overheating engine

[imported_ricardo]

if my evinrude 235 engine overheated due to a sand bank tha i took wile cruising and did not realized what was happening till i started to hear a sound coming from the engine and i looked to the temp gauge and the niddle was at the highest temp then imediately the engine stoped and started geting out from the engine smoke smelling like melted plastic or something , beside the water pump and impelets could something else may have goten affected by the overheating ? if yes what may have damaged? i cranked the engine about 20 minutes after it sounded ok but the engine did not start o::^

 

[Kajun37]

Re: overheating engine

i wouldnt try to start that motor until i pulled the heads and lower unit off it.....before you do anything do a compression check on it .... check out this thread to see what came out of my motor after hitting a sand bar.

http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=28;gtid=1231934

 

[F_R]

Re: overheating engine

You should fully expect that powerhead to be toast. Anything less would be a bonus. It overheated to the point of siezure, which is death on the pistons. If nothing else, the head gaskets and exhaust gaskets will all be burned and must be replaced.

 

[Ralphy]

Re: overheating engine

Does not sound like the engine is siezed "cranked the engine about 20 minutes after it sounded ok" so it cranks but will not start. I agree with start with comp test and pull heads. If it got hot enough may have melted some wiring, plastic components and/or other electronics. Don,t try to start it until you check all potential damage and definitely clear the debris that may be left in your LU.

 

[imported_ricardo]

Re: overheating engine

today i did not go to work so i stayed home dealing with the lower unit andtaking out the cylinder heads to check if the water passages had sand in them to my surprise the impeler was intact there was no sand obstruction on the cyl heads but when i opened the thermostats both were melted and the port side thermostat the pasage ways were obstructed im wondering wat hapened that the engine got so hot because there were no visible sand obstructions , could have been all about the thermostats ? what else could have been here are some pictures i took what you think ?

 

[imported_ricardo]

Re: overheating engine

today i did not go to work so i stayed home dealing with the lower unit andtaking out the cylinder heads to check if the water passages had sand in them to my surprise the impeler was intact there was no sand obstruction on the cyl heads but when i opened the thermostats both were melted and the port side thermostat the pasage ways were obstructed im wondering wat hapened that the engine got so hot because there were no visible sand obstructions , could have been all about the thermostats ? what else could have been here are some pictures i took what you think ?

 

[Joe Reeves]

Re: overheating engine

While you have the cylinder heads off........

(Water Deflectors)
(J. Reeves)

Water deflectors are actually lengths of 3/8" outside diameter rubber hose, installed between the top cylinder and any cylinder beneath it, and also between the bottom cylinder and the block. The purpose of the deflectors is to have the water follow a deffinite path around the cylinder walls. Unfortunately the deflectors between the cylinders will at times swell sideways due to either a previous bad overheating problem, or simply due to age and salt corrosion. This causes a water flow restriction which usually allows the water to cool sufficently at low rpms but not at the higher rpms.

This hose material can be purchased reasonably at any automotive parts type store if you care to make your own, or you can purchase individual deflectors at any Evinrude/Johnson dealership at a somewhat higher cost.

Removing and installing them can be a hassle at times, but not always. I use a sharply pointed scribe with about 1/4" of the tip bent at a right angle whereas I can reach in, jab the tip sideways into the rubber, then yank it out. It's necessary to clean the seating surfaces where the ruber contacts the block with a small rat tail file to eliminate salt deposits etc. When installing the new rubber deflector, coat the deflector and the metal surfaces with WD40 which will act as lubrication to allow it to go in as easily as possible.

Make sure that you insert something into that deflector area before cutting and installing the deflectors if you make your own so that you will be certain that they are the right length and also that they will be seated properly. Usually a very small amount will be left extending about the block sealing area..... simply cut the excess off with a single edge razor blade.

Now.... With the heads and the lower unit still off, scrape out and with pressurized air, blow out every water passage you can get at.

Install a complete new water pump, not just an impeller. Also, install new thermostats, water bypass valves and their associated diaphrams. Use sealer on the edges of the diaphrams.

After you have the sealing surfaces of the block and cylinder heads cleaned thoroughly, and are in the process of installing the heads. Be sure to torque those head bolts properly to 18 to 20 foot pounds in the sequence as follows.

13....14
.9.....10
.5.......6
.1.......2
.4.......3
.8.......7
12....11

Check and tighten every bolt on that powerhead as the heat has loosened all of them.

 

[imported_ricardo]

Re: overheating engine

ive cheked everything , i eaven used an air compresor tu clean the water bypasses and nothing came out the only weard and damaged area i saw was both thermostats melted and water ways at thermostat clogged , can the water pump be damaged eaven if the impeller looks ok?

 

[emdsapmgr]

Re: overheating engine

What material/debris was clogging the water ways? Impeller must get replaced and it's housing. The pump ran without water long enough to cook the engine, so reuse of the pump is a big, unnecessary gamble. You did not mention hearing the hot horn warning you of the overheat-something that should also get fixed at this time. If you ran over a plastic bag, it could obstruct the cooling pickpups in the lower unit, causing the problem you mention. Once the bag falls off, you are left wondering what happened to cause all the damage.

 

[imported_ricardo]

Re: overheating engine

the thermostat water ways were clogged by a white hard sediment i cleaned the water ways and used presurised air to clean the water ways i took some photos but i dont know what happens that i cant attach them so you can se the debry anyway ill try again

 

[Silvertip]

Re: overheating engine

Your photos need to be "hosted" on a site like Photobucket.com. You upload your pictures there and then copy and past the link here in your message. I echo what Joe said. Replace the engire water pump. It is essential, especially since you already have the unit apart. Your warning horn is not working and had it been, you would have known about the problem immediately thus preventing any engine damage you may not have found yet.

 

[imported_ricardo]

Re: overheating engine

thats right hey silvertip this is my first time with a boat and i do not know mucho, where is my warning horn ? is it a sensor? and if you know or someone knows where is suposed to be llocated?

 

[Silvertip]

Re: overheating engine

If the ignition key switch is on the console, the warning horn is probably located under the console. If you have a side mount control (throttle shift control) the horn is inside the control box. The overheat sensor can be located on the engine cylinder head. It has a tan wire coming from it. In normal operation, when you turn the key to RUN (not START), the horn short give one short beep. That tells you the system is working. If you don't hear that beep, disconnect the tan wire at the inline connector which will be 8-inches or so from the point where it exits the head. With the key in the RUN position, ground the end of the tan wire (not the one from the sender -- the other end) to the engine block. If the horn does not sound, you need to troubleshoot that system. If it does beep, the system is ok but the sender is bad. That system is important because it also works with the oil injection system to let you know about low oil and no oil problems, as well as fuel restriction issues. With that system not working you obviously would not know about a lack of oil can also severely damage the engine.

 

[imported_ricardo]

Re: overheating engine

here are the photos i took when you see them please tell me what you think of that thanks
http://s173.photobucket.com/albums/w54/ricardo1_09/

 

[imported_ricardo]

Re: overheating engine

could the clogged water passages o n the thermostat could have caused the overheating?( see the photos) and tell me what you think thanks

 

[Silvertip]

Re: overheating engine

Of course clogged water passages can cause overheating. No water flow - no cooling = overheating. And just so you know, just because the water pump is pumping water, that is no guarantee that the engine is being properly cooled. A thermostat stuck shut can cause overheating. Lean fuel mixture due to gummed up carbs can destroy and engine. Disintegrating diverters that were mentioned earlier disrupts water flow and can cause overheating. The cooling system exists to keep the engine cool. Anything that distrupts or interfers with water flow through the engine will cause an overheat, That's why it's essential you fix the warning horn so you have an "audible" warning as well as a visual. Guages are nice, but then one must look at them periodically and understand what they are telling you.

 

[Silvertip]

Re: overheating engine

Forgot to look at your pictures but after doing so, I can only say it appears there is a great deal of scale build up inside this engine. The appearance of a water pump impeller can be misleading. What might appear to be a good impeller may in fact not pump an ounce of water. On the other hand I've seen impellers full of cracks and pieces missing and still pump water. Fact is, you have it disassembled, replace it as you'll never have a better chance. However, you really need to run a compression check and then pull the heads on this engine and see what other damage might have occurred before spending any money on it. You can do a compression test with the lower unit removed.

 

[imported_ricardo]

Re: overheating engine

thanks alot you all have been of so much help in making me understand this overheating problem its causes and ways to correct them .... silvertip did you see the link of photos that i posted earlier check it out and tell me what you think ,thanks

 

[OBJ]

Re: overheating engine

Ricardo....Silvertip has looked at your pictures and has posted some excellent advice. Also go back and re-read the whole thread and take note of the advice offered from the helpers. Very good advice from each.

Do you have a service manual for the engine? You may want to invest in one. It would be of great help to you in repairing the problem.

Here is a link to the BRP site that you can look at and view the parts breakdown for your engine. Just chose the product in the upper left corner of the site and follow the prompts...you should have your model number handy.

http://epc.brp.com/(X(1)S(voeexofnrcwpxv45xr3rtc55))/login.aspx?ReturnUrl=%2fdefault.aspx%3fbrands%3dej%26lang%3dE&brands=ej&lang=E&AspxAutoDetectCookieSupport=1

And don't hesitate to post any questions you may have. And try and keep your questions in this thread. They will be easier to follow.

 

[imported_ricardo]

Re: overheating engine

silvertip i already pulled the heads of and it all looked ok the pistons moved ok the cyls pushing oil my direction , the head gaskets where not burn looked old but ok if you saw the pictures the port side thermostat housing was with alot of scaled build up but the starboard as you can see haded a black color like burned, do you think this could have been all about the thermostats and passageways?