1998 temp guage

1998 Tahoe 350 auto 4wd. I had what I thought was a simple problem. Temp gauge was working fine until I put a new gm crate motor in and changed out radiator, water pump, all hoses and thermostat. So then I changed both temp sensors. The one on top of engine and the one on side of engine by # 1 cylinder. I checked the gauge by grounding the gauge sensor wire on gauge side to a ground and the gauge pegged out when key was turned forward. The problem I'm having is the gauge will only go up to almost the quarter mark and stop. It will start out a little less then 0 and when at operating temp it's only at a quarter and not around 210. Thanks.

What T-Stat did you put in? Should be a 195. The sensor in the intake is for the ECM and the one by #1 plug is for the gauge. Resistance spec for 194 deg = 241 ohms. 176 deg = 332 ohms.

I will have to check into that one. I'm not to sure. I was thinking the 195 degree, but I bought alot of parts that day for the engine install that it could of walked out with a 170 and not even noticed it. The shop that changed the engine put the thermostat in so I will have to pull it apart.

Before you pull it apart, check the resistance values. Could have a bad or wrong sender in the head.

could be the wrong sensors . these if wrong will throw off the temp gauge use the old one for test.

possible the T stat is bad many I have tested do not close fully then the low temps

Thanks for the response guys. I'll check into it more friday when I'm off. I didn't change out the sensors until after I notice the temp gauge was wrong. So both original and then new sensors are doing the exact same thing. I think I will be checking into this thermostat on my next day off.

UPDATE: Changed thermostat... problem solved. Bought a 195° and put in. The one I pulled out was a 180°. But on the bright side I now have all new sensors and the right thermostat... Thanks guys yall are awesome.