98 S70 non turbo loss of power

45DegreesPDX · Post by **45DegreesPDX** » 25 Feb 2018, 17:34

Hello,

I have a 1998 S70 non-turbo that is having some issues. Car was running fine until one day the engine completely lost power. This wasn't electrical as all of my electronics still worked, it was just directly the engine. I was able to start it back up and limp home, with it dying on me a couple more times. It now has a rough idle, and gas smell. After idling for a while it'll lose power too. Codes thrown are a misfire in all 5 cylinders and a issue with the catalytic converter. Would a clogged cat be the issue? Or maybe a hose for air intake?

Thank you

Post by **RickHaleParker** » 25 Feb 2018, 17:45

Would a clogged cat be the issue?

Any clog in the exhaust can cause misfire on all cylinders. I could be the cat, resonator or the muffler. If you determine that the source is a clogged exhaust system, make sure it is not the resonator or the muffler before you replace a expensive cat.

When the exhaust get clogged up, the engine cannot rev up to full RPM due to back pressure, you might hear a whistling noise, which is back pressure escaping out of the exhaust system seams. You have any of these symptoms?

WhatAmIDoing · Post by **WhatAmIDoing** » 25 Feb 2018, 17:48

Do you know how long the plugs, wires, cap, and rotor have been on there? Would also be a good idea to check for vacuum leaks and unmetered air infiltration. A misfire on all cylinders would lead me to suspect cap and rotor or the coil.

45DegreesPDX · Post by **45DegreesPDX** » 25 Feb 2018, 18:27

The engine seems to rev just fine. I just went back out to see if I can experience any more symptoms. On some starts the engine will die immediately after not even reaching 1000rpm. On other starts it seems to run and idle fine once I push on the gas a little when I start it up. Made it down the block just now before it died out on me again. But I didn't hear any whistling when I was revving the engine at all

45DegreesPDX · Post by **45DegreesPDX** » 25 Feb 2018, 18:30

I don't know how long they have been on there. Guy I bought it from about 25k miles ago rebuilt the whole top end. Not sure if he replaced the cap, rotor, wires or plugs.

WhatAmIDoing · Post by **WhatAmIDoing** » 25 Feb 2018, 18:35

Easy to pull and check cap, rotor, and sparkplugs. Since you don't know their age, good idea to check.

Post by **RickHaleParker** » 25 Feb 2018, 18:50

Start it up, warm it up, then bump up and hold the RPMs at 5000 with the transmission in park to check for back pressure. If you cannot get it up to 5000 or cannot hold it at 5000 it might be back pressure. Do this with the windows rolled down and your ears wide open.

45DegreesPDX · Post by **45DegreesPDX** » 25 Feb 2018, 19:10

I'll try again at holding it at 5000 and check the cap, rotor and plugs.

45DegreesPDX · Post by **45DegreesPDX** » 26 Feb 2018, 19:10

Alright, I was able to run it at 5000 rpm and hold it. Wasn't necessarily a high pitched whistle or anything but I did hear some swooshing, sounded like someone blowing air. It's running extremely rich and I'm beginning to stink up the neighborhood. I also tried unplugging the MAF to see if it was that. Seemed to start good but then slowly begin to vibrate and have a rough idle. Still have yet to check cap rotor and plugs. Will do that tonight.

Post by **RickHaleParker** » 26 Feb 2018, 19:30

You can rule out clogged exhaust system.