What radiator did you put in? I had two bad Nissens from different retailers. Both times, my truck runs at like 188 on the freeway up to around 70F then creeps up from there. I get fed up with trying to get a Nissens one so I bought an Allisport which I'm hoping to put in next week. I've been running my truck with a severe duty clutch and only in mild weather so it hasn't been a problem except for long climbs up to Tahoe or Yosemite.

 

nissens

Can I ask how you knew they were bad ? Did you get one from someone else that changing out the radiator alone fixed the problem?

 

The radiator I pulled out was fine but old and i was running 177-180 on the highway up to 85F prior. I never could get the Nissens to cool down to 177 unless it was below 50mph. I would have put my old one back in but I did it my friends shop and they tossed it for me. Sadly we didn't know the Nissens was bad until it was too late.

I could also tell something was off with the Nissens because it would go from 188F while sitting in traffic down to 168F once got moving which made me suspect it was kind of clogged. Couple that with really quick to rise temps when climbing grades even with my tstat out pretty much pointed to a bad radiator. My WP was installed only 15k miles ago so while it could be on its way out, that's pretty unlikely given its age and low miles.

 

So you are about 10-15 hotter with the thermostat in it sounds like. That should not be the case, your thermostat element might not be opening up enough. PM me with your order # and I will send a replacement. I am still not sure you can't rule out a plugged radiator. I have a Nissens sitting here that worked perfectly I just pulled it out due to age (end tanks get brittle and crack) if you want to pay shipping I can send it to you for testing although I would be cautious running it long term with a pressurized system. Keep in mind throughout your testing and improvement work you have added substantial load with your lift, tires, roof rack, and winch and your truck will probably never run below about 200 at 70. I am sure we could get some comparisons using MAF readings but my guess is your rig is using substantially more air and fuel which equals BTU's the radiator has to get rid of and it just was not big enough from the factory. I am guessing you are probably getting around 10-12 mpg at that speed right? And 80, well its your decision but I am uncomfortable driving D2's at that speed for any period of time at that speed.

 

I don't drive it 80 very often for the same reason - maybe occasionally to pass someone - but wanted to see what the temp would be yesterday.

I ordered both a 170 and 180 T-stat from you and have been running the 170 the last week before I changed the radiator hoping it would help (although I know once its open, the T-stat temp doesn't make a difference).

So before we start shipping parts around the country, let me put the 180 back in today and go for a drive to see if it gets me closer to the temps I was seeing with no T-stat at all.

But I think you said it best - I should be focused on a goal on running something around 200-205 at 70 mph when it is 90 degrees outside with the load I have created - not some unobtainable temp in the 190's like others are able to get but probably not pulling the weight or wind resistance of my rig.

I will let you know what I figure out later today. Thanks for all the help.

 

That makes sense - you had a good baseline to know what temp you should expect with your rig before you installed a new one. Unfortunately I only have anecdotal evidence from other people like yourself and the "story" I got from the PO - something that has not been true for most things I was told including the "open checkbook" maintenance plan he told me he had.

I would really be interested to know about the Allisport radiator does for you - as Extinct stated, it seems like my best solution would be to find a radiator that has a better cooling capacity than stock one or the Nissens even when they work. I searched several forums but never found anyone that installed the Allisport and then came back to a thread to report if and how well it worked for them.

 

I am very curious in the allisport radiator performance as my truck runs about 188 all the time but when I was climbing a serious grade (mountain pass) in over 100 degree heat it will climb all the way to 230. It’s only happened a couple of times but I don’t like it.

 

So with the other Tstat - the 180 - installed I would say it was pretty much the same as with the 170 installed. Maybe a little better. At 70 mph, AC blowing full and the temp around 85 today I was between 206 - 210 mostly sitting at 208.

If I turn off the AC it drops down to 202-206. If I slow down to 65 but leave the AC on I get the same 202-206

At this point - i guess I can keep changing out parts - better water pump to increase flow (like the more expensive Airtex?),bigger fan like the Dorman 620-112 and the 2991 Severe Duty Clutch?, Different higher capacity radiator (not sure this exists), better AC Fan, different coolant?

Or do I just live with the idea that with my load - 2" lift, 33" tires, winch, roof rack, rock rails - I can going to run 210 at 70 miles an hour in the summer in Texas with the AC blowing.

Or do I just bite the bullet and do an LS swap and get rid of all of this?

 

@FtWDisco2 Well I have a 2 inch lift, 155 lbs on the roof ( RTT & Rails) 30.5 tires, rock rail steps and I still run well under 200 at 70 201 ish running A/C at 90 deg uphill, in BC everything is uphill. @acg on here is much heavier winch, winch bumper etc I, believe he is in the same range as me temperature wise.

 

I’m running 33s with rtt, arb with winch, and bumper lights. I used to run the same with 31.5 prior to swapping the rad without issue being 177-182 up to about 85F.

I’m hoping the upgrades allisport will bring me back down to those temps so I have good cooling overhead on long steep grades without having to resort to the severe duty fan like I’m running today during the warm weather.