04 Trailblazer heats up going uphill sometimes
October 2nd, 2019, 1:05 AM
#1
CF Beginner
Thread Starter
Join Date: Oct 2019
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
04 Trailblazer heats up going uphill sometimes
I already added the tranny aux radiator and flushed the tranny with all new fluid even replaced the pan with one that has a drain bolt.
Everything else has also been replaced. AC Delco 190 thermostat, AC Delco water pump, radiator is 2 years old. Fan Clutch is also new off the market. New CTS also. I tested the wires from the PCM to the relay 45 and fan harness and they show continuity. Using a OBD2 Autel I can read fan speed and it goes to 800 on the freeway. The fan seems to engage but when it goes hotter it doesn't seem to go faster. It's an off the market one not original. Truth be told I didn't check fan speed at higher temps. It gets up to 128 or 130 on a relatively short hill on the 405 at Sunset. I tested compression and it's at 205 on all. I used a vacuum gauge and it stays in the green. I tested the exhaust and the gauge showed 0 so no restriction from the cat. I flushed the radiator and filled it to specs.
The only thing I can think of is the speed of the fan. The 45 and 46 relays are side by side and one night the lights went out while on the freeway, and I know it's from the relay. I used the fog lights to the destination which was 2 minutes away and after shutting the car off and back on it was ok. I have a tendency to switch those 2 relays around so maybe that's why I sometimes get hot and sometimes not. On the relay number 4 contact that goes to the white wire on the fan harness shows ground only. I actually took out the relay and jumped 2 and 4 and the clutch got louder but not airplane loud. It went to only 800 or so Fan Speed which is low I did have the Autel opened at the fan readings. So jumping 2 and 4 did not provide the full blast airplane noise. Maybe the harness is not making full contact or the fan is bad. I was going to check resistance between the black and white wires at the harness going to the fan itself and giggle the connector at the fan to see if it changes anything.
Any advice would be appreciated
Everything else has also been replaced. AC Delco 190 thermostat, AC Delco water pump, radiator is 2 years old. Fan Clutch is also new off the market. New CTS also. I tested the wires from the PCM to the relay 45 and fan harness and they show continuity. Using a OBD2 Autel I can read fan speed and it goes to 800 on the freeway. The fan seems to engage but when it goes hotter it doesn't seem to go faster. It's an off the market one not original. Truth be told I didn't check fan speed at higher temps. It gets up to 128 or 130 on a relatively short hill on the 405 at Sunset. I tested compression and it's at 205 on all. I used a vacuum gauge and it stays in the green. I tested the exhaust and the gauge showed 0 so no restriction from the cat. I flushed the radiator and filled it to specs.
The only thing I can think of is the speed of the fan. The 45 and 46 relays are side by side and one night the lights went out while on the freeway, and I know it's from the relay. I used the fog lights to the destination which was 2 minutes away and after shutting the car off and back on it was ok. I have a tendency to switch those 2 relays around so maybe that's why I sometimes get hot and sometimes not. On the relay number 4 contact that goes to the white wire on the fan harness shows ground only. I actually took out the relay and jumped 2 and 4 and the clutch got louder but not airplane loud. It went to only 800 or so Fan Speed which is low I did have the Autel opened at the fan readings. So jumping 2 and 4 did not provide the full blast airplane noise. Maybe the harness is not making full contact or the fan is bad. I was going to check resistance between the black and white wires at the harness going to the fan itself and giggle the connector at the fan to see if it changes anything.
Any advice would be appreciated
Thread
Thread Starter
Forum
Replies
Last Post