1998 Volvo S70 - Large Coolant Leak, but Where is it?

Post by **nickelghandi** » 27 Apr 2017, 05:59

Hello everyone. This is my first topic on this forum. I have searched this site and several others to no avail with this issue. If you know of a thread that answers this, please point me to it. I know there are other mystery coolant leak threads on here, but I haven't found an answer yet. I know how to do a little research and the importance of doing so before posting. I work in IT which is known for not being the nicest field when people go asking questions without looking for obvious answers first.

I have a 1998 Volvo S70 GLT. I recently had the head gasket replaced by a Volvo specialist shop near me. I had oil in the coolant and coolant in the cylinders if I didn't relieve the pressure after it had been running so I figured "head gasket" and took it in. They replaced all gaskets and any broken or rotted hoses as well as the water pump, pulley and timing belt along the way. They milled the head and put everything back together nicely. In total it cost me $1700 for the head gasket job for a car I bought last August for $1200 as a beater and fell in love with. The car ran great for about 2 weeks after the work was done and still runs just fine.

Now suddenly it is hemorrhaging coolant. My commute to work is 23 miles one way. The other day my low coolant light came on so I stopped at a gas station and bought some 50/50 mix, waited a bit with the hood open for the engine to cool, took off the expansion tank cap, topped it off and went home to further diagnose the issue. On the way I did notice a tiny bit of steam rolling out of the drivers side of the hood. I have dye in the system and a UV light, but I cannot find the leak anywhere. When I had the bad head gasket, I hardly lost any coolant. The tiny amount that I found in the cylinders wasn't enough to lower the coolant level, but caused the engine to run quite rough on startup, so I would think if this much coolant were disappearing and going into the cylinders, I would have some nasty misfires and possibly even hdyro-locking of the whole engine. I have pulled the plugs and looked for coolant and found none. I have compression tested the system and all 5 cylinders read and hold pressure between 157 and 163 PSI on my cheap pressure gauge, so I am pretty sure all the cylinders are not leaking. I have no coolant in the oil and only the residual tiny bit of oil in the coolant from the original head gasket leak.

If it is not burning/using the coolant, where else could it be going? I have no loss of power, no smoke out the tailpipe, no sweet smelling exhaust, great MPG (19 city, 26 highway). My only symptom is the coolant vanishing from the reservoir enough to set off the light after just 46 miles. Could it be leaking onto the exhaust somehow near the turbo and evaporating? I haven't pulled the heat shield off yet to see, but I plan to today. I know that if I were leaking this much internally even after the combustion chamber that there would be some clear evidence. I love this car and will take it back to the shop if I must. They stand by their work and the head and head gasket are guaranteed for the rest of the car's life, but I worry that they'll find some simple leak I could have found and charge me for it. I don't mind paying for it, but I want to save myself some embarrassment and money if I can.

Any help or tips on further diagnosis is greatly appreciated. I have lots of tools and pretty free afternoons to tinker with things so hopefully with a little advice from here I can get this sorted quickly. Thank you for any help you can offer.

P.S. If I do start posting some pictures to this thread, be forewarned: My hood and trunk are currently white. The old ones (and the roof) had badly peeling clear coat and paint damage. I figured it'd be easier to scuff the flawless white surface and have someone shoot nautical blue onto it than to try to feather out the flaws on the badly damaged old parts. Anyway if you see my car, please don't think that I am turning it into a racecar or even trying to make it look like one.

Post by **kahl** » 27 Apr 2017, 07:02

I would look at the short 5 inch coolant hose situated on the turbo charger. You can get a good look at the hose from under the car.

Post by **abscate** » 27 Apr 2017, 07:48

Greetings and don't sweat the search. It's tough too get the right search parameters o something like this

The P80 cars often blow heater cores or the connections at the heater core, and the coolant ends up under your carpet. I had about a gallon under mine. Many people can't smell coolant that well. I could barely smell mine.

There is deep thick padding on Volvos so you might have to lift and cut to get to the floor. Most of my coolant ended up unde R the carpet in front of the rear, passenger side seat!

Post by **cn90** » 27 Apr 2017, 09:14

For Turbo hoses, use only Volvo OEM hoses, they are cheap.
Detail below:

viewtopic.php?f=1&t=55306

FCPEURO · Post by **FCPEURO** » 27 Apr 2017, 09:29

The best thing to do is to pressure test the coolant system. This will force the system to leak at its weakest point, simply follow the drips back to its origin.

You can usually rent a pressure tester at a local Auto Zone, Advance Auto, or O'Reillys.

I hope that helps

Jason

kaneelschep · Post by **kaneelschep** » 27 Apr 2017, 10:02

Mine leaked quite heavy too. Couldnt find it without a bridge. Because it leaks past everything and falls on the ground at another place. It was indeed from the short hoses under/ next to the turbo. A hose got soft overtime from a little oil leak from the turbo. And it started leaking at a clamp. When hot it would squirt out. But not all would come out. So thats why it was still drivable. Check those well! Take em off and see if they are bloated or not.

Post by **shiloh51933** » 27 Apr 2017, 12:40

As Abscate mentioned, the heater core's go and the heater hose inlet/outlet hoses for the heater core...they go through the firewall and they fail after time. I'm supposed to change out my friends heater core on his '98 V70XC this week and while I'm doing that I recommended changing out the heater hoses inlet/outlet lines.

Personally if there's any residual oil left inside the cooling system I'd re-flush and re-flush again until there's not even a hint of oil in the cooling system. The 98 has a soft cooling hose that goes to the turbo(I believe they got rid of the soft line in '99/'00), this soft line is a weak point. The hose under the expansion tank is a weak point and there's another hose near expansion tank near firewall.

Post by **E Showell** » 27 Apr 2017, 15:41

Check for whitish residue around the expansion tank cap. Sometimes the caps leak and the coolant vaporizes and escapes without creating a visible leak. Whitish residue by the filler neck is a dead giveaway. If you haven't changed the expansion tank cap under your ownership, it could be cheap insurance. Go with Volvo OEM only.

Post by **nickelghandi** » 27 Apr 2017, 17:32

Thanks for the quick replies! I had to wait to check the hose when I got home. I drove my other vehicle to work today.

As for the heater core... I should have mentioned that it has been replaced. I have complete service records from the previous owner dating back to 1997 when it was bought new. The heater core was replaced about 7,000 miles before I purchased it I believe. I pulled apart the lower dash and pulled up the carpet a little while back when I had the head gasket problem to see if it was leaking because I could hear a slurping/bubbling sound moving through the core. That turned out to be exhaust gases making the sound. The heater core showed no signs of leakage and neither do the two connectors by the firewall. That's not to say that oil couldn't have clogged it when I had the leak, but it seems doubtful due to the tiny amount that ever got in.

I checked it out this afternoon underneath and there is definitely an external leak. There is coolant all over the frame crossmember and the axle. The turbo looks pretty dry, however I am sure that with how hot it can get, the coolant would evaporate off rather quickly. I will try to get some pics but it's pretty tight under there even with the jack and stands holding it up. I need to buy some ramps I suppose. Anyway I guess I will take it back to the shop that did the gasket. They removed the turbo during the work to avoid getting anything inside of it, so maybe they failed to tighten something. I'll report back what I find out.

Post by **nickelghandi** » 28 Apr 2017, 07:18

So in looking more closely at it, I have decided that it will probably be easiest to just replace all of the hoses at and around the turbo. All of them look mighty old and they are relatively cheap; even for OEM. It isn't clear which one is leaking so I will just go for all of them and probably not have to do it ever again.

Do you think it is easier to remove the turbo for this or try to work from under the vehicle? I am not a large person by any means, but it is still pretty tight down there. I might just have the shop do it. They use OEM Volvo parts. I need to start stockpiling replacement hoses and things for this car I think. It seems like every other week or so I find another cracked, old vacuum line or hose hiding somewhere.