Help with my Oldsmobile
 

Yes, I drive an oldsmobile. :)

A '95 Oldsmobile Cutlass Supreme. A 4-Door sedan with the 6 cyl. 3.1 L. engine and automatic transmission that up until a few weeks ago ran like a dream.

Anyway, it putters. Putters real bad sometimes. It putters as you accelerate and it putters once you reach cruising speed, although then it feels like someone is hitting the gas with a regular rhythm. As the car drives away, it sounds like a small machine gun rat-a-tat-tatting. I should mention that it runs fine idling. A bit choppy, but really nothing like when it's going down the road. I had a local shop (not one I particularly like, but I had no choice) replace the serpentine belt as the old one had completely popped off, but other than that no considerable work has been done on the car in the last 3 months.

Now, I know next to nothing about cars aside from...you know...the regular maint. stuff. I've been all over the internet and my problem could be anything apparently. Fuel filter, clogged line, bad water pump, timing...the list goes ever on. I guess because the search parameters are so vague. Anyway, I don't expect to fix it myself (unless it's just ridiculously easy), but I'd like to know what it most likely is before I run it up to my mechanic.

Any and all help appreciated

Any smoke, or smells to go along with this?

I would do fuel filter first, it sounds like your car is getting enough fuel to idle properly but once you step on the gas its getting starved. Whens the last time you have had plugs and wires dones? Also whats your mileage?

it really COULD be alot of things, one would really have to hear the sound, it could be an exhaust manifold, it could be an exhaust donut it could be your valve train, it could be an number of things... :/ try to notice WHERE exactly the sound is coming from... stick your head right in there, and if it only does it when your moving... i suggest you have someone who knows stuff about cars to sit in the passenger seat and have a listen.

Nope. Nothing. The only thing I've noticed, other than the obviously annoying pitter-patter my car has developed, is that it runs a little warmer than it used to, if that means anything...

I've had the car about a year...six months ago (before the big heat hits us down here) I had a fellow check all the plugs, the wires and the distributor to make sure everything was hunky-dory.

I thought it really might be the fuel filter. I've changed those before. The fuel filter for my car, as I understand it, is in the tank itself, which may prove a bit more difficult, but I could probably manage.

I'll get the mileage when I get off work...

You can't so much hear it as you can feel it. You can hear it putter out the tailpipe as it moves on down the road, but other than that, you don't hear much at all. You know it feels like when you're on a roller coaster and the cars latch to climb that first big incline. That rocking front to back as the car climbs the links up to the apex, you know what I mean? That's what it feels like going down the road.

Thanks gents, for all the help so far. If you got any other questions, please ask... I've got a guy looking at it soon, so this is probably just an intellectual exercise; I just didn't want to look like a total jerk when I go in there. :)

The fuel filter for these cars is on the drivers' side, about where the rear seat is. Depending on when it was last changed, it cand and will be a pain to change. I cut the line, bought a new line from a GM dealer, cut it, and then spliced the two together with rubber hose. It works great...does NOT leak.

In your last post, you mention a putter out the tailpipe. Just dealt with one of these that did that, and they ran some Seafoam through it (HAVE A MECHANIC DO THIS. DONE WRONG IT WILL SCREW THINGS UP) and it cleared up. I would start there. Changing the fuel filter will not be a bad thing...I'd do it, just because it will need it.

Start there, should run about $75 to have that service done...some may use Justice Bro's Fuel Injection System Service...that is good as well. May run about $100.

Sounds like it's misfiring on one cylinder. My escort was doing the same thing a while back - fine at idle, misfire under heavy/moderate load. I changed the plugs and it was fine. Maybe the guy who did your plugs didn't gap them properly, or didn't use dielectric grease on the terminals and they corroded, or one loosened and is leaking down compression, or maybe a wire is shorting or is torn. If you're unlucky, it's something like a bad ignition contorl module. Check that stuff, the next step is fuel. It's probably a port-injection setup (someone verify?), and a periodic miss would point to a faulty fuel injector.

I was talking to my uncle this evening and he's of the opinion that it's in the fuel line somewhere because the problem is sporadic. I mean, it gets real bad, then it gets better, then it gets bad again.

Could a cylinder misfiring account for that? Like I said, I'm kind of an idiot when it comes to this.

Under the driver's back seat...? I just took the AutoZone guy's word for it. He brought out the part and showed it to me, it looked similiar to the one I had to replace in my 89 GMC, which was in the fuel tank. Maybe I just assumed...

Justice Bros. Fuel Injection System Service... I better write that one down :)

Thanks, guys. :thumbsup:

I don't think it's actually misfiring. That will USUALLY set a Check Engine light. Like I mentioned above, I'd definitely start with a fuel injection system cleaning. This isn't the stuff you pour in the tank, exclusively. THey'll do that, too, but there is probably carbon built up on the pistons, in the combustion chambers, and on the valves. That causes problems all over the place. It's funny that you mention this...I just saw this same issue a week ago!

Well, I'm glad I've got access to a whole passel (can I call you guys a passel?) of folks with such knowledge. At least, I won't look like a total nimrod when I take it in.

The check engine light doesn't come on and this morning I distinctly smelled gas while I was climbing a hill, so, you're almost certainly right. It's going to my mechanic Thursday morning, I just hope it'll chug it out til then :p

Thanks again, guys

Cool. Let us know what he finds.

Well, with a little sweet talking, I managed to get the guy to look at it this afternoon.

He figured it out and I feel pretty stupid, which, I guess was inevitable. :)

I walked in there with my big list of things. Rattled off a bunch of nonsense about how I thought it was something to do with the fuel system.... blah blah blah....

I left him to his work and not an hour and a half later he called me at work.

I love this guy. :D

I WIN :D

A 95 has OBDI not OBDII, so it'd have to be misfiring pretty bad to set a check engine light. Trust me, I have a beater Corsice that is a 95 with the 3.1 as well. Ironically, mine started to sputter when I step on it hard, or cruise at 60-ish, just about two weeks ago. On my day off Friday I'm going to do plugs and wires. I bet it solves my problem, as I know the fuel filter and the fuel pump are only months old. If I were him, I'd start with that too. :) Could also be a clogged cat causing too much back pressure maybe?

I feel bad about that one, I suppose, but it stood to reason off of what I'd JUST seen. Either way, glad it's fixed. Yeah, I know about the 1995 model year being what is termed OBD 1.5, and I was kind of hoping that it was good enough to pick up misfires.

Plugged cats can tend to do similiar things that fuel starvation does. If it can't breathe, it doesn't run right. At idle and part throttle, it's not a big deal, but open it up, and it is.

And, zerosignal667...good call.

LOL I was going to say air filter:D