SwedeSpeed - Volvo Performance Forum banner
41 - 60 of 78 Posts

·
Registered
Joined
·
3,412 Posts
Noticed some condensation on the windshield passenger side
Same exact situation, I couldn't figure out why/how the condensation was appearing for the life of me (I kept thinking it was a bad front window installation or sunroof) and then my CEM went haywire and crapped out, which is what clued me into the heater core situation. Most likely you've got a leaking O-ring. In my situation, the plastic snap connector had popped off and only time/grit held the o-ring in place until, at some point, the vibration took it's toll and shredded the o-ring and caused about 1 gallon of fluid to slowly leak under my carpet. Only at the very end (when the horn was blaring on its own), was I able to find any external coolant in the car. Once I pulled up the carpet, there it was and I felt like a dumba$$ that I had waited so long.

So do yourself a favor and pull the CEM and fix the o-rings now before the coolant fries it.
 

·
Registered
Joined
·
21 Posts
Same exact situation, I couldn't figure out why/how the condensation was appearing for the life of me (I kept thinking it was a bad front window installation or sunroof) and then my CEM went haywire and crapped out, which is what clued me into the heater core situation. Most likely you've got a leaking O-ring. In my situation, the plastic snap connector had popped off and only time/grit held the o-ring in place until, at some point, the vibration took it's toll and shredded the o-ring and caused about 1 gallon of fluid to slowly leak under my carpet. Only at the very end (when the horn was blaring on its own), was I able to find any external coolant in the car. Once I pulled up the carpet, there it was and I felt like a dumba$$ that I had waited so long.

So do yourself a favor and pull the CEM and fix the o-rings now before the coolant fries it.
CEM feels dry under the pipe and I nestled a towel up there for a drive and it came out dry. But will pull it and take a look at it, reseat that clamp, and keep an eye on things until it goes to shop. Going to have them get a good look at it and if they decide that it's the O-rings we'll see what they quote. Fairly confident in doing that myself but would rather just have them get it done if it ensures a correct diagnosis and I hate dealing with draining and filling the cooling system on sealed systems.

Mercdude: did you have any other of the other symptoms I listed? I'm kind of worried it's the core and that the O-ring clamp is a red-herring. Based on the smell and way the coolant is getting on the floor but not on the pipes...but I'll try to get a better look.

Anyone get the smell and have it turn out to just be O-rings?
 

·
Registered
Joined
·
3,412 Posts
CEM feels dry under the pipe and I nestled a towel up there for a drive and it came out dry. But will pull it and take a look at it, reseat that clamp, and keep an eye on things until it goes to shop. Going to have them get a good look at it and if they decide that it's the O-rings we'll see what they quote. Fairly confident in doing that myself but would rather just have them get it done if it ensures a correct diagnosis and I hate dealing with draining and filling the cooling system on sealed systems.

Mercdude: did you have any other of the other symptoms I listed? I'm kind of worried it's the core and that the O-ring clamp is a red-herring. Based on the smell and way the coolant is getting on the floor but not on the pipes...but I'll try to get a better look.

Anyone get the smell and have it turn out to just be O-rings?
Yeah I did


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
122 Posts
Stuff wads of paper towel around the heater core pipes just below the clamps and examine the towel in a few of days for signs of wetness and staining. If the leak is fresh, it may be difficult to detect visually because the coolant quickly evaporates as it runs down the side of the hot pipe.

Every situation is going to be different. In my case, the leak wasn’t continuous, and I was able to go for a couple of weeks at a stretch with no visible loss of coolant at the expansion tank and then it would suddenly drop about 500 ml. I never saw any coolant on the carpet, and the CEM was never touched. While there was an occasional brief maple-syrup smell when turning on the heat, there were never any signs of windshield fogging.

Given the age of your car, it would be difficult to imagine that one of the O-rings is not leaking, especially with one of the clamps falling off. As a first step, it would be best to get a closer look at the O-rings before considering the heater core as the source of the leak.

Below, we see the upper pipe coupling is dripping coolant, and the lower pipe coupling shows signs of prior leakage.

Just for fun, I recently began losing coolant due to a failed O-ring in the lower heater hose that connects to the large inlet pipe behind the engine. I happened to catch this only because I added UV dye to the coolant system.


 

·
Registered
Joined
·
21 Posts
I am fairly sure it's the O-rings. Got a good look at lower one and can see a bit of coolant. Right now I've got the CEM slid down and some towels shoved around the pipes to hopefully keep anything off the CEM till it's fixed.


For reference if it helps people in the future here's my upper one with the clamp missing. This should give a good look at it if you're trying to visualize better when reading the instructions. I was able to reach up and replace the clamp that had fallen without unplugging the CEM (just moving it down like you're replacing a fuse,) but obviously for doing the full job you'd need to fully remove.

 

·
Registered
Joined
·
3,110 Posts
Isn't that where MNIWT popped the pipes apart, slid on some hose and hose clamp so even if the orings ever leaked again, it wouldn't leak out of the pipes? Or was that through the firewall?
 

·
Registered
Joined
·
3,412 Posts
That right there is a shredded O-ring. You shouldn't even be able to see the o ring, but you can because it's swelled-up and been cut up. You'll see what I mean when you take it out - you'll wonder how it didn't leak more. So my suggestion would be to finish putting a new o-ring and plastic clamp (have fun with that!), and then take silicone tape and wrap the entire connection tightly and then zip-tie the ends of the tape so it never comes undone and/or leak. You could try the heater hose trick like MNIWT, but this is an easier way to make sure your joint never comes apart again. Btw, what a lame idea to use (basically) a plastic exhaust v-clamp to hold the metal lines together. If you're going to do it like this, use metal clamps that screw together. Over time, the plastic deforms under heat and stress, allowing the metal lines to slip apart and then shred the underlying o-ring. Bad idea.
 

·
Registered
Joined
·
21 Posts
That right there is a shredded O-ring. You shouldn't even be able to see the o ring, but you can because it's swelled-up and been cut up. You'll see what I mean when you take it out - you'll wonder how it didn't leak more. So my suggestion would be to finish putting a new o-ring and plastic clamp (have fun with that!), and then take silicone tape and wrap the entire connection tightly and then zip-tie the ends of the tape so it never comes undone and/or leak. You could try the heater hose trick like MNIWT, but this is an easier way to make sure your joint never comes apart again. Btw, what a lame idea to use (basically) a plastic exhaust v-clamp to hold the metal lines together. If you're going to do it like this, use metal clamps that screw together. Over time, the plastic deforms under heat and stress, allowing the metal lines to slip apart and then shred the underlying o-ring. Bad idea.
Yeah I think clearly the O-rings need to be changed. If I reach under the heater core plastic box and feel around I can come away with just a little bit of liquid on my hands, so wondering if the heater core itself is also leakng or if the liquid from the O-rings is getting down there somehow. I really don't see much escaping and don't see any trails down the pipe at all but can smell it when driving periodically fairly strongly and the car is now fogging up pretty good when left parked. On the other hand it's going through very little coolant and it probably was leaking for awhile to get to this point.
 

·
Registered
Joined
·
3,412 Posts
Btw I just realized this was the same exact o ring that gave me trouble.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
687 Posts
Btw! , what a lame idea to use (basically) a plastic exhaust v-clamp to hold the metal lines together. If you're going to do it like this, use metal clamps that screw together. Over time, the plastic deforms under heat and stress, allowing the metal lines to slip apart and then shred the underlying o-ring. Bad idea.[/QUOTE]

Totally agree! It was a HUGE pain in my @$$ over a 2 week period I thought I had it fixed 3 different times. it’s finally fixed
 

·
Registered
Joined
·
21 Posts
Shop identified the O-rings/pipes as source of leak, but for various reasons we ended up putting in a new Volvo heater core (they weren't confident in the quick fix not leaking, etc.) I also just don't have the time to deal with this myself for a few weeks and needed to use the car, it was making me feel sick (literally) driving it around with the coolant fumes (oh man just thinking about it is making me nauseous) and was continuing to get things wet. Carpet wasn't too wet luckily, caught this fairly early. We've been getting a lot of rain here so was checking the floors every day. When we got the core out there were some signs of corrosion, likely from the leak, so ended up being glad we did the full job instead of doing this twice. The O-rings were total garbage when we got them out. The new part has the clamps in the same places but according to shop the pipes on the newer cores are solid underneath, though I doubt it.

If I had time to do the quicker fix myself I'd have done it. Based on people on this thread posting about how they had to do it X times before getting it right it definitely isn't the kind of procedure a shop should do.

Now when I have time next I'll pull the carpet out and give it a good cleaning.
 

·
Registered
Joined
·
3,110 Posts
Do we have an example of some good small v-style clamps that would do this job? I'd rather get to it early rather than later.

Also, I had considered putting in a KAT's 1500w block heater to give me heat in the cabin at startup through the heater rubber heater core lines in the engine bay, but that's a project for another day.
 

·
Registered
Joined
·
2,542 Posts
I saw somewhere, possibly the UK Volvo Forums, where they cut the lips off the pipes and joined them with rubber heater hose, securing with hose clamps. Seemed pretty secure.

When you do the "O" rings, be careful to to bend the heater core pipes around. I apparently weakened the weld where the pipe attaches to the heater core and it broke about a year later.
 

·
Registered
Joined
·
4 Posts
In which order did you attach the hoses?

I love this solution - much better than those silly clips! Did you put the radiator hose on the pipes that pass through the firewall first, or did you slide them over the pipes that are soldered to the core first? I would imagine it makes a difference when trying to reconnect the pipes in that tight space.

Thanks,
Tom
 

·
Registered
Joined
·
3,110 Posts
I love this solution - much better than those silly clips! Did you put the radiator hose on the pipes that pass through the firewall first, or did you slide them over the pipes that are soldered to the core first? I would imagine it makes a difference when trying to reconnect the pipes in that tight space.

Thanks,
Tom
The way I am going to do it is to slide two small rings of hose, one over each end that fit snug onto each pipe. Then one larger piece to slide over both of those, and then fit two hose clamps over each end and it'll fit snug, come apart easy, and never leak. From what I was messing with while my hands were down there, there's more wiggle room and flex on the top pipe, but both sides are usable for such thin applications.
 

·
Registered
Joined
·
2,542 Posts
Be careful not to put too much pressure on the pipes coming from the heater core. It is pretty easy to crack where they are welded to the actual core. I found out the hard way.
 

·
Registered
Joined
·
4 Posts
What size hose did you use?

Old O ring vs. new.


Drained the coolant from the radiator and didn't have too much trouble getting the pipe apart. Putting them back together was the real challenge. I eventually removed the fuse box for better access.


I must say, this pipe is one of the worst designs I have ever seen in this car. Two metal pipe, mated with a tiny rubber O ring in the middle, expecting them to be held together by a plastic clip?!?! Yeah... No.
I bought a new plastic clip, but considered this to be a weak point. Especially since less than 1mm of separation in the pipe will result in a failed seal and another leak. So I replaced it with a rubber coolant line and hose clamps. It's nice and tight, even if the pipes do slightly separate and the new O ring fails, this shouldn't ever leak again.
I have some 3/4" ID hose that doesn't seem to fit over the wider parts of the pipes near the end. Did you use a larger size heater hose, or did you modify the pipes to make it possible to slide the hose over?
 

·
Registered
Joined
·
4 Posts
The way I am going to do it is to slide two small rings of hose, one over each end that fit snug onto each pipe. Then one larger piece to slide over both of those, and then fit two hose clamps over each end and it'll fit snug, come apart easy, and never leak. From what I was messing with while my hands were down there, there's more wiggle room and flex on the top pipe, but both sides are usable for such thin applications.
That sounds like a good approach - I assume you used 3/4" ID hose as the small hose, and 1" ID hose as the hose on top? Out of curiosity, how did you get the smaller hose over the pipe that's welded to the core?
 

·
Super Moderator
Joined
·
15,184 Posts
3/4" hose here, wanted to make sure it kept a real tight fit. You can heat it up a bit to make it a little more pliable.

I found it easiest to attach the hoses to the bottom heater core first (this was with the heater core removed) and then work them onto the upper hard lines. You may want to disconnect the lines from the engine side by the firewall to get more movement out of them.

As mentioned, be very careful when applying any force on the heater core's hard lines, as you can very easily break them at the core.

This is still probably the worst job I have ever had to do on a P1 Volvo.
 

·
Registered
Joined
·
3,110 Posts
That sounds like a good approach - I assume you used 3/4" ID hose as the small hose, and 1" ID hose as the hose on top? Out of curiosity, how did you get the smaller hose over the pipe that's welded to the core?
A thorough coating of windex usually allows for slip factor to increase significantly, then just dry up or wait to dry. Hasn't failed me yet.
 
41 - 60 of 78 Posts
Top