98 S70 glt Engine issues major!

[Duake]

I bought some Heet to try and get the water out of the gas tank just in case. After driving a little bit, the engine just went into cardiac arrest and just putts along at a dangerous 1000 rpm barely going anywhere. The ironic thing is that it seems to get random spurts of being good but dies away. During these times though, the engine doesn't want to upshift to a higher gear and just adds more RPMs than moving forward. What would this indicate?

[difflock54]

The egg / sulphury smell is from your catalytic convertor.

[Duake]

That smell may have to do with the maf being disconnected as the fuel is more concentrated and smells like that when burning it off.

I had to leave my car at a parking lot tonight because it just wouldn't work correctly. At points it wouldn't even rev and seemed liked the car was dead but was still running. What would cause it to just not get fuel in drive, but can rev up in Park and Neutral most if the time? Something with transmission?

[rspi]

Hey Dauke, a motor has to breath, that means air in and air OUT. So, if the cat is clogged, the car can NOT breath OUT. Either disconnect the exhaust before the cat and see if it will run, or keep chasing your tail. The guys here telling you what to do will only last so long.

How many people do you need to tell you that your cat finally gave out? Did you have someone help you with the quick test that a few people have suggested? The exhaust paper test? The intake tube test?

If the car has NO LOAD, it doesn't breath hard in park or neutral, to get the RPM's over 3,000.

[Duake]

Hey Dauke, a motor has to breath, that means air in and air OUT. So, if the cat is clogged, the car can NOT breath OUT. Either disconnect the exhaust before the cat and see if it will run, or keep chasing your tail. The guys here telling you what to do will only last so long.

How many people do you need to tell you that your cat finally gave out? Did you have someone help you with the quick test that a few people have suggested? The exhaust paper test? The intake tube test?

If the car has NO LOAD, it doesn't breath hard in park or neutral, to get the RPM's over 3,000.

First off, I have been posting while I was driving trying to find different things I could try as I was out. I left work early and I have 5 kids at home, so I can't just do things on the spot like other people without these responsibilities.

As I have posted before your reply, I stated that it's in a parking lot because I left it there. Kind of hard to just grab my paraplegic girlfriend and our kids and just sit out in 15 degree weather in a parking lot messing with my car.

To everyone with the suggestions: I appreciate the help and will post when I have tried what I can. Thanks!

[Duake]

I replaced my MAF sensor Saturday and that didn't help, though it needed replaced regardless. The CE light is on so I'll have to get a OBDII reader to see what it means. It didn't happen when my car was sputtering before.

If my catalytic converter really is messed up at 156700 miles, then that's a shame. I've never had that happen to me on any other car I've owned. Since there is no way to just disconnect it from the piping other than sawing it off, I can't check to see if something is rolling around in there. I did the test with my son with the paper. Again, in Park or Neutral, I can rev the engine just like normal sometimes. It's when I go into drive and try and go somewhere does it instantly fail. Could that really be the catalytic converter? Seems odd if that's the case. Does the exhaust not act the same in ANY gear when the gas is applied?

[socompsp]

yes, you can disconnect the whole downpipe from the turbo, car will be loud but if the problem goes away then you know what it is.. and that kind of miles on a cat on a rich running car would fail around then.

[JimBee]

If it is the catalytic converter, this post has information for an economical fix:
https://www.matthewsvolvosite.com/forums ... =1&t=50269

I have a couple of other thoughts:
Smell the exhaust when it's running. If it's running very rich you'll smell raw fuel. If for some reason the ECU is dumping too much fuel through the injectors, that would stifle increased rev's.
Also, raw fuel going into your cat will light the cat up red hot. There's a heat shield over it, but that can still be dangerous. You can look underneath and if it's that hot you'll be able to see it.

Also, check your large "accordion" hose from the air box (by the battery) to the throttle body. Feel around behind where you can't see and underneath to make sure that are no tears in the plastic covering the wire loops. I have replaced 2 within a short period on a '96 850 and still don't know what caused the perforations. They caused hard starting and stalling on mine. Just one more thing to eliminate.

As far as water in the gas, I doubt there would be enough moisture in the tank to cause an enduring issue like this. It would be at the bottom of the tank, get picked up, go through and would be gone. If the problem started right after you put gas in the tank, the gas itself could be bad. If the problem did not start right after you gassed up, it's probably not that.

Also gas related: after it has been running really weak and you shut it off, check the fuel pressure by pressing in the schrader (tire stem) type valve at the end of the fuel rail. Wear GOGGLES because if it's normal it will squirt possibly towards you. If it's weak, it could be a weak fuel pump or a clogged fuel filter.

You'll get it solved.

[cn90]

You need to start with very basic stuff:

1. Air Filter: is it clogged? This is a 2-minute check.

2. Spark Plugs, Cap/Rotor and wires.
What are their conditions?

3. Fuel Filter, how old?

4. Is gasoline contaminated?

5. If you unplug the MAF and the engine is smoother (Limp Home mode), then it is bad MAF.

6. BTW, clean the ICV (Idle Control Valve). Take it out, clean with solvent, just make sure the hoses are clamped when done. They have a tendency to become disconnected if not clamped.

Finally, check for any broken hoses, which can cause air leak ---> unmetered air!!!

[pred]

Really, Have someone hold it at about 2000 rpm the feel the exhaust as it leaves the tail pipe,
IF silky smooth flowing out = clogged cat.
Ive seen this at idle too,
Exhaust should surge in and out fast, NOT be steady smooth air flow.
Saw one mis diagnosed as bad automatic trans, Many dollars later same issue, Loss of power, Foot to floor and cant get car to move swiftly,, Mechanic didnt even refund the money to friend,
This can happen,
Cats can get old and start to break apart at times clogging the pipe,
Some folks will simply make 1 cut behind the cat, Beat a 1/2" rebar they cat and install a band clamp at cut and call it done, While this is not legal, It will get the gasses to get thru the cat and out the tail pipe.
Let us know what happens,