Evidence of leaking heater core, but unsure if it's just the core

[SonicAdventure]

I have the $40 Swedish car parts heater core ready to install on my 96 850. Did some preliminary inspections the other day. Appears to be the original Volvo core in the car. I’m not having any odd smells or foggy windows, but when I pulled back the black plastic kick panel and carpet on the drivers side, there is evidence of a small leak just below where the heater core attaches to the steel in/out hoses. See photo.

There was a small moisture puddle about the size of two US quarters under the carpet on top of the foam pad about a 6 inches back from the Gas pedal toward the drivers seat. The odd thing is there is no evidence of moisture at the juncture of heater core and tubing, even though you can see the mineral deposits where coolant has dripped in the past in the photo. Does this suggest problems other than the heater core? I was thinking O-ring failure in that connection, but figured if that was the case there would be moisture on the plastic housing just below the screw and there isn’t.

[abscate]

That’s probably an oring failure at that junction, I agree

[scot850]

I have found the quality of the seals is variable with aftermarket seals. Their thickness can vary as well as be too hard so they do not compress sufficiently when under pressure to prevent leakage. I normally suggest paying up for OE seals, but even that may not be perfect on aftermarket cores as the recess may be deeper or shallower. If you car has an original core, compare to the replacement.

I replaced the core in my last car due to a similar leak, but reasoned as I had a new one due to the hassle, I changed the core as well but it was actually ok.

Good Luck!

Neil.

[Volvebaker]

I would just switch it out, especially if you already have a replacement.

These OE ones eventually fail almost guaranteed, usually the seam split at top-that's what happened to mine. It's not a hard job to do at all, I had mine out and a new one in (got the same Swedish Car Parts-came with lifetime warranty!) in less than 30 minutes. Haven't had a problem ever since!

Do note, though, some of the earlier 850's used I think plastic pipes going through the firewall and a lot of people choose to replace these with the later brass/copper/some kind of metal (I'm not sure the composition lol) that Volvo began using when they do the heater core job.

[SonicAdventure]

I would just switch it out, especially if you already have a replacement.

These OE ones eventually fail almost guaranteed, usually the seam split at top-that's what happened to mine. It's not a hard job to do at all, I had mine out and a new one in (got the same Swedish Car Parts-came with lifetime warranty!) in less than 30 minutes. Haven't had a problem ever since!

Do note, though, some of the earlier 850's used I think plastic pipes going through the firewall and a lot of people choose to replace these with the later brass/copper/some kind of metal (I'm not sure the composition lol) that Volvo began using when they do the heater core job.

Hmm interesting. My car was made in September 1995. Seems to be coated steel or aluminum pipes coming in from the firewall on my car. If they were plastic, what color would get be?

[scot850]

I have had both. If they are the plastic version they started as a white/cream and turn a beige/yellow with age.

If you are using the cheap (but generally good) aftermarket core, read up on the pre-clean of the core before fitting or choose to have a noxious smell for a while until it burns off.

Neil.

[Sufbug]

I have had both. If they are the plastic version they started as a white/cream and turn a beige/yellow with age.

If you are using the cheap (but generally good) aftermarket core, read up on the pre-clean of the core before fitting or choose to have a noxious smell for a while until it burns off.

Neil.

I may do this job too. What is the preclean of the core procedure....how is that done?

[abscate]

I have had both. If they are the plastic version they started as a white/cream and turn a beige/yellow with age.

If you are using the cheap (but generally good) aftermarket core, read up on the pre-clean of the core before fitting or choose to have a noxious smell for a while until it burns off.

Neil.

I may do this job too. What is the preclean of the core procedure....how is that done?

Many have had luck running it through a dishwasher for a few cycles. Pots and Pans cycle of course

[scot850]

As per abscate. Seems the most popular method for guys and un-popular for their partners!!

Neil.

[Sufbug]

Hahahha. Gotcha!