Something Wicked This Way Comes On The 06 2.4i
 

Well, it's been a little over a month since I did the timing belt and water pump job on this car. I drove it last friday and could've sworn I smelled coolant in the car. When I got out of it I couldn't see anything leaking. The wife calls me last night from the grocery store saying she thought it was going to catch fire. So I drove down there and I couldn't see anything obvious. So I told her to drive my service truck home and I drove the volvo. It did fine it seemed until I'd driven it about 6 or 8 miles. I was watching the temp gauge and it went a little over the halfway mark which it's never done that I know of. It came right back down to where it normally runs (about the halfway mark) and I smelled coolant in the car again.

I got it home and pulled under my patio and looked all over it. I didn't see anything leaking. But it was a little low on coolant. She said she could hear a boiling noise. I got out there a little while ago and let it run until it got up to operating temp according to the gauge. The one thing I noticed was that when I turned the heat on it wouldn't blow any hot air. She said it's been like that since we got it. You had to start driving it before it would start blowing any hot air she told me. So that doesn't sound right to me. I could see where it looked like some had been pushed out of the surge tank onto the timing cover and dried.

So I started thinking maybe a sticking thermostat or possibly a faulty heater control valve. After I shut it off I seen something dripping from the bottom. I thought it was condensate from the A/C. But it's definitely coolant leaking. Before I got it jacked up I was thinking a defective water pump. But it's not leaking in that area. It's coming from a little farther back. I couldn't nail it down because of all the shields in the way. But it's coming from the right side floorboard area and dripping onto the rear subframe beam. I'm thinking that has to be the heater core. The only other thing I touched on the cooling system was the surge tank. I over filled the original one a tad when I got done with the timing belt job and noticed that it was pushing out of the top of the tank where it had some tiny spider cracks in the top. I replaced the surge tank and thought I was done with it for a while. Looks like I was wrong about that. I was just wondering if anyone has had a similar problem and what it actually turned out to be. The only conclusion I can come to so far is that the cooling system wasn't holding pressure due to the surge tank. Now that it should be with the new tank. Could that have started a leak with the heater coil or something else entirely?

check the carpet in the foot wells for wetness - you could have a slow leak in the heater core or its hoses. That would give you a smell of antifreeze as well. Also inspect the hoses from the block through the firewall for the heater to see if those are leaking. If the S40 is like the 850s you should be able to remove the lower trim on the sides of the center console to get a look at the heater core. I need to do this repair on my daughter's 850 (just waiting for warmer weather!). Could be as simple as replacing the o rings where the hoses meet the heater core as well.

They've got O-rings for the hoses on the heater core? I checked it yesterday morning because she had to go to the doctor. I left the cap loose so it wouldn't build so much pressure. That thing's got a 21 psi cap on the surge tank. I don't think I've ever seen that before. She said she didn't have any problems. Temp gauge didn't go over halfway and she said she didn't see any fluid on the ground anywhere when she got ready to leave. It's really strange. What all is involved with getting it out. I did a search on VIDA for the job and didn't see it. All VIDA showed was a coil that was externally mounted and said that it used electric elements to heat the coolant. I haven't gotten back under it to see what the picture was showing. But the leak I saw was definitely coming from the passenger side floorboard area. I didn't see anything in the floorboard area inside the car. I can only assume that the smoke she said was coming into the cab the other night was actually steam from the coolant system because she said it had a sweet smell to it.

Yes, the coolant tubes do join to the heater core at an O-ring sealed union. I believe he joints are in the passenger foot well.

Well, the wife finally talked me into putting in the new heater coil. Whoever designed it the way that it is should be taken out and killed very slowly and painfully. I need a little advice because I'm stuck in one spot and have been trying for hours and haven't gotten anywhere. I have the new coil in place but I can't get the plastic couplings that hold the pipe extensions on the coil together to stay put. There's very little room to work and I can't really see what I'm doing. I'm basically trying to feel my way through it. The few times I was able to get one of them on properly it pops back off as soon as I try to put the other one on. There's got to be a trick to it that maybe someone here can tell me.

Have you seen this?

Heater Core O ring replacement

Thanks heavens I have not had to learn about this first-hand.... yet. Let us know how it goes!

I'm replacing the whole core although it was only an o-ring that was leaking. I told my wife it would be foolish to go through all of that trouble and not go ahead and replace the core. Mine looks a little different from the one in your link. The heater hoses twist lock on to the tube extensions. That's what has the o-ring inside. I worked for about 3 hours last night trying to get it back together. The tubes are held together by little plastic clamps. I spent another 2 hours this morning and finally got them secured around the tubes. I just tried hooking the heater hoses back up and the plastic clamps popped back off. I had to drop my wrenches and come inside to take a break I was so frustrated. I don't believe they could've come up with a worse design if they tried.

I feel your pain! The key for me was the proper size o-rings and a set of helping hands. Place the o-rings inside the female ends, not onto the male ends. Have your helper hold the female pipes from the firewall side while you gently push the halves together. You need just the right angle to avoid damaging the o-rings. I chamfered the male ends a tad and used grease. If you put the o-rings on the male ends the stupid plastic clamps will not fit.

Above you mention o-rings on the plastic twist locks. These probably do have some sort of o-ring inside but it should be integral to the twist lock and not something you add. The o-rings I mention go in between the metal pipes inside the car. These were the source of my leak.

Oh it got worse after my last post. I decided to put the hoses on outside first and then go back to try and put the tubes and clamps on the coil. That was another couple of hours of much cursing and frustration. But I finally got it! I wanted to start it up and check for leaks BEFORE I put it all back together. But you can't do that either, the car won't start without the head unit in it. So I put it all the way back together. The o-rings I mentioned are the ones that go in the tubes. I was thinking about those hoses as I was putting them on outside. Boy, now there's a piece of modern marvel engineering. Whatever happened to the good old days of just pushing a heater hose directly onto the stubout of a heater coil and fastening it with a hose clamp? These have plastic twist lock connections.

So as I said, I had to put it all the way back together pretty much so I could start it. As soon as I did, the coolant started pouring from the top hose fitting where it locks on to the extension tube on the firewall. So in the process of trying to see what was going on with that. Pulling it off and back on to make sure it was right. Well the clamps popped loose again! AFTER I had already put everything back together inside the car. I cut the plastic twist lock connector off the top hose. I took the bottom one loose(it also came apart inside) and cut one of the old tubes and bypassed it for the time being.

I decided I had enough and was going to tell her to bring it to someone else. But I got to thinking about it yesterday. I was just going to go ahead and do it and then post here about it. But I don't believe it would hurt to have a little input. I believe I can make it a helluva lot better than the way it came. I'm thinking about ordering some high quality silicone hose and some good heavy duty stainless steel hose clamps. Cut the ends off the tubes and the coil and push the hose on the tubes and the stubouts of the coil and tighten the clamps up real good. I'll bet a dollar to a doughnut that those hoses and clamps will outlive those o-rings by a long shot. What do ya'll think?

I recall reading a similar post (perhaps on the 850 board?) where they replaced the hoses through the firewall with generic tubing then used stainless hose clamps to secure to the heater core with good results.

I broke one of the plastic twist locks too. The dealer had them in stock for a decent price so I was lucky. It's a totally over engineered system.

I think your idea will work if you enlarge the holes in the firewall for the new hoses. Space through the center console will be tight also. I would consider putting some kind of flair on any shortened pipe to prevent a hose slipping off.

As bad as I hate more connections because more connections equals more places for leaks. I was thinking I would just use the aluminum tubes that go on the core and just stick them through the firewall. I'll have to cut the ends off where the o-rings go. That's a good idea about swaging the ends. I have a flaring/swaging tool set that I use for my HVAC business. I've never used it for aluminum tubing though, only copper. But essentially I would have the silicone hose from the tubes to the coil and 4 clamps inside. That's basically what I did the other day. I cut the bad twist lock hose end off. I took one of the old tubes and cut the end off where the o-ring goes. I hooked the hose to the tube and tightened a hose clamp on it and just left the other end stock with the notch in it and hooked it to the bottom twist lock hose and bypassed it. The wife drove it to Atlanta yesterday. Probably about a 200 mile round trip with no issues. So once I get the inside done. All I'd have to do is unhook the end of the hose with the clamp. Hook my silicone hose up to that end and run the other end to the tube sticking outside the firewall. A clamp there and do the same thing for the other tube and that's it. I know I'll feel a lot better about it when it's done. I'll post back with some pics after I've driven it a while with my modification.

Well I wanted to update this one. I got this done a couple of weeks ago now. I've just been too busy to update it. It's got about 500 miles since I did the job and so far I've had no issues. In my haste I forgot to take pictures of the inside. But I took pictures of what I did on the outside. It looks about the same on the inside. It's just 2 short hoses and 4 clamps. It's real tight with the larger hose inside the box but I made it work. You have to make sure that the clamps on the inside are turned with the worm gear towards the driver side. Or else the ECM wont bolt back in its spot. Maybe I should send these pics to Volvo and tell them I'll take a low 6 figure salary versus a high 6 figure salary and I can make this stuff last the lifetime of the vehicle! If I would've had more time and the car up in the air. I would've discontinued the twist lock hoses completely instead of just the short extensions that go to the firewall and hook up. At least if it leaks now it should be contained to the outside which will be much easier to fix. Hopefully this will help someone else with the same problem.

The update is helpful.

It's not really cynical to point out that Volvo engineers weren't really worried about lifetime durability, only about durability beyond their warranty obligations. This has been true for a LONG time:

The Deacon's Masterpiece, by Oliver Wendell Holmes

"The Wonderfuil One Horse Shay" is the earliest example of design life I know of.

And to be fair, it's not just limited to volvo either. I believe they're building almost all of them that way now. It just pisses me off when I see things on vehicles that are designed to fail. You pay what some of these newer vehicles cost and you expect it to last a long time. I practically begged her to buy a toyota instead. You just don't see very many maintenance issues with some of the asian auto makers. Well, it's done...for now. Hopefully I wont have to raise the hood on it for a while except to change the oil.