Does this sound like the heater core?

charleskennedy23 · Post by **charleskennedy23** » 30 Aug 2019, 16:06

I think I may have a heater core issue but I'd like to get the group's thoughts based on my symptoms…

1998 V70 T5 automatic...

For the past two years or so I have had a small coolant leak in that I have had to add water every 300-400 miles to the expansion tank to keep it full. No big deal. However today things went south...

On Monday I filled the expansion tank up and on Wednesday night I got gas and checked the coolant and everything was good. Then today I drove the car to the store and had no issues. When I came back out the car didn't want to start so I popped the hood and noticed all the coolant was gone. Everything else looked good. So I went inside, bought some water, filled up the expansion tank and cranked the car up. Everything seemed ok but after driving about 3-miles the temperature gauge started rising (peaked at 234 F), smoke started coming out the air vents, and the windshield fogged up. I pulled over at a gas station after driving for a total of about 5-miles. Popped the hood and checked the expansion tank and it was bone dry again (everything else was ok). So I filled up the expansion tank again and the water in the expansion tank was gurgling really bad as I added water. I eventually got it filled up and tried again. Drove 2-miles and same thing happened. Temperature jumped up to about 234 F, smoke coming out the vents, and windshield fogged up. I pulled over, popped the hood, and expansion tank was empty again. I checked the passenger side floormats both times this happened and I didn't feel any water. Hoses and radiator were replaced about 4-years ago.

To me it sounds like a heater core (it is original as far as I know) except for the dry passenger side floor board. What do you guys think?

Tanks in advance for the advice!

Mstrshkbrnnn · Post by **Mstrshkbrnnn** » 30 Aug 2019, 16:36

This would be a very rudimentary way to test, but turn on a hose and put it into the expansion tank, and turn the car on, and watch for where the water comes out. Make sure the car is cold before doing this so you don't risk overheating it.

charleskennedy23 · Post by **charleskennedy23** » 30 Aug 2019, 16:53

I was thinking the same thing... I think I'll try this.

Post by **BlackBart** » 30 Aug 2019, 17:59

charleskennedy23 wrote: 30 Aug 2019, 16:06...., and the windshield fogged up.....

Bingo!

Any of the sickly sweet antifreeze smell around the dash or floor...or is it all water by now?

charleskennedy23 · Post by **charleskennedy23** » 30 Aug 2019, 18:21

no smell and nothing on the passenger floorboard.... that's what is giving me pause about the heater core... Although I have been adding water to the coolant for 2-years so I'm not sure how much of what is in my cooling system is still coolant. It's been almost 3-years since I did my last coolant flush so I'm due for that service...

Also not sure if the windshield fogging up was due to the heater core or the fact that there was a boat load of steam flowing out of the air vents. I swear when I opened the window it looked like something straight out of a Cheech and Chong movie!

Post by **June** » 30 Aug 2019, 18:35

You should not add water to a hot aluminum engine. As you described the tank gurgling which indicates the engine was too hot to add cold water. You'll be lucky if you didn't damage the engine. Your car now needs a oil change if you didn't damage the engine.

Did you check the driver's side floor? If you did have antifreeze in the system, you should smell it when the heat is on. It should be pretty loud smelling. Also I noticed with mine the car got a funky wet cardboard smell I couldn't pinpoint. June

Post by **abscate** » 30 Aug 2019, 18:39

The water ends up under the carpet due to the deep amount of padding In These cars.

It will be wet under the rear carpet but you can’t feel it. Pressure test the system to see if it leaks. Then find the leak.

charleskennedy23 · Post by **charleskennedy23** » 30 Aug 2019, 18:48

"You'll be lucky if you didn't damage the engine."

Well that's not good, lol. It would be a bummer if I killed the engine. Until this happened engine was strong a pulling hard. I saw Robert's video about bypassing the heater core and his note about the rubber under the carpet. I'll pull the carpet in the morning to see if it's wet.

Post by **abscate** » 30 Aug 2019, 18:50

You might want to wait a few more days for that check.

Good luck

charleskennedy23 · Post by **charleskennedy23** » 31 Aug 2019, 07:01

Wet under the carpet... Ordering the heater core now... Thanks for the advice guys!