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V70 '98 Heater Core Going?

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
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1997 - 2004 C70

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j-dawg
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Re: V70 '98 Heater Core Going?

Post by j-dawg »

Peeling back the carpet and popping out the panel that hide the heater core is not a difficult or time-consuming job. If you've got any doubt, you don't have to guess. If it is your heater core, spare yourself the removal of a gallon of coolant from your interior and swap that core. Changing the core is easy, but getting the juice out of the sound deadening foam under the carpets is a tedious, painful, and messy job.

Haze on the windshield can also be caused by the dashboard. I used to suffer severe windshield haze which returned very quickly after I cleaned it, even after replacing the heater core. You may notice this by a lack of haze roughly corresponding to the location of the defrost vent. This haze only went away permanently after I wiped the entire dashboard down with Windex. It's weird, but if you're seeing haze on the windshield and your heater core ain't leaking, give the dashboard a wipe.
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abscate
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Post by abscate »

I spent an entire day removing foam and rinsing with water on my 1999 when I core went. Ugly, sticky, nasty job. Mine was leaking where the pipes met at the core..it may have not even been the core itself. I replaced core and pipes. I had one gallon of coolant mostly in the rear passenger footwell, even though the leak was on the front driver side. I had a mild coolant smell but no fog, which makes sense if the core metal wasn't breached. Posted it all up in an epic AC evap plus heater core thread in April 2013. MVS was like powder milk biscuits ..it gave me the strength to do what needed to be done. Has your family tried them?
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mika
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Post by mika »

abscate wrote:I spent an entire day removing foam and rinsing with water on my 1999 when I core went. Ugly, sticky, nasty job. Mine was leaking where the pipes met at the core..it may have not even been the core itself. I replaced core and pipes. I had one gallon of coolant mostly in the rear passenger footwell, even though the leak was on the front driver side. I had a mild coolant smell but no fog, which makes sense if the core metal wasn't breached. Posted it all up in an epic AC evap plus heater core thread in April 2013. MVS was like powder milk biscuits ..it gave me the strength to do what needed to be done. Has your family tried them?

It is messy:

One thing that worked for me when my heater core went and all the coolant was in the floor:

When reinstalling carpet, I layed down paper notebooks (ripped covers off), under the carpet. They are flat and will slowly absorb coolant over time, especially with your feet pressing on the carpet. You can reinstall the carpet (fold it back in place) when the notebooks under the carpet. You can leave this in for months before needing to pull it out again. I have tried rags but they don't absorb as well.
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Post by Thunderbox »

I just cut my wet padding out and went to a carpet store and got some mold resistant carpet under lay of the right thickness. Cut to size, laid it in and the smell is gone. Total cost was about 12 dollars.

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Post by rspi »

alausch wrote:This is great info, I'm having the same problem with my 99 V70 with 126K miles. I think it's actually gotten worse over the past month or so. Looks like I'll need to change it soon. Very recently, I can actually see a bit of fog coming out of the vents when I fire up the heater.
If you suspect that your heater core is leaking, and you have not proof that it has been replaced recently, do it TODAY. Most of the Volvo's in the junk yards are there because of heater core failures. Your core may NOT be leaking under the carpet, but building coolant in the core chamber. If it explodes, and they do, it will cause you to loose ALL of your coolant in seconds and can overheat your engine in less than a minute.

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Post by E Showell »

I commented on this is another, more recent thread, but my brother and I did a heater core replacement recently to my wife's wagon without draining the coolant and we spilled very little coolant into our well-positioned trash bag.

How did we do that, you might ask? Well, my driveway has a 15 % grade so we parked the wagon with the grill facing the bottom of the driveway and backed it up on ramps to elevate the rear even higher. This put the coolant reservoir lower in the system than the heater core so the coolant drained back into the reservoir.
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Post by JRL »

Small bucket also works
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Post by E Showell »

Brother and I just replaced the replacement heater core in the same car (a Behr I'm pretty sure I got from FCP way back when). Looks like that one was replaced in the fall of 2010, so I got seven years out of the replacement [seems like the Volvo core from new lasted about 11 years]. Not such a bad job.

We've done the "incline method" twice now -- I've got a driveway with a 15 degree incline at its steepest. I back up and put the rear of the car up on ramps as well so the car has a pronounced nose down attitude. Then I use a turkey baster to drain the coolant expansion tank. We still lay down a trash bag under the core, but we lose very little coolant this way -- probably less than a cup. The drawback is the steep incline makes what is already a job for a contortionist, one for the Chinese acrobats. I guess it's a question of choosing your poison.
'98 V70 NA FWD 5 spd, silver sand metallic (sold)
'99 V70 NA FWD Auto, dark blue (sold)
'99 S70 NA FWD Auto, black (sold and resurrected -- Don't cry for me Argentina . . . )
'07 S80 3.2 FWD Auto, Barents Blue Metallic
'06 V70 R AWD Auto, Sonic Blue Metallic (sold)
'04 XC70 Ruby Red Metallic (sold)
'95 855 auto (sold)
'86 245 manual (sold)
'05 V70 T5 M (totalled)
'06 V70 FWD Auto (totalled)
'02 Honda Insight CVT
‘04 Honda Insight CVT — “Yesterday’s car of tomorrow” (sold)
‘06 Honda Insight CVT

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