Roadmaster heater issue

Next time, do a'back-flush' - go in the other side!

 

Not going to matter,,,sludge don't care what way it goes in or out....sludge is sludge......damage IF it happens does not care

 

Does the dash have to be removed on these RMs? On the older ones, it was accessed from under the hood. If you do have to remove the dash, be VERY careful, indeed, about making sure you are safe with that air bag. Those things can kill you if they go off, and it takes time, or the proper procedure, for the capacitors to discharge safely. Air bags scare the bejesus out of me!

Tedy: I'm surprised the Fox was that difficult. My 79 T-Bird, no air, took about 2 hours, total, and all I had to remove was the glove box door and the box itself. On Nora, with air, the heater core is accessed from under the hood. Undo about 6 bolts and lift the cover.

 

I am going to take a different view of this than some of the other posters. If you reverse the direction of the heater hoses, you will flush the blockage out. I know this from experience, not theory. Direction does make a difference, since the core can block from only one direction, and that is where the coolant enters the core first. Trying to push the blockage through to the other side is just going to pack it in tighter.
Next, I will disagree with shutting off the coolant from flowing. If the coolant is old and acidic, then allowing it to stay stagnant in the core, will cause the core to disintegrate faster than if it is moving.
If the core is blocked, that indicates that the entire cooling system has been neglected, and the only thing to do is drain the entire system and flush it with a commercial cleaner until the drained liquid is as clean coming out as it was going in. Then, and only then will you know that the cause of the blockage has been eliminated. The blockage is caused by the fine particles of rust that form in the engine block. None of this would happen if the car were properly serviced from the beginning of its life, until now. Not pointing fingers at anyone, just pointing out the facts of automobile ownership neglect leads to costly repairs later in life. Once you get the engine block cleaned, then you might find that there is going to be other "leaks" that have been "sealed" by the rust sludge that you have removed. Better to have them happen while you are at home to have repaired, then to have them go on a road trip. Chances are that all the rubber hoses need to be replaced at the same time that you do the engine cleaning. Also check the engine drive belt for wear, since usually if the coolant system has been neglected, so has the belt(s). The last item to check is the water pump. If the coolant has been neglected, chances are that the water pump might be on the way out from both age and shaft seal failure. Sure this is going to cost you a few hundred dollars, but just think of the cost if it breaks down on the road, for the tow, and to have it serviced "on the road", where you know nothing about the person doing the work, and he charges an outrageous hourly rate. You won't be in a very good bargaining situation, other than pay and get back on the road.

 

I don't think the rust in my system is completely from poor maintenance. It was owned by an elderly couple in Texas basically from the time it was new until I got it back in July and by all appearances, they took excellent care of it. There is almost zero rust to be found anywhere on the frame or anywhere else, the interior is excellent and the engine compartment appears to be exceptionally clean. I'm sure it spent it's whole life garaged and well taken care of.
Plus, it only has 68,000 miles on it. And all mechanics that have seen it seem to think it's in excellent condition.

I'm wondering if it could have been the GM dex coolant that started the problem. I suspect the texas couple might have had all maintenance done at the dealer who probably would have used dex, right? Sometime later someone might have added green stuff and created the problem.

At least that's what I've read the mixing dex and green can create sludge.

At this point, it's probably best to do a complete coolant flush. I'm going out now to flush the core again. No sign of leaking since the first flush, but I'm not sure it 's giving as much heat as it should - maybe there's still a little crap in there. Everything is working fine, just not sure if the heat I'm getting is the full amount you would expect with a RM. Hard to know for sure.

 

Flushed again and now I've really got heat. Much better than after the first flush. Surprising because it looked like hardly anything more came out. I had may garden hose wide open in both directions for 20-30 minutes. There appeared to be no restriction anywhere - as soon as I opened the valve on the hose, I'd get the same output immediately on the other side.

The heat can drive you out of the car now. Still no sign of any leaking, so I'm hoping for the best.

Since the RM has become my daily driver, I'll have about three weeks of driving to test it out before the trip North.

Learned a nice trick on another forum on how to make the cabin temperature control display read the engine temperature instead - she levels out at about 187F and stays steady as a rock.

 

Just got in on this thread, but I'd like to suggest that maybe there was air in the system.
You have to bleed it out from the relief valve on top of the head.

 

Dex-Cool wasn't used until '96, so your '94 was spared that curse. More than likely the heat will only last you a few weeks, I could be wrong, but that's how it goes with 70-80% of the LT1 cars. Remove the knock sensors and flush the system with a lot of water. I have a old gutted t-stat that I put in place of the t-stat and run water in every hose I can. When you flush the core again, and you will, run the flush water through a screen, you see tiny white particles, those are the culprits of you clogged heater core. That stuff settles after the car sits, that's why you should remove the knock sensors in the block and flush it out good.
And no, don't block off the core from circulating the coolant, it's part of the system, not an add on like older cars. You could bypass the core by connecting the 2 heater hoses, but you need to keep coolant moving in those hoses for the system to work properly.

Where in NY are you going?

Mike

 

Near watertown

 

Are you gonna tease us with that and not even give us a link to the thread ?

 

Link from the Impala SS forum:

http://www.impalassforum.com/vBulletin/showthread.php?t=230311

Mike

 

Thanks !

Thanks for posting the link - I'll give it a try on my 1994 Roadmaster wagon today :2_thumbs_up_-_anima

 

sorry for not posting the link. thanks to 200OZ for finding it.

BTW, my heater is still working great, no leaks and I'm 3 days from my road trip North - keeping my fingers crossed it'll be OK.

 

hoping to pick up another RM in Maine and tow it back. A 93 woody. Forty feet, and 10,000 lbs of Texas Steel rolling down the interstate ought to be a pretty sight (a wood delete, towing a woody) and a lot of fun. If anyone sees that combo going down the road, you'll know who it is.

Seriously though, I shouldn't have any trouble towing one RM with another, should I? I'm hoping to get one of those u-haul dolly setups.

If it's not doable, I'll pay the man, fly back and drive it home. My co-pilot won't drive either one of the roadys - scared I guess.

 

Good luck on the trip. Don't tell U-Haul what your towing, they won't rent the trailer or dolly to you. Tell them your hauling a Malibu with a 3/4 ton truck or something. Don't forget, we're gonna need pics of the trip.

Mike