A/C leak impossible to find

[bimbim]

I have a seemingly impossible to find A/C leak in my 95 318ti. I cannot find any posts that relate to this.

I've tried the dyes, sealers, several times, but they all leak out after a week of use.

When charged, everything works great, ice cold blowing, no problem

After approx one week, the refrigerant all leaks out and its back to blowing hot.

I've replaced the suction valve with a new one, thinking that would solve the problem, but no.

There are no traces of dye anywhere in the system from the leak detector product I've used. The green black light stuff did not work, no trace of the dye anywhere, except maybe the suction line where I put it in, thats why I replaced the valve.

There is no smell of refrigerant inside the car, so the evaporator is not leaking, at lease Im pretty darn sure (please don't tell me its this).

I guess I need to get this professionally diagnosed, but don't want to ger ripped off.

Does anyone know of why it a major pita to find the leak?

Thanks

[Dr ///M]

Let me know if you find out the answer because I have the same problem. Thanks.

[bimbim]

If there is an impossible location for a leak, where would it be?

[Mallard]

after reading the post propperly...


checked the klima cooler obviously yes?

[bimbim]

klima cooler? you mean the knob that turns left to right that opens/closes the damper opening to the heater core?

[Mallard]

no thats the valve

i meant the radiator / condensor / cooler

[bimbim]

The expansion valve does make that machinery sound, kind of noisy. I know there is supposed to be a service advisery on that, but it cools when there is refrigerent in the system.

Are you saying that the valve may leak out in a location that can't be seen?

[Mallard]

...yup

[bimbim]

evaporator core is bad. I have a bently guide, but the pics are horrible, they look like neil armstrong walking on the moon.

[Philly]

i will have all AC parts for sale shortly, after you determine what your problem may be, let me know.

[E30/36Bubba]

Take your black light under the car and look up in the area above the front of transmission. That is where mine had drained the dye to the point that I could see it with out the light. This would mean the evarorator is done.

[FloridaTi]

I've been to two respectable ac shops wh both knew at the end of the day they weren't going to do the job, and with the same symptoms, they said the evaporator thing was leaking. They all seemed to think it was very common with BMW's. It was the first I have ever heard of such a thing.

[bimbim]

I used super seal after I last posted and its late June and its still Holding. So use super seal, comes in a white/red can cost around 20 bucks. Worth it.

so far so good, I'd recommend it for evap leaks.

[FloridaTi]

awesome. Thanks for the advce. I'l try it out.