Chevy & GMC Vans

Hi

I bought an 89 Astro van this week and at first everything was fine. I cranked in several times and rode it around before I shelled out the cash for it. All good. My first stop after purchasing it was the post office. When I got back in it, it would not start. Just cranks but not starting. Brought it to the mechanic up the road and he hooked it up to his tester and it came back as a bad coolant sensor. he said the sensor was telling the computer it was too hot and wouldnt let the motor start. He charged me $103 to fix it and 2 hours later I was on the road and life was good. I did however notice that after he fixed the sensor, the temperature guage stopped working and it WAS working before he fixed it. I put it out of my head because I didnt have time to go back to the mechanic yet to ask him about it. Anyways, after driving the van for 3 days with no problem it is doing the exact same thing. It wont start and now Ive run the battery down. Im a long ways from that mechanic so I thought Id post on here and try to fix it myself.

Is it possible the "new" sensor went bad already or maybe the mechanic didnt put the correct sensor in? If it makes any difference, the van did start for about 1 second when I tried starting it today...then nothing.

Im not sure about these things but I am somewhat intelligent and I think I could change the sensor by myself but Im just not sure if its the same sensor or a different problem. I read the post about how to check the codes with a paperclip. Should I do that?

Thanks in advance for your time and any responses recieved.

Ryan

Couple things to explain first. There are two coolant sensors. One is by the thermostat housing and it is used by the computer. The second one in on the drivers side of the engine on the head. Right by the front spark plug. It is used by the temp gauge. The coolant sensor will not affect the engine from starting when the engine is cold. Only after the engine has warmed to operating temp. This has to do with how the computer works. It runs on fixed values until the engine warms up a bit. It then reads the sensors.

That being said you will have to do a little work and tell us when the problem occurs. Cold (I mean all night) or warmed up. Let us know. Maybe he changed the wrong sensor. The sensor itself is around 10 t0 15 bucks and easy to replace.

Your check engine light would be on if it set a code. If it is on you can check it with the "paper clip". Check it anyway and tell us what it comes up with.