temperture gauge slowly rising, is engine running hotter??

[DMCBRANDON5873]

So I've been using 5873 for a daily driver now for nearly 2 months, and drives just fine, but within the past week or so I've been noticing the temperature gauge is rising up higher than it has ever before, on the hottest days in the past with the AC going on my gauge it would never go past the first quarter mark, but each day I've been driving now it has made its way slowly to the half way point on the gauge. I've check fluids and everything looks ok, but its been probably 10,000 miles since last coolant flush which was over a year ago. Any suggestions? And on another note even when the engine is off and cold the lowest the gauge falls is in between the very first mark and the quarter mark. Thanks brandon

[Chris 16409]

Your cooling fans are coming on right? They should come on before you reach the 220 degree mark.

[jmpdmc]

Do you have an original radiator or a replacement metal one?


Jeff

[Bitsyncmaster]

When you start a cold engine the temp gauge should be below the first mark. If it starts above that you have a bad temp sensor or the gauge circuit is faulty. Since you said it slowly start do this, I would guess it's your temp sensor.

[sdg3205]

Is it possible the thermostat is stuck only partially open?

[Ozzie]

Even though you said you checked:
Check that the coolant level in the reservoir bottle is above the outlet (bottom hole on bottle).

You may have some air trapped in the system, so:
On a cold/not recently started engine, take the cap off the bottle, and start the car and watch the flow of coolant. The coolant should be flow continuously, not in spurts, w/o any bubbles. You can recap after a few minutes, to let the system rebuild pressure.
Finally, try bleeding the system at both near the thermostat (if you don't have self bleeder) and then at the radiator (top hose).

If there was air in the system, bleeding will eliminate most all of it, and you should see your system stabilize under the same conditions.

[DMCBRANDON5873]

Ok thanks guys, and also let's say I start the engine when its warm/ hot the gauge starts at the very top and then slowly goes back down to the middle, im thinking it might be the gauge, but yes I do have a orginal radiator

[TTait]

If I read your post correctly it sounds as though your putting 10k miles a year on your car. It's not a weekend driver, I'd set aside a bit of cash and plan on putting in a new radiator in the future. Even if its not leaking and the flow is good, the plastic tanks on the sides have a limited lifespan.

I'm not suggesting that the radiator is the problem your having now (yes, it could be getting plugged up), but it would be appropriate to have reduced confidence in it.

Make sure your pressure cap isn't more than a few years old. If it doesn't open at 15 PSI your pressure will go higher, and your temp will go up a bit. And higher operating pressures and temperatures are also no friend to plastic radiator tanks either.

While cooling is on your mind, also make sure you have a cable tie around your otterstadt.

[DeLorean03]

Ok thanks guys, and also let's say I start the engine when its warm/ hot the gauge starts at the very top and then slowly goes back down to the middle, im thinking it might be the gauge, but yes I do have a orginal radiator

That sounds like a bad temperature gauge. Could be that or the wiring leading to it, the paper-thin circuit board leading to it, or a possible ground starting to act up. The circuit board is probably good as there's very little that can go wrong with it if you're not taking your binnacle off a lot. Same goes for the wiring leading to it - shouldn't be giving you many issues as it's an area that doesn't get messed with too much.

My bet: bad gauge. Way to know for sure: get yourself a laser temperature gauge gun. It's a gun that shoots a laser and the laser measures the temperature of whatever the laser is hitting. Take that and hit your temperature sensor switch. Its location is on right rear head of the engine. When you hit that switch with the laser gun, if that temperature matches what's on your gauge, your gauge is probably all right. If not, gauge is going bad.