1997 volvo 850 wagon...

jaypaulstrong · Post by **jaypaulstrong** » 28 Oct 2011, 11:55

I am in way over my head with this one...

So I have very limited in experience when it comes to working on cars. I can do simple things like change the oil and the spark pugs and such, I have the mechanical ability to do a little bit more complicated stuff than that, and access to most of the tools I need, but not the trouble shooting no-how I need to work on them myself.

The car:
I have a '97 volvo 850 wagon. I don't know the mileage because both the speedometer and the odometer are broken. I don't know if those two are related, but neither work. I also have a problem with the brakes, the a/c, and I have a very bad oil leak which I have been told was the oil pan gasket, (a friend told me, I'm not sure if he knows what he is talking about.) None of these issues are what I'm here for today, I'm just listing them in case they have something to do with my problem.

The problem:
This morning the wife ran out of gas on her way to work. She constantly drives the car with the gas gage below the red line and the gas light on which frustrates me to no end. She happened to be right next to a gas station when she broke down so she simply bought a gas can and got more gas. When she started the car again she said it ran really rough, like shaking the whole car rough. She pulled in to a shopping center and turned the car off. When she tried to restart it, the engine would not turn over. I went to pick her up and see if there was anything I could do. I figured that perhaps there was just a bunch of air in the fuel lines or something since the car had run completely out of gas. The engine would try to kick over when started, but never quite make it. I decided to try and pour a little bit of gas on the air filter hoping to kind of kick things into motion. We tried the engine again and this time there was a very loud popping noise coming from under the hood. I opened it up and there was a very strong smell similar to gunpowder coming from the engine. The hose to the air filter box had blow out, and the plastic cover that goes over the throttle cable had been blown off, along with two electrical cable assemblies whose correct location I'm not sure of. I pulled the cover off of the air filter box to look at the filter, and it looked like the engine tried to suck the middle of the filter in through the hose. The weirdest part was that the filter box was now filled with dirt and grass. I had just recently replaced the air filter so the dirt had to have come from the engine, or at least the hose to the engine.

more info: I just changed the spark plugs about a week ago, three of the five spark plugs looked normal, but two of them didn't. The spark plug in the very middle was covered in soot, even up to where the cables connect to it. I scraped about a cubic inch of sticky black residue off of it. The next spark plug to the right, (going towards the driver's side,) did have dirt all over it, dried dirt. Even down where the spark should be. I don't know what to make of this situation, I don't have a lot of money, so I can't afford a mechanic. I'm not sure if I should just cut my losses and try to find a new car or try to fix this one. The reason why I changed the spark plugs was that my wife was complaining that a big cloud of blue smoke would come out of the tail pipe from time to time. Changing the spark plus seems to have eliminated that problem.

Any input would be greatly appreciated.

shegarty · Post by **shegarty** » 28 Oct 2011, 13:19

where to start ...

i have no idea what you have damaged by adding gas to the air filter box but you may have f***ed the engine beyond YOUR ability to repair it - what most likely caused the initial failure after running out of fuel was a clogged fuel filter (~$15 and 10 mins to replace) - by adding fuel to the intake side of the motor you most likely caused a detonation in your intake manifold which is what caused the "popping" sound and the resulting damage

try to trace the electical connections back the wiring harness but they are most likely the connections to the throttle position sensor and the idle air control valve which are both located near the throttle body and intake manifold - try reconnecting these (if the clips are damaged beyond repair), replace the fuel filter and crank the engine

if it starts, great (it may take several seconds to build proper fuel pressure) - if not turn off the engine and check that you have fuel pressure on the rail by depressing the schrader (tire) valve on the fuel rail with a screw driver - if you have proper pressure a fair amount of fuel will squirt out so make sure you have a rag to catch it - if you have fuel pressure and it still won't start its likely an electrical problem but there's no telling what you have damaged and it could be a long road to find the culprit - so maybe better to cut your losses ...

if you do get it running you might want to look into replacing the PCV as this could be causing the plug fouling by allowing oil to enter the combustion chamber - a clogged PCV could also be contributing to the oil leak by way of increasing pressure and causing the rear main seal to fail - you can test to see if your PCV is glogged by pulling the dipstick while running (if you get it going!) and looking for smoke

good luck, you're going to need it ...

alexk243 · Post by **alexk243** » 28 Oct 2011, 13:45

I agree with the detonation idea. I think the gas on the intake caused a small explosion in your intake.

The reason it probably didn't start after running out of fuel (if similar to motorcycles) is that when you run low on fuel the car begins to pick up all the crud that has been in your tank forever, but never got low enough to get sucked up. When you ran out it sucked up this crud and clogged something, most likely the fuel filter. Happened every time I ran out of gas on the motorcycle.

jaypaulstrong · Post by **jaypaulstrong** » 28 Oct 2011, 14:06

Wow, thanks for the detailed replies, I'll change the fuel filter and see what happens...

Post by **erikv11** » 28 Oct 2011, 18:41

The initial symptoms, from running out of gas, could also indicate a dead fuel pump. The pump is cooled by the fuel that passes through it, so if you run it until the tank is empty you risk running dry and overheating the pump. Especially if this has happened a few times.

jaypaulstrong · Post by **jaypaulstrong** » 29 Oct 2011, 20:44

Ok, so I changed the fuel filter and the engine ran a little rough for about ten minutes but now it runs just fine. I think I might have lucked out with the whole minor explosion thing. Now I know never to put fuel in the air filter again. After I went back and looked at the cables that were hanging freely, it looks like they came from a little plastic panel that is located in the very front of the engine compartment, right above the fan. The whole panel had fallen forward and two of the cables had come loose. I put them back where I think they went. The check engine light had come on; I took it to auto zone and it had two codes showing. One was the o2 sensor, and the other was a #2 piston miss-fire. I think they might have both been from the lack of fuel pressure that was causing the engine to run rough earlier. I'm going to unplug the battery and let the codes re-set to see if they go away now that I replaced the filter. Either way, the car is running great right now. I really appreciate the help, my wife depends on this car to get to work, and we would not have been able to afford sending it to a mechanic. I don't know what we would have done if it wasn't for this forum.