-40C loss of boost

Post by **IVIUSTANG** » 09 Dec 2009, 23:28

Hey guys,

The weather here has been TERRIBLE here, minus 40C. My car has a boost guage and it will not go above 3 inches of vacuum, it doesn't even reach boost. Although the turbo is obviously working. As a result my car has good driveabilty but has ALOT less power when I rev it, something is blocking or restricting power. Last winter I had the same problem but it was worse, I took it to a mechanic because I was at a loss, and supposedly my intercooler was filled with water(and froze) and I had a broken vacuum line. The severity of this is about 1/3 of that situation but I hate it! My car has been left inside a garage overnight where I work and it was fine on the way home, in a few hours after sitting I drove it and noticed this. First things to check?

Post by **matthew1** » 09 Dec 2009, 23:42

Look for collapsing intake tubes. If I recall correctly, that's what has been bedeviling XC90 owners in very cold weather.

Post by **IVIUSTANG** » 09 Dec 2009, 23:53

Nothing looks collapsed prior to the turbo to me.

Post by **jblackburn** » 10 Dec 2009, 00:18

You will likely only see them collapse under boost, not at idle. Which makes it all that much harder to track down. Have someone keep a VERY firm foot on the brake, and give it gas to build up the revs and look at the pipes. I suggest standing to the side of the car for obvious reasons. Don't do this for more than ~5 seconds at a time, it's not good for the transmission for longer than that. Also, I know this was a problem with older turbo Saabs in the winter, the intercoolers would ice up and restrict air flow completely to the turbo. If there is any moisture in the turbo lines, this can happen as well.

Wow, that's cold! I thought the 17 degrees (F) it was here last night was getting cold. I'm not ready for it to be in the single digits again.

Post by **tjts1** » 10 Dec 2009, 08:26

IVIUSTANG wrote:...minus 40C....

It was 16f here this morning (-9C). I can't imagine what -40c is like. I'm amazed the car even runs.

Post by **IVIUSTANG** » 10 Dec 2009, 13:07

tjts1 wrote:
IVIUSTANG wrote:...minus 40C....

It was 16f here this morning (-9C). I can't imagine what -40c is like. I'm amazed the car even runs.

Does more than runs, it starts without the block heater. The best way to check for fluid in the intercooler would be to let the car sit in a garage for hours then remove the lower hose to the intercooler?

- Jesse

Post by **jblackburn** » 10 Dec 2009, 13:13

The best way to check for fluid in the intercooler would be to let the car sit in a garage for hours then remove the lower hose to the intercooler?

Yup, sounds like a good idea. Assuming the garage isn't frozen too

I'm amazed at how well these things run in cold. It seems like the colder it gets, my car is that much happier to be out and about. My Saab was the same way - it ran better than it ever had when it was below freezing outside; my Honda absolutely HATED cold - it got down to 1 one day, and it just flat out refused to start. Crazy Swedes

Post by **IVIUSTANG** » 10 Dec 2009, 16:36

It's only minus 20 now and my car runs perfectly now. Does this give anyone more hints about the cause?

- Jesse

Post by **jblackburn** » 10 Dec 2009, 18:22

That it's too cold for ANYTHING to be alive there

The turbo area itself should still be warm enough to keep ice out of that area., but it still sounds like restricted airflow to me, which was why I was thinking the intercooler freezing up. When the temperatures drop again, see if the power drop comes back. It could have just been a fluke.

Post by **IVIUSTANG** » 10 Dec 2009, 20:35

-26 right now and still no repeat.

- Jesse