Coolant loss lead to transmission failure

eldims · Post by **eldims** » 29 Feb 2012, 22:25

Model : S60 2.3T5
Year : 2003

Just to share. A few months back i kept loosing coolant but was too ignorant to do anything about it. Tried looking around where the leak was but couldn't find it, and i ignored it. The coolant low alarm would light up every week or so and i was OK with having to fill it up every now and then. i stupidly thought it was "vaporizing" somewhere.

Unfortunately the coolant was actually going into the transmission and that is why i couldn't find the leak. The transmission fluid goes through the radiator for cooling, and there was an internal crack which causes coolant water to sip into the transmission. After enough water gets in, my tranny finally gave up and there goes a large chunk of my $ as well in getting it replaced. So anyone losing coolant, please consider this possibility if you can't find where the coolant is going. as a future pre-caution, i'm installing a separate cooler for the transmission fluid that is independent from the radiator.

Recently, i have started losing coolant again. this time i'll be hunting down till i finally know where all that water is going. but i'm wondering if anyone has the service manual or a diagram of somesort that shows how the cooling system works (more specifically where those coolant are normally going) for me to narrow down my search. i've been looking high and low for an S60 service manual and cooling system diagram but couldn't find any. Any help/ideas..?

Post by **regent** » 01 Mar 2012, 12:40

If a small amount of coolant is escaping in the engine compartment or through a crack in the cabin heater, you could usually smell the vapors.
I would check the condition of the engine oil to make sure it is not the oil cooler. I am attaching VADIS parts diagrams for the cooling system on your MY; hope this helps you sort it out.
Thanks

eldims · Post by **eldims** » 01 Mar 2012, 19:43

Checked the tranny and engine oil. Looks good. So i'm guessing its not escaping to these parts.

I've narrowed down to problems with the head gasket. Read somewhere that having engine oil around the spark plug thread could be a sign of worn out gasket. Also read somewhere that faulty head gasket could cause coolant to escape. Wonder if i'm going down the right path.

Post by **regent** » 02 Mar 2012, 11:37

1. A failing Valve Cover Gasket will allow oil to leak around and into the spark plug wells.
2. If the Head Gasket is blown, then coolant can leak into the bores or into the engine oil or both. I would take the plugs out to see what they would tell me, and go from there.

3. A faiure within the turbo cooling system is another possible path for oolant loss.

philbrooksjazz · Post by **philbrooksjazz** » 05 Jan 2016, 18:18

I had the same problem on a 2002 V70 XC, I got this repaired within 5 days, and the car worked fine for 2 months, before the transmission slowly started failing. I choose to not to get it fixed as I lived in Maui at the time and a replacement was ~7000.

A fix for this issue is to install an after market transmission cooler, and route the trans. fluid through that and not the combined engine / transmission radiator. This way there is no chance of contaminating the transmission.

This car was in beautiful shape with only 94K miles, body and interior perfect.

I think Volvo should take some action on this and help us out - I have owned volvos for > 35 years, and would consider a V70 again, but for now it's a Chevy HHR.

Post by **abscate** » 06 Jan 2016, 04:07

You should be able to get a good used trans for 1000 to the Islands, then another 1000 to put it in.

Replace that radiator with a new one and run another 15 years

philbrooksjazz · Post by **philbrooksjazz** » 06 Jan 2016, 10:04

I only found 1 shop on Maui that would even consider working on it, and they would only put in the Volvo replacement, which is sold as 'new' but as I was advised was actually a rebuilt.

statvolvo · Post by **statvolvo** » 11 May 2016, 01:28

Have a 2007 XC90 D5 here in Australia that had a similar event with coolant disappearing ever so slightly. The engine computer gave dashboard warnings of check cooling and stop safely and engine service required . We can only deduct (and I am not a mechanic) that the mix of coolant and transmission oil corroded the pipe work limiting any flows (if any) to the transmission unit (and possibly saving the transmission) hence the check cooling warning and repeated engine service messages. We replaced the radiator / oil cooler, pipework that was clogged and flushed engine and transmission. Fortunately no milky residue was found on first flush of transmission and thus believe that if any water coolant made it to the transmission it would have been a small amount. Mechanic was happy with the result. Currently gear changes are very, very smooth and drives like it did prior to this event. I Will update as things progress.