'99 V70 Heater Core Replacement

Post by **E Showell** » 23 Dec 2014, 06:05

Wife's '99 V70 has been losing coolant at a ridiculously slow rate. I checked all the usual suspects -- no joy. I'm betting it is a heater core leak although I do not get a strong maple syrup smell and the windows have no slimy film of coolant. Nonetheless, I think it is a minute heater core leak.

In the last year-and-a-half or two she's gotten a new radiator as well as all new cooling system hoses and clamps. Expansion tank and cap are relatively new. Thermostat and ECT are newish as well.

I just ordered the Estonian replacement heater core from Swedish auto lamps for less (price has gone up to $48.95 (with free shipping)). The kit comes with new O-rings.

Here's the question: Should I be thinking about replacing any of the other heater system-related components while I'm in there anyway? I've done a heater core before, but it has been a while.

Is 185,000 miles on the original about the expected service life -- longer than average -- shorter than average? I happen to have an extra plastic heater core/firewall junction laying in a parts box. I do not know the technical name for the part, sorry. Thanks.

Post by **abscate** » 23 Dec 2014, 06:33

Mine went about 130k before going on my 1999. The failure was actually at the connection between the pipes and the heater core, and may have been fixable with just an oring replacement. Since I already had the part and new connections, I replaced it.

IF you are original on those heater hoses, I would think about replacing those for SWMBOs car. I still have my originals but am carrying the new ones (VOLVO only) in my trunk as I still take this car on business trips 5 hours from home. I think I am going to retire it from that duty at 175k next fall.

Post by **E Showell** » 23 Dec 2014, 07:03

Steve -- Just a guess, but the heater hoses are probably original and they'd be pretty much the only original parts still left in the system after the core was replaced. I may well follow your suggestion and replace them for good measure.

Anybody know if I can run the Estonaian core safely through the dishwasher with the foam insulation on it?

Post by **rspi** » 23 Dec 2014, 07:07

I would try to remove the foam.

Post by **cn90** » 23 Dec 2014, 08:20

I am in the exact same boat: stock heater core at 165K, very very sloooow coolant loss, maybe 1 cup every 5K or so.

So, this is my plan for the Spring of 2015:
- Heater Core from Estonia as you mentioned.
- Cut the metal pipes near heater core and run generic 5/8-inch heater hose to firewall.
- Eliminate firewall coupler.
- Remove old heater hoses and dremel the crimp so I can re-use the metal elbows.
- Run heater hoses to engine block.

Once this is done, I don't ever want to do this job again b/c chances are I don't keep this car 10 years from now.

It will be done exactly like the thread below by @songzunhuang:

1998 V70 T5 Replacing the Coolant Hoses in Pics
https://www.matthewsvolvosite.com/forums ... 7&start=42

Post by **j-dawg** » 23 Dec 2014, 08:31

I washed the Ebay core with dish soap and boiling water. A few weeks of (infrequent) driving later, I've still got the sweaty towels smell, and it can be alarming - at first sniff, it almost smells like something burning until my nose resolves it more clearly. I'm sure it'll get better, but it's a bit annoying.

If you have access to a dishwasher go for it. I don't know how it would have been had I not washed it at all, but it must be a pretty powerful odor to have withstood my assault.

Post by **dosbricks** » 23 Dec 2014, 12:49

I washed mine for about five minutes by sloshing it up and down in a pan of hot water and strong dishwasher soap while wearing latex gloves. I used some corks to plug the inlet/outlet holes. It did not smell when installed in the car.

Post by **Ben850** » 23 Dec 2014, 13:47

I had just done that for my '96 wagon over the summer.

My newly purchased '98 XC has a coolant smell after warming up. I know what that means.

I will refer to the link above as the s/v series dash and console area is a bit different than my 850s.

I am seeing many posts regarding the '98 model year. As I mentioned in another thread, I am also seeing them at the junkyards in abundance lately.

Good timing for me I imagine? It just seems to be their time?

A couple years ago I was finding '93-'96 850s for the most part. Now I rarely see them as often.

Post by **kahl** » 23 Dec 2014, 15:17

I replaced the heater core in the 850 in June and last week in my new to me 98 V70 AWD. Both times I neglected to wash the core before install but have detected no odor. Also from a previous post we talked about air blow by of the Swedish core. I noticed on one side of the box there was an air gap of about 1/4 inch. I adhered some foam from the old core to fill this gap. I experienced no difference of install between the 850 and the 98 V70.

the only thing different is this time I did not drain the core into a bag with a hole.

Post by **dosbricks** » 23 Dec 2014, 16:27

kahl wrote:the only thing different is this time I did not drain the core into a bag with a hole.

Sounds funny now, but probably not at the time.

My OCD made me doubled up (bags).