1998 XCV70 auto tranny issue, help me understand

thaedge · Post by **thaedge** » 11 Jan 2015, 13:38

OK. Pretty simple. My car has sat for the last 7 days or so. It has been really cold, -20 at night. I started the car and let it get to temp about 3 days ago because it was cold and I wanted to make sure the battery kept a charge. Started right up, ran fine, but I didn't move it. Today, its about 10 degrees, I start the car, let it run for about 5 mins before getting in it to drive it. Shift the tranny into R, rev the engine, NOTHING happens. The tach went up, but the car did not move, the tranny did not engage. I try every gear, nothing, no engagement.

I was thinking the tranny had gone out, but it didn't make any sense, I parked it there 7 days ago, not it won't move.

about 4 hours later, the outside temp is about 20 degrees, I start it up, put it in reverse, and it moves, no issues.

No idea whats up, the only difference I can think of is the air temp.

Tranny fluid is at normal level, looks good. No dash lights etc.

Any ideas?

thaedge · Post by **thaedge** » 11 Jan 2015, 13:39

Also, when it initially didn't move, I turned it off an on many times and tried shifting gears in difference sequences etc, nothing.

Post by **scot850** » 11 Jan 2015, 17:33

This is a problem we get up in Canada with these cars. When it gets really cold, the intercooler freezes and the car can't get air through it. This prevents vacuum being drawn and the car won't move until the intercooler has thawed. The original 'fix' was to drill an 1/8th" hole at the lowest point in the intercooler to allow any condensation that forms to leak out. This does not affect how the car runs! I found this helped, but as the engine/turbo get older oil gets into the intercooler and moisture gets trapped more easily. Removing the intercooler and getting the internals cleaned to remove any old oil will also help.

In Europe Volvo used to make a plastic cover for the grill to deflect cold air and allow the engine/intercooler to warm more quickly. These are not available anymore, but a piece of cardboard zip-ted to the inside of the grill works. Just remember to remove when the temperature outside gets back about 32F/0C!!

Neil.

thaedge · Post by **thaedge** » 11 Jan 2015, 19:18

A frozen intercooler will cause the engine to be able to rev, but the car won't move?

Post by **scot850** » 11 Jan 2015, 22:55

If you open the hood when the car is like this, if it is really bad you can see the intercooler hoses collapsing inwards.

Neil.

thaedge · Post by **thaedge** » 12 Jan 2015, 08:57

Interesting. Thanks for the help guys.

Post by **Matty Moo** » 12 Jan 2015, 10:11

I know exactly what he's talking about because I had the exact same thing happen last winter. When you out the car in any gear, even reverse it just revs as if you were in neutral or Park. It only happened when it was around zero or lower.

I never did find out was the cause of it was and I never got a single code.

Post by **xHeart** » 13 Jan 2015, 09:08

scot850 wrote:If you open the hood when the car is like this, if it is really bad you can see the intercooler hoses collapsing inwards.

Neil.

Insightful and very timely!

I never experienced gears not engaging -- car not moving.
But my wife did bring it up the other day when our car was parked on the street with subzero temps. It moved, she said, after idling for 3-5 minutes.

I assume you are referring to freeze inside following part, yes?
This is 2001 V70XC Intake Tube Between Intercooler and Throttle Body -

Post by **Ozark Lee** » 13 Jan 2015, 09:47

xHeart wrote:I assume you are referring to freeze inside following part, yes?

There is a weep hole in the intercooler that is supposed to drain condensation that occurs when the air is compressed by the turbo. If the weep hole clogs the intercooler pools water and it can freeze, thus blocking the air flow through it.

...Lee

Post by **scot850** » 13 Jan 2015, 17:08

Nope, it is not that part, it is actually the intercooler itself that freezes with moisture inside it. Like I said in my earlier post, Volvo did a 'fix; which was to add the small drain hole by drilling the lowest point of the intercooler to allow moisture/condensation to drain. Not sure this is 100% effective, as I reckon it is actually oil gathering in the intercooler that acts like plaque in an artery and clogs the paths in the intercooler, making it easier for the moisture to 'clog' the pathways. Cleaning the intercooler chemically may help further. Best thing is to garage the car, and blank the airway to the intercooler to allow the engine to warm quicker, but also it will be less likely to freeze in the first place!

Neil.