I posted a question about changing my heater core in the Discovery section but havent had a reply yet. I have a 1997 Discovery and it has a coolant leak in the passenger side foot compartment. Just in front of where the center console ends I have antifreeze dripping out from the dash and soaking the carpet. It is coolant for sure because it's green. I have read in these forums that it may be some O rings or a valve of some type causing the leak. How much of the dash has to come out to see what the problem is? I really don't want to have this thing tore all apart in the garage waiting for some stupid O ring to show up. While at the same time have a new $150.00 heater core I don't need. It seems really weird to me that a heater core would just start leaking. I've never had one go out like this in the 17 years I've been owning and working on cars. When the engine is running and up to temperature (temp gauge in the middle) it blows cold. I have bypassed it again for a temporary fix but I'd really like to know what my odds are of the full on heater core vs. some simple fix.

Any comments or suggestions of your previous experience would be greatly appreciated. The bitter Idaho winter is on it's way and I don't want to face it without a heater!

Thanks in advance,

Erick

 

Okay!-- this gets a little sticky....cuz... the shop labor time to replace the heater core is 8.0 hrs. Factory warranty paid 5.7 hours for a journeyman mechanic to replace it. The real seasoned techs can do it in a couple of hours because they know how to extract the old core and re-fit it without completely pulling the heater /AC box out. Problem is in the fittings and the delicate material and wall thicknesses involved. The attachment method requires absolutely perfect alignment or you will have leaks. Try to force things, and you will damage the new heater core. So-- the good news is the whole dash does not have to come apart as is the case on the Range Rover. Bad news is-- this is a job for a competent shop or a owner that is very patient and accepts the risks involved.

Oh!--by the way, this failure is something we address about 10-12 times a year on the Discovery I here in Northern California. We replace heater core O-rings on twice that number of Range Rovers in a given year.

Regards,

Mike McLaughlin
www.eurotekapg.com

 

reply for GeoMan...

Ok, I'm at the end of my rope. Looking at this thing I figured that about the only way to get the old heater core out (without pulling the entire dash) was to slide it out toward the passerger side. It worked great but I think the hard lines got bent and now I can't get the new one aligned to save my life! I'm thinking about cutting the metal lines about three or four inches away from where it goes into the heater core and then cut about 4 inches out of them. I will replace that section with rubber heater hoses... this way I can put those worthless clamps on outside the car... slide it in and tighten the retrofitted rubber hoses up. They probably should have designed it that to begin with... would have made an 8 hour job into a 2 hour job. I've got probably 4 hours alone in trying to align it! What do you think about my idea?

 

to 97DISCOIDAHO,

Yep!...you ran into the design shortcomings on this job. Re-alignment to allow the clamp to seat the hoses is a bear, and we have seen guys ruin a new core in frustration. The "go around " you have suggested is not recommended because the water temp at that location can approach 200 degrees and any leaks would be under pressure that could injure a passengers legs. It's your call, unfortunately.

Geoman
www.eurotekapg.com

 

I think it's my only option at this point. I'm thinking about overlapping the rubber hose about 3 inches or so over the aluminum hose... double clamping it (with the worm clamp running opposite directions)... then wrap the whole thing in some type of heat tape. Isn't the cooling system under about 16 pounds of pressure? I think I should be ok with the double clamps.

 

Yep!-- it would be under system pressure. Probably a good idea to double-clamp it and then wrap the whole area as you described.

Best of luck!

Let us know how it works out.

Geoman
www.eurotekapg.com

 

It worked!! (actually pretty good) I went to EVCO house of hose and had them get me a heater hose that fit nice and snug... I got their best silicone hose. I didn't cut any aluminum pipe out... it pretty much just butts end to end where I cut them with about 3 inches of silicone hose covering each splice. I just ran the new hose up the aluminum pipes on the car and then slid the new core in with the aluminum stubs already attached. All I had to do at that point was slide the pieces of hose onto the stubs of pipe coming from the heater core and tighten the 8 worm drive clamps. I think I may have overkilled the clamps... the hose probably would have held with no clamps at all (it fit pretty snug). I let it idle up to regular temperature then let it idle for about 10 minutes... no leaks. We'll see what happens right now when I drive it to work.

I must say one thing about the Disco 1 heater core... this is probably the biggest design failure I've ever seen in all my years of working on cars. I'm not an ASE mechanic or anything but I've done my fair share of wrenching. I've never seen anything designed so poor! If they wanted the O-ring style connections... why didn't they just do it like an A/C line where you tighten the nut down?? It would have been so easy to put threaded connections on the core and nuts on the lines!

I don't get it!

 

Congrats!--- about the design shortcomings--It very often comes down to a cost savings, however menial. And the servicing of the vehicle after sale is not always considered. I had a buddy who was a design engineer for Littlefuse, a company that supplied the Detroit big three with oem flashers. He was very proud of a design that surpassed the manufacturers expectations....except...he was told he had to lower the cost by 3 cents per unit. As a result he had to scrap the entire design and start over.

The bean counters sometimes cause major problems when trying to shave costs. Like the Taurus SHO with the Yamaha engine and Mazda Transaxle. To save money they decided to fit a Clutch assy. out of a Ford Tempo on the production line. It was not up to the task and the warranty claims against Ford ran into the millions of dollars before they fitted a proper clutch in subsequent production years.

Anyway...best of luck!

Geoman
www.eurotekapg.com