97 Evinrude 175hp Thermostat vs. Overheating

[dboram]

PLEASE HELP! I am having trouble with my 97 Evinrude 175hp OceanPro overheating. I have had it in the shop twice and spent over $1400 and the problem still is not fixed. The symptons are that anytime I attempt to run at normal speeds (4500RMP+) the high water temp sensor rings and the engine goes into safe mode. The mechanic has replaced the water pump, temp sensors, thermostats (none were in it), head o-rings, and power head gasket as well as cleaning as he goes. The last time it happened, I just pulled the thermostats. Since then, I have had no problems. My problem now is living with the fact that I have spent a ton of money for nothing. My questions are...1. What temp should the thermostats open? 2. What is the normal running temp for this engine? 3. What temp does the high temp buzzer go off? Furthermore, I cannot find any info on these thermostats to verify that they are the correct model for my engine. I did do an experiment where I heated them in a pot. One opened at 155 and the other at 160. PLEASE HELP IF YOU CAN!

 

[angus63]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

Welcome!!!!!!<br />My normal running temp is 140-150° F on my 1995 175HP Oceanpro. The high temp alarm is around 180°F from memory. Before dumpin any more money, I would verify the high temp sender isn't sending a signal early (low temp), new ones can be bad too. Are you certain that it is a high temp signal and not a fuel restriction signal (both are a continuous tone!!!)? Also improper ignition timing may cause high combustion temps and cause overheat at high rpms. Verify WOT timing to rule that out. You can use an Infrared temp gage to check head temps when the alarm goes off to verify if you have a high temp issue.<br />Good luck

 

[WillyBWright]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

Do you have resistor/supressor sparkplugs in there? Radio interference can send a false overheat signal, especially at specific RPMs. Not likely the problem since removing the stats seems to have stopped the alarm, but...<br /><br />Might the sensor(s) be oversensitive?

 

[MCM]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

Have you got a service manual for this motor, for the money you've spent already you should, it will tell you the normal operating range,<br /><br />I know I have a different motor and its overheating at 163 deg. and your t'stats aren't even opening until they get there.<br /><br />Anyway as long as you've got them out replace them with the proper ones, not sure of the part# as there are several for that year and hp.<br /><br />Then troubleshoot it from there

 

[dboram]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

Thank you for the gracious welcome and info!<br /><br />I called the mechanic back and he said the t-stats should open at 142, but my little kitchen test does not agree. I could pick up another set, but do not really want to spend the money after the beating I just took.<br /><br />What do ya'll think about leaving the t-stats out all together? Everyone I talk to down here on the Texas coast has said to leave them out, but I am worried. Any thoughts?<br /><br />MCM--Thank you for the thought on the service manual. I will be ordering one of them very soon.

 

[seahorse5]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

First of all, you have to determine if and where the motor is overheating. Use an infrared temp gun to check the temps of each cylinder head.<br /><br /><br />Do you know if the correct water pump kit was installed? There are 2 almost identical kits used and if they are wrongly installed, you will have either overheat or overcooling problems. What is your complete model number on the motor and what number water pump kit was installed?

 

[dboram]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

My complete model number is E175SLEC.<br /><br />In March 05 Water Pump Kit 18-3390 was put in. Last week, Water Pump Kit 18-3315 was put in with T-Stat Kit 435597.

 

[MCM]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

If you're sure about that model# it indicates a 1998 175hp 60 deg. v6 w/T&T 15" shaft.<br /><br /> EDIT: Should be 20" shaft<br /> <br />The correct t'stat is OMC p/n 435491 ,the correct water pump kit should be OMC p/n 435929 or Sierra p/n 18-3315.<br /><br />Your water pump is correct, I'm not sure what that t'stat goes to.<br /><br />Also these parts would be the same for a 1997

 

[dboram]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

MCM-I looked up the t-stat info. The part number you provided is the t-stat #. The number I listed is for the kit that includes that t-stat.<br /><br />So...it sounds like I have all the correct model #'s.<br /><br />I don't know if ya'll caught the info that I ran a test (but I guess not a truly scienfic one) to check what temp my t-stats opened. One opened at 155 and the other at 160. Is there a better (more scientific) way of do this than on the stovetop w/ the wife's candy thermometer?<br /><br />Can it hurt anything to just leave the t-stats out?

 

[Dhadley]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

We run into this from time to time. There can be a build up (kind of like a scale) in the water passages in the head. Sometimes we can correct the problem with soaking the head, sometimes you have to glass bead it. <br /><br />Anyway, I'm sure thats one of the places Seahorse was going with the temp gun. The temp gun will tell you where and if it is actually overheating. Dont discount a bad sender. And make sure you have the latest sender. There may have been a bulletin about that. <br /><br />Anyway, your first step it to verify that you actually do have a problem. For 1400 these guys should fix it or refund the $$$.

 

[MCM]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

Leaving them out is not recommended, it could cause your motor to run too cool which isn't necessarily a good thing eitheR.<br /><br />Missed the word "kit" on the impeller (1st cup) <br /><br />The best thing is to solve the problem, you could get some thermomelt sticks, one 125 deg. & one 163 deg. to verify if the motor is actually over heating or if its something else.<br /><br />Or as seahorse mentioned use an infrared temp gun.

 

[Dhadley]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

Oh -- when they put the heads back on they need to make sure they didnt get wild with the RTV sealer. That has been known to cause problems too. This is another case that a little is good but more can be bad.

 

[clanton]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

Check waterpump housing for correct one, like Seahorse said. Part number means nothing, you need to eyeball housing for correct one. Some temp sensors defective when new.

 

[MCM]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

Sounds like you've decided to do the work yourself now, correct? what kind of thermometer are you using?<br /><br />If you have a Walmart, Taraget etc. go get a digital thermometer, the one used for testing turkeys and such, about $10.00 or so. I've used them for developing slide film, slide film has very very little tolerance for mistakes, these thermometers are accurate to within 1-2 degrees.<br /><br />Retest your stats, if they open at 142 as they should reinstall them, paying att. to Dhadley's advice on the gasket sealer.<br /><br />Then verify you are overheating by using the thermomelt sticks or the infrared gun.<br /><br />No sense chasing your tail until you know if its overheating or not, correct

 

[dboram]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

I have talked to the mechanic about my disatisfaction and he stated that I brought it in with a problem and he did everything he knew how to do to fix it...on my dime.<br /><br />The mechanic pulled the powerhead and replaced that gasket and pulled the heads. He said the heads were relatively clean and touched them up.<br /><br />I need to locate a heat gun and shoot it. Where do you get thermomelt sticks?

 

[angus63]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

Hey D<br />Check out the first response I posted on this thread. Have you verified your alarm is not a fuel restriction? Have you verified your WOT timing is set correct? You won't need melt sticks if you procure an IR gun. You can pick one up anywhere tools and meters are sold. I verified mine was accurate by shootin' at the Mrs caboose and it read 99°F (Didn't need my glasses for that shot!!!! )<br />Good luck

 

[MCM]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

You'll need to find out which ones you need for your motor either the 125 & 163 deg., or more likely the 131 & 175.<br /><br />Your mechanic may have them or Iboats or I found them at Ishopmarine.com<br /><br />125-OMC P/N 507978, 163-P/N 507979, 131-P/N 501896, 175-P/N 501897 about $17.00 ea.<br /><br />Infrared laser is ISM p/n ESIEST70 about $180.00

 

[MCM]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

Angus, what'd you pay for the gun?

 

[dboram]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

Angus, if I had a fuel restriction, would the motor go into SAFE mode?<br /><br />Also, an ignorant question...what is WOT timing?<br /><br />Thank ya'll for the help.

 

[Tom Scully]

Re: 97 Evinrude 175hp Thermostat vs. Overheating

WOT is Wide Open Throttle.