Topic: Temp gauge spiked but not overheating ?

[1ofakind]

Hey Gus so I just got my motor in a couple days ago and the car runs pretty damn good. It's a 93 with the Ej20g. So since I got it running I am having an issue with the temp gauge reading max hot, even though it's only ran a minute or two in this cold. I have heat inside the car and the Lower rad hose is cold, meaning the rad is cooling the coolant. I just pulled my codes and I have two one being 24 and the other 44. Totally unrelated to the cooling system I think. So what gives? Is my temp sensor garbage?

[VTAKLOL]

Sounds like you have air in the system. And the lower rad hose being cold usually means your thermostat hasn't opened.

[05LGT]

Are you sure the coolant isn’t frozen somewhere and there’s an air bubble?

[1ofakind]

I thought I got it all out, every time I check the expansion tank for coolant it's coming out the top slightly so I know it's full... thermostat must be open since I have Heat in the car no?

[1ofakind]

Update, lower rad hose is also warm when at operating temp. Is there's some way I can ensure I got the air all bled out?

I tried to burp it again and seemed to get some of the air out of the upper rad hose. Should probably let it sit over night and try it tomorrow to see if the gauge spikes again after sitting. Then I'll add some more coolant, when I rev it up with the expansion tank open the level drops. Seems like the water pump should be flowing so how could it still have air  damn thing

To add, I also have a cold start issue. I heard can be directly related to the coolant semp sensor causing he iac not to open making my cold idle really rough. So my code 24 (iacv) could be my problem here too

[DWS]

For my 0.02, I's say you have a shorted out gauge wire...  If it reads max hot, it's being grounded somewhere along it's run.


Doug

[1ofakind]

For my 0.02, I's say you have a shorted out gauge wire...  If it reads max hot, it's being grounded somewhere along it's run.


Doug

I agree, i haven't gotten around to changing the sensor but I'm also reading other place she that could be my problem so I ordered a new one.

[1ofakind]

update, i changed my sensors (both of them) while fixing some boost leaks and made no difference, now to hunt down the wire causing me issues. Any one know where the gauge grounds?

[DWS]

Most gauges ground through the sensor body to the engine through a ground strap to the frame and then back to the battery.  The sensor is basically a variable ground, the warmer it gets, the less resistance to ground, the higher the gauge reads.  A short caused a solid ground, which causes the gauge to go to max.  Check the engine ground as well to ensure it's still good as well.

Only recommendation I have is to start at the sensor and follow the wire back through the loom to the bulkhead, then pick it up again inside the car and follow it to the gauge.  I had one that was burnt through because it was ever so slightly touching the exhaust manifold when corning, and would throw a warning light on one of my cars when cornering.  Luckily it was easy to find and fix in that case.


Doug

[1ofakind]

Thank you for the replays. Still trying to find the issue. J put a new cluster in to try and still have it so that eliminates the cluster. Now I know it's a definite wire issue. I just need to find where..