Exhaust and crankcase condensation

befarrer · Post by **befarrer** » 13 Feb 2021, 07:12

Does anybody else, who lives in a colder climate notice if their Volvo makes more condensation out of the tailpipe than the average vehicle? I have noticed it since I started driving in Sept 2019, it's not coolant, my coolant level has not dropped since then, and the condensation is only when below freezing. I also added a catch can in line with my PCV system in line right before the PTC nipple. I only ran the catch can for a few weeks before it froze and plugged and I disconnected it. I just now removed it, and there is a good 3-4oz of clear water in there, with maybe 2 tanks of fuel at most. I did a compression test in the springs, and was about 25psi low on cylinder 2 and 15psi low on cyl 1, adding oil brought it up, so it's rings. I think this is the source of crankcase condensation. But the tailpipe seems odd, maybe a trait of the engine, or running 91 octane? Doesn't matter where I fill up.

Sommerfeldt · Post by **Sommerfeldt** » 13 Feb 2021, 07:29

All the turbo Volvos I've had, have been "steamy".

I ran a catch can on the last one for a while, and it'd see quite a bit of stuff and water, and even then it'd be white-smoking quite a bit.

I'm not sure it's got anything to do with the fuel - I assume you guys in Canada use the same system as US, so you're running 91 AKI? I've used both 95 and 98 RON (91 & 93 AKI) in my Volvos, and it has never had an impact on the steaminess.

- S

Post by **scot850** » 13 Feb 2021, 10:52

I've owned Volvos both here in Canada and in the UK for over 45 years. They always have condensation in the oil cap and muffler systems. Only way to reduce this is to give then a good long run to let the systems dry out. The issue is not just a turbo issue.

In the 70's and 80s we were lucky to get 2 years out of a 240 muffler. They rotted out in the muffler just forward of the rear axle there the pipe met the rear of the muffler.

The simple answer is in cold climates the hot to cold cycle is much shorter causing more condensation. Getting the car out for a good long run a few times a month will help.

This issue is not limited to just Volvos. I have seen other brands where people have turned a corner and a stream of water runs out the muffler.

Neil.

befarrer · Post by **befarrer** » 23 Feb 2021, 06:12

I changed the oil the other day and did an analysis on the oil. 7000km on the oil, using 10w30 synthetic. The oil was thinner than it was originally, and my water concentration was very high, I think it was almost 0.1%, no traces of glycol was reported. Basically, I should shorten my oil change interval. I might change this at 5000km and do another sample.

Comparing the PCV setup in these cars to most, there is no way for fresh air to enter the crankcase on these, only a way to vent out the gasses, so the air removed by the PCV system is replaced by blowby. I might pick up a spare oil cap at the wreckers, modify it to be a fresh air intake, see what happens.

befarrer · Post by **befarrer** » 15 Feb 2022, 06:01

I should update, my last oil sample also came back high for water in the oil, no glycol. I did an oil change after doing 4, 1 hour long highway drives with no short drives in between. However, when I filled up the other day, the station was out of premium and only had 87 octane, so I filled with that, had 1/4 tank of 91. I noticed no driving difference, but my exhaust condensation is on par with other vehicles now, I can see out my back window when accelerating yesterday, when it was below freezing outside. I think I might do an experiment where I keep on 87 octane for the rest of this tank, and see if my condensation in the oil drops.

Here is my sample result:

Volvo Oil 2021.pdf: (86.99 KiB) Downloaded 80 times

Post by **abscate** » 15 Feb 2022, 08:47

What are you doing with that barely used engine oil?

befarrer · Post by **befarrer** » 15 Feb 2022, 11:32

I was due for an oil change, but right before I changed it, I did 4 1 hour long highway trips. Figure if there would be any condensation in the oil from short trips, it should boil off with the longer trips.

Post by **scot850** » 15 Feb 2022, 11:37

I do not recommend running a turbo on 87. The engine runs hotter (which might explain the lower condensation) but the danger is burning a valve due to the higher running temp of the engine.

Neil.

Post by **Krons** » 16 Feb 2022, 07:46

befarrer wrote: ↑15 Feb 2022, 11:32 I was due for an oil change, but right before I changed it, I did 4 1 hour long highway trips. Figure if there would be any condensation in the oil from short trips, it should boil off with the longer trips.

It is surprising the water didn't burn off with those longer trips. Will be curious id the octane makes a difference.

I run 87 but based on guidance in the manial may run 91 in the heat of summer here:

Fuel requirements
Octane rating

MINIMUM

Volvo recommends premium for best performance, but using 87 octane or above will not affect engine reliability.

Volvo engines are designed to achieve rated horsepower, torque, and fuel economy performance using premium 91 octane fuel.

RECOMMENDED

In demanding driving conditions, such as operating the vehicle in hot weather, towing a trailer, or driving for extended periods at higher altitudes than normal, it may be advisable to switch to higher octane fuel (91 or higher) or to change gasoline brands to fully utilize your engine's capacity, and for the smoothest possible operation.