First off ill start by saying im no mechanic, but im treating my 850 GLT as a project so i need to learn so i have a few questions:

-What are the signs that my car might need new springs or any sign that something is wrong with the suspension?

-Will i get the same gas mileage if i leave my car in sport?

-Somebody recommended that i clean my throttle body, where is that located?

 

The throttle body is located below the throttle linkage (the black cover is removed in the photo). The black tube elbow attaches to the front of it. Make sure if you try to clean it you only use throttle body cleaner and not carb cleaner. You might want to pull up a youtube video or two and watch how someone else has done theirs. You should have a throttle body gasket on hand if you try to remove it for cleaning as it's likely the old one will rip coming off.

Your question on the suspension is a little too vague. There are any number of noises that could indicate a problem with any number of components in the front or rear suspension systems. Noises, vibrations or clunks can all indicate a problem.
Your springs would definitely be worn out if you notice your vehicle bottoming out on minor bumps or sagging excessively with only a minor load in it. There is also a table where you can measure your "ride height" to tell if the springs are sagging.

Sport mode is "sportier" and would use more gas, how much more I don't know but maybe someone has run a tank or two in each mode and can chime in with their results.

Down load the manual and do a little reading.

http://www.matthewsvolvosite.com/dow.../Volvo_850.zip

If you haven't used it yet you should also do a little research on Matthewsvlovosite.com

 

the most common suspension noise usually seems to come from the front strut bearing plates and/or spring seat.

 

Here's my 2 cents worth. Please send the money to my paypal account.

SUSPENSION: Stop by an alignment place like Firestone and ask for a front end alignment. They will tell you of any bad parts in the suspension. If you do NOT turn wrenches, I guess you'll have to let them fix it. IMO, the front suspension is the weak part of these cars.
Most common items in the front end that need work/repair/service, however you want to put it:
- Control Arms: You can jack the car and grab the tire at 3 and 9 O'clock and try to move in and out. If it moves at all, it needs replaced. At the wheel location of the control arms are the ball joints. I have seen them very loose as well.
- Tie Rod Ends: Look for torn rubber end links and any movement when you try to wiggle the wheel when jacked.
- Sway Bar End Links: Grab the end links and try to wiggle. If they wiggle or click they need replaced. They will also have torn boots.
- Spring Seats: Open the hood and bounce the car up and down while watching the top of the strut. If the nut and cap goes up and down in the strut tower away from the body frame they are worn out. Some people try to twist the parts on top of the strut by hand. If it twist, it's worn out.
- Strut Mounts: If your strut tower nut and cap is not centered in the body frame hole, they are likely broken.
- Axels: They cause vibration while driving and often have torn boots with no grease left in them. They will also wiggle when pulled on.
- Sway Bar Bushings: Boots torn and they click when you try to move them.
- Struts: They get bouncy, leak and get stuck down sometime.
There may also be bent parts. Again, the suspension place will tell you what's bad and in need of replacement.

TRANSMISSION SWITCH MODE: I have found that if you are good with hypermilling techniques, you will likely get better mileage in S mode. I was able to do so in the R sedan I had, plus I had my kick in power at my finger tips. If you are normally heavy on the foot like most people are, the E mode will save you about 10% on gas.

THROTTLE BODY CLEANING: That should be done maybe every 50,000 miles or 5 years unless something is leaking on it to get it dirty. I usually remove it with the PCV system and clean it up. If you do it alone, I would just pull the tube and spray the cleaner in it while moving the butterfly valve. It is sensitive and can be damaged easily so I will use my finger to rub the build up off or a tooth brush.

Hope this helps.

 

You earned it

 

As usual everything was very helpfull, i cleaned my throttle body which was pretty dirty (did not use carb cleaner lol) and i tested out a full tank on sport and it dropped my mpg from 24 to 18!!!! So ill just keep it on economy lol but the suspension still seems to be a problem, whenever i hit a bump my back tires scrape the wall, when i got my alignment the guy said it was because my tires in the back are thicker but it was scraping before i got the thicker tires put on, any suggestions? Should i get regular size tires or get someone to check the suspension in the back?

 

Whats the difference doesnt it work the same?? I've used carb cleaner everytime but the other day i tested the new seafoam spray for induction cleaning and it worked great, when i turn the car on it was burning everything clogged inside there with white smoke until it cleaned. IM curious if i have done something in the past that could had damage my cars?

 

My car never enters econ, and im averaging 23 to 25 city and 28 to 30 hwy..

 

The reason most throttle plates are kind of a yellow is that they have a coating to keep them from corroding. At idle that plate has to almost perfectly block the bore and if it deforms in any way, ie rust or corrosion there is a chance it will start to stick or jam when closed at idle. That "yellow" is a protective coating and carburetor cleaner can eat it away leaving the plate exposed to combustion gasses and moisture. Throttle body cleaner is designed to clean without attacking that coating. If you use carb cleaner sparingly you might be ok but it's safer to spend 5-8 bucks and get a can of the right stuff.

 

How about telling us what size you have on it now and what size you think "regular" would be ??

Can you tell from the liner in the wheel well where the tire is scraping ??

 

I don't see how that was possible. To properly test this you need to run more than 15 miles to the store and back. Run it in S for no less than 200 miles. So reset your trip, drive 200 miles, then check the mileage. The beggest difference I ever had when not trying to save gas was about 10%, 2 mpg.

 

Thanks for the tip, makes sense for me, i will be using throttle cleaner now :-)

 

I started my trip meter last time i filled up, put it in sport, drove it when it got down to six and did the math. Could anything else be wrong? I read on another thread that spark plugs and fuel filter could effect your gas mileage, do you think its time to replace them?

 

Sorry about that! The front tires are 205/65/15, that's the tire size that came on the car and that's what i meant by regular lol and the back tires are 215/65/15!

Also it doesn't scrape when its just me in the car, somebody has to be in the back seat for it to scrape, that's why i was thinking something could be wrong with my suspension.

 

Spark plugs yes. When they get worn they can cause problems and hinder the efficiency of the mixture in the cylinder starting to burn.
But the fuel filter ?? If it's neglected and left in there too long it will start to get plugged and cause a restriction but not a loss of mileage. Driveability issues under heavy load or highway speeds would be the first sign you are way overdue to replace it.