant) leaking into the raw water before it's passed out through the exhaust?
Craig
Craig;
Yes,... today before the run, I pulled the heat exchanger, replaced the end gaskets and o-rings, new zinc,....I can see clearly through the tubes, they are not obstructed.
Steve
Michael,
Two simple thoughts. Did you verify that the thru hull was not blocked? Sea weed, plastic bags etc. Take your water line off the thru hull and you should see daylight and a lot of water come in. If not use the many recommended methods to clear the thru hull. Dinghy pump pressure or a 1/2" x 8" wooden dowel to poke out the obstruction.
Second, over time the many fittings from thru hull to engine sometimes need tightening and RENEWED teflon tape. Even a small air leak may not show a water leak but can allow air entry and loss of vacuum.
Gary
Steve - I wasn't implying an obstruction, but a leak. You probably need to pressure test the coolant system. I rented a radiator tester from a local rental firm. I then removed the zinc and pressurized the coolant tank. As I suspected, but didn't want to learn, coolant was leaking into the raw water side of the HX.
You may have a crack somewhere else.
Craig
Craig,Gary;
Again, thanks guys....This forum is SO helpful for us dummies!
This heat exchanger was cleaned/checked last year....I did pressurize the engine collant side todaywith dock water to check for leaks, and there were none...Since that side wasn't leaking, I saw no reason to go further......
Also, I'll clarify that this seems only to be when under a load, (in gear at the dock)....and after at least a 5-15 minute run.
Steve
Steve : Contrary to some of the written publications that I've seen, the internal coolant flows thru the tubes in the inside of the HX. The raw water flows around the outside of the internal tubes. Especially look at the tubes near the Zn to see if there might be an internal leak.
If you have a coolant recovery system and the bottle level has remained constant - disregard what I've said !!
BTW : "White exhaust smoke" is usually unburnt fuel that can be caused by excessive fuel or poor combustion. A thought
Thanks Ron;
I think it's time that I stopped being so damn cheap and hire a good mechanic......the season's almost over for us.
Steve
Replaced thermostat, right? What temp. thermostat?
What is your engine operating temperature under load?
Everyone....
Thanks soooo much for your help....
The thermostat was the one reccommmended (160 degree).
When warming up, everything is fine, then as soon as I put it in gear under load, it starts to overheat gradually..... I've always shut down before 180 degree mark.....
Tomorrow, I'm moving the sea water intake to the adjacent 3/4 inch through-hull (new strainer also) because the loss of vacume idea sounds logical.
Here's hoping....If this doesn't work out, I'm bringing in the mechanic!
Steve
Steve : If you have an over heating problem when under load, you have a restriction in your raw water flow.
Start at the thru hull & strainer and work yourself thru the raw water pump to the heat exchanger. Could be something as simple as old broken impeller blade/s in the outlet elbow of the raw water pump ?!
Steve,
White smoke in the exhaust can mean over heating. I know as my raw water intake plugged twice in the last two weeks..temp rose quickly toward 195 degrees and visible white exhaust. As Ron says start by opening the lid on the raw water strainer. When I did it nothing happened. Thats bad, as with the sea cock open there should be water pouring out of the top of the strainer.
But thats also good because it means your problem is likely the blocked raw water inlet. I duck taped my high pressure dingy pump to the hose after removing it from the strainer ( that can be the hardest part). That idea came from Ron or Stu. A few swift pumps and all cleared.
Hope its that simple for you.
Hawk
Dinghy Foot Pump clearing of raw water intake: see Reply #2 here: http://c34.org/bbs/index.php/topic,4635.0.html
No duct tape required... :D
Hawk must frequent the same kelp, algae, and eelgrass infested anchorages that we do. This is a common enough occurrence that we usual notice the change in exhaust color now even before the temperature gauge registers a change.
Along these same lines, our temp gauge consistently climbs up to the 160-162 operating range during warmup, but never runs above 162- even when the white indicator exhaust starts to appear. Is it possible that following an intake blockage we could be getting white vapor in our exhaust while still in the 162 temp range (we always shut down immediately and clear it, rather than wait for the temp gauge to go up) or is it more likely that the temp gauge is malfunctioning? I recall that the first time this happened several years ago, we didn't recognize the significance of the white exhaust until the exhaust sound changed and the temp gauge was reading over 180. Is it possible to test the gauge by putting the sensor in boiling water or something?
Quote from: Peter Lewis on August 15, 2009, 12:57:25 AMIs it possible to test the gauge by putting the sensor in boiling water or something?
The engine manuals are available on our website. http://www.c34.org/manuals/index.htm
Yes, you should be able to do this. See page 23 of the manual, PDF page 3 of the second part of the engine manual, here: http://www.c34.org/manuals/Operators-Manual-2of2.pdf
It shows the location of the temperature sender. Remember that if you take it out to test it, you will need a ground wire, since the sender is grounded right to the engine when it's screwed in.
GOOD MECHANICS ARE ALMOST IMPOSSIBLE TO FIND.
There was a discussion on co.com about this issue, see: http://forums.catalina.sailboatowners.com/showthread.php?t=111166 While some have, I haven't found a mechanic worth a hill of beans.
With this message board, and others, and all of the information now available, it seems that even "weekend warriors" may be able to do a better job than any / most "mechanic" can. This does not include complete engine teardowns and rebuilds (although Dave Sanner has reported on his work in great detail: http://www.c34.org/projects/queimada/m25xp/), but it does apply to the routine maintenance and troubleshooting that is necessary for day-to-day operations and consistent performance. I once had a guy tell me he was so surprised that my engine started every time I tried to start it! His didn't, so I suggested he find out why and fix it!
On another board I wrote this:
As for "professional" help...I must admit I find that phrase an oxymoron when it comes to boats. The ONLY work I ever had done on my boat (other than standing rigging) was by a "qualified" mechanic who took my old riser off and installed the new one in 2003. He didn't put in the specified muffler patch paste on the flange threads, which caused blowby and made me have to remove the riser in 2008 to fix his screwup. He also installed a curved black hose to the muffler, in lieu of the hump hose I spec'd. It wore itself through quickly and I'm glad I checked his work. And replaced the hump hose that was there before he did his work.
Quite frankly, anybody who lets other people work on their boat is nuts because it's a safety issue. The more you learn about your boat, the safer you are.
Having said that, after my skiing accident last January I have developed a new sensitivity to phsycially challenged situations, and am much more 'Understanding' of folks who HAVE to have someone else work on their boats. However, there is no excuse for most of us to NOT do our own work. Anyone can learn how to use tools and take it a step at a time. Boards like this one, which explain HOW to do things, with information that just wasn't available even five or ten years ago, makes wonking out and "having the yard do it" a lame excuse. Most stories I hear are horror stories of shoddy and poorly done work. The backside is YOU do NOT get to know your engine and systems, end up with a big bill, and have to eventually fix it yourself.
We put off buying a big boat with a diesel engine because it was far easier to take our 7.5 HP Merc off our C25 and bring it in for servicing. Boy, I missed many years of more fun sailing on our "new" boat 'cuz of that. I was "a-feared" of diesels in 1998. Now I love my engine, because, being from here in California, "I have become one with my motor!"
Now that my leg is about 60% back to normal, last week I changed the diesel fuel filters, did an oil change and transmission fluid change. I also CAREFULLY INSPECTED my engine and found, GASP, a MAJOR crack in the alternator housing casting. NO, I repeat, NO "boat mechanic" would've caught that puppy, simply because "it ain't his boat!" See: http://c34.org/bbs/index.php/topic,5127.0.html
We have all learned so much from these kind of forums that unless there is a physical disability (believe me, I know) I see no reason to NOT learn how things work.
It makes you and your guests on board SAFER.
It seems that tracing down overheating issues on our engines almost always starts with the raw pwater pump and the continuity of the raw water system, including the heat exchanger. Michael, in your case, at least you got a new head gasket in the process.
Ron's absolutely right about the way the HXs work, the fresh water (anitfreeze coolant) HAS to go through the tubes. Why? Because if it didn't when you replaced the zinc you'd get coolant all over the place instead of saltwater (or lake water). Right?
Anytime you smell coolant, ya have to figure out where they (can) mix and work from there. Sorry you did the head gasket thingie before coming here, but we're pretty sure that it's your HX.
Please keep us posted, and all the best.
Peter : You can test the temperature sender, but it's a lot of screwing around with two 12v + and a 12v -wire tied to the sender and a 12v power source.
You can go to your Kubota dealer and get another sender for about $20. Just make sure that it has the correct size pipe thread and temperature range ! Take the old one out and you're sure to get a correct replacement. A thought
Sorry this took so long to reply to ....
So far this season, we pulled the head, replaced all upper end gaskets and seals. Had a "speed" shop check the head and valves since it was already out of the boat, they were fine. Replaced all of the external hoses except one (we'll get to that later).
Inspected the muffler, (I have access to cameras to do this kind of stuff). Reconfigured the intake from the sea water fitting, from the original 1/2 inch intake to the 3/4 intake for the sink (new strainer), and pulled and cleaned the heat exchanger twice. Replaced the oberdorfer seawater pump thermostat, and the fresh water pump also.
After all of this work, I ran for about 2 hours under load, everything worked well ! Actually it never ran this cool!
Came back to the marina, cleaned up, and returned the following weekend for a quick sail. Only to discover that the ONLY hose on the outside of the engine which I didn't replace, leaked about 4-6 gallons of fuel into the bilge. I probably set the head on it while reinstalling it. Fortunately. the switch is electronic,( Water Witch) and did not turn on, (It would have created an environmental nightmare in our marina).
I'm not comfortable that this could have happened, and am going to install a high water alarm on the boat (with a float switch). Also, a piezo buzzer in parallel with the bilge motor to let me know every time the bilge pump does turn on.
I cant than
Michael : To really check the engine for temperature use a IR thermal gun. Shoot it at the thermostate housing and at each end of the HX. Then you'll know the real temperature.
Also make sure that none of the metallic covering on the engine cover insulation is touching the temp. sender. To make sure that that metallic covering isn't touching the sender, put a "rubber boot" on the wire that connects to the temp sender.
A few thoughts