Overheating w/the AC on full blast in stop and go traffic

[VX KAT]

I had a Ron Davis racing radiator built and installed a few months ago. Got to give it a real test this week in Moab, temps in the high 80s, low 90s. I could run the A/C sometimes, as long as we were moving, but it would start to rise if we weren't moving for more than 5 mins. I'd shut off A/C and it really didn't make much difference, just went down a little. But it never officially hit the "H", and returned to normal when moving a little faster, even with A/C.

Others were having same issue with increasing temps. I don't have a scan gauge, but others that did said it was reading temp up to 220, Dumke said his was hitting 250, all w/o A/C.

Here's the thread on the aluminum radiator build:
http://www.vehicross.info/forums/sho...ight=ron+davis

Detailed specs on my Ron Davis radiator-

• Has more cooling capacity than OEM
• No plastic parts, all aluminum
• RD Part number 1-24RO9397
• Can call Bill Williamson at RD and order it with that number. He's SUPER helpful and explains everything in great detail.
• About $600.
• Bill Williamson
  Ron Davis Racing Products, Inc.
  7334 North 108th Avenue
  Glendale, AZ. 85307
  Tel- 623-877-5000 Ext.16
  Fax- 623-877-5001
• http://www.vehicross.info/showpost.p...72&postcount=5

MORE specs on my RD radiator:

• http://www.vehicross.info/showpost.p...2&postcount=25

[ojmagg]

I have the same issue. I'm fine till the outside temp gets to around 90 degrees...I've flushed my rad. Thermostat was replaced a few years ago...not sure what temp thermostat was used...

[crager34]

I was having overheating issues as well, all the time. What seems to have worked for me so far is a new OEM radiator, FFD Radiator Fan, new AC compressor. Finally installed the fan when I was in Nashville and it's been great since. I haven't been in the 90 degree heat yet, but mine used to get hot just sitting at a light.... most any weather... with the AC on.

Good Luck.

[VX KAT]

Talked to "Bill" again, at Ron Davis radiators to tell him about my Moab temp experience with the new radiator.

A few VERY IMPORTANT POINTS he made:

• DO NOT USE ANY OF THE COOLANT ADDITIVES!!!!! (LIKE PURPLE ICE, etc) IT WILL EAT AWAY THE METAL OF THE RADIATOR EVENTUALLY CAUSING IT TO LEAK. He's seen numerous customers have this occur and come back to RD claiming they built a faulty radiator.
  
  Bill explained it this way: The additives list a very detailed set of instructions on how to use it properly, but most users don't read the very long detailed info. Coolant that's been in for some time can form a buildup and coat the metal. This coating slows the erosion by the additive, but will still develop leaks. So the instructions on additives actually advise to wait until coolant has been in for a period of time, before using it. After the additive consumes the various minerals/metals in the coolant water, it then erodes the metal of the radiator itself.

• He heard that the RedLine additive doesn't do this, but ALSO DOES NOT reduce the temp.

• If you put a 2nd fan on the front side of the radiator, it actually blocks airflow and probably only about 30 percent of the airflow makes it through the radiator, so it's very unlikely to solve the problem.

Overheating was discussed in pretty good detail in a prior thread:
http://www.vehicross.info/forums/sho...heating&page=3

Seems like more and more folks are having overheating issues, wonder if it's due to age and/or miles accumulating?? ....or maybe global warming??

[VX crazy]

Talked to "Bill" again, at Ron Davis radiators to tell him about my Moab temp experience with the new radiator.

A few VERY IMPORTANT POINTS he made:

• DO NOT USE ANY OF THE COOLANT ADDITIVES!!!!! (LIKE PURPLE ICE, etc) IT WILL EAT AWAY THE METAL OF THE RADIATOR EVENTUALLY CAUSING IT TO LEAK. He's seen numerous customers have this occur and come back to RD claiming they built a faulty radiator.
  
  Bill explained it this way: The additives list a very detailed set of instructions on how to use it properly, but most users don't read the very long detailed info. Coolant that's been in for some time can form a buildup and coat the metal. This coating slows the erosion by the additive, but will still develop leaks. So the instructions on additives actually advise to wait until coolant has been in for a period of time, before using it. After the additive consumes the various minerals/metals in the coolant water, it then erodes the metal of the radiator itself.

• He heard that the RedLine additive doesn't do this, but ALSO DOES NOT reduce the temp.

• If you put a 2nd fan on the front side of the radiator, it actually blocks airflow and probably only about 30 percent of the airflow makes it through the radiator, so it's very unlikely to solve the problem.

Overheating was discussed in pretty good detail in a prior thread:
http://www.vehicross.info/forums/sho...heating&page=3

Seems like more and more folks are having overheating issues, wonder if it's due to age and/or miles accumulating?? ....or maybe global warming??

I want to know too, cuz on my other VX, took til about 110k miles to do this and it had newer ac compressor, my current VX has done it every summer since about 80k miles........hmmmmm

[ojmagg]

My overheating issue was solved by replacing the fan clutch...now I can hear the cooling fan when I hit the gas...

Although the diag was free, my garage wanted $370 for parts and labor ($70part)...I replaced it when I bought the VX back in 2002...it takes about an hr to replace. Did it myself...again. This time I greased the spring, as the old fan clutch spring was a little rusty...

[CrnCnn]

I figured I would ask in this thread because I am having the same problem here in Tucson when it gets above 100 and I have stop and go.

How easy should the fan clutch move by hand? I have a friend that says it should be pretty hard. Mine moves fairly easily. I don't want to spend $100 for nothing.

[VX KAT]

I figured I would ask in this thread because I am having the same problem here in Tucson when it gets above 100 and I have stop and go.

How easy should the fan clutch move by hand? I have a friend that says it should be pretty hard. Mine moves fairly easily. I don't want to spend $100 for nothing.

FYI -Talking to Merlin last week about fan clutch...there's been a redesign and you now HAVE to buy it (~$250....OUCH ) AND a new fan blade (~$100....OUCH again)...

[USMCvxOFFROAD]

this my have nothing to do with this but I just got a new job and moved my family to Pittsburgh from Lancaster county PA where i had been run nothing but pure non ethenal 89 gas now where i'm living i cant get that and i now have started having issues in traffic with the ac on and my check engine light has been on since the pure gas dried up maybe related or not i just thought i'd give my two bits

[tomdietrying]

My VX started running hot this summer too. It only happens if it's about 100 and I'm in stop and go traffic. When it happens, I turn on the heat, roll the windows down and it goes back to just below the half way mark very quickly. If I get on the highway afterwards, I cannot get it to raise up. It only happens in stop and go traffic when it's about 100 degrees.

I took into the shop a couple of weeks ago to fix the issue (also to fix my windows) it sticks. They replaced the hoses and a gasket. They said it was fixed. I noticed when I pick up my VX the fozzel on the door handle was a little different looking. I reached down to check it out and they had broke it. They didn't even get to my window either. Anyhow, they bought me another fozzel from St. Charles, but it's going to take 6- 8 weeks to get here. In the meantime, someone threw the old fozzel away and I have to drive around with a naked looking door handle.

Oh yeah, my over heating issue wasn't fixed. I took it back in and they replaced the thermostat. Long story short....it's still not fixed. They said the fan was working fine so they don't have an answer yet.

I'm going to drop it back off when my fozzel comes in.

Peace.
Tom

[CrnCnn]

I put new hoses and water pump on when I did my timing belt over Memorial day weekend.

I noticed the first summer I moved back to AZ that it will get real hot and the AC will not blow nearly as cold in stop and go traffic or when I am driving uphill a lot. Even the Moab trip in '08 we had to roll down the windows for the hills.

[princejazzbo]

glad to see i'm not the only one with this problem that can't seem to figure out the cause. I live in northwest arkansas and it has been in the upper 90's since i got my vx home a few weeks ago. on the interstate it's fine but in stop and go traffic it creeps up not quite to the h mark but close. did a scan a few weeks back and it was at about 226. replaced the clutch fan with a dual speed electric fan and replaced the theromstat. still does it. but if i kick the heater on it drops back down in just a few minutes. or if i start traveling about 40mph or more. guess i just need to fix my windows to roll up and down correctly and learn to deal with the heater on during summer traffic.

[PontiacPureBred]

OK this is from a complete outsider on this issue since I have yet to even purchase a VX, but classic GTOs have had this issue for years.

What we have found over time is a multi pronged attack. Of course proper cooling system (i.e hoses, radiator, fan, thermostat, coolant) looks like you've all tried this. We also discovered that the fan shroud itself made a HUGE difference on how the fan pulled. But in some cases that STILL was not enough, after further investigation it was discovered that fuel and timing were also a big part of the equation. With the inability to get leaded high octane gas it was causing detonation in the combustion chambers raising the temps, as would an engine slightly out of time or having a bad advance setting on the distributor. Has anyone looked to see if over time the timing belt stretches just enough to let it get a tad out of time, or if the ignition system needs tweaked? Just an outsiders observation.

[CowboyErik]

Bezare thread; had my VX for 7 years, AC has never failed or caused the engine, heat or anything to act up, in stopped, idle or highspeed traffic; something is going on with your unit, should not need to cut holes in your hood, has to be a circulation problem but sounds like you've been thru all that; if a compressor is putting alot of stress on the belt I guess that could overload and cause an abnormal heatup; bezare; my AC is ice cold, to cold, aside from the extra fan noise when I run the system I don't notice any strain on the engine

[evillecutter]

when i kick on my ac it does cause a little extra drag on my engine that is slightly noticeable - the rpm's go from 600 to about 750 at idle and it makes my exhaust sound just a little meaner - no difference in temp gauge though - new aftermarket ac compressor installed about a year ago when the bearings went out on the original - you could def hear when the bearings go out it gets very loud - its almost fall you could always get a shorter belt and bypass the compressor until you figure it out - might help from overheating in the meantime - also might tell you if its actually the compressor or not