Is it possible the second new heater core leaks within a year? I put in a new one a year ago and noticed the smell and sure enough when I pulled it, I could see a little spot where it was leaking. Put in a new on and lately the heater has been giving off that distinctive smell again. I pulled the new one last weekend and didn't see evidence of a leak, put it back and I still get the maple syrup smell when I turn on the heat. They aren't cheap but I am tempted to buy another. What else could it be?

Leaking cores are fairly common on these cars. I'm on my third (one warranty replacement at 3 years old, one replaced by me at 6 years old). At that rate, I should need a new one again in about two more years.... FCP Groton has reasonably priced replacements.

Always replace the O-rings when you're replacing the core. They're cheap, and they'll save you from a common source of leaks.

I would think that if it's leaking again, you'd be able to see it on the console hump if you pull the trim out and pull the carpet back.

--
Jim Rothe, '99 S70 T5M,
http://www.jimrothe.com/volvo/index.html

Could you take the core to a radiator shop and get it pressure tested? Very unusual to have a leaking core. I wonder if the cooling system is over pressured?

Klaus
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(V♂LV♂s 1975 164, 1995 854T, 1998 V70R)

Did you replace the O rings. Another place which could leak is where the heater hoses go through the firewall. The plastic piece can break, I know. Check those areas before going for the third core.

dick

I inspected the o rings and they looked fine. Plus if the o rings leak, it looks like that would be outside of the "box" where the air goes thru and I would see "external" leak to the floor and carpet. Same with the fire wall. Or am I missing something [again]?

Thanks.

Highly unusual. OEM core? FCP Groton has good aftermarket. Sorry, I'm not much help if everything else checks out, it must be the core, but I would highly recommend new O rings any time you change out hoses of any kind.

dick