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Old 04-27-2015, 09:23 AM
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epnault epnault is offline
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LT1 Running Too Cool

Hi Guys,
Working with a friend at the lake and his '93 205 cooling. On the gauge, that is verified working and temp sender changed, it will only read barely above 120F after skiing. If you all recall the temp sender is not located on the circulating pump casting (mine is on my 95). After he changed the temp sender he changed out both Tstats, gaskets, and orings with the MasterCraft spec tstas. I really thought that the 160 tstat was stuck open and this was causing the issue. Our water temp here is cold (about 50F) but my LT1 on the same lake is running up to operating temp. Also, we did a feel test on the location where this temp sender is mounted on his 205 and it is noticably cooler than that location on my engine. We are stumped on this one and wondering what you guys think we should be thinking about to get his engine running up to operating temperature.
Eric
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Old 04-27-2015, 09:27 AM
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Old 04-27-2015, 09:35 AM
mgs96ps mgs96ps is offline
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Old 04-27-2015, 05:25 PM
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Shaun R Shaun R is offline
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You have an engine temp gauge? My 190 just has a temp overheat light and a gauge for the trans.
LT1 take two temp readings, one comes from the sensor in the waterpump and the other comes from the plug in the side of the block. Waterpump will always read lower than the block.
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Old 04-27-2015, 05:40 PM
mgs96ps mgs96ps is offline
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Old 04-27-2015, 06:22 PM
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Table Rocker Table Rocker is offline
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Quote:
Originally Posted by mgs96ps View Post
Tablerocker will figure this one out.
Ha! I am trying to remember which sensor is for the gauge and which is the switch for the ECM.

I do think the problem is that his sensor is in the mixer housing which is a poor location for it. He could move that same sensor to the front of his water pump and get better readings. That is what Indmar did.

If he has changed the thermostats, the only way I can think of that could cause him to actually be running colder would be to have water flowing through the heater and back via a Y pipe. That would cause his engine to constantly replace hot water with mixed water.

I guess if his mixer was really rusted out, it could cause too much water to bypass the mixer thermostat. I doubt that is what it is though.

I think the best bet (stated by mgs96ps) is he is running a good temp, but showing cooler due to the mixer sensor location.

To ShaunR: My '96 has a temp gauge.
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Old 04-27-2015, 06:46 PM
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Shaun R Shaun R is offline
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The one on the pump goes to the ECM, the one on the block does not. I am wondering if the PO replaced my gauge with an O/B temp gauge instead of a regular engine one.
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Old 04-28-2015, 08:20 AM
jprocto3 jprocto3 is offline
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Please educate me. What is the problem with running 120F or below?


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  #9  
Old 04-28-2015, 08:46 AM
Jorski Jorski is offline
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The engine was designed to run in a certain temperature range. While too cold is not catastrophic like too hot, it isn't great.

On the LT1, the block is cast iron, the heads are aluminum, and the pistons are obviously steel. As they are made of different materials, they expand differently as they warm up to operating temperature. The engineers, know this and spec the various parts to fit properly at the design temp.

If you run too cold, the tolerances will be slightly out of spec. This will cause a shortened life span and worse gas mileage etc.

FWIW...I also think that the OP is getting a bad reading. The 140 degree t-stat, holds water until it warms up to 140 before releasing it to the rest of the cooling system....so that should be the lowest temp possible after warmup.
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Old 04-28-2015, 08:50 AM
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mikeg205 mikeg205 is offline
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Have you checked the temps with a temp gun? you can get them pretty cheap... $25 for decent one.
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