Not sure if this is in the right place but if not I apologize! I've got a 07 LbZ and the A/C will blow ice cold for a minute, then just cool for a few seconds then back to ice cold. My clutch kicks on and off at idle when on low blower settings but seems to cycle on and off less frequently when on the higher blower settings. I bought some stuff called kool-it from lubeguard and used it to clean my Evap coil but the problem still seems to exist? Thanks!
A/C blows ice cold then just cool then ice cold again?
- Thread starter LBZ_Baker98
- Start date
need to know the pressure readings of the a/c system. both high and low side with good gauges (not harbor frieght or those single gauge deals you get on a can of r134a at an auto store)
Check your high and low side pressures, compare to ambient outside temps, should be within range.
Maybe I'm just being picky, I put a digital instant thermometer in my center vent. When I'm driving temps fluctuated between 40*F and 44*F after idling for about 15 minutes temp at then vent was between 48*F and 52*F idling was done in direct sunlight. It's about 92 out here in Texas today! These temps seem normal?
When I was cruising it was ice cold. I was happy with the temps while cruising and okay with the temps while idling. Just was wondering if the temps were relatively normal? Is it normal for A/C temp to fluctuate a few degrees?
no it will get cooler at idle.
to accurately check temp, turn the a/c on max (recirc on and a/c on), blower motor at max speed, run engine rpm to 2k and then check vent temps after a minute or so when the engine cooling fan has kicked on.
yes it is normal for temps to fluctuate but generally not to the point you can feel the difference unless you are on a high blower motor speed and the vehicle is at idle with the engine cooling fan off.
I'd be looking at putting some t-stats in. At 92*, truck shouldn't be running that cool
That seems a little warmer then my lbz runs here in TX. If you haven't added and freon since 07 you are probably due for some. My truck was a little warm 2 years. The tech added some freon since it was low and it's been fine since.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
too much r134a can cause the same issues. its not a good idea to "throw some in" unless you look at the pressures that are being ran and even still, checking them now wont do much good if he cant get the cooling fan to engage. i have seen untouched systems hold a proper charger after 15 years. if its leaking out, the leak should be fixed. its not like a trans service where it should be checked and topped off
not having the engine cooling fan affects how well the a/c performance is. the condensor must have air coming across it to get the r134a to drop in temp enough to turn to a liquid. sitting there idling without the fan on and a/c going heat soaks the condenser and the r134a can not relieve enough heat from its self. pressures increase and the compressor starts cycling. 40-44* temps in 92* OAT is a really good temp when cruising. the temp coming back up tells me its a cooling fan issue. that should be address even before gauges go on as it will affect the pressures seen. the fan must be running to get accurate readings. otherwise you just chase your tail.
I've never been in an LBZ or LMM that had a fully engaged fan at idle unless it just stopped after pulling a heavy load up a hill or doing some other sort of hard work or there was a cooling system problem. I don't recall my coolant temps going over 185 either unless I'm pulling a fairly heavy trailer.
i have no issue doing it. turn a/c on, run idle up to 2k, sit there for a few minutes and temp gets hot enough to kick the fan on. this is 95+ degree heat too though. everyone brings me their broken shit when its the hottest out side.... go figure
Okay, it's only 88 today and cloudy but I parked my truck and put my high idle on which takes it up to about 1750rpms. Let it sit for about 15 minutes. The highest ECT i could get the truck to do was 203* not sure if thats enough to kick the fan on or not. Vent temp got to 52* and stayed around there. I haven't been able to get ahold of any gauges yet but still trying to locate some!
When I accelerated after being stopped whole testing Ac I could hear fan running. Also heard a wears whining noise coming from driver firewall area that I have never heard before. Sound increased with rpm and went away when fan turned off?