Owner reviews for heater core

Non-turbo 8v Volvos are unstoppable. I have a '91 740 with about 150k (odometer broke at 103,000) and the only thing that's gone wrong in 4 years besides normal maintenance stuff (brakes, tires...) is the heater core. Watch out for that, it's probably the most expensive repair on this car.

My heat was getting weak again,so I just did another flush with HOT vinegar water mix 50/50. blow out with a bit of low pressure compressed air, flush again with the same solution, reheated again. Lots of gunk came out. Heat is good again.

Nissens for the radiator and Valeo for the heater core - $120-ish for both. Both have proven reliable for me after 6 years, and Valeo is VW's supplier for heater cores.

Update: After several days with my newly flushed heater core, the heat output is amazing. Almost too hot at times! I have never experienced such hot air before on any vehicle I have driven.

It's fixed I have heat thanks to all yous, I flushed the heater core both ways low and behold I have heat.

so far i have determed that u can fit a mk3 vr6 gti heater core/box into a mk1 failry easy and not looose much if any foot/leg room on the passinger side of a caddy cabbin.

When the heater core blew on my '91 Golf, I called VWoA and they arranged for a free goodwill replacement even though the official recall only covers up to 1990 models.

Uh oh, an antifreeze odor coming from under the dash is usually a heater core leak.

I replaced the heater core in my 1991 mk2 8-valve RV coded engine in May 2022. I replaced it with a new Valeo unit I got off FCP Euro and the install went just fine. Every year I do a mid-winter start-up since I live in Minnesota and after running it last night for about 20 minutes the heater core popped and dumped a ton of hot coolant in my driver and passenger footwells...

OK, so I have heat now. When I pulled the core to check and see if there were any plugs in the lines I found a major defect in the core. deep inside one of the fittings you could see that there was no coolant passage. The thing was molded shut! So I drilled the fitting out and blew out the shavings from the opposite side, slapped it back in the truck and had heat right away.