S70 GLT shakes & vibrates when I apply break

skyorbital · Post by **skyorbital** » 23 Jun 2007, 02:08

I tried to read topics in the forum but still can not find any answer.

It always happen when the tempature is higher than 85F and after I changed oil.

When I apply break, the vibration just starts before the car almost stops and keep vibration about 3~5 second. That menas the vibration keep going at least ~2 seconds even though the car stops. If I release the break when I start feeling the vibration, the shaking will stop.

This vibration will not happen if the weather is cool and oil change has been done for ~6 weeks.

Would everyone tell me wht this happens and how to solve the problem?

This situation has already bothered me for three years.

Thanks for anyone's help

Tsquared · Post by **Tsquared** » 23 Jun 2007, 03:49

I think you have more going on or the symptoms are masked by other issues. I don't believe that an oil change would have anything to do with it. I would suspect engine mounts on a stopped car that shakes and vibrates or a fouled plug.

Post by **JRL** » 23 Jun 2007, 05:28

C/mon this is probably automobile 101.
You may need brake rotors.
If you feel the vibration in the steering wheel you need fronts, if you feel it under the car you need rears.
The more you drive with these the worse they will become, but this is the way it starts, at high speed after they warm up, in a couple of thousand thousand more miles you will start feeling the vibrations almost all the time and at lower speeds.
If I'm all wrong here, then you may have a transmission problem and it's BRAKE not break.
It's a bit hard to give a correct answer the way you are describing it. Try and see if you feel anything at all when hitting (just heavy tapping them is OK for test purposes) the brakes at over 60 mph.
Oil change should have nothing to do with anything here

flaco · Post by **flaco** » 23 Jun 2007, 08:27

brake rotors???? if the car is not moving and it still vibrates?

definitely NOT rotors...

Post by **MadeInJapan** » 23 Jun 2007, 08:38

If you're stopped and you have vibrations, I would check the motor mounts...the round one at th top of the engine as well as the one under the timing belt and the tranny/motor mount that looks like a belt buckle at the front (under the air dam). Good luck figuring it out...mine vibrates too (and I live with it) but that's because I put in all very hard non-rubber motor mounts.

skyorbital · Post by **skyorbital** » 23 Jun 2007, 09:20

Thanks for your help.

I still have some question about this.

Why does it happen only when the weather is hot?

My s70 does not have any problem in winter as long as I do not change oil.

I know this is very strange. I guess it might not be a rotor problem because it seems the vibration is not from wheel/tire.

I feel it comes from the front of my car.
However, I can not be sure for this because sometimes the vibartion is too strange to find it out.

By the way, I live in Los Angeles, California. The weather is very hot in summer time.

Post by **MadeInJapan** » 23 Jun 2007, 09:37

The more I think of your situation, it could be related to the fan coming on....I'm talking about the large cooling fan at the front of the car. If you're car is hot or the oil is in a shape that it isn't adequately cooling your engine, that fan will come on....AND if the fan is slightly off kilter, then it will affect the over-all vibrations coming from the engine bay....this coupled with one or more bad motor mounts could cause the vibrations you mention. Check your fan after a good hardy run....stop your car in the driveway and lift your hood, having someone else sit in the driver's seat with the transmission in "D" and foot on the brake....see if there are vibrations when the fan comes on.

skyorbital · Post by **skyorbital** » 23 Jun 2007, 10:07

I will try afternoon because it won't vibrate in the morning.
The outdoor temputure is not high enough now.

Post by **JRL** » 23 Jun 2007, 13:23

skyorbital wrote:I will try afternoon because it won't vibrate in the morning.
The outdoor temputure is not high enough now.

Fan
Motor mounts, you have three (3)

Trilarry · Post by **Trilarry** » 23 Jun 2007, 15:54

Motor mounts are dense rubber, when it's cold the rubber is Stiff and tight as the rubber and temperature heats up the rubber gives and loosens, my guess would be the motor mounts are worn. I paid 15.00 for the top one that's pressed in from the dealer. I changed it at 167000 miles.

I could see the engine moving when the brakes are pressed because of the momentum due to bad mounts but I'm in the Tsquare and JRL camp I believe that your rotors are warped along with possible bad mounts, 3 years is a long time to have these issues, but let's start with the motor mounts first.
Tri