Today I noticed my car crept up to just over 90 to about 100 degrees. It's warm so I didn't think much of it. Later on I saw it had gone to 105, this is as high as it read, so I thought I'd try and put the heaters on to take some heat out. The thing is, they blow cold. I have run the engine with the coolant cap off and squeezed the pipes to remove a possible airlock, but there doesn't seem to be one. The engine was running, and the gauge was at 90, so I put my finger in the coolant tank and it was warm, but definitely not 90! Car hasn't been using any coolant at all, and runs really nicely with no smoke so I'm confident it's not a headgasket, so what could it be?