Hey all. New to this site but owned my 1500 conversion van since new in 03. Only has about 59k original.
I've had issues with the ac for awhile now. I've replaced the compressor, front expansion valve, drier, and condenser. Ive taken care of what I had initially thought was an overheating issue due to a faulty ac system. Ended up replacing radiator and flushing, replace thermostat, fan clutch and burp system. Even added 2 pusher electric fans on condenser. Runs at 180-186 consistently now. With ac on in hotter temps engine temp slowly climbs sometimes as high as 216. When running the ac after numerous vac and recharges temp at vents get to 40ish when it's ambient temp is 73. When it gets upwards of 95 degrees, vent temps are only 73 at best. I also notice that vent temps gradually get warmer if I am at a higher fan speed (compressor always engaged). Can't seem to figure out where I went wrong. I am by no means an ac guy so any input would be awesome before I rip my hair out.
Thanks folks!

 

If you can get to it easily, pull the blower fan out, and see how much crud has accumulated on the evap core. Probably need to clean that out. Make sure the condenser is clear as well. Probably wouldn't hurt to just flush it with a hose..... blow all the accumulated crap out. (condenser, not the evap core. )

Running hotter with a/c on in high temps isn't a surprise. So long as the engine temp stays in the 'safe' range, yer good.

 

took blower motor out and cleaned the little bit of crap in there. The condenser is literally a week old and no restrictions there. But no matter what the temp is outside, the coolest I'll get thru the vents is at most 15-20 degrees less than ambient temperature. Even with a laser thermometer, the temp of the block of evaporator is same as air temp coming out of the vents, so no restrictions in the box.. I may have accidentally added a little bit too much oil when putting new compressor in. I tried to empty some from the compressor but to no avail. Last thing I can think of is that some way some how that extra oil is sitting in the bottom of the evaporator itself?? Tried to blow compressed air thru the evaporator but got very little to come out. Maybe I'll have to bite the bullet and try to remove the air box and get this blasted evap core out.. also do notice that with ac on, engine temp gradually keeps rising until I turn the ac off, driving or not. any other suggestions?? Ideas??

 

These things have a valve that cuts off the coolant flow to the heater when you have recirculate going. Mine has a second valve someone added the I can manually cut the flow of hot coolant to the heater core. Makes a big difference in the temp coming out the vents. Doubt it would do anything for the engine temps going up though.

 

I haven't swapped out that valve yet for sure. I can put a manual shutoff and see if it helps. Its odd too because if the van is leaning forward on an incline, sometimes the ac gets colder and engine temp goes down. Like there's some kind of blockage. Very strange.. Thank you for the input.

 

Might not be a bad idea to pay someone to completely evac the a/c system, and recharge it.... make sure you have the correct amount of refrigerant/oil.....

The 'runs cooler at angle' thing does indeed sound like an air pocket in the cooling system somewhere. I know the truck are notorious hard to get all the air out.....

 

I've evaced the system and recharged multiple times with the exact 2.87 lbs with the rear ac system it says on the sticker with a robinair shop machine. I've bled the cooling system for an hour and a half with one of those big coolant bleeding funnels higher than the level of the front heater core (highest point) and there are 0 bubbles in the system, unless I need to run it more than 90 minutes. I would understand the coolant getting hotter at a certain angle because of air pockets, but temp stays normal at any angle as long as the ac is off. It almost sounds as if theres some restriction within the ac system at certain slopes.. open to more ideas

 

Obviously, there are multiple issues going on here, there will likely be multiple solutions needed. The higher vent temperatures at the higher fan speeds are a sign that the evaporator is not getting cold enough, or heat is leaking into the air flow.

1. Those vent temperatures you're getting, is that at idle, or city driving, or highway driving?
2. When running the AC for a while, does one line get very hot and the other very cold, or do both feel about the same temperature?
3. Have you investigated your blend door to make sure it goes all the way to cold side and is not leaking heat into the air flow?
4. Regarding the climbing engine temperature, is that at idle, or city driving, or highway driving?

 

I'm not sure if this is true for all models, but for my 2000 for the first 3 indicators on the temperature ****, the coolant valve to the heater core is closed, after the first 3 it is open; regardless of the air flow selector switch position.

 

Ok. So vent temps at idle are at most 15-20 degrees cooler than ambient. City driving the ac temp goes down maybe another 3 to 4 degrees max and then engine temp gradually rising all the way up to about 210 when ambient temp is 90.

After running for awhile, low side line is definitely cooler but never gets below 60-65 according to infrared thermometer, this is same temp on evaporator side of expansion valve. The high line does get relatively hot, upwards of 130ish degrees.

I havent torn out the box yet and was hoping it wouldnt come to it since the evaporator itself isnt getting cold enough (flange sticks out from box)
but can certainly hear it move full sweep from hot to cold. when was sitting certain way, ac got as cold as 40 degrees on low.

The engine temp gradually goes up with the ac on whether its idle or city driving. Goes up much faster with city driving upwards of 214 if I don't shut the ac off and when the ac is off, it stays at 180. ( i did put a 180 stat in it since its now in a hotter climate. 85-100 degree days)