2005 S 4.2 NA US Model LH Drive - Still working on my DCCV - I was blowing only hot on both sides - put in new Gates DCCV, I now have air on passengers side but still blowing hot on drivers side. I am going to do some further tests but I suspect the new DCCV may be faulty [I have heard they are sometimes faulty from the factory]?

The real question is - how does one bleed the coolant system? Is it bled by the bleed screw on the top of the expansion tank? Some of the articles that I have read mention a bleed screw or valve under or in front of the throttle body. I removed the air intake system leading to the throttle body [cleaned the throttle body and mass air flow sensor as long as I had it apart] for a better look and I do not see any bleeder valves at this location. Was this used on the V6 or the earlier 4.0L engines? Is the bleed screw on the top of the expansion tank the only bleed point on the 4.2 NA?

 

Can't help with the specifics of bleeding your engine, but have you tried driving the car yet?

From my limited and preconceived perspective, the official coolant bleed procedure was to make sure everything was up to snuff when returning the vehicle to the customer after service. If you just drive it, you'll initially get some gurgling noises from the heater, the temp gauge might show erratic behavior, and you'll need to top off the coolant level before each drive until everything settles down.

Now if I'm wrong, I'm sure those in the know will quickly chime in to point out the error of my ways, before you cause any damage. But with my '02 V6, I've pretty much given up on the official bleed procedure. If you do want to run through the whole process, there is one thing I've learned. Where it says to recite a particular Latin incantation while sacrificing a chicken: You have to use a live chicken, not a bucket of KFC. The manual is not very clear about this important detail.

So if the pros have no serious objection, I suggest trying a little test drive. Don't get on the freeway at rush hour or slug through stop/go traffic, or anything like that. Pick a time and place when you can just go for a genteel drive in the country, maybe 10 miles or so. Set the heater to manual HI. Expect some gurgling from under the dash. Keep a close eye on the temp gauge. It's okay if it climbs slightly above center, but if it looks like it's going to shoot past 5/8 or so, be prepared to quickly shut it down. (The highest I've seen on my car is 5/8, and only momentarily.) After your little test drive, let the engine cool for several hours and top off the coolant level. Repeat this for a few cycles, topping off the coolant when cool. Usually after the third cycle all is back to normal, at least in my experience.

Not sure what to suggest with the suspect DCCV. I don't think air in the coolant would cause too much heat. Unless you've got a bad signal to it, this sounds like a bad part, straight out of the box. Start troubleshooting from the beginning again to be sure. Check the new valve and the commands to it. Keep us posted.

 

Karl,
Thanks for the response - I think I have it on the coolant level - apparently the 05 4.2 NA has a bleeder screw on top of the coolant recovery tank that you can mess with - I tried using it and found it a bit messy - I'm trying the tried and true old school method that you described and I am acquainted with - fill it up, drive it with the heat on high, bring it back and let it cool then top it off and repeat.

I agree with your thought that it is probably a defective DCCV out of the box. A method to bench test would be nice but I have not found a reliable test.
The valve for the drivers side is not fully closing and letting hot coolant flow past while the passenger side is blowing ice cold [confirmed under the hood on the 3 heater lines running to the firewall 2 hot and 1 cold]. The plan is to recheck the signal from the interior connecter block on the left hand fascia end panel to the DCCV connection with a multimeter, check the harness and connector for damage and clean the contact points. I'm reasonably sure that the signal from the CCM is good as I had the CCM rebuilt by JaguarClimateControl a few years back which included their fault-protection upgrade so it should be good.
If that all check's out I will return the DCCV to Rock Auto and try again with another valve [I picked the Gates as it has a limited lifetime warranty]. To my knowledge this is the 5th DCCV in this car - the p.o. replaced the original with a Bosch, I replaced with another Bosch, my local mechanic replaced that one with a Bosch [he insisted that I installed a bad valve - turned out it was not bad but a broken wire in the harness so he left it in at no charge] now the new [suspected defective] Gates.

 

Have you used the heater bleed port?
It's a bit hidden up by the brake MC.
I don't touch the one on the tank. That tank is failure prone enough as it is without me trying to mess with the bleed port!
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Thanks for the information, I was not aware of a heater bleed port in that location - I'll take a look. I agree, the tank is a fragile item and should be disturbed only when absolutely necessary! Luckily, my tank is only a few months old and still pliable.

 

Have you finished the bleed yet, either the official chicken sacrifice method or my lazy man's version? Just wondering if one of the DCCV seals may have stuck after the part sat on the shelf for who knows how long. Maybe with a smidge of luck it may free itself after a few heat/cool cycles.

 

Clubairth1,
I looked for this heater bleed port that you described and there is not a port near the brake MC. I see that you have an STR - I have a naturally aspirated 4.2 L - perhaps there are differences in the coolant system on the supercharged units?

 

Karl,
I finished the bleed using the old school method. Others have claimed there is a heater bleed port up near the brake MC. I could not find such a port - probably on the supercharged version,
It does not seem to be a stuck valve - We have a warm day with no rain In Detroit today so back up on ramps and tracing wires today before I order a replacement DCCV. I have not buttoned up all the underbody/wheel well panels so it will be a rather quick job for now.

 

It's very well hidden and yes I had a STR but think this is on the NA versions too?

Here is a diagram of what to look for;


It's just a SOB to find sometimes and people have claimed they never could find it?
This picture may help as well.



But let us know because I am not 100% sure with the different variations out there.
I found that just driving and letting the car heat up and cool down got it to bleed just fine after a few days. Be sure and check the coolant level as the air comes out.
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As you may be able to see on the photo looking at the firewall from in front of the master cylinder it appears there is no bleed port or heater hoses at this location [US driver's side] on my 2005 S 4.2 NA

 

I agree. I have nothing like that on my ‘06 STR

to bleed, open bleed port on overflow tank. Fill until it bubbles out hole and replace plug. On supercharged engines open bleed port on the intake duct up by the right hand (bank 1) charge cooler and continue filling until coolant comes out and replace plug. Done

 

OK glad you checked. Just another variation in how they were built. Really surprised your 2006 STR does not have one but we did see a number of differences with the 2006-2007 STR's as they got VVT and a few other things.
I never open that large hex plug when changing the coolant on my old STR.
It seemed to bleed itself after a few heat cycles.
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opening the big hex makes a huge difference. I saw lits of air. But im an idiot and accidentally broke the port off the housing. Its not very structurally strong

 

That's kind of funny because that was one reason I left it alone.
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I did exactly the same. I could tell by the amount of torque it needed to remove the screw that it was going to break free of its base..
I would say there's some corrosion in the threads causing it to stick. Mine hasn't been removed for a decade + I would think. My fault, I should have removed it more often.

 

Hi Karl,

Your suggested procedure mirrors exactly what I have found works best, except I hadn't thought to try sacrificing the live chicken. I can't believe the ability of these motors to hide away little pockets of air just long enough to convince the unwary user that 'surely this must be the last of it' - and then gurgle pop and the red light comes on AGAIN with the 'Low Coolant Level' message. I guess its all part of the fun of doing your own work on the car.

Cheers,

Roger

 

Yes I agree! I now have gone to using a vacuum filler and have no more problems. One and done.
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