1997 Ski Nautique 196 engine running cold.
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=38715
Printed Date: October-07-2024 at 10:19am
Topic: 1997 Ski Nautique 196 engine running cold.
Posted By: helidean
Subject: 1997 Ski Nautique 196 engine running cold.
Date Posted: May-25-2016 at 11:08pm
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I own a 1997 Ski Nautique with PCM Gt40 engine. Last time on the lake the engine would not warm up. (no temp indicated on guage and heater would not put out heat). I thought is was the thermostat so I removed it and tested it. It opened just fine in boiling water. Next I noticed inside the lower thermostat housing what I think is a hole in the casting between the small port on the casting(front side) and the large gallery under the thermostat. Does anyone know if this connection between the two sides is normal? Also does anyone have any other ideas why the engine will not heat up? Thanks in advance for your response. |
Replies:
Posted By: Gary S
Date Posted: May-25-2016 at 11:17pm
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Stuck open thermostat. When you took it apart most likely closed. Best just to replace it. Hole is a bypass and is supposed to be there ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: helidean
Date Posted: May-25-2016 at 11:31pm
| Thanks for the reply Gary. Do you know how big that hole should be? Just wondering if it has eroded bigger due to corrosion. Is the bypass hole there to feed the circulation pump? Won't the hole allow cold lake water into the engine block and not allow the engine to warm up? Thanks again for your help! |
Posted By: Gary S
Date Posted: May-26-2016 at 12:56am
I have the same conversion running in salt and have not had problems yet,knock on wood,I doubt you running in fresh,if you are,would. Very hard to see and measure but the hole seems to be 3/4" wide by 1/2" high. This is the lower thermostat housing it feeds the water into the circulation pump then into the block. The thermostat keeps the water in the block,as the water warms up the 'stat opens allowing cool lake water to enter into the system thru the hole This is the upper. The hole is approx 1/2" This is where the fresh water comes into the engine it bypasses all the time into the exhausts to keep the manifolds and exhaust hoses cool. As the thermostat opens the hot block water also exits into the exhaust manifolds. Your thermostat,if stuck open will just bypass all the water never keeping it in the block long enough to heat up  These parts are no longer available new,used is your only option ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: helidean
Date Posted: May-26-2016 at 1:19am
| Hey Gary thanks for your response and the pictures are great help. It does now seem like the thermostat is the issue. I didn't think so because it tested fine in hot water. Your help is very much appreciated. |
Posted By: Gary S
Date Posted: May-26-2016 at 1:48am
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I think it was stuck open and when you took it apart it closed back up. I doubt you celebrate this weekend like we do but if you want to save the weekend it might be worth a try to reuse it while you wait for a new one. Unless you can get one up there easy. Just keep an eye on the temp gauge. I had one stick closed this season on it's first run but after shutting it down and restarting it never happened again. It's on my list to change though. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: gun-driver
Date Posted: May-26-2016 at 11:03am
| The other problem it could be is the impeller isn't pumping any water. With no water in the block the temp sensor doesn't have any liquid to get a reading from. Same with the heater core no water no heat. |