HVAC issues with high RPM

[chris1982]

i have 2015 Explorer base AWD with 46xxx miles, tried searching with the issue I’m having not much luck. Dealership told me it’s normal, want to ask if anyone else is having this problem. With hvac off “zero” air coming out the vents. If I give it gas to go uphill downshifting etc, hot air comes out the vents till it shifts back up. The dealership says the engine is taking vacuum from the blend door at high rpm, gives it back after shifting. Still have CPO warranty wondering if they don’t want to touch it without money from me.

 

[peterk9]

Welcome to the Forum Chris.
I don't recall this situation being talked about before so I don't know if it's normal or not since my HVAC is never turned OFF. With a warranty the dealer will get paid by Ford if it turns out to be a warranty item. By the reply you received it sounds like the dealer/tech feels it is normal. Maybe some other members can jump in and give advice.

Peter

 

[traveler100]

i have 2015 Explorer base AWD with 46xxx miles, tried searching with the issue I’m having not much luck. Dealership told me it’s normal, want to ask if anyone else is having this problem. With hvac off “zero” air coming out the vents. If I give it gas to go uphill downshifting etc, hot air comes out the vents till it shifts back up. The dealership says the engine is taking vacuum from the blend door at high rpm, gives it back after shifting. Still have CPO warranty wondering if they don’t want to touch it without money from me.

Hey Chris I have same issue on our 2012 60K 3.6l V6 basic explorer. Started about 55K out of warranty, so the repair is on me. I assume we have a vacuum leak somewhere as I didn't loose dash air flow on hard acceleration for the first 54K miles. This forum or web hasn't provide much info on this generation of Explorers for this specific issue. I'm trying to locate the vacuum manifold (tree) on the engine that supplies vaccum to the HVAC system as a starting point to isolate the leak. A vacuum diagram would be helpful to start the leak search, but haven't found one yet. If I do I'll post the link. We're leaving for a road trip during the month of September, so I'm looking hard for some input and repair suggestions prior to 9/1/18

 

[Jon M]

My HVAC is never off, but it does shut down on hard acceleration, by design. I think, after reprogramming for the exhaust smell issue, it's a lot more prominent. It's certainly more noticeable than it was in my '13.

Every vehicle I've ever owned has done it, but it has always been more noticeable on my Fords.

I'll try to remember to shut the HVAC off and see if I get warm air next time I'm out.

 

[traveler100]

My HVAC is never off, but it does shut down on hard acceleration, by design. I think, after reprogramming for the exhaust smell issue, it's a lot more prominent. It's certainly more noticeable than it was in my '13.

Every vehicle I've ever owned has done it, but it has always been more noticeable on my Fords.

I'll try to remember to shut the HVAC off and see if I get warm air next time I'm out.

Oh my Jon M, did you just save me a lot of time and frustration. Since you mentioned the cabinet exhaust odor that's exactly when we started noticing the hard accelerate issue with fan speed change. It was after the "Courtesy Inspection" and I believe reprogramming was mentioned by the Tech, but I never put two and two together. I knew Ford had always disengaged the AC clutch on hard acceleration, but not fan speed.
Thanks again Jon M!

 

[chris1982]

Thanks guys for chiming in on this issue, my wife and I are starting to believe this was programmed with the recall for CO’s. I haven’t looked for the blend door motor in my explorer yet, but online the part looks electronic. The dealership told me it was ran off vacuum? I may try to ask my neighbor if he is having the same issue too.

 

[sheltonfilms]

That vacuum bit is a load of crap. That was an issue back on the 2nd gen (95-2001) Explorers when they used vacuum actuators.

All actuators on 5th gen are fully electric.

 

[traveler100]

That vacuum bit is a load of crap. That was an issue back on the 2nd gen (95-2001) Explorers when they used vacuum actuators.

All actuators on 5th gen are fully electric.

Nothing's a load of crap until you understand the nature of any issues. All one can do is rely on past experience. But thanks for your input. I did learn that all actuators are electronic from your post. I'll ignor the "load of crap" comment.

 

[SeanK]

I have an '02 with the same issue. It cuts off fan and a/c under a load. I knew Ford did this under WOT but even under load? Strange. Doesn't do it under acceleration though. Vacuum resevoir problem, maybe?

 

[chris1982]

Took a lot of digging, but I believe this answers my question. What are the odds of asking to go back to the original program. Seeing how I work in a refinery and have access to CO readers, time to put the explorer to the test.

Thanks everybody that commented this post

 

[bigtexan99]

i have 2015 Explorer base AWD with 46xxx miles, tried searching with the issue I’m having not much luck. Dealership told me it’s normal, want to ask if anyone else is having this problem. With hvac off “zero” air coming out the vents. If I give it gas to go uphill downshifting etc, hot air comes out the vents till it shifts back up. The dealership says the engine is taking vacuum from the blend door at high rpm, gives it back after shifting. Still have CPO warranty wondering if they don’t want to touch it without money from me.

After the CO2 repair/recall, I noticed that If I'm running with the AC on MAX, as soon as I pass 4K RPMs, you can tell that the MAX disengages (to allow fresh air in) because the fan noise drops considerably. After about 5 or 7 seconds, the MAX re-engages (the MAX light stays on the whole time) and you can hear the fan noise increase. Since you are running with the AC OFF, it sounds like its still opening the fresh air vent and with your AC off you re getting a blast of hot air.

 

[sheltonfilms]

Nothing's a load of crap until you understand the nature of any issues. All one can do is rely on past experience. But thanks for your input. I did learn that all actuators are electronic from your post. I'll ignor the "load of crap" comment.

I was referring to the OP’s post of where the dealer stated it was a vacuum issue. I don’t have a problem with someone being ignorant on a subject unless it is their job to know it. That’s my gripe.

 

[traveler100]

I was referring to the OP’s post of where the dealer stated it was a vacuum issue. I don’t have a problem with someone being ignorant on a subject unless it is their job to know it. That’s my gripe.

Thanks for clearing that up, as I thought your response was in regard to my input. The issue acted like vacuum loss, as my grandson would say from the olden days. Oh and thanks for the info HVAC actuators. Never liked vacuum operation, but guess it was the least expensive way to operate systems.

 

[ProjectSHO89]

The last Explorers that used vacuum to control anything in the HVAC system were the 2010 models. All electric starting in 2011 MY.