DCCV in 2002 LS V6

shorod · 09-28-2007, 12:07 PM

+1 for a DCCV causing an air conditioner performance issue in a 2002 LS. I tackled my wife's last night and the DCCV appears to have fixed the issue.

On hers, the A/C blew very cold when set to 60 degrees. However, with an ambient temperature in the 80's, a temp setting of higher than 66 degrees would cause heat to start blowing.

I performed the climate control self test as well as connected my scan tool to the car and queried the system. No faults. The datastream for the climate control system was interesting as well. The ambient air temp sensor was reading accurately as were the various in-car temp sensors. I also checked the position sensors for the doors and they were all reading what I would expect. After doing some research here and on some other forums, I decided to try a new DCCV, even though I was not noticing a difference from the passenger side to driver's side.

When I got the new one installed successfully, I decided to tear apart the old valve. What I found was that apparently if was sticking due to coolant making it past the seals in the solenoids. Both solenoids had traces of coolant in them, even though it appears they are not intended to be immersed in coolant. Also, some of the coolant appeared to have caused one valve to stick, which is probably why at a setting of 60 degrees, the valve was able to close, but during modulation, the valve would heat up and stick in the open position, allowing coolant to pass to the heater core.

What I don't understand is why, even though only one valve appeared to be sticking, the temp from both driver's and passenger's side seemed the same.

From the short amount of driving the car and getting the coolant up to operating temperature, the DCCV appears to have fixed the issue, but I'm curious if there's something that can be done to prevent this from happening in the near term. The coolant is in good shape, and there was not a build up of silicates or similar in the valve assembly. Has anyone had good luck with Water Wetter or other cooling system additives not causing futher DCCV failures?

-Rod

hondasf42000 · 09-28-2007, 04:57 PM

Thanks Shorod for posting that

My 01 LS has the exact same issue, where is the DCCV located and how hard was it to R&R?

shorod · 09-29-2007, 12:45 AM

The DCCV is located on the passenger side front of the engine compartment, below the ABS pump near the radiator. It looks worse to change than it really was. It took around 2 hours to change out. Getting to the mounting bolt and nut was a lot easier once I took the small splash shield out near the front mounting location of the passenger lower control arm. Also, it took me awhile to realize that moving the red tab on the electrical connector was actually exposing a thumb button rather than being the connector retainer by itself.

The most painful part was paying the $160 for a new one.

-Rod

lovemyLS · 11-12-2009, 08:11 PM

where did you get the part for $160? Lincoln is telling me almost $500 for a new DATC unit....

joegr · 11-12-2009, 09:52 PM

Quote:

Originally Posted by lovemyLS

where did you get the part for $160? Lincoln is telling me almost $500 for a new DATC unit....

I believe that the $160 was from the DCCV (Dual Coolant Control Valve aka heater valve), not the DATC control head.

shorod · 11-12-2009, 11:21 PM

Correct, the $160 was for the DCCV.

I happen to have a DATC in the garage that I bought off eBay as a spare. The wife recently traded in her 2002 LS for a 2010 MKZ so it's just sitting there.... I think the DATC is different between 2002 and 2003 unfortunately, especially if you have heated and cooled seats.

-Rod

lovemyLS · 11-13-2009, 11:56 AM

Yes, I have heat/ac seats. I'm getting the DCCV & the DATC mixed up.
Just a few more questions before I get back to work on my car
The DCCV is next to the radiator & fan correct? where is the DATC?
Does anyone have a picture of teh Heater control valve? and where it is?
Thx for all the help guys

danielsatur · 11-13-2009, 12:07 PM

The DACT is the HVAC control for your car!
Yep! The DCCV is next to the radiator, and the electric water pump.

Dont forget to check the fuses & relays for the DCCV, and the water pump.

A bad coolant bleed procedure could cause No HEAT, see http://www.Alldata.com

joegr · 11-13-2009, 12:56 PM

Quote:

Originally Posted by lovemyLS

Yes, I have heat/ac seats. I'm getting the DCCV & the DATC mixed up.
Just a few more questions before I get back to work on my car
The DCCV is next to the radiator & fan correct? where is the DATC?
Does anyone have a picture of teh Heater control valve? and where it is?
Thx for all the help guys

The DCCV is the heater control valve, and it is next to the radiator as you say.

The DATC is the thing with the buttons and the temperature displays, below the radio and above the ash tray.

danielsatur · 11-13-2009, 04:59 PM

How about one LS for the summer, and the other for winter!

lovemyLS · 11-13-2009, 07:22 PM

I'll have to try that after I win the lottery this week....I guess I'm still wondering why Lincoln told me my DATC was bad when it's not.. Makes you winder if they'd have told me that after they fixed it.

shorod · 11-13-2009, 09:43 PM

They may have been giving you a "worst case" estimate so that, if you opted to have them perform the work, you'd have been very pleased to get out of there with "only" a $500 bill rather than the $800 or more they quoted you.

-Rod

lovemyLS · 11-13-2009, 10:53 PM

Just finished. I took the valve and all the hoses off. It looked like hard clay in all of it. I had to take a screw driver and dig it out. It really felt like hard clay. Have you heard of this before? I've never put anything in my radiator before...

shorod · 11-14-2009, 07:38 AM

Has a previous owner maybe put some stop leak in? Was the color dark, or was it more white? If more white, that may have been silicates that built up from not changing out the coolant regularly or from using tap water rather than de-ionized water. I'm making guesses here based off what I've heard others say, I'm no chemistry expert. Hopefully a similar build up is not in the heater cores.

-Rod

danielsatur · 11-14-2009, 09:31 AM

How many miles are on this car?
Was the coolant & flush on schedule for change?
Was this car using orange or green coolant?
Whats the normal life of a DCCV?

The age of coolant might be more of an issue, than mileage.

I would consider a flush with old parts, a new DCCV, water pump, and thermostat.

A good premium green coolant, might have a better rust protection aginst mix metals.
50/50 mix by the gallon is better, than using 50% tap water!

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