Well as ive started to put some kms on the new motor ive ran into this issue as i got stuck on the 401 toronto traffic jam at the 400/401 this weekend going to Street Classics. Car when driving at normal cruise speeds usually sits about a 1/4 and as traffic got bad and was crawling the temps started tp creep up to about 1/2 and there was no way i was going to stay on the hwy putting along with the temp rising. Once i got off the hwy and took the streets and resumed driving at normals cruising speeds the temp came down gradually. I noticed this issue when i was going in for etest and i let the car idle for about half hour and came back out to see that it was about 3/4 so i shut it off and once i started it up and went on my way to the etest it came down again. I havent looked at the car since to try and figure it out but im guessing either a fan issue in the tune possibly or have to crack the bleeder if there is some air in the system. What should i look for in the tune to make sure its at the right specs?

Ideas?

fan.

I might still have my slp fan switch. But than again you can also tune your fans to come on when you are in highway traffic.

Looks like im going to have to screw with the tune as the the high/low rpm fan setting was set at 80*c for low and high for fan 1 and 2. So i changed them to the proper settings which should be 82.25 *C for low on both fans and 88.25*C on high for both fans which is suppost to be the recommended settings for a 160 stat. I also had to change the fan high low threshold from sitting at 0MPH to 35mph which will active the fans to come on sooner while in traffic as the temps go up and return to normal when back up to speed. Have yet to sit in traffic or let it idle for a long time to see if its going to do it again!

Settings changed and still no high fan kickin on while driving

i had issues with my fans... still have, but with one now. ended up being my chip on the ecm. do you have access to a GM manual for ur car? those things are handy (2 binders of 3 inches plus a manual). thats how i found it was my ecm. for your second fan, check voltages, relay, use the multimeter in ground setting and check any wire is grounding proper or not. its "scientist work" lol

I will go for the thermostat valve maybe it's not openning enough sometimes.

what are the odds it only sticks in slow traffic. its a fan/ airflow through the rad issue

+1

Vetty, check you high fan speed relay...you have 3 fan relays, all under the hood.

Well took a look at fan issue again and for some reason i dont think my car which is a 94 came with a Fan 3 Relay as they are not pins for the relay to contact same with the Traction control junction they are no pins for a relay to sit in. The car never came with Traction control either. So i swapped out Relays 1 and 2 from my dads car and took it out for a rip to get the temps up to see if it would turn and on and big negative. So i think im going to run a fan switch to make life easier so i have full control and wont overheat when sitting idling.

You shouldn't need to run a manual switch. Either your settings are screwed up or the temp sensor for the pcm is not reading properly or your gauge sender is not reading right and the coolant isn't as hot as you think.

Well only thing I changed prior to checking the relays is change the tune temps to 82.25 for lows and 88.25 for highs which is what they should be for a 160 stat and changed the fan threshold from 0 to 30 mph in hopes they would turn on sooner. The temp sensor in the head came with the wp when I got it so it could be bad? Would that be the one that controls the fans or the one on the head? The one on the head came from my old motor that should have been working.

pump is pcm head is gauge