1995 Volvo 940 Too Much Coolant? Issues?

Las940 · Post by **Las940** » 08 Jul 2014, 15:52

Purchased this car used about 2 weeks ago. The coolant appeared to be very low at the time of purchase, but I didn't notice at first until overheating occurred at high RPMs. When I went to top off coolant, I noticed it was boiling. The overheating issue was solved when I added 1 gallon of coolant. Temperature reads exactly in the middle as it should.

One week later, I check coolant level in reservoir. It is well below the minimum mark, but not overheating. Temperature still is exactly in the middle. However, I decide to add more coolant (approximately 1/2 gallon this time) just to prevent any future overheating. I should mention I live in Hawaii...

Here is the issue:

Yesterday, after arriving home from my 30 minute commute from work, I notice a small amount of steam expelling from under the hood. I turn of the engine and pop the hood. The source of the steam is the upper radiator hose, which had a loose connection to the fitting on the radiator. I noticed small drips of green coolant on the ground. Once the engine was cold, I adjusted the upper radiator hose, tightening the clamp, and putting it back in place. As I adjusted the hose, a small amount of green coolant dripped out. Once the hose was back in place, there was no smoke to speak of when I tuned on the engine again. Coolant appeared to be at normal level, too.

I drove to the repair ship to have them check the cooling system pressure. No smoking on the way, but still dripping coolant. Mechanic's diagnosis was that all hoses good, coolant reservoir good, and coolant level good. But he mentioned the leak, attributing it to the radiator, which I find hard to believe...

I have heard that excess coolant in the system can increase the pressure, causing coolant to leak out of the drain when the engine is warm. If that's the case, do I simply allow drain some coolant? Or is a new radiator in order? I am at a loss...

lummert · Post by **lummert** » 08 Jul 2014, 17:25

How would excess coolant leak out of the drain? The block drain requires manually opening or closing. The coolant was leaking at the hose just as you found. The coolant reservoir level should be checked when the engine is cold.

Las940 · Post by **Las940** » 08 Jul 2014, 18:04

Just checked coolant reservoir... It's at the minimum mark. Am I looking at a radiator issue?

Las940 · Post by **Las940** » 08 Jul 2014, 18:48

Okay, so I just went for a quick 15 minute drive. When I parked, I noticed coolant dripping from the upper radiator hose where it meets the radiator, and could hear bubbling. This confirms my theory that the radiator is fully functional.

Now, what would cause coolant to seep from the end of the hose when it's connected securely? Do I simply need to replace the hoses? Would a coolant flush help? I've never dealt with cooling system issues before, so any help would be appreciated. Thanks.

lummert · Post by **lummert** » 08 Jul 2014, 20:17

If the hose isn't fairly recent I'd just replace it and the clamps. Hoses have been known to leak after over tightening the hose clamps. The upper hose is fairly simple and not expensive.

Las940 · Post by **Las940** » 08 Jul 2014, 23:17

I just replaced the upper radiator hose and clamps, but I am still getting "steam" and drips from where the hose meets the radiator. I am now even more confused...

Ethan Rode · Post by **Ethan Rode** » 09 Jul 2014, 03:39

It's highly possible that your radiator is cracked at the hose nipple. Radiators do crack on occasion, especially plastic ones.

lummert · Post by **lummert** » 09 Jul 2014, 04:49

The radiator was the next thing to check.

Las940 · Post by **Las940** » 09 Jul 2014, 19:53

One thing I did not mention is that the coolant seems to never return to the expansion tank when the engine is cold. My guess is that this has to do with a leak in the vacuum of the cooling system. But I can't be too sure. I am also wondering if there could be air trapped in the cooling system? Or if the radiator cap is bad? For ease of diagnosis, here is what I am experiencing:

-NO overheating (temperature gauge needle always in the middle when engine is on)
-Small leak where NEW upper radiator house meets radiator (only leaks when temperature reaches normal level)
-Both upper and lower radiator hoses are very warm (normal?)
-Coolant does not return to expansion tank from the radiator (coolant level is full)
-NO pressure in coolant expansion tank at any time
-Coolant seems to boil once temperature gauge reaches normal level
-Takes a long time for the engine to become cold again once it has been idling (or driving) for only 10 minutes. Again, temperature gauge needle never gets past the middle.

lummert · Post by **lummert** » 09 Jul 2014, 21:02

The coolant flows from the top of the radiator tank via a small hose into the reservoir, then back to the radiator via a hose from the bottom of the reservoir. If the coolant is too low it won't be able to flow through the reservoir.