dougal813

I took my car to the shop today for a problem where coolant was leaking onto my drivers side floor mat. I figured it was the heater core but wanted to make sure and sure enough it was. Acura told me it was 2000 to fix it which is insane for a $450 part. They mentioned that you could effectively bypass the heater core to stop the leak but I would lose my heat (not a big deal).

Does anyone have any idea how to do such a thing or has anyone replaced the heater core? Any help would be great

01tl4tl

If its like a normal car- you run a rubber heater hose (temp rated) from the in port and out port on the engine block water system -that feed the heater. Then it loops back into itself at the engine and never sees the heater core

Come fall and winter this will be a bummer~
The heater is a small radiator that the coolant passes thru when ON, when off- a valve closes the line and the coolant in the heater core sits doing nothing,
so circulate it now and then so fresh stuff is in the core.

Since I am gen2 and never looked at replacing the core- but did find it next to the blower motor- behind the glovebox, when changing the cabin air filter,
Yours is probably in a similar place
If you remove the core yourself- a radiator shop can usually fix the leak, or hook you up with a new one for a good price if needed. They may make a new one right there for you!!
A radiator shop may also do the labor for you with the removal and install.Make some calls of places in the yellow pages of the real phone book

Lesson to all: Coolant goes acidic after 5 years and eats aluminum- doesnt matter about the 100k miles or anything else- time is time, change the coolant- read owner manual for procedure, its easy

Bluish

So, what have you done to fix this problem? I'm seeing the same thing right now, except I'm not overheating - just leaking about a cup every 1000 miles.

TexasHonda

On most cars, Acuras included, replacing the heater core is a really tough job. I would first try to use some "stop leak" to see if that might fix the problem. Not always successful or permanent, but a whole lot easier than removing the heater core.

You can bypass the heater core (no heat) by either connecting the inlet/outlet hoses together or plugging both hose ends.

Replacing heater core is not a first time DIY project, and will challenge anyone.

good luck

Bluish

TH: This isn't the first time you've shared your experience with me. Thanks

Last night I decided to see if I was up to replacing the heater core myself. You were right, but using the service manuals I successfuly removed the dash board and inspected the heater unit. It was a complex and messy job, but I kept good control of all the parts I removed each step of the way and marked notes on the service manual pages to help with re-assembly.

I found the leak on the lower pipe where the copper pipe is clamped to a hose. I tightened the clamp and cleaned of the blue crusted crude that has been accumulating from the Honda coolant. I re-assembled the dash board but kept the pipe cover off so I can visually inspect the suspected leak area. Total task took about 6 hours - but if it's successful, it beats a $2K service charge.

What do you think my chances of success are?

TexasHonda

Good Work. Most jobs are possible for DIY, however I hesitate to recommend diving into a complex job w/o knowledge of person's abilities. I'm glad it worked out.

Was the leak at the engine side of the heater core? I should have suggested you remove the heater hoses, cut the ends, and reinstall. It's very tricky to remove the hoses from heater core w/o damaging the heater core ends. Sometimes better to cut the hose, and split the retained hose end to remove.

good luck

Go90go

That's the truth! I had no problems getting mine off, though, all it took was a set of rounded pliers that could grip around the hose and a little bit of patience in turning it back and forth until the seal breaks free. Come to think of it, I should check to see how mine are holding up. One of the hoses was barely long enough to make it onto the end, and I had just enough space to stick a clamp on it.

I don't have the valve for closing off the heater core when the AC is on high or starting up anymore. It's just a straight hose connector because I crushed the bracket and the valve unit itself when my motor was going back in. Heater nice and hot, AC still, surprisingly, cold. I suppose I could install the replacement I got, but I'm lazy and it hurt to get my hands in there.

~Cheers~

Bluish

I have some pics, but could not find a thread on how to post them so I'll describe it the best I can.

There are two coolant lines that come into the interior of the car. Normally you can not follow the pipes all the way to the heater core because they are covered by the "Pipe Cover". Once I removed the pipe cover, I could follow the pipes further. Just before the pipes take a 90º bend to go into/come out of the heater core there is a transition from a rubber hose to a copper pipe. There is a hose clamp with a 10mm adjustment head that also has a Phillips-head fitting on each of these transition points. The leak was on the lower of the two pipes, which I presume is the flow from the engine. I never removed any hoses - I just tighted the hose clamp where it was leaking. Since the leak was very slow (~1 oz every 200 miles), I'm hoping the tigher clamp will buy me a few more years of operation.

TexasHonda

I hope your repair works. When access is difficult, I replace the parts w/ new to reduce potential for a faulty repair.

Let us know how it works.

good luck