Overland
NAXJA Forum User
- Location
- The Chihuahuan Desert
I have an 86 I'm thinking of converting, I'll have to check it out.
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96 XJ overheats at idle with air
- Thread starter Overland
- Start date
- Location
- MilkyWay Galaxy
What is missing from that chart is the fill, and cooling rate of the ambient air flow, ie. efficiency of the condenser and fan!!!! If you can get the outlet condenser internal temp down to 135 F (using 105 F ambient air)the high side pressure is only 196.9 PSI!!!! Mine runs at about 30 PSI low side, which is 35 F on the cold side evaporator (maybe too low as it can form ice in theory if it goes any lower), a little too low on the charge but I get colder air, and lower pressure and cooler over all running system.
I was looking at this.
Overland
NAXJA Forum User
- Location
- The Chihuahuan Desert
What's this static pressure with a temperature range only achievable before ten in the morning?
Overland
NAXJA Forum User
- Location
- The Chihuahuan Desert
That chart is confusing, as a static pressure would read the same on high or low side with the system inactive.
Last edited:
- Location
- MilkyWay Galaxy
The refrigerant reaches an equilibrium (static) pressure throughout the system when the AC has been off for awhile. That pressure varies with ambient temperature. If you have a static system with 20 psi at ambient that should be 80 psi, it is way under filed but still has a little charge and is thus still OK to recharge if there are no serious leaks
Overland
NAXJA Forum User
- Location
- The Chihuahuan Desert
I'll have to hang the manifold back on it and see.
Same song and dance yesterday, but switching to normal ac slows it down. I have to idle it up to at least 1300 to keep it down, and if it's allowed to get up, only driving it seems to help.
Maybe I just don't want to turn the air off when I'm idling in the sun.
Same song and dance yesterday, but switching to normal ac slows it down. I have to idle it up to at least 1300 to keep it down, and if it's allowed to get up, only driving it seems to help.
Maybe I just don't want to turn the air off when I'm idling in the sun.
- Location
- MilkyWay Galaxy
This is backwards of what it should be, I think.
"switching to normal ac slows it down"
That should increase the heat load on the condenser and compressor.
Edit, I take that back, thinking out load here, if the system is on Max AC, and the flow is restricted in the expansion valve (for any reason like dirt or..), the expansion valve is letting less refrigerant flow due to less heat load, and that backs up the high pressure side till the pressure switch cuts off the clutch) and higher pressure means more work for the compressor (that part is complicated, determining the work load), so maybe not, but I was always under the impression it ran hotter load wise on normal???
I wonder if they sold you the wrong water pump, the one with a reverse direction impeller, made for I think the grand cherokee? It has happened before!!!! Look up the part number they sold you. If it was the wrong pump in the box, you need to pull it to visually determine this. old_man has mentioned this issue here before I think.
Needing 1300 rpm to keep it cool on Max AC sounds like the wrong water pump to me, but I am no expert on that, never had that problem, just read about it here and do not recall the detailed facts. You might Google search it?
"switching to normal ac slows it down"
That should increase the heat load on the condenser and compressor.
Edit, I take that back, thinking out load here, if the system is on Max AC, and the flow is restricted in the expansion valve (for any reason like dirt or..), the expansion valve is letting less refrigerant flow due to less heat load, and that backs up the high pressure side till the pressure switch cuts off the clutch) and higher pressure means more work for the compressor (that part is complicated, determining the work load), so maybe not, but I was always under the impression it ran hotter load wise on normal???
I wonder if they sold you the wrong water pump, the one with a reverse direction impeller, made for I think the grand cherokee? It has happened before!!!! Look up the part number they sold you. If it was the wrong pump in the box, you need to pull it to visually determine this. old_man has mentioned this issue here before I think.
Needing 1300 rpm to keep it cool on Max AC sounds like the wrong water pump to me, but I am no expert on that, never had that problem, just read about it here and do not recall the detailed facts. You might Google search it?
- Location
- MilkyWay Galaxy
From post number 1:
"When jumped, the idle increases noticeably, but not quite to the 1k mark I expected."
Jumped???
"When jumped, the idle increases noticeably, but not quite to the 1k mark I expected."
Jumped???
- Location
- MilkyWay Galaxy
Dash gauges on Jeeps suck at accuracy. Have you used an infrared gauge yet at the T-stat housing to verify the actual peak temperature coming out of the engine? Is the new Temp sensor defective? I have yet to find a signal after market one that works on my jeeps. I may have a bad dash ground on one, but make sure it is not a sensor-gauge- or dash ground issue. Or an air bubble trapped under the sensor gauge in the block
Overland
NAXJA Forum User
- Location
- The Chihuahuan Desert
Yes, jumped. I used a wire with a pair of flat terminals to bypass the pressure switch on the power steering system so as to increase the idle. I thought about wiring it to the fog lamp switch (not factory equipped) but left it jumped when I realized it was a minor increase.
I had a Renix sensor in there before with an adapter made for the connection. Worked for a while, but being temporary, it started to read erratically. I know what you mean, though. My 4.0/AW4 would boil long before it got to the red. Would probably still be on the road had that not escaped me once between Albuquerque and Truth or Consequences.
It's not boiling, although once or twice I caught it doing so after shutting it off. I hadn't noticed the gauge when I parked, but when I started it to cool it off, it ran right up into the red before backing down. I always try to make sure I don't shut it down hot, and I'll start and run it to cool down in case I don't. Gauge seems accurate enough.
I had a Renix sensor in there before with an adapter made for the connection. Worked for a while, but being temporary, it started to read erratically. I know what you mean, though. My 4.0/AW4 would boil long before it got to the red. Would probably still be on the road had that not escaped me once between Albuquerque and Truth or Consequences.
It's not boiling, although once or twice I caught it doing so after shutting it off. I hadn't noticed the gauge when I parked, but when I started it to cool it off, it ran right up into the red before backing down. I always try to make sure I don't shut it down hot, and I'll start and run it to cool down in case I don't. Gauge seems accurate enough.
Overland
NAXJA Forum User
- Location
- The Chihuahuan Desert
Grands never had the 2.5.
Only difference in four cylinder pumps is what kind of sheave it comes with, V belt or serpentine.
Only difference in four cylinder pumps is what kind of sheave it comes with, V belt or serpentine.
Overland
NAXJA Forum User
- Location
- The Chihuahuan Desert
Also, on the normal setting, less air is crossing the evaporator. Less cool air inside equals less hot air in front of the radiator. The temperature exchange goes both ways.
- Location
- MilkyWay Galaxy
A bit more complicated than that. "Also, on the normal setting, less air is crossing the evaporator" But the air that is crossing the evaporator can be at 110 F on normal instead of at 75 F, so there is a huge increase in the heat capacity of that slower moving air transferred to the condenser and compressor and the compressor works harder (which is also cooled by the low pressure refrigerant flowing through it from the suction side).
Overland
NAXJA Forum User
- Location
- The Chihuahuan Desert
Well, I got a P0118 again, and a P0551 or something like that. Computer says "Hey, I see what you did there". Removed the power steering sensor jumper wire to no noticeable detriment, and when I kick on the air, the engine is pulled down for just an instant before stabilizing where it was before.
The sensor was recently replaced, then boxed and replaced again. It was from Tru-Tech, second line Standard part. Should I purchase a better quality sensor or chase the wiring up to it? I already worked up the connector to be sure it wasn't an issue, and it was installed without teflon or anything else in the threads to create resistance.
There were a couple of weeks between sensor replacement and the code coming up again.
The sensor was recently replaced, then boxed and replaced again. It was from Tru-Tech, second line Standard part. Should I purchase a better quality sensor or chase the wiring up to it? I already worked up the connector to be sure it wasn't an issue, and it was installed without teflon or anything else in the threads to create resistance.
There were a couple of weeks between sensor replacement and the code coming up again.
- Location
- MilkyWay Galaxy
118 sounds like a wiring problem, could 551 be related wiring?
Overland
NAXJA Forum User
- Location
- The Chihuahuan Desert
The P0551 was the computer's way of telling me it knew there was a jumper in the power steering pressure switch. It indicated a bad switch, probably because it was closed all the time. I removed the jumper and left the plug hanging, there is no longer a pressure switch to connect.
Basically all it did was open the IAC a little to compensate for spikes in line pressure during slow maneuvers. I had it compensating all the time to see if it made a difference. It didn't.
1100rpm is not enough to keep it cool when stationary, but slow cruising brings it back down immediately. I'm going to say it's the road debris in the condenser cutting airflow when parked, but the only other condenser I have to try is R12, so I'll just wait until I have the extra cash and buy one.
I'll get back when I do, may be a while.
Basically all it did was open the IAC a little to compensate for spikes in line pressure during slow maneuvers. I had it compensating all the time to see if it made a difference. It didn't.
1100rpm is not enough to keep it cool when stationary, but slow cruising brings it back down immediately. I'm going to say it's the road debris in the condenser cutting airflow when parked, but the only other condenser I have to try is R12, so I'll just wait until I have the extra cash and buy one.
I'll get back when I do, may be a while.
iwannadie
NAXJA Forum User
- Location
- Gilbert, Az
How about cleaning the condesor? They make sprays for just that job plus a vacuum or compressed air you should be able to knock all that junk out.
- Location
- MilkyWay Galaxy
Does not work on deeply embedded mini rocks accumulated over the years, plus corrosion and loss of fins. I am lucky to get 4-5 years on a residential AC window condenser.
Overland
NAXJA Forum User
- Location
- The Chihuahuan Desert
Yeah, it's just chock full of tiny rocks and bug bits. I've combed it, blasted it with steam, brushed at it, and there it is. There's really no saving the fins or making it any better than it is.
I feel like a bit of fine expanded stainless behind the grille would deflect a lot of the crud, or at least slow it down some without disturbing airflow.
Them things is expensive, got to make it last forever.
I feel like a bit of fine expanded stainless behind the grille would deflect a lot of the crud, or at least slow it down some without disturbing airflow.
Them things is expensive, got to make it last forever.
iwannadie
NAXJA Forum User
- Location
- Gilbert, Az
I'm sure people have done this and I will google after I type this. Why not a piece of screening to block stuff. Maybe removable for offroading when bugs and dirt are at the worst and easily replacable when it clogs.
