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Lou P. master tech
Lou P. master tech, Mercedes Technician
Category: Mercedes
Satisfied Customers: 3740
Experience:  15 years master certified 100% fix rate and have access to factory radio codes, wiring, and instructions.
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What would cause a major loss of power when running the AC?

Customer Question

What would cause a major loss of power when running the AC? I have 91 Mercedes 300ce. mechanic is saying it's a tired motor. I'm thinking its might be the idle control valve
Submitted: 1 year ago.
Category: Mercedes
Expert:  Lou P. master tech replied 1 year ago.

Hello. Ca you explain more about the "major loss of power "? Does the engine run bad? Or just lose all performance ?

Customer: replied 1 year ago.
Its runs great idles fine. If I have the AC on at a light then try to go I have no power. I have to turn the ac off then the power restores and I'm on my way. Then I can engage the AC.
Expert:  Lou P. master tech replied 1 year ago.

Ok , so the fact that it runs good is a good sign. This sounds like 2 things. 1- the ac compressor is starting to fail so the bearing and internals are putting excess drag on the engine or 2- the freon is overcharged so the pressures are higher than normal and the engine has too much load on it. Have you had the ac properly evacuated and recharged ? How does it sound when it clicks on ?

Customer: replied 1 year ago.
I had it converted to R134A. Would a failing compressor also effect the heater. That doesnt work either.
Customer: replied 1 year ago.
I was checking my receipts and I already replaced the compressor1991 Mercedes 300CE A/C Compressor -(###) ###-####Denso - $208.35
Expert:  Lou P. master tech replied 1 year ago.

Ok so did this happen before or after the compressor replacement ?

Expert:  Lou P. master tech replied 1 year ago.

And no , it won't affect the heater.

Customer: replied 1 year ago.
After the compressor replacement.
Expert:  Lou P. master tech replied 1 year ago.

Ok , that tells me that it's either overfilled(most likely ) or the new compressor is faulty. Usually when you charge a older car with 134a you need to fill it to 75%-85% of the original charge since the freon is lighter. Hope this information helps

Customer: replied 1 year ago.
Ok thanks
Expert:  Lou P. master tech replied 1 year ago.

No problem. I'm here to help. Let me know what happens. Lou. Please take a second and click the box and rate my service GOOD OR EXCELLENT SERVICE if you feel I have been helpful and please request me in the future. If you feel I have not been helpful please DO NOT RATE BAD OR POOR AND WASTE YOUR MONEY , I will opt out to see if another expert can provide more or better assistance so you're not wasting your money!!. Thanks for choosing just answer. Lou. also , if you feel i deserve one , BONUSES are GREATLY APPRECIATED ! 😉 Keep in mind then when you rate it does not end our conversation. you can still return here to me for follow up information if needed, Lou.

Expert:  Lou P. master tech replied 1 year ago.

I have taken my time to answer your question the

best i could and i will continue to help if you need

follow up information , all i ask is that you PLEASE

take a second to rate my service so i may recieve my

credit for assisting you. Thank you.

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