Skip the auto shop - Our mechanics make house calls

Q: Failed to downshift to lower gear

asked by on

I have 125,000 miles on my car and kept up with all maintenance. Now there is a transmission issue with the computer reading failed to downshift to lower gear. And there is a humming noise after warmup.

A: Greetings. The humming noise is likely caus...

Greetings. The humming noise is likely caused by a faulty PCV valve or oil trap hose. The engine of the vehicle produces a lot of suction and the PCV valve and hose is made to regulate some of the suction by the opening and closing of the valve. The PCV valve commonly becomes stuck open in old age after warming up,which will allow too much air suction. The suction usually can be heard as a humming or whistling noise. The Volvo dealers are aware of the issue and have extended warranties on those parts. I suggest calling your local Volvo dealership and ask them about the warranty of that part on your vehicle. If it is under warranty they will replace it free. Regarding the transmission issue there is a software update available from the dealership that addresses hard shifting and no downshifting. A simple reprogramming will likely fix your problem. If it doesn't and the transmission still has issues I suggest checking, then changing the fluid if necessary. 80 percent of all transmission failures stem from a fluid related issue.(lack of fluid or old fluid)

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Especially when cold, I notice shifts in low gears on my transmission

Hello. If servicing the fluid and filter did not help, then it may be possible that the transmission is worn. If any of the clutch packs that the transmission uses to shift wear out, they may slip and cause harsher...

Q: White smoke coming from exhaust after turbo blew

Hi! A leaking turbo will usually present itself through white smoke exiting the exhaust. Usually the white smoke will result from the turbo leaking oil internally but will occasionally result from internal coolant leakage. There will probably be lots of...

Q: How to install or replace the shift shaft cable and linkage

The only way to see how to install one is to see if there is a video online or watch a mechanic do the work. The shift cable does not go bad very often on these vehicles. The most common...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...