9-5 2008 terrible mileage; rough idle; hesitation on hard acceleration

[doobyranger]

Heeeeeeeeeeyyy everybody! Thanks for taking the time to read my post.


-My 2008 9-5 has been getting terrible mileage (as in half a tank for 60 miles).
-I have refilled my radiator coolant twice in one month, though I see no signs of leaking.
-It takes about 3 seconds of turning the key to start the engine, and has had this characteristic since I bought it about a year ago.
-It idles rough, with a "purring" vibration. By that I mean the amplitude and frequency of the vibration seem to ebb and crescendo together, like a cat's purring. Once I get to highway speeds the vibration goes away.
-If I slam the accelerator the engine hesitates, almost dies for two-three seconds, then responds with acceleration and misfiring.
-My OBD II reader registers a p1181 code.
-And last but not least, once the fuel level gets below 1/4 of a tank the level indication isn't trustworthy. It will stay on 1/4 of a tank for a while then drop to almost empty. Some times if I turn the car off and back on the level will increase. Two weeks ago I ran out of gas on the road, causing the car to die, but the level wasn't yet on empty.

So these are my symptoms, and I have noticed some additional clues.
-I don't see any leakage around any of the block gaskets, but two of the fuel injectors have tar build up/goop at their entry points into the block that smell like gas (the other two are clean).
-I don't see any kind of smoke out the tail pipe, and I don't see bubbles in the radiator fluid.
-I tried doing a smoke test and a propane torch test to check for vacuum leaks and didn't find any.

At first I was worried I might have a head gasket leak but using bar's leak gasket repair didn't improve anything. I am worried my fuel pump might be bad, but I'll have to spend 1500 to have the tank dropped to inspect it (thanks GM). I am wondering if my fuel injectors are leaking, and since both fouled injector sites are on the same side of the engine, if that is causing my vibration? Any help would be great. Oh, and is there supposed to be a hose coming out the back of my oil dipstick tube? I don't have one, just a naked nozzle.


are 2008 9-5's supposed to have a hose here?

[Digger]

Loosing coolant is a problem and block seal won't fix a pin hole leak (the kind of leak that only passes steam and lets air suck in on cool down) or a warped / improperly torqued head. Teakettling, AKA the white smoke out the tail pipe happens when you get coolant in the combustion chamber and this takes a while to show out the tail pipe, a byproduct of coolant with combustion is a very clean cylinder. You have two clean injectors and if you have two super clean plugs in those same two cylinders you have found your coolant leak.

Terrible gas mileage, missing vacuum line and a massive air leak code, common sense says start with the missing hose.

$1,500 to check a gas gage not trustworthy below 1/4 and it's "Thanks GM". If you haven't heard this before, it's time you do. Fill the darn tank and keep it above 1/2. Less than a 1/4 or over 1/2, $10 is still $10 and a half tank of gas helps reduce contaminating moisture condensation, cools the fuel pump, saves you an immediate costly repair. Regularly running any car at less than a 1/4 tank is asking for trouble.

[nordwulf]

Here are the details for P1181 from the WIS: Saab 9-5 P1181.pdf

Probably a good idea to get the WIS yourself: http://saabworld.net/showthread.php?t=33310

[doobyranger]

Hey, thanks for responding.

Do you think the lack of gunk near the fuel injector sites indicates clean cylinders due to a possible coolant leak through the head gasket? If so, is it normal to have gunk built up around the injector sites?

[Digger]

Hey, thanks for responding.

Do you think the lack of gunk near the fuel injector sites indicates clean cylinders due to a possible coolant leak through the head gasket? If so, is it normal to have gunk built up around the injector sites?

What do I think?
I think you bought a 10 year old, rough idling car that takes a couple of extra seconds to start. I think that clean and dirty means that you are not the first person to look into this problem. I know that pin hole leaks are tough to find, that block seal doesn't fix warped or improperly torqued heads and that lacking the most obvious sign of compression leak I think that you should pull the plugs and look to see if you have a suction side coolant leak.

[Spellbound]

...Oh, and is there supposed to be a hose coming out the back of my oil dipstick tube? I don't have one, just a naked nozzle.


are 2008 9-5's supposed to have a hose here?[/QUOTE]

Anyone answer this? I've looked through various docs on hoses and routing but it isnt clear to me? Maybe someone can just check there 2008 or 2007 9-5 and see if the nozzle is there at all? Most of what I looked at indicates it shouldn't be there but anyway I have the same situation on my 2007 9-5.

Thanks

[Mike Brennan]

Yes the empty nozzle is normal. Start feeling up all your hoses. You have a leak somewhere. Also replace your coolant tank cap. If your fuel pump is failing it would not impact the injectors as you have described. 2 or 3 second delay on acceleration suggests you have someone inspect your turbo for bad spin and lose connections for coolant loss, and waste gate movement and also the boost control.
in other words get to a shop.

[Dave T]

... Fill the darn tank and keep it above 1/2. Less than a 1/4 or over 1/2, $10 is still $10 and a half tank of gas helps reduce contaminating moisture condensation, cools the fuel pump, saves you an immediate costly repair. Regularly running any car at less than a 1/4 tank is asking for trouble.

Slightly off topic but...

I've thought carefully on when to fill my gas tank and have concluded that I should ideally fill it when it is 37.5% full (half way between 1/4 and 1/2). In reality, I usually fill it when the tank is about 45% full.

My conclusion was based on if you fill the tank too early, like when it's 3/4 full, you waste time with repeated visits to the gas station and old gas in the tank gets used up very slowly. If you wait until the tank is half or slightly less than half full, then the old gas gets used up. Mathematically, if you wait until it's 1/2, then 50% old gas, 50% new gas. Upon the next refill, it's 25% old old gas, 25% old gas, 50% new gas. Upon the 3rd refill, it's 12.5% old old old gas, etc. If one drives infrequently and fills up every month, the "old, old, old gas" will be 4 months old. Therefore, unless one has a museum piece, the car should be driven at least about 300 miles per month. If one drives more than that, which I do, then these calculations are less important.

The reason against driving beyond 1/4 tank full is what Digger mentioned about the fuel pump. There's also rumor that sediment might enter the engine though I have mixed feelings that this is not too relevant because gas gets mixed while the car moves. Another reason is that there is a chance that there will be an earthquake and no gas will be available until the electricity is restored.

What I end up doing is to wait until I drive past my favorite stations that are cheaper and are my preferred brands. I then fill up. That results in a fill up usually between 35-55% full. I end up buying about 8-10 gallons.

[GeoffR]

Slightly off topic but...

I've thought carefully on when to fill my gas tank and have concluded that I should ideally fill it when it is 37.5% full (half way between 1/4 and 1/2). In reality, I usually fill it when the tank is about 45% full.

My conclusion was based on if you fill the tank too early, like when it's 3/4 full, you waste time with repeated visits to the gas station and old gas in the tank gets used up very slowly. If you wait until the tank is half or slightly less than half full, then the old gas gets used up. Mathematically, if you wait until it's 1/2, then 50% old gas, 50% new gas. Upon the next refill, it's 25% old old gas, 25% old gas, 50% new gas. Upon the 3rd refill, it's 12.5% old old old gas, etc. If one drives infrequently and fills up every month, the "old, old, old gas" will be 4 months old. Therefore, unless one has a museum piece, the car should be driven at least about 300 miles per month. If one drives more than that, which I do, then these calculations are less important.

The reason against driving beyond 1/4 tank full is what Digger mentioned about the fuel pump. There's also rumor that sediment might enter the engine though I have mixed feelings that this is not too relevant because gas gets mixed while the car moves. Another reason is that there is a chance that there will be an earthquake and no gas will be available until the electricity is restored.

What I end up doing is to wait until I drive past my favourite stations that are cheaper and are my preferred brands. I then fill up. That results in a fill up usually between 35-55% full. I end up buying about 8-10 gallons.

Some good thinking but the problem with going below 1/4 tank isn't sediment, it is water. Any water is more dense than fuel and will collect at the bottom of the tank. A small amount isn't a problem but a larger amount can have unfortunate consequences.

[Mike Brennan]

Slightly off topic?
Really.
you guys have way too much extra time in you lives.