spdracerIROC

Hey All,


I did the TB Bypass a few weeks ago, and the car seems to be running about 10-15 degrees warmer than normal. I replaced the thermostat today with a 180 unit with 4 1/8" holes drilled in it, and it seems to have dropped the temp slightly. Now the guage reads just below 240.

The car used to run right at 240 after warming up.

The cooling system has no leaks, and both my cooling fans work properly.

Is there any way I can hook something up to the sending unit to get an idea of how accurate my guage is?

Thanks in advance.

Danno

240 is way too hot for an average temp. I have worked on a bucket full of these things many with cooling problems and the normal indication on the guage with a 195 stat is when the car is moving around 40mph or higher the guage will rest on the line between the 100 and 220 callouts on the guage. With a 180 stat the guage will read about a needlewidth lower from that line. That being said the first thing to do is to confirm the guage accuracy. There are a couple of ways to do this, I use an old Weston 4 inch analog guage that has a long metal probe. With the rad cap off I place it in the coolant and let it warm up some then simply compare the 2 readings. Before you start to troubleshoot the cooling system I would find out how far off the guage is. If the guage is high, try replacing the guage sender located on the driver side between cyls 1&3. It has a single wire connected to it. Get an OE part, not an aftermarket. The OE units have much better calibration to the guage than do the aftermarket ones. If it's a cooling problem first is of course, the airdam. It's a critical part that provides airflow to the rad when moving, without it the temp will rise and average around 220 or so or until the electric fans come on. With a 180 stat and 4 holes you have effectively recalibrated the stat down to somewhere around 165 or so. I don't recommend it but a lot of people do it. A straight 180 without the holes is probably better since the average temp will be closer to where you get the best engine operation with EFI. The TB bypass does nothing to alter the operating temp with a properly operating cooling system. Otherwise normal cooling system components should be checked. Plugged radiator, restrictions in the system will cause it to run hot. Air in the system also, but that should self correct after 100 miles or so fo driving. A common thing also is the system not holding pressure. The rad cap and system components must hold at least 15psi. Hope this helped. One more thing is the fan operation. Dual fan setups the pri fan comes on at about 225 degress and will very quickly bring the temp down. The aux comes on at 243.