hey team. got referred here by a few friends who read the board to try to find some help for the problem im having right now. the truck is an 89 toyota pickup 22RE with over 400000km on it (still runs beautifully, for the most part). There are a few problems happening right now that might be interrelated, so who knows. here it goes:

Recently, the truck started to have some weird issues with some major engine clunking. Basically, it happens at any speed, any gear, any temperature. What happens is that when i give it some gas, the engine just clunks and the truck jerks, even at high speed on the highway. it will kind of happen in spurts - sometimes it will happen ever 30 seconds and sometimes it will go an hour before it happens again. also, the check engine light comes on sometimes when it happens...but not every time.

It also has some troubles that sound similar when it starts up warm. i have to give it a lot of gas and it shudders a lot before it gets going. Sounds kind of like it should sound when starting it up in cold weather.

the other problem is with temperature regulation. When i am sitting in traffic barely moving, the truck heats up significantly - almost overheating. as soon as i start driving again and getting some air flowing across the rad it cools right down to normal. This isnt really that big of a problem but it might have something to do with what i found out at the toyota dealership today.

I took it in to a dealership today to get it diagnosed. they told me that the check engine light gave a "code 22 - temperature sensor failure". When i picked it up the mechanic was gone and the guy I talked to didn't know much about the part. From what I searched so far on here I couldnt find anything about this.

So my question is, why would a water or coolant temp sensor cause the truck to do this? doesn't make sense to me and I don't really feel like replacing things that don't need to be replaced. Let me know what you think.

Thanks!