Anyone know why my heat and ac only blow through defroster vents when i step on the gas. Works fine otherwise. Everytime I step on the gas it switches to only top vents. Someone mentioned anoth vaccuum line or relay in a weird spot on their car. It was behind the headlight on their jeep. Anyone heard of anything like this on a taurus.
2007-07-08 11:58:16 · 4 answers · asked by jlm7852 1 in Cars & Transportation ➔ Maintenance & Repairs
Already took it to shop and all vaccuum lines were replaced. It still does it weather you use heat or ac.
2007-07-09 12:59:45 · update #1
You have a vacuum, leak somewhere. Where is the sixty four dollar question. It can be anyway. What's happening is when you step on the gas your engine for want of a better word is loading down. and your intake chamber pressure where your vacuum line connects to the intake manifold. is going positive meaning on vacuum. on your vacuum line.
To counter that you have a check valve on your vacuum line coming from your engine and a vacuum tank. The check valve keeps you from losing vacuum and the vacuum tank maintains enough volume of vacuum to keep all your vacuum operated a/c and heater valves working when your engine is not drawing a vacuum.
What is happening is you have a vacuum leak causing your vacuum to leak off. When your vacuum leaks off the vacuum operated valves and solenoids operating your a/c ducts will not stay open so all your air starts coming out your defroster vents.
Sounds like it is most likely going to be a vacuum line split a little at one of the connectors just enough for you to lose your vacuum when under hard acceleration but not enough to make you lose vacuum all together so when you are not in a hard pull you have enough vacuum to over come the leak and the system works ok!
Now for the fun part I hate. It is always my luck the lines that split have always been up under the dash making them hard to get to and hard to find the leak.
I hope I explained it where you can understand it a little. Always had trouble trying to explain a vacuum system in simple terms.
2007-07-08 12:21:40 · answer #1 · answered by JUAN FRAN$$$ 7 · 0⤊ 0⤋
When you step on the gas the vacuum is lost that controls the vent doors. I think that is why you are getting the air switched to a different location. Not sure if there is a cure.
2007-07-08 12:03:08 · answer #2 · answered by David 3 · 0⤊ 0⤋
I would say you are most likely looking at a vacuum line leak. Take it to a repair shop and have it looked out or you may be pulling your hair out for hours or even days trying to find it. The repair shop should have a schematic of the vacuum system and can generally pinpoint it fairly quick.
20 Years ASE Certified Technician
2007-07-08 12:02:39 · answer #3 · answered by Mark M 2 · 0⤊ 0⤋
You have a bad vacuum check valve. Not sure where it's located but it will be in the main vacuum line going into the passenger compartment.
2007-07-08 14:15:47 · answer #4 · answered by Ron B 6 · 0⤊ 0⤋