My Overheating problem

For those of you familiar with my previous posts about my 3.5L overheating, I wanted to ask this. For those not familiar, just do a search, you can find my posts.

Anyway, I have definatley narrowed part of the overheating problem down to turning the A/C on. When its on, the temp gauge will rise above the 1/2 mark and I have had it climb near the 3/4 mark on very hot days. When I turn it off using th "Econ" button within a minute or 2 it will drop below the 1/2 mark and usually stay there for the most part. Sometimes it will creep up to 1/2 but it usually will not go above it unless I turn the air on.

Now yesterday when I got home I had turned the air off so that it would be back down to under the 1/2 mark before I pulled into the drive. I got, popped the hood and saw both fans running. I turned the A/C on and within a few seconds it seemed like the drivers side fan kicked up to a second speed. The passenger side did not, from what I could tell. I turned the A/C off and within a minute both fans actually turned off. Of course I did not run it long enough for the temp gauge to go above 1/2 so the fans turning off do not surprise me since the car was not running hot.

Guess my question is, do both fans have 2 speeds and could the one on the passengers side not be kicking into high when the A/C is on and that be causing it to get hot? Both the A/C and thermostat are on that same side.

Please feel free to comment. Thanks to all who are trying to help.

For those of you familiar with my previous posts about my 3.5L overheating, I wanted to ask this. For those not familiar, just do a search, you can find my posts.

Anyway, I have definatley narrowed part of the overheating problem down to turning the A/C on. When its on, the temp gauge will rise above the 1/2 mark and I have had it climb near the 3/4 mark on very hot days. When I turn it off using th "Econ" button within a minute or 2 it will drop below the 1/2 mark and usually stay there for the most part. Sometimes it will creep up to 1/2 but it usually will not go above it unless I turn the air on.

Now yesterday when I got home I had turned the air off so that it would be back down to under the 1/2 mark before I pulled into the drive. I got, popped the hood and saw both fans running. I turned the A/C on and within a few seconds it seemed like the drivers side fan kicked up to a second speed. The passenger side did not, from what I could tell. I turned the A/C off and within a minute both fans actually turned off. Of course I did not run it long enough for the temp gauge to go above 1/2 so the fans turning off do not surprise me since the car was not running hot.

Guess my question is, do both fans have 2 speeds and could the one on the passengers side not be kicking into high when the A/C is on and that be causing it to get hot? Both the A/C and thermostat are on that same side.

Please feel free to comment. Thanks to all who are trying to help.

Seems to me that both fans should kick up to a higher speed when the AC is turned on. You are getting closer to figuring this out.

I am having over-heating problems in my 99, The fans in my car seem to be running a the low speed. Is there a switch or a sensor that I need to check for the fans to kick into the higher speed?

1998 Olds Intregue. I'm wondering, are these temp, blower and AC problems connected? I was told I had a bad AC compressor last yr, they said coolant wouldn't last a wk. I had it filled anyway and it lasted all summer. This yr no ac again. The temp goes up when in traffic, but stays normal on highway, a mechanic said fans are working. Also the lower blower doesn't blow heat, put a new fuse in, no luck. Please help!

I wish I could give you guys techinical advice but I can do google searches. Here's a person who was as frustrated as all of you. There a couple of suggestions that may help. Hope it can help.

http://www.myhonestmechanic.com/articles/1999-oldsmobile-intrigue-overheating.shtml

I really appreciate any help I can get, so Thanx for the link. I'll start from scratch again, this problem started over a yr ago and I don't take long trips because of it. I got allot of good info just looking thru old posts. I do have a temp. checker and will do that 1st.

I was wondering if I remove the plastic covers infront of the rad will help the overheating problem. One other point many years ago I removed the lower air dam or what ever it's called, just thinking if it is a good idea to put it back on that may force more air in the rad area. I was also thinking of going to the bone yard a look for another rad. What are your thoughts

I was wondering if I remove the plastic covers infront of the rad will help the overheating problem. One other point many years ago I removed the lower air dam or what ever it's called, just thinking if it is a good idea to put it back on that may force more air in the rad area. I was also thinking of going to the bone yard a look for another rad. What are your thoughts

I would put back on the lower air dam. I doubt that the radiator is the source of your problem since it appears that the overheating only occurs in certain situations. Also, I fill my reservoir tank slightly above the HOT mark when the engine is cold.

Does the engine speed pick-up slightly when you engage the A/C? If this does not happen, the engine temp will go up. Also, have you checked the PCV valve? If this is not operating properly, the engine will run warmer.

What about the water pump???? Anyway that could be slipping occasionally?

Next time it overheats turn on the heater and put the selector so it puts all maximum heat. Try this with the windows down. Try it with A/C on and again with it off. What are the results?