# of hours labor to replace heater core in 525i?

[Russell]

Looks like mine is starting to leak. Guess I will have my indy do it. Coolant/water is dripping under the car on right drain and the coolant light came on this morning. Noticed it a few days ago.

I will turn heat all the way to off. I don't think that stops flow to the heater core though. Anyone know?

May do the bypass trick. Guess I will need to search for it.

[genphreak]

As you probably know, If the right coolant has always been used and regularly changed the core should be okay. Just the O-rings on the plastic pipes could need replacing. By removing the console, radio, obc, heater control unit and main middle bracket you can gain the access needed to do that. I'd allow myself a day on the weekend to nail it at my own pace, with time for beer.

But then again, the last time I did the ac expansion valve the car stood in the drive for about 2 months- I the column bolt defeated me for a while (had to buy a Dremel as the grinder wouldn't reach), and then the fasteners in the valve (that my Chinese Allen keys pronounced 'incorrect size' at the height of their anguish (and promptly expired). It wasn't until I finally found the right size tool, a Bosch part, that I could crack them from upside down, pointing back down, between the pipes and cables that prevented access.

It learned me though, could do the whole thing again in a half a day if I had to.

[Russell]

Interesting. So If I dive into into it and I see leaking around the O-rings. I may just replace teh offending O-ring or rings and be good to go. I can possibly do that. I think the car is drivable enough to test for a couple of days semi-apart like this.

Do the rings have a BMW part number?

Any images of the car apart as you describe?

BTW, only BMW and Zerex G0-5 antifreeze has been used while I have owned it for the last 180,000 miles.

[shogun]

the o-rings you find on realoem.com with your VIN.
And also mentioned here by Trevor who made a nice write ip with many pics


DIY E34 heater core R&R (IHKA content)
*DIY E34 heater core R&R (IHKA content)

First time I did it was 1 full day, now I can do it within 4-5 hours. There is also a write up with pics on my website from an E32

[Russell]

Thank you

[Russell]

Going to remove the passenger side carpet covered panel to see if I can seen anything regarding the heater core. You know, like you are changing the cabin filter which I also need to do. Doubt if I can as there is a cover over the core. Just sort of thinking out loud. My passenger side under car drain is where antifreeze is coming out. Makes me think/hope it is just an O ring on that side. Think I am ordering all the O-rings and dive in.

It does not seem to be too much trouble to get the lower dash apart. I have had the console, driver's side under panels, glove box OBC and radio out before. However, never had the heater controls (slide type) out. Not sure if there are issues there??

Thoughts?

[genphreak]

Its easy to do, you just have to commit.

You need a good torx set / torx screwdrivers to get the filter out from in front of the heat exchanger. The coolant will probably leak to the side lowest when parked. But the pan drains may not be open (factory the seals are inserted- has someone removed/pushed one up?). This is to prevent salt water ingres but allow water to be drained if necessary- they are easy to take out/reinstall from below the car when on a hoist. I believe they put salt on the roads in countries where people drive steel cars to work in the snow in order to destroy them as quickly as possible (Here in Oz we'd just 'chuck a sickie' if the weather was that bad)!

There is a knack to removing the heater panel, you first pry the AC switch out as you can then use a screwdriver to release the panel's facia clip. However they often just come forward easily enough with the AC switch left alone. Then remove the green red and blue pipes and it comes right out. The OBC/clock module has a swinging arm that you can reach from the back of the module (getting to the back is another thing of course- I don't think I can describe that in words), unless you take the radio out first- which if stock requires the right size little allen keys to just loosen the wing flanges and then unusually co-operatively slides forward and unplugs. After that it is all console work, keeping the fasteners in a divided box labelled as you go so you don't leave anything aside when you button it all up and extract yourself, knurled and curled from the interior with all kinds of aches and pains- all bent like a 300 year old oak tree and proclaim success!

Be sure to have put a beer in the fridge for that moment!

[Russell]

Its easy to do, you just have to commit.

You need a good torx set / torx screwdrivers to get the filter out from in front of the heat exchanger. The coolant will probably leak to the side lowest when parked. But the pan drains may not be open (factory the seals are inserted- has someone removed/pushed one up?). This is to prevent salt water ingres but allow water to be drained if necessary- they are easy to take out/reinstall from below the car when on a hoist. I believe they put salt on the roads in countries where people drive steel cars to work in the snow in order to destroy them as quickly as possible (Here in Oz we'd just 'chuck a sickie' if the weather was that bad)!

There is a knack to removing the heater panel, you first pry the AC switch out as you can then use a screwdriver to release the panel's facia clip. However they often just come forward easily enough with the AC switch left alone. Then remove the green red and blue pipes and it comes right out. The OBC/clock module has a swinging arm that you can reach from the back of the module (getting to the back is another thing of course- I don't think I can describe that in words), unless you take the radio out first- which if stock requires the right size little allen keys to just loosen the wing flanges and then unusually co-operatively slides forward and unplugs. After that it is all console work, keeping the fasteners in a divided box labelled as you go so you don't leave anything aside when you button it all up and extract yourself, knurled and curled from the interior with all kinds of aches and pains- all bent like a 300 year old oak tree and proclaim success!

Be sure to have put a beer in the fridge for that moment!

Thanks for the advice on how to get the heater panel and obc out. Been there on some interior removal. You make it all sound like fun.

[ahlem]

Don't forget the sore muscle massage request you ask of your wife. Hah!

[ryan roopnarine]

you can bypass with a t and leave the repair off indefinitely. I'd recommend putting a bypass in immediately regardless of whether or not you do the repair yourself+ save yourself the aggravation/cost/whatnot of an overheating event.

your target in bypassing is the three hoses going into the firewall of the car. Connect the common one to the bottom part of the T, connect the independently controlled sides to the top. A tee costs less than $5 from any autoparts store and may save you more of a headache than you might be cognizant of at this point.

when my HC went kaput my leak was a prolific one out of the a/c drain--i'm thinking like yours.

if you run at high speeds and take good digital pictures you can bust this repair out in 6 hours. stay organized and put every bolt and screw into its own ziploc baggie and everything will go back together remarkably easy. I wouldn't pay someone to do this if I had a weekend to devote to the repair.

The best of luck,

Ryan