[re_guderian]

Well I finally got my OBD-II cable for my '95 FZJ80, and thought I'd collect some data on my cooling system. Some background...

• AC works great, except on super-hot, low speed situations. Will blow ~58 deg. Otherwise blows 40-45 deg.
• Trying to assess health of cooling system in preparation for towing a pop-up all over AZ, all year long, meaning lots of hills and temps up to 115 deg.
• Blue fan clutch purchased last year. Modded to open at 95 and filled per LandTank's instructions with 7000 CST OFNA fluid from the hobby shop.
• I have a bunch of crap in front of the grill, ARB, winch, and winch control box, and dual batts in the engine compartment.

Went for a drive last Friday to test it out. Test conditions:

• Ambient was 110 degress, 4-5 PM. Low humidity
• AC on.
• I'm running stock gears, 255-85-16 MT's, winch, ARB, rear bumper, snorkel, new air filter...
• Mostly flat terrain. The only hills I could find were short (< 1 mi. in the Ahwatukee foothills) without blowing $50 on gas to get to some long, steep ones.

Conclusions:

• Well, I'm "pretty" happy with my cooling system, but think it could do better at slow speed situations. peak was 212 deg.
• OBD-II doesn't monitor AC temps, but I had a thermometer in the vent, and at any speed above 30 MPH, it blew 40 deg air. Under 30 MPH, vent temps went up to ~60. Coolant temps ranged from 195 (once warm) up to 212 just after freeway run and idling in driveway, but stayed mostly in the 195-205 range, with expected behaviors for engine load, speed, hills, etc.
• Need to check AC charge levels and verify correct.
• Need to check belt tension/condition. I don't think these are OEM belts.
• Assuming all is good with the AC charge and belts, I'm not sure whether going to a thicker oil or a seperate pusher fan would be the best course to help the slow speed AC performance. At 110 ambient, the fan clutch valve should have been fully open just sitting in the parking lot... More, and thicker, oil might help. At shutoff, the fan will only spin one blade position when rotated by hand.

Graph data:

• Total test time = ~70 minutes.
• x-axis is seconds of the test. Left Axis is vehicle speed (line in green), right axis is Coolant Temp (in red on graph).

[CappyKD]

Interesting results. Which radiator do you have? I'm planning on doing the JDM electric aux fan to help keep things under control.

[re_guderian]

Originally Posted by CappyKD

Interesting results. Which radiator do you have? I'm planning on doing the JDM electric aux fan to help keep things under control.

Pretty sure it's OEM aluminum. I haven't changed it, but I've only had the truck 2 years, 4K mi. BTW, truck has ~152K miles on it now. PO had flushed well, running Toyota Red coolant.

[alaskacruiser]

great data. I can't do that kind of detailed logging with my ScanGauge (can I?) but I will post temp results with my unmodded new blue fan clutch and aux fan shortly.

[re_guderian]

If I get time and gas $, I'll re-install the OEM silver base fan clutch and wait (not long) for another 110 degree day...

[CappyKD]

you can do the extra logging with a scangauge if you get the data logging option.

[re_guderian]

Originally Posted by CappyKD

you can do the extra logging with a scangauge if you get the data logging option.

Freeware at

http://www.werner-digital.com/obd/software.html

should work with any cable setup. I got the elmscan 5 unit, but no software. Freeware is out there for real time and logging.

[CappyKD]

I'm dying to hear what happens as I'm fighting a hot running truck right now. I live inland in SoCal and it gets pretty hot here. (100 the other day) I have the hayden aftermarket replacement in the truck now (I just switched from the blue hub that was in the truck when I got it.) I also have a Landtank modified New bluehub on the way, so I'll try to gather some comparison data but my damn trucks not ODBII so I can't use my scangauge II.

[cary]

Your results are pretty consistent with what I have observed on my truck with a new blue hub clutch, thermostat, and radiator. When it was 108-110f here, I would see about 200-205 on the freeway, with it getting to 210-215 under full throttle long climbs. Sitting waiting 15 minutes at the drive through, same conditions after coming off the freeway, I was at 210-215F. Like you, A/C performance suffers considerably when stopped. I found at things like drive throughs in really hot weather, throwing the truck in neutral and bringing the RPM's up to about 1500 get enough air moving (you can hear the fan roaring) that the temp stays down and the A/C holds it own.

[alaskacruiser]

Originally Posted by CappyKD

you can do the extra logging with a scangauge if you get the data logging option.

Cappy- I just searched the ScanGauge website and I cannot find any mention of this data logging option. Would you mind posting a link? Thanks!

[CappyKD]

I'll call Ron the owner of Linear Logic (the company that makes scangauge) It was supposed to have been out about 6 months ago.. I'll post up a follow-up after I talk to him..

[TroutBear]

Brief hijack - How do you like your 255/85-16s? Had them for ?? miles? driving type mix is? What did you have before these?

thanks

[re_guderian]

Originally Posted by TroutBear

Brief hijack - How do you like your 255/85-16s? Had them for ?? miles? driving type mix is? What did you have before these?

thanks

So far so good, but I got them used, with over 50% tread. I had 305/70/16 MTR's on there. I'd really like to go 35x10.50 soon. No problems airing down to 16-18 PSI. Mostly AZ dirt and rocks. I've only put about 2K mi on them in the year they've been on. Better road manners than the worn MTR's, for sure.

[re_guderian]

Bleh. Put the manifold gauges on the AC tonight and both high and low side were low. Will have to round up a shop to find out where it's all goin'...