V 6 running hot on one side

[dc in ms]

I have a 1978 Evinrude 175 hp 90 degree V6 model number 175849C which appears to have run "too hot" on the starboard side at some point in the past prior to my purchase. I say this because the three ignition coils on that side look as if they melted their plastic casings at some point. You can see where the melted plastic ran off the coil and onto the engine itself. Also, I think related was the faulty powerpack on the same side.<br /><br />I removed the two thermostats, cleaned, tested and replaced them. I removed, cleaned and replaced the two pressure valves. The starboard side NOW seems to be running alot hotter than the port side. Alot hotter. This is based on touch only....Icompare the temperature of port and starboard cylinder blocks. I am afraid to let it run for more than a few minutes because the overheat switch on that side is not reliable. It seems to have a short in the wiring somewhere because the alarm goes off periodically and unexpectedly for no reason at all.<br /><br />So, these are my questions:<br /><br />1. Does it sound like it ran hot at some point in the past?<br />2. If so, what are some of the signs I need to look for? <br />3. What sort of hidden damage do I need to look for? <br />4. And, what will cause it to run hot now on just one side.<br /><br />The impeller is new and working well...water discharge seems to be appropriate..the thermostats open at 140 (during test)..<br /><br />Feedback appreciated<br /><br />Thanks

 

[mikeyzx2]

Re: V 6 running hot on one side

the catch is, you may be getting good water flow, but there's probably some restrictions in the heads themselves. Have you ever popped the water jacket covers off the heads themselves? There are defLectors, which are pieces of tubing placed in certains spots to route water flow, and if they become dislodged from their locations, the circulation will be altered or interrupted and the heads will get hotter. <br /><br />How's that for a long sentence? Anyways that or deposits built up in the heads over time. I just replaced the two hoses that go to the heads on my '77 V4 and there was plenty of funky buildup in them.

 

[DHPMARINE]

Re: V 6 running hot on one side

The clue is how much hotter is hotter.Both heads should be 150 degrees or less.The starboard head (on your engine )will always be hotter (warmer) because of the way water goes thru your block.You can purchase wax crayons that melt at certain temps.If the 163 degree wax melts,SHUT her down.<br /><br />DHP<br /><br />at work I have a digital pyrometer that I can hold against the head and read temps.Last week or so Craftsman sale,infrared unit was on sale $49.00 .I bought it,but have yet to test it

 

[dc in ms]

Re: V 6 running hot on one side

I have not pulled any covers, only thermostats at this point, but looks like I may be on my way to a little deeper investigation before too much longer...pulling the heads that is. Is there any big deal to this if I simply follow manual?<br /><br />I called my local marine dealer the other day and asked if they had any temp crayons in stock and the guy (at the parts counter) acted like he had never heard of them. I had to explain to him what they were . Actually, what's funny is I didn't know what they were either two hours prior to making the call. I learned about them in my repair manual and thought they would be a great tool...I now will find them on the net and order!<br /><br />Thanks for advice

 

[papasage]

Re: V 6 running hot on one side

you might tri N A P A auto parts they have axcess to marine auto parts

 

[Joe Reeves]

Re: V 6 running hot on one side

A little info on the deflectors:<br /><br />(Water Deflectors)<br />(J. Reeves)<br /> <br />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.<br /> <br />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.<br /><br />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.<br /> <br />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.