www.iFourWinns.com

Hello. New to the forum. Sorry for no boat pics. Will add soon. I was excited to find a Four Winns specific forum!

I have a 1995 Horizon 190 and last week I had the impeller replaced. The first time back in the water I noticed that the dashboard temp gauge seems to not be working properly. It never goes above the lowest mark (120 degrees). The engine temp should sit around 150-160. I am not sure where to look next. Would a thermostat that is stuck open read that low on the gauge? Or could it be an electrical problem? All of the other gauges seems to work ok and the temp gauge worked before the impeller was replaced. The temp gauge needle does move from its resting position up to the first mark when I give the electronics power so I think the gauge is at least getting power.

Could something have been loosened when the impeller was put in? Or would my best bet be to get a new thermostat and see if that fixes it? Or could the temperature sensor be bad? Any help will be appreciated.

Take off the connector on the temp sensor, with key turned on ground the sensor wire to block, if the gauge goes to max your sending sensor is bad, if not wire or gauge issue

_________________
2008 H190 4.3L Blue W/Red Graphic
2002 Honda CBR954RR BLK/SLVR slightly modded
2003 Yamaha Warrior 350 6spd < SOLD!

Did the old impellor break up? If so, there may be a piece of it jamming the thermostat open.

Graham

Please post how you resolve it. I have the same problem. Had sending unit replaced but gauge still doesn't read properly. Could the thermostat be stuck "open"?

_________________
Matt-

2007 Four Winns H190
Earth First, We'll Mine the Other Planets Later

About the most common boat problem is a stuck open T-stat. Muck, and impeller parts tend to get them, as does rust. A T-stat typically fails open (full cooling). I'd replace the T-stat before even thinking about a faulty indication. I've had the same issue on my last boat and many cars over the years... all with the same result.

_________________
Walt B
"Debt-Charged"
Black '07 H210SS
6.2L Bravo One turning a 21P HIFive
Wakeboard Tower with Perfect Pass Stargazer version
Missouri River; Kansas City, Mo.

Thanks Walt-

My boat has had this problem for over a year now, and nobody can resolve it. The gauge is good and the sending unit is new. It stopped reading after hitting a sand bar. When I first got it back from repair, I hooked the flush kit up and ran it for about 15 minutes (choke on) and it started to give a reading after about 15 minutes. However, under normal operating conditions (choke off) I have no reading. Where is the thermostat on the block and how hard is it to get to/replace? Is it a thermostat that I can purchase at an autoparts store (4.3L GL)?

_________________
Matt-

2007 Four Winns H190
Earth First, We'll Mine the Other Planets Later

If you have to ask, have it done professionally. It can be installed incorectly, and cause your engine to overheat resulting in block/heads warped, as well as other problems. The T-stat is typically located above the water pump on top/front of the intake manifold. It's basically where all the hoses come together. A marine T-stat is different from it's car-cousin due to the configuration, temperature (Car=180-220F; Boat= 140-175F) and capacity of the cooling system. Just like in a car, you can remove the t-stat, place it in boiling water, and see that it opens. However, if you've gone that far and are in doubt, replace it! Running with a bad T-stat means parts of your engine never gets up to normal operating temperature, while other parts may be over heating depending on the configuration of the cooling system. Poor gas milage (not typically noticed by boaters) and Oil not getting warm enough to "cook off" any accumulated moisture, resulting in lube problems and premature wear/failure. Best of luck.

_________________
Walt B
"Debt-Charged"
Black '07 H210SS
6.2L Bravo One turning a 21P HIFive
Wakeboard Tower with Perfect Pass Stargazer version
Missouri River; Kansas City, Mo.

My money is on a bad thermostat...

You know how things go, your oder the part and the thing starts working again. I've had two weekends out where I didn't register anything above 140. I immediately figured the t-stat was bad and ordered one. Took the boat out last weekend and it started working normally again, go figure. I'll drop the new one in anyway for peace of mind and knowing it needs to be replaced sooner or later since it's already going out.

_________________
Nubby


Living the DREAM

Talked to my Four Winns dealer today...he stated that it can't be the thermostat if the gauge isn't reading? He said it is likely the gauge. This does not seem right, especially after reading Walt's post. I am going to check the gauge today (ground to engine block) and see what happens at the gauge. From what I understand....there are three possible scenarios: bad gauge, bad sending unit, or bad t-stat. Looked at FourWinns manual and the t-stat looks easy to replace and cheap.

_________________
Matt-

2007 Four Winns H190
Earth First, We'll Mine the Other Planets Later

HI, I have a 98 horizon 180QX 4.3l and get no reading on gauge. Replaced gauge and Tstat - still no reading. Can one of you gents tell me where the sending unit is on the engine? If it easy to get to, I'll just replace it and see if that does the trick. Any other ideas - I'm all ears. Thanks,

On most Chevy 4.3s the temp sensor is in the intake manifold on the front left side as you fact the engine.
One good way to troubleshoot the thermo (is it opening or not) is to feel the hoses. When you start the engine, the hose feeding the water into the thermo housing and the hoses feeding the manifolds from the thermo housing will be about the same temp (cold engine, both will be cold). The thermo is closed, all the water in the engine recirculates and the raw water goes right out the manifolds. But when the thermo opens (warm engine) you should feel the hoses to the manifolds get warm because when the thermo opens, the water coming out of the engine mixes with the raw water coming in and then exits via the manifolds. So if those hoses are cool after running the engine for a while the thermo could be stuck open or not closing.

A better way is to use an IR heat gun. I take readings every so often. When my temp gauge on the dash reads 165 or so, the area of the intake manfold right under the thermo housing will read 155-160 or so. The top of the thermo housing reads cooler like 135 or so.

I have battled the thermos not closing too. What will happen is that if it does not close all the way, the engine will idle at 120 or so, it will not rise up to a normal temp (160-175) till you run on plane and then it will drop as you come off plane and the engine cools off.

If the gauge doesn't move at all, then you have to do the electrical tests and make sure there are no old impeller pieces in the thermostat.

The nice thing about having the IR temp gun is you will know right away if the thermo is not closing, your reading from the intake manifold under the thermo housing will be low like 100 -120 at idle. And you can also tell how much approximately your temp gauge is off by, mine reads about 5 degrees high, not a big deal.

Last if you are a salt water boater you can check the manifolds and risers when they are new and have a baseline of what normal temps are.

_________________
88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

You did not say which engine. The '95 190 Horizon I had did that frequently. It was a Ford 5.0 EFI. The thermostat would get a little sand or grit in it and stay open a little so it would never come up to temp. That engine came from the factory with a 145 deg F thermostat. I changed or pulled and cleaned the thermostat several times. It never seemed to be a permanent fix. The temp would frequently read 110-120. Some times on a warm day after a session of pulling a tube or a skier and then stopping for a few minutes to retrieve or change victims on the other end of the rope we would notice that the temp gage would go above normal momentarily then settle down on 145 where it belonged. It was never a problem with a faulty gage system. For what its worth the engine has over 2 thousand hours on it and runs great.

_________________
Surface Interval: A scuba diving term for that time between dives to relax and prepare for life's next great adventure.

Current boat: '02 FW 268 Vista
Previous boat: '95 FW 190 Horizon

I was under the impression the engine is Volvo 4.3GL, not Chevy. Does that change the location of the temp sensor?
As far as the gauge reading low - it doesn't move AT ALL. completely pegged to the left and never moves. Seems like it's not getting any power. So I think electrical. Other posts talk about checking the ground. Any suggestions on how to do that? Any help appreciated. Thanks

All 4.3 V6 engines are made by GM whether it is the Volvo model or the Mercruiser model.

Hello I know, thats really an old thread, but I have a problem with my temperature gauge on my Horizon 192 CB (1995, OMC 4.3GL), too.
The gauge shows the wrong temperature. I replaced the t-stat and the temp sensor, but my problem is not fixed.

I think I have a temp sensor with the wrong resitance range.
Can somebody tell me, which temp sensor I need.
It would be very nice.