***urgent*** i'm having a baby tomorrow 12/20/2012!

[HardCorps325]

2003 MDX Touring w/ Nav

Cabin heat only gets 10-20 degrees Farenheit above exterior temperature, which isn't very effective in 30 degree weather. The problem existed before I completed the following:

• New OEM water pump from AcuraPartsWarehouse.com (previous ebay special leaked). The problem existed before the previous water pump was changed too.
• New water valve (previous had a hairline leak).
• Thermostat changed in 2010 (shouldn't affect this issue, but what the hell). I believe I used a high-temp unit which should allow coolant to get hotter before opening. The units are either 170 degree for OEM or 180 degree for high-temp, so I didn't expect a big difference anyway.
• Air mix motor assembly verified operational by me. I grabbed a flashlight and a screwdriver and got under the dash.
• Mode motor assembly not visually verified, but there is a distinct change felt in the air from the vents. ***
• Blower seems to be working because there is significant air flow.
• Numerous flushes and even used CLR isolated to the main heater core through the firewall.
• All air removed (No rushing water sound anymore).

Here are some of the experimental controls and variables in place:

• Climate control set to max heat (90 degrees Farenheit) which should take internal cabin temperature sensors out of the loop. I verified that the water valve opens and that the blend door moves.
• When enabling rear controls, no heat comes from the rear either. From looking at the set-up, both heater cores are in parallel, not in series, so I can't see how one would affect the other.
• I have 50/50 mixed coolant and verified that it is full. I'm slowly adding full strength from now on to help keep the fluid hotter until I find the real problem.
• After idling for 30 minutes with an exterior temp of 37 degrees Farenheit:
  • The inlet to the main heater core after the water valve is hot.
  • The outlet from the main heater core is luke-warm.
  • The top radiator hose is hot.
  • The bottom radiator hose is luke-warm.

I really don't think a bad main heater core could cause problems with both heater cores. I thought it might be a flow problem, but where could it be. A flow problem could be what caused my previous water pump to fail after 2 years. Remember, the problem existed BEFORE I changed the water pump last time. I tried to take it to Acura in Woodbridge, VA but the technician thought the heater cores were in series and that a flush would fix the problem. Well, I've been around long enough to know that flushes are good for preventative maintenance, not corrective maintenance in most cases. Now, if they can do a high-pressure flush, we might find the restiction if there is one....

Please help!!!! I'm having a baby TOMORROW (12/20/2012)

[Bill_de]

Rent a car until the baby is home, then deal with the car. Priorities

And Congratulations.

[nsxtasy]

Originally Posted by Bill_de

Rent a car until the baby is home, then deal with the car. Priorities

Yup. Also, you have turned the car into a "DIY project", one that you are spending a lot of time playing around with various systems on it (and living with them not working properly for extended periods of time, due to problems you have possibly caused and clearly failed to fix in your DIY efforts), rather than a car that can be relied on to get from point A to point B in comfort. This is fine if you have alternative transportation, but it sounds like you don't. Otherwise, on those occasions when you need reliable comfortable transportation, like to get you and your bride to the hospital for the birth, you need to do something else. Rent a car or call a cab.

And if you need a car on which everything works pretty much all the time (which you probably will, with a child in the house), I recommend you buy a second car for your wife to use, and leave its maintenance to a professional.

[HardCorps325]

The professionals seem to know lesss about it than I do unfortunately. This is my wife's car. I have an 02 TL, and a 97 3000GT VR4. The 3000GT is a Mitsubishi so it's plagued with problems right from the factory (this is my 3rd one). My best gas sipper is the TL, so it's my commuter car. The MDX is my wife's car and she works in the same town we live in, so gas isn't an issue. She can't drive a manual so she can't use the 3000GT. Also, two car seats won't fit in the 3000GT either, and I find the TL to be very tight since my wife is going to want to travel in the back seat with our newborn and our 3-year old. My dad was a mechanic, so I grew up working on cars. I have a solid understanding of the basics. I also was a microwave multichannel radio technician in the Marines, so electronics is easy for me too. I also have a nazi HOA manager that lives across the street from me that fines me for looking under the car for leaks (sarcasm).

This problem with the MDX seems to have everyone baffled so I figured I try out the forums which have always seemed to help. I myself contribute to the 3SI.Org forums regularly regarding 3000GTs. Since I work 60 hours a week, and don't have much $$$ to play with, I am forced to do everything myself that doesn't require a lift. If it's something outside the car, I do it at night with a flashlight strapped to my head.

Right now I'm seeking advice regarding anything that I may have missed, overlooked, misdiagnosed, misunderstood, etc. I have been using the exploded view diagrams from AcuraPartsWarehouse.com as reference material. Your assistance is appreciated.

[HardCorps325]

Originally Posted by nsxtasy

Yup. Also, you have turned the car into a "DIY project", one that you are spending a lot of time playing around with various systems on it (and living with them not working properly for extended periods of time, due to problems you have possibly caused and clearly failed to fix in your DIY efforts), rather than a car that can be relied on to get from point A to point B in comfort.

I don't know how I could have caused any of this being that I never worked on it until this issue arose, other than the standard oil changes and such. Based on what I mentioned before, Do you see anything that I could have messed up? I had the timing and water pump done by a mechanic. I only messed with the other components personally.

[nsxtasy]

Sorry, I really don't know what the causes are of the problems you're having. Hopefully someone else here can help.

Incidentally, you say that the MDX has everyone baffled, but you didn't trust what the tech in Woodbridge said. I don't know anything about that dealership, but I can tell you from experience that some dealerships are much better than others. One advantage of dealerships is that they work on the same kind of cars all the time, and they communicate problems and solutions back and forth with Techline, the service at Acura HQ that tracks the frequency of problems and diagnoses ones that local dealerships have trouble with. You might want to consider giving a different Acura dealership a try. Or a really competent independent mechanic. (EDIT: As noted below by Tim, it's also possible that the diagnosis by the Woodbridge tech is accurate.)

I think your best bet is still to rent a car (or call a cab) for the trip home. You need a reliable, comfortable, and BIG car. Whatever cars anyone has, every once in a while you run into a special situation where you need a kind of car you don't already have in your garage. You might want to rent a minivan or request one from a cab company. Sounds like you're just talking about a single one-way trip, so a cab ought to do.

[hondacuraplanet]

The tech is correct. I have seen this exact problem only once before, on a 2004 Pilot. The heater core was about 75% plugged, which caused everything that you described, verbatim.

As an aside, I did Mitsubishi parts for 4 years. You couldn't pay me to own one.....

[nsxtasy]

Originally Posted by hondacuraplanet

The tech is correct. I have seen this exact problem only once before, on a 2004 Pilot. The heater core was about 75% plugged, which caused everything that you described, verbatim.

And don't forget, much of the 2004 Pilot is the same as the 2003 MDX.

[HardCorps325]

Originally Posted by hondacuraplanet

The tech is correct. I have seen this exact problem only once before, on a 2004 Pilot. The heater core was about 75% plugged, which caused everything that you described, verbatim.

As an aside, I did Mitsubishi parts for 4 years. You couldn't pay me to own one.....

LOL. I don't even like Mitsubishis! But the 3000GT is a sweeeet looking car, even by today's standards.

Thanks for your help! I appreciate it.

[HardCorps325]

Originally Posted by hondacuraplanet

The tech is correct. I have seen this exact problem only once before, on a 2004 Pilot. The heater core was about 75% plugged, which caused everything that you described, verbatim.

If it is the main heater core, any idea why the rear heater core isn't working if it has unobstructed access since it is in parallel to the main heater core? I would think that the rear would be hot as hell and the flow would have a much faster rate without the main heater core in the mix.

[kokerj]

Any chance you installed the thermostat backwards?

[HardCorps325]

Originally Posted by kokerj

Any chance you installed the thermostat backwards?

I'm 100% sure. I don't think it'll even seat properly if put in backwards.

[osb]

Not trying to steer this in the other direction..but damn dude. Way to wait last minute to make sure your car was drive-able.

=|

[Bill_de]

Originally Posted by osb

Not trying to steer this in the other direction...
=|

Of course you are!

[hondacuraplanet]

Originally Posted by HardCorps325

If it is the main heater core, any idea why the rear heater core isn't working if it has unobstructed access since it is in parallel to the main heater core? I would think that the rear would be hot as hell and the flow would have a much faster rate without the main heater core in the mix.

After thinking about it, I remember one other such circumstance where someone had tried to stop a radiator leak with what we used to call "rabbit turds in syrup" (aka Bar's Leak). It got into everything but the actual lines going to and from the cores, and stopped up both cores like leaves in a sewer grate.