Help! 2005 S40 floor soaked with coolant

[Joshj118]

Hi everyone, newer member and newish Volvo owner here. Hoping someone will be able to help me out with diagnosing and fixing my 2005 volvo s40 with 195k. Just recently we realized the floor was soaked, coolant checked and low, refilled and same result, most of it ended up on the floor, the entire floor, all sides and in the back too. It is not a roof leak. On top of that the leaks seem to be causing the wipers to short because they'll randomly turn on to the highest setting once the coolant gets flowing and they wont turn off until the battery is disconnected or shut of the car and the coolant stops flowing. So thinking it'd be an easy diagnosis we began to take apart what was needed to get to the heater core and it doesnt seem to be the unit itself and maybe a bad O ring or attachment because the can see the mositure occurring within an electrical conduit on the passenger side floor next to the exposed heater core. Whelp, any help is appreciated....hopefully someone on here has dealt with a similar issur and it wasn't as big an issue and cost as im suspecting. Any help is greatly appreciated and glad to be part of this wonderful community of Volvo owners!

[MyNameIdeasWereTaken]

Sounds one of the O rings connecting the heater core to the hard lines that pass through the firewall. Very common point for failure. Check the S40/V50 section for help with the replacement.

The bigger problem is your electrical issues. Where those O rings leak, they can drip coolant onto the central electronic module and risk frying things out. A new CEM with programming will cost over $1200.

Do not drive the car until you get this fixed. Not only are the electronics at risk, but your engine is greatly in danger of overheating from loss of coolant.
You'll also want to pull up the carpets and thoroughly dry everything, as there is a risk of mold and also damaging other electrical components.

[avenger09123]

Hi everyone, newer member and newish Volvo owner here. Hoping someone will be able to help me out with diagnosing and fixing my 2005 volvo s40 with 195k. Just recently we realized the floor was soaked, coolant checked and low, refilled and same result, most of it ended up on the floor, the entire floor, all sides and in the back too. It is not a roof leak. On top of that the leaks seem to be causing the wipers to short because they'll randomly turn on to the highest setting once the coolant gets flowing and they wont turn off until the battery is disconnected or shut of the car and the coolant stops flowing.

So thinking it'd be an easy diagnosis we began to take apart what was needed to get to the heater core and it doesnt seem to be the unit itself and maybe a bad O ring or attachment because the can see the mositure occurring within an electrical conduit on the passenger side floor next to the exposed heater core. Whelp, any help is appreciated....hopefully someone on here has dealt with a similar issur and it wasn't as big an issue and cost as im suspecting. Any help is greatly appreciated and glad to be part of this wonderful community of Volvo owners!

Consider writing things out a bit more - it's kind of a blob and was clearly written in a hurry, which I understand, come back and fix it for us if you get the time.

Two things here to check:
#1 There is an AC drain, which is a rubber hose coming off the box and going into a white piece that snaps into the body and drains the AC condensation on that side too. into what would be considered the "transmission tunnel" on a normal rwd car. Pull the hose and that white plastic piece off, separate them, and clean them out. Might as well while you're down there.

#2 - check your heater core pipes at the joint. Any blue means there's a leak. Put your fingers on it to feel, and you will either feel crusties or greasies. Consider doing what most of us have done, and cutting off both ends that require an oring and putting a section of rubber hose and tighten some hose clamps down over them. Cheapest and most permanent solution, or you'll be back here in another 75k-150k.



Clean up your CEM with some electronics cleaner and a clean new toothbrush and you should be good to go on the wiper front as well.

[AutoGeek]

I knew it would happen sooner or later. 156K miles and mine just started leaking. I had replaced the o-rings on my previous V50 twice and the heater core itself. Knowing that this would eventually happen to this V50, last summer I zip-tied a plastic shield (bag) to prevent coolant from spraying on my CEM.
396.jpg

I think I'll do the hose instead of o-rings this time. What size hose did you use and what did you use to cut the pipes?
Thanks
Stan

[avenger09123]

IIRC it was 1/2" or 5/8" ID and 3/4" OD hose.

I and others used a dremel. If you can separate the hose from the metal using a prybar in the enginebay, you can remove both the heatercore AND the pipes that the hoses hook too, pull them all out and cut the joints off with a hacksaw. Otherwise, I used a dremel and a cutting wheel - I removed the heatercore entirely and chopped it's joints out and reached in and up and held the two pipes with one hand (another person put a clamp on the enginebay side to hold them steady) and cut them off without removing them. If you can remove them and do it outside the car, highly suggest you do that, but that's iffy and that crap is brittle as hell.

The aluminum itself is low grade - with a hard surface and cuts easy as hell once you get through it.

[ThomasR]

Is there a quick way to get a look at the connection?

I'm at 148k and losing a little fluid which could also just be winter taking its toll.

[AutoGeek]

IIRC it was 1/2" or 5/8" ID and 3/4" OD hose.

I and others used a dremel. If you can separate the hose from the metal using a prybar in the enginebay, you can remove both the heatercore AND the pipes that the hoses hook too, pull them all out and cut the joints off with a hacksaw. Otherwise, I used a dremel and a cutting wheel - I removed the heatercore entirely and chopped it's joints out and reached in and up and held the two pipes with one hand (another person put a clamp on the enginebay side to hold them steady) and cut them off without removing them. If you can remove them and do it outside the car, highly suggest you do that, but that's iffy and that crap is brittle as hell.

The aluminum itself is low grade - with a hard surface and cuts easy as hell once you get through it.

Thanks. Last night I actually found my spare metal tubes that go through the firewall from when I did the core in my other V50. I can easily use a tubing cutter on those. I'm mostly concerned about cutting the ones on the heater core without stressing the welds at the core itself. I'd rather not pull the core but I much rather not bust it either.

If I swap the firewall tubes, what is the likelihood that I'll need new hoses at the firewall? I know the connectors get brittle and break. You can see how a job like this snowballs.

With 2 herniated discs, arthritis and a pinched nerve in my neck; I really am not looking forward to this again. The dealer didn't seem to want to touch it last time. I ended up walking out with a gallon of coolant instead.

[AutoGeek]

Is there a quick way to get a look at the connection?

I'm at 148k and losing a little fluid which could also just be winter taking its toll.

If you are loosing coolant then do check the upper radiator hose. There is a plastic T in the hose that tends to crack and leak. Also check the thermostat housing (behind the air cleaner) and the reservoir tank for cracks.

It would be a good idea to check. I've been checking my regularly and last night I caught a whiff of coolant in the cabin. I think it just started because there isn't much in the carpet yet. I shoved a rag to absorb for now but I have some absorbent puppy pads that might work better until I get it fixed.

Pull back the carpet on the right side of the console. You will see a molded plastic that holds the heater core pipes. Follow it as far forward and up as you can, past the CEM and you will spot the connections. If you can't see them, reach your hand up there and feel for wet or crust.

[LMGVolvo]

If I swap the firewall tubes, what is the likelihood that I'll need new hoses at the firewall? I know the connectors get brittle and break. You can see how a job like this snowballs.

Difficult to say. Unfortunately, the connectors are very close to the firewall, making it difficult to grab onto the locking tabs and rotate them to the unlocked position. When replacing the O-rings for the heater core pipes, I attempted to disconnect the hoses at the firewall to remove excess coolant. The locking tabs wouldn’t budge, so I left them alone for fear that something would break or cause the connector to leak if I attempted further.

I purchased a full set of Volvo heater hoses as one of them has intermittently sprung a leak and intend to replace them when the weather gets warmer. I’ll be using the Lisle 39200 Heater Hose Disconnect Tool to remove the connectors when the time comes.

[AutoGeek]

Cool, you are in MD too. I'm in HOCO.

I should invest in one of those tools. With the pipes separated at the o-ring location, you can slide the pipes out a bit to get a better grab on them to disconnect / reconnect.

When I did my previous V50, I had a shop vac running to suck the coolant that would have been dumped inside the cabin when separating the pipes.

[mgm7890]

I’ll be using the Lisle 39200 Heater Hose Disconnect Tool to remove the connectors when the time comes.

Wow. That little tool would have saved me from having to destroy the connector on a heater hose. Thanks for showing this!

[avenger09123]

What I did to prevent coolant-mageddon was wrap some needle nose vice-grips in tape and then pinched off the two lines as far back as you need to go. From there you can practically replace everything with minimal coolant loss (I used a towel where I disconnected it) and it was more than sufficient to catch what was remaining in the lines.

That's a cool tool. Might have to get me one.