Thanks for the response to the what is the problem with my 1993 volvo 940, the shaking with idling...but...

Question

I recently replaced the distributer cap and the car had a tune-up/new sparks/plugs within the last 6 months. I bought this car from a "friend" a little over a year ago cheap, but it's been one problem after another, I've put lots of money into it. It seems the previous owner did little maintenance on it. Could my problem of shaking while idling at a red light, which improves in neutral, be something worse, like the transmission?

Answer 1

well my experience/w bad motor mounts is that it lifts the engine during acceleration and would shake during idle and rob the horse-power,,,                                                                    anyhu have U been engaged for 7 YEARS  its time to jump da broom   hahahaha lol,,,

Answer 2

I doubt very much it's a transmission problem. One thing you could do or have done would be to clean your mass air sensor. This device acts sort of like a carburetor would on a non-fuel injected engine. It does carbon up over time and will create idling and other problems.

The reason you have rough idles at stops and notice improvement when in neutral is that the idle speed drops when the car is in gear thus magnifying any idling problems.

It's unfortunate that you've had so many problems with your 940 because they are usually very dependable. That's certainly evidence that Volvos require routine care just like any other car. Maybe getting the idle problem taken care of can allow you to relax and enjoy your car a bit more.

Answer 3

Ah this is notorious on Volvo's. Idle shake is your motor mounts are bad. For whatever reason Volvo's have this issue on there cars.  

Answer 4

I agree with Arther that it sounds like the air mass meter. Just make sure you don't use just any cleaner on it, strong solvents can damage it. I'll link below to a product from CFC that's made specifically for that sensor.

Also, it could be a dirty fuel injector. You can try adding an injector cleaner for a couple of tanks. Just be sure to use a good one, like Techron or Prestone, not one of the one dollar ones.

BTW, it's not a motor mount. A bad motor mount won't shake an engine at idle, it'll do it on acceleration.  

Answer 5

If your problem is more like a vibration then have a look at the engine & transmission mounts. Does the vehicle accerlate ok? If you have no other issues besides the "shaking" then it would say check into the mounts. Good luck & don't be to concerned about your volvo, once you iron out all the little things you can't beat them just keep up w/ your maintenance and it'll run forever!!!! I do have one other suggestion since you said the pervious owner did no maintenance I would look into doing the timing belt.

Answer 6

the problem you are describing is a worn or old motor mount, specifically the one thats down on the transmission. you need to replace all three at the same time. they are inexpensive, but can be pricey to install, as an engine jack is usually required. best way to test if this is what you need:

lift the hood of your car.

start your car. leave it in park.

peek under the hood, keep an eye on your engine.

rev the engine (never go above 2000 rpms)

if you notice the engine move when you rev, in an up and down type motion, you need to replace the mounts this can actually rob your car of Horsepower (your get up and go) and can damage your engine if left unchecked