Leghome Posted May 8 Posted May 8 My SBC 350 has two temp sensors. When we first hit the road the temp gauge for the Dakota Digital reads up to 250 degrees while the gauge for the Holly Sniper only reads 168. The sensor for Dakota is on the head so I know it will read higher than the Holley sensor that is on the thermostat housing. I stop the car turn it off and sit for 2 to 3 minutes sometimes less and the gauge goes back to 185/190. I have a 160 degree thermostat so the water jacket temp is good and the running temp for the Dakota I am comfortable with at 190 or less. Any suggestions on what to look at or for to help solve this mystery. I have dealt with it since we got it running good after installing the aluminum heads last year except for this baffeling snafu. Quote
420ponies Posted May 8 Posted May 8 Larry, I would think that the block temp.(cylinder head )would be lower, than right by the thermostat housing. That thermostat gauge reading would be going up/down with the thermostat opening and closing. I could be mistaken? 1 Quote
Jason72 Posted May 8 Posted May 8 I would remove the sensor that is showing high. Put in a mechanical gauge and see what happens the sensor itself could be faulty Quote
Leghome Posted May 8 Author Posted May 8 I talked to my mechanic/son in-law Jamey earlier and he rminded me that the wire going to that Dakota sensor had been againnst the header and that could be giving me a false reading. Going to callDakota Dkigital in the morning and see about getting a new pigtail 4 Quote
jft69z Posted May 8 Posted May 8 12 hours ago, 420ponies said: Larry, I would think that the block temp.(cylinder head )would be lower, than right by the thermostat housing. That thermostat gauge reading would be going up/down with the thermostat opening and closing. I could be mistaken? The cylinder head reading in my experience is usually a little higher, maybe 10-15 degrees. I put the EFI temp sensor near the water neck, as it's more representative of the cooling system temperature. I also picked the temp for the Dakota digital from that thru the CAN bus. The Dakota temp sensor is in the head, but just as a backup if needed. 3 Quote
Leghome Posted May 8 Author Posted May 8 49 minutes ago, jft69z said: The cylinder head reading in my experience is usually a little higher, maybe 10-15 degrees. I put the EFI temp sensor near the water neck, as it's more representative of the cooling system temperature. I also picked the temp for the Dakota digital from that thru the CAN bus. The Dakota temp sensor is in the head, but just as a backup if needed. This is also my setup 2 Quote
Leghome Posted May 9 Author Posted May 9 Just talked to my mechanic/son in-law Jamey and he remembered that the Dakota Digital sensor wire had gotten against the header and had melted slightly so called Dakota got the part number for the sensor and pigtail and he said to get it quicker order it from Summit so the parts are supposed to be here tomorrow 6 Quote
Leghome Posted May 11 Author Posted May 11 Well changed the lead for the Dakota heat sensor and no change. Mowed the yard again and put Ole Red’s nose in the air on Jack stands and fired him up. The temp got to 230 the thermostat opened and it dropped to 184 according to the infrared gun. That is another story that I can not figger out you hold the trigger and yesterday it was reading about half of what I thought should be normal. Today it jumped up to 800 to 900 Fahrenheit. I used the type k probe and the it matched the temp gauge dead on. I will try again tomorrow and see what kind of reaction I get. Now it is time to plant some garden 3 Quote
Leghome Posted May 12 Author Posted May 12 5 hours ago, Scott S. said: Time for a new heat gun ??? This is a new gun just got it Saturday 1 Quote
Scott S. Posted May 13 Posted May 13 The only thing that comes to mind is a sticky/slow thermostat. But jumping to 800-900 degrees..... Your engine should have seized before you get readings like that. Even the headers don't get that hot. 1 Quote
Leghome Posted May 13 Author Posted May 13 29 minutes ago, Scott S. said: The only thing that comes to mind is a sticky/slow thermostat. But jumping to 800-900 degrees..... Your engine should have seized before you get readings like that. Even the headers don't get that hot. The motor is not getting that hot just that new heat gun thank goodness because the motor would be fried 😁 1 Quote
Scott S. Posted May 14 Posted May 14 21 hours ago, Leghome said: The motor is not getting that hot just that new heat gun thank goodness because the motor would be fried 😁 Yeah.... Those T-bones would get extra crispy on that manifold. 1 Quote
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