engine heating up

Well I have a problem and not sure what's going on. My motor heats up about 3/4 of the way to the H then comes back down to normal temp in a few seconds. Any ideas?

it sounds to me that is your thermostats opening up i have a car that does the same thing it heats up almost to the pint of were i want to shut it off but then drops down once the thermostat opens

That's not too uncommon, I've heard others here talk about that.

If that bothers you, install a new thermostat.

Did you just replace your thermostat?

Mine did that the first few times after replacing my thermostat (and doing the head gasket). It would heat to the second mark from the top (the one below the H, top of the range) before dropping to about 2/3. I haven't really watched it that closely, but it doesn't seem to do that now.

Alright thanks guys I was thinking thermostat but wasn't sure. But no I haven't replaced anything recently so maybe my thermostat is just starting to go out. Thanks again everyone!