Coolant Leak and System Issues [1997 Volvo 850 GLT]

Post by **1997volvo850** » 22 Jul 2016, 09:57

Please feel free to direct me at the appropriate threads.

I believe there are two issues concerning my 1997 Volvo 850's cooling system. The first is a leak that may have developed due to the second issue.

When I first purchased my Volvo 850 years ago I recall the days when I would turn off the car and the fan would run for a few minutes. While I thought this was strange the user manual indicated this was normal behavior. I no longer hear the fan running after I turn off the car though I do hear the fan come on when I'm sitting stopped in traffic on a hot day.

Last year when a crack developed in my overflow tank I observed basically normal operation and cooling while my car is running, with fan turning on and off, and little coolant leaking until I turn off the car. Once I turn off the car, with the cooling system shut down, the coolant would seem to boil and leak and stream out all over the place. I believe this is caused by the residual heat in the motor block and no cooling happening. I believe the fan motor staying on after turning my car off was to address some of this residual heat.

I'm not sure whether my overflow bottle leak was due to the added pressure after I turn the car off. I suspect there is a relay or sensor that is responsible for telling the fan to come on after I turn the car off. Any help is appreciated.

The new leak is just behind the engine above the heat shield (?) for the turbo. The small hose coming out of the overflow bottle runs behind the engine and splits into a Y with one section running along the back of the engine. This is where the leak is happening. When I add water to the overflow it simply streams out an unseen hole in the hose and runs over the shield to the ground.

This hose appears to be metal and covered with rubber, or partial rubber with metal - I'm not sure since this happened this morning and I needed to borrow my wife's car and rush to work. So I'm wondering if repairing this line (is this going to turbo?) is easy or complicated. Any help on this is appreciated.

I suspect the lack of fan cooling after I turn off the car is contributing to excessive pressure and possibly causing some of these leaks.

Thanks again for any help. I will try to post photos of the area this weekend. The crystals/sediment on some of the coolant lines may indicate other issues so I'll try to get these posted as soon as I'm back home.

Post by **JDS60R** » 22 Jul 2016, 10:12

You have a lot going on here.

I am concerned that the crystals are the remainder of a head gasket sealer - easier to call once your pics are up.
I think the broken tank and bubbling after you turn off the motor may be a result of a head gasket leak.
The cooling line may just be rotted out.

Either way - Volvo's hate overheating and generally respond badly to it if the condition is not fixed right away.

Without pics - I would tell you to go rent a block leak tester/head gasket tester/combustion gas tester at your local parts store . You will pay a little for the test liquid.
You sample the air above the coolant for combustion gasses.

Here is a video

Post by **abscate** » 22 Jul 2016, 18:58

The Volvo cooling system requires pressure to prevent local boiling in the engine. Our can't run these cars with leaks in the cooling systems very long

That metal pipe feeds the turbo, Feeds into the block. Best way to fix a hole is probably a piece of quality hose over the tube after cutting off the holed piece

Post by **tryingbe** » 22 Jul 2016, 20:52

Replace the hose and move on?

https://www.fcpeuro.com/products/volvo- ... -6842894oe

Sommerfeldt · Post by **Sommerfeldt** » 23 Jul 2016, 02:02

What tryingbe said - just replace the hose. I'd recommend changing all the coolant hoses over to silicone. Lots of peace of mind, at a reasonable price.

As for the hose section at the back of the engine that you're talking about (http://www.do88.se/sv/artiklar/volvo-sl ... lning.html ), it's a PITA to replace, basically because you have to put it on one of the metal parts, slide it onto it far enough to clear the gap, then slide it over the other end. If that made sense at all.

Took me about 15 minutes.

- S

Post by **MrAl** » 23 Jul 2016, 14:08

Sommerfeldt wrote:What tryingbe said - just replace the hose. I'd recommend changing all the coolant hoses over to silicone. Lots of peace of mind, at a reasonable price.

As for the hose section at the back of the engine that you're talking about (http://www.do88.se/sv/artiklar/volvo-sl ... lning.html ), it's a PITA to replace, basically because you have to put it on one of the metal parts, slide it onto it far enough to clear the gap, then slide it over the other end. If that made sense at all.

Took me about 15 minutes.

- S

Hi,

Can you get silicone hose for the top and bottom radiator hoses too?
And if so, do you get this from an auto parts store or buy it yourself from somewhere else and cut it to size?

LATER:
I found a kit but the price is wayyy out there, 100 bucks to almost 200 bucks.
Also, looks like regular hose wont work because the rad hoses have different diameters at each end of the hose while most regular silicone hose has same diameter from end to end.
These prices are a far cry from the standard rubber hoses which could last 10 years anyway and cost under 20 bucks each.

Sommerfeldt · Post by **Sommerfeldt** » 23 Jul 2016, 16:04

Yeah, those two on the do88 site are turbo coolant hoses. They also have kits for the other coolant hoses - expansion tank and the others. You need custom made hoses, because the bend weirdly and like you said, aren't the same diameters at each end. As for prices, you're right - the silicone kits are expensive.

On the other hand, they're more durable than rubber, stand up to temps and oil/chemicals better, as well as pressure. Since our engines absolutely do not permit coolant loss and overheating, I feel good about having tough hoses all round. It's probably an emotional thing mostly though, since OEM rubbers are very good hoses too.

- S

Post by **1997volvo850** » 05 Aug 2018, 16:47

I noticed this old thread and see that I never brought it to closure.

The leaking hose I had to replace was about five inches long and located in back of engine on passenger side (As I see Sommerfedt also identified above). This appears to feed turbo. The other metal line runs into block.

This was a pain to get into place. The hose was about five inches and the gap between the two metal connections was about two or so inches.

Working on a heater core failure in another thread. Thanks for all the help.