1998 Volvo S70 - Noise from Suspension

sixdown · Post by **sixdown** » 09 Nov 2007, 15:57

1. I've been noticing this often, but when I hit a pothole or a bump very hard, the respective wheel will rebound and a weird whirring noise will start, and I'm not exactly sure how to describe it. It usually lasts around 3 seconds and stops.

I was thinking it had something to do with ABS or Traction Control.

2. Another thing, whenever I start my car, it smells extremely rich. It's as if the exhaust smells like a gas station; huge amounts of smoke appear (white smoke), for a few seconds, and then the smell begins. Is there a way to tweak the amount of fuel vs air? Maybe the engine is running rich.

Klausc · Post by **Klausc** » 09 Nov 2007, 16:06

There is a cold air pump which is supposed to operate when you start your car. The pump turns off after a minute or two. It sounds like your air pump is not working, allowing a very rich condition to heat up the cat and exhaust rapidly.

As for the 3 second noise when you hit a bump? Still too many possibilities to list.

Klaus

Post by **Ozark Lee** » 09 Nov 2007, 16:10

Another thing, whenever I start my car, it smells extremely rich. It's as if the exhaust smells like a gas station

Also check for a fuel injector seal leak if you are smelling it inside the cabin.

...Lee

sixdown · Post by **sixdown** » 09 Nov 2007, 17:14

Klausc wrote:There is a cold air pump which is supposed to operate when you start your car. The pump turns off after a minute or two. It sounds like your air pump is not working, allowing a very rich condition to heat up the cat and exhaust rapidly.

As for the 3 second noise when you hit a bump? Still too many possibilities to list.

Klaus

If the pump is the problem, I see no point in spending 400 bucks for a new one. The car runs perfectly, except that smell at start-up. Nothing gets into the cabin, it's just that smell in the first 10 minutes after start. Anything past 10 minutes of running smells normal. Now, the worry...does it affect overall fuel economy? I've been getting terrible fuel economy lately.

As for that noise, its a quick whirring noise, like a mechanical sound. Imagine scratching an old washboard at high speed for a few seconds. That kind of sound, but much much faster, only for three seconds.

Another thing, over every bump, my hood rattles...a lot. Is something broken, since I can't find anything wrong with the latch? It's just loose on the left and ride front corners and moves up and down ever so slightly.

Post by **MadeInJapan** » 09 Nov 2007, 17:57

If your mileage has gone to pot and you have pretty high mileage on your car (over 100K miles) then I would say it's probably time to change out your front 02 sensor. About the hood rattling. I had this too...it wasn't the latch. It seems that the rubber bits that buffer the hood wear down after many years. I just rubber cemented some more rubber pieces onto the ones there (they are square- you'll see them) and no more rattle.

tripleb · Post by **tripleb** » 09 Nov 2007, 19:44

" I've been noticing this often, but when I hit a pothole or a bump very hard, the respective wheel will rebound and a weird whirring noise will start, and I'm not exactly sure how to describe it. It usually lasts around 3 seconds and stops. "

Does it happen only when you have your foot on the brakes? If so, it is the ABS.

I've seen possible so many of these cars with failing or failed air pumps and have never seen smoke come out of the tailpipe because of it. But when the pumps fail, it can because they get filled with water, so maybe it is pumping water into the exhaust? You can disconnect the pump hose to the check valve and see if the smoking stops.

B

sixdown · Post by **sixdown** » 10 Nov 2007, 16:38

MadeInJapan wrote:If your mileage has gone to pot and you have pretty high mileage on your car (over 100K miles) then I would say it's probably time to change out your front 02 sensor. About the hood rattling. I had this too...it wasn't the latch. It seems that the rubber bits that buffer the hood wear down after many years. I just rubber cemented some more rubber pieces onto the ones there (they are square- you'll see them) and no more rattle.

Well, my mileage is only 84,000 Miles, which is substantially low, so I doubt its the O2 sensor, unless worst case, it's gone bad.

Thanks so much with the hood issue, it certainly stops an annoying noise from the bumpy roads around here.

tripleb wrote:" I've been noticing this often, but when I hit a pothole or a bump very hard, the respective wheel will rebound and a weird whirring noise will start, and I'm not exactly sure how to describe it. It usually lasts around 3 seconds and stops. "

Does it happen only when you have your foot on the brakes? If so, it is the ABS.
...

Thanks! I suspected the ABS or something, but wanted to make sure it wasn't something bad. Yes, it only happens when I'm on the brake and hit a hole, which proves that my ABS still works. I guess the wheel looks for traction while I'm braking and engages ABS to compensate.

As for start-up smoke, it still happens if I disengage the hose. The exhaust has a strong fuel smell, which I've not noticed until recently.