1998 s70 T5 Help with a bunch of codes

V_T5 · Post by **V_T5** » 20 Mar 2015, 13:31

My 1998 s70 T5 is running like crap, sputtering like crazy, and it seems to only happen after driving 30-40 minutes. It will barely get out of its own way and small little puffs of black smoke out of the exhaust while the car is running like this.

I got the car scanned and here are the following codes:
P0172-too rich bank 1
P0131-oxygen sensor bank 1 sensor 1, circuit low voltage
P0102-mass or volume air flow sensor circuit low input
P0455-evap system leak detected
P0300-random cylinder misfire detected
P0301-cylinder #1 misfire condition
P0303-cylinder #3 misfire condition

Can anyone help me diagnose these by any chance? Don't worry about the EVAP code, it's probably because there is no gas cap, getting one today.

My plans are as follows:
Install new gas cap.
Clean MAF.
Clean throttle body.
Check all vacuum lines for leaks or broken hoses.
Pull spark plugs to inspect and check the gap. 0.028 correct?
Install brand new MSD Blaster coil I have sitting around that I never used.
If this doesn't fix my issue, get new oxygen and MAF sensors. Does this sound like I'm headed in the right direction?

Little back story to give you guys a little more info. I bought the car last week for somewhat of a deal. When I test drove it, the car ran fine and had no misfires. My test drive was not 30-40 minutes long so the issue hadn't come about.

I have a receipt from some work the previous owner did in November. On the shops invoice it says "customer states car not running good. Not staying running. Has misfire codes & black smoke from tailpipe. Spark plugs filled up & wires cap rotor resistance out of specs."

Work order on same shop receipt from November:
New distributor cap.
New distributor rotor.
New ignition wire set.
New spark plugs.

They changed all the ignition components except for the coil pack, seems strange. Obviously none of this fixed the problem since I am having the same issues as before the work was even done.

Discuss. . .

Post by **erikv11** » 20 Mar 2015, 17:06

I would definitely check under the distributor cap and make sure the car doesn't have a blown rear cam seal. And that could be cause by clogged PCV, do you know when PCV was last serviced?

Sounds like you are on track, I like your plans right up to O2 and MAF: I wouldn't jump to those unless you have good evidence they are bad, mostly just because they are a little pricey and you want to take care of all the little nuisance things first. Reset the codes and see what comes back, several times along the way if needed.

You can test the MAF by unplugging at and driving around. If that makes the car run better, then the AF was bad. You'll get a code for no MAF, of course. Plug and unplug with the car off, not on.

V_T5 · Post by **V_T5** » 20 Mar 2015, 20:31

I have no clue when the PCV was last serviced, but I plan on deleting it along with the EVAP system after I get my issue resolved. There is no need for that stuff. Removing it will clean up the engine bay, simplify everything, and have less parts that can and will fail.

I pulled the distributor cap and saw some oil around the edges. There was no oil on the rotor tip, so I'm not sure if it is a cause of the issue I am having or not. I will be changing that cam seal and the valve cover gasket since they are both leaking a tad.

There are 3 nipples on the front of the intake manifold on the driver side(2 big nipples side by side, and 1 smaller nipple underneath the 2 big ones). I had 2 split hoses, 1(big nipple top left) that led to the hard line for the fuel pressure regulator, and the other(small nipple underneath the 2 big ones) that leads to the bypass valve. I replaced both and cleaned the MAF with 91% alcohol.

I took the car for a 30 minute ride and all was well, I thought I had fixed the issue. Not quite. A few blocks from home the car started to sputter again so I pulled over. It was idling really low(400-500rpm's) and then it stalled. I started the car, it idled low and stalled again. This happened about 3 more times. On the 4th re-start, it idled fine so I took off and drove it home and it did not sputter along the way. Weird:mad:

While I was digging around in the engine bay, I saw another hose/line that was not connected to anything. It was on the driver side of the fan and ran down under it to the passenger side.

Does anyone know what it is or goes to?

Post by **erikv11** » 20 Mar 2015, 23:38

There shouldn't be any oil under the distributor, change that rear cam seal. Moisture gets in there and interferes with the rotor sparking.

Don't mess with the valve cover gasket except as a last resort if it is certainly leaking, they almost never leak and it is a pretty big job. There is no actual gasket part, just a chemical sealant.

The PCV you want to keep and it must be clean. You are probably thinking of deleting the SAS.

I don't recognize that fan part in your pic, maybe part of the EVAP system, pic looks odd.

V_T5 · Post by **V_T5** » 21 Mar 2015, 11:10

pretty big job? I'm sure I can handle it. rebuilt plenty of engines and did many clutch jobs, VC is cake work. yes, I will delete the SAS too. Also going to get rid of the PVC. ill do like I did on my audis, delete alk the stock crap, and either run a catch can, or dump it to the ground. I dont want all that junk recirculating back I to my engine.

draser · Post by **draser** » 21 Mar 2015, 11:51

I'd stick with keeping PCV as suggested, one reason being that some of that metered blow by is routed back into your intake. If you're missing that air you'll get a rich condition, sounds familiar? Looking at your codes it looks like the driving one is p0172, so engine gets more fuel than air. The way this post is going, I'd follow suggestion and go after PCV, but otber causes may be high fuel press, leaky inject., ECT, thermostat. If you post freeze frames or live data there will be more info for better diagnostic. That is for condition of o2 sensor, MAF, ECT, etc.

Post by **FLXC90** » 21 Mar 2015, 14:13

Keep in mind, it's not a valve cover, but the top half of the cylinder head. The cam bores are split which entails more work than an engine with caps over the cam bearing and a separate cover. Also, unless you just go catch can, the removal of PCV sets you up for blown seals.

V_T5 · Post by **V_T5** » 21 Mar 2015, 14:53

draser wrote:I'd stick with keeping PCV as suggested, one reason being that some of that metered blow by is routed back into your intake. If you're missing that air you'll get a rich condition, sounds familiar? Looking at your codes it looks like the driving one is p0172, so engine gets more fuel than air. The way this post is going, I'd follow suggestion and go after PCV, but otber causes may be high fuel press, leaky inject., ECT, thermostat. If you post freeze frames or live data there will be more info for better diagnostic. That is for condition of o2 sensor, MAF, ECT, etc.

how and or where is the PCV metered? are you sure you arent confusing that statement metered air from the bypass valve? not sure how I even got a rich condition when the line to the fpr wasn't even connected? I have no way to post freeze frames or live data, I just got the car and have no specific diagnostic tools for it. im still waiting for my haynes repair manual to come in the mail.

FLXC90 wrote:Keep in mind, it's not a valve cover, but the top half of the cylinder head. The cam bores are split which entails more work than an engine with caps over the cam bearing and a separate cover. Also, unless you just go catch can, the removal of PCV sets you up for blown seals.

well its black around where the sections connect, plus, dont I have to take off the valve cover to do that rear intake cam seal anyways?

also, the car is weird because through all of this, the check engine light doesnt even come on, not once. I know the bulb in the cluster works because right before you start the car all the lights in the dash light up.

draser · Post by **draser** » 21 Mar 2015, 20:11

PCV=positive crankcase ventilation. The way this works, the blow by gas from crankcase is routed back into intake thru a .... valve. So inside the PCV there's a spring loaded valve which lets some of the gas out, but keeps a positive pressure inside crankcase, hence the name PCV. What the spring does it lets different amounts of gas out depending on engine rpm, hence the metering.

V_T5 · Post by **V_T5** » 21 Mar 2015, 20:41

draser wrote:PCV=positive crankcase ventilation. The way this works, the blow by gas from crankcase is routed back into intake thru a .... valve. So inside the PCV there's a spring loaded valve which lets some of the gas out, but keeps a positive pressure inside crankcase, hence the name PCV. What the spring does it lets different amounts of gas out depending on engine rpm, hence the metering.

I know how a PCV works, but never heard of it being metered. id lay odds that it isnt metered on a volvo either since its blowby. it goes back into the intake to keep the crap from ogoing to the atmosphere, its strictly for emission purposes. have you ever seen what crap gets caught in a catch can? do you want that in your engine? I dont. what do you think stock PCV systems do?they put that junk back into your engine, all because of emissions.