AC blows ice while moving but mild at idle

[nadodude111]

hello! Sending an update. I installed a new (used) and free remanufactured Bosch compressor and reloaded with R12. Blows 40 f while idling and 40 while on the highway. Doesn’t cycle just consistently blows cold. We’re ready for Texas summer :)

[nadodude111]

hello! Sending an update. I installed a new (used) and free remanufactured Bosch compressor and reloaded with R12. Blows 40 f while idling and 40 while on the highway. Doesn’t cycle just consistently blows cold. We’re ready for Texas summer 😎🥶

[cory58]

Just found this thread. Assuming you are in the USA. Original E30 compressors can definitely be rebuilt. My Touring had a similar "basic" R134a conversion. The front seal in the Seiko compressor failed and I had it rebuilt by Discount Auto AC in Daytona Beach, FL. Great customer service and price. Replaced the condenser and drier at the same time (nothing under the dash) and been ICY ever since. Your situation is a little bit different - my compressor was still working fine when the seal failed, but it may still be worth your time to contact Discount Auto AC. Best of luck.

[nadodude111]

We'll get you a refund right away.

t

Goodwill would never.

[TobyB]

this thread is useless because people would rather share political opinions about Freon type rather than answer my questions. People don’t take the time to read either or you’d see I posted the pressures.

Idling: Low: 50 and high: 115. 6pm 85F ambient temp.

We'll get you a refund right away.

t

[nadodude111]

Here's your temp and pressure chart.
For 86 degrees ambient you should be about 32 degree on the evaporator, 30psi on the low side and about 175psi on the high.
yeah... you have a tired compressor.

thank you. First worthy answer. After some research, looks like I can still have the R-12 compressor rebuilt. May source another r-12 compressor at a junk yard to send off for rebuilding. Then switch them out so I don’t go weeks without AC.

[uturn]

Here's your temp and pressure chart.
For 86 degrees ambient you should be about 32 degree on the evaporator, 30psi on the low side and about 175psi on the high.
yeah... you have a tired compressor.

[nadodude111]

this thread is useless without high side and low side pressures.

The compressor on the ti is failing- below 1500 rpm, there's hardly any pressure differential at all,
but by 2000, it'll build to almost normal* and cool reasonably well.

t
*corrected for temperature and humidity.

this thread is useless because people would rather share political opinions about Freon type rather than answer my questions. People don’t take the time to read either or you’d see I posted the pressures.

Idling: Low: 50 and high: 115. 6pm 85F ambient temp.

[TobyB]

this thread is useless without high side and low side pressures.

The compressor on the ti is failing- below 1500 rpm, there's hardly any pressure differential at all,
but by 2000, it'll build to almost normal* and cool reasonably well.

t
*corrected for temperature and humidity.

[e30davie]

Like all good things the "nasty" stuff works best. and the replacement less nasty stuff often underperforms in direct comparison.

You could ague that if it was that cold it was overperforming - the bean counters approach.

[Panici]

R134a gas works perfectly fine in my Australian summer. This whole "R12 was the best" is just old thinking. A proper working r134a system is cold at all times. I still have the "apparently inefficient" r12 evaporator on my car and the AC is ice cold in 40deg C temps at idle.

I distinctly remember my dad's Pontiac 6000LE blowing literal FROST from the vents when you kicked up the fan speed.
I can't say I've seen anything even in the same ballpark from a modern system.

I know why we transitioned away from R12 and I'm not saying anyone should use it, rather just sharing a memory of how well A/C systems used to perform.

[e30davie]

You either have to do things properly or not at all. If I was in your shoes here's what i would do.

- find a proper AC mechanic who knows what they are talking about
- buy new TX valve to suit R134a
- buy new pressure switch to suit R134a
- buy all new O-rings (if they haven't been changed)

Get it all installed with R134a gas, and get it confirmed that the pressures are correct to R134a (it sais them on the gauge) before you pay the bill.

This is assuming your compressor is in good working order. if its not, youll never rebuild it. either get a new one (if you can) or convert to a sanden one.

Then youll never have to worry about it again.

R134a gas works perfectly fine in my Australian summer. This whole "R12 was the best" is just old thinking. A proper working r134a system is cold at all times. I still have the "apparently inefficient" r12 evaporator on my car and the AC is ice cold in 40deg C temps at idle.

[nadodude111]

[QUOTE=e30davie;n10126554]What did the guy say who checked it? doesnt he know about AC systems?

What pressure switch is in it to turn the compressor on and off? is it the right one for the gas you are using?

[/QUOTE

He’s a general mechanic and not well versed in e30s nor R12 Ac systems. He thinks it’s the expansion valve. The low side line was very cold while idling while the pressure side was warm but not hot. I’ll double check but the pressure switch looks to be the original R12 switch.

[e30davie]

What did the guy say who checked it? doesnt he know about AC systems?

What pressure switch is in it to turn the compressor on and off? is it the right one for the gas you are using?

[nadodude111]

Yep - aux fan is blowing air towards the condenser.

So just had the pressures checked at idle. Low: 50 and high: 115. I believe low should be at 25 and high at 160-200. Any ideas?