Dirty oil causing hard starts?

Don’t laugh - this actually happened on my wife’s XC - poor idle and hard starting.

PCV system was in good health. But she drives gently. The engine intake tract had oil from the PCV system, causing stumbling at idle, and hard starting, because it was never pulled through the engine at high RPM/boost.

I cleaned the throttle body, changed the oil, then took it out for a drive. A couple of full throttle acceleration runs and the car had visible exhaust. Not really smoke, but enough exhaust to see in the mirror. By the third run that smoke/exhaust was gone.

And so was the stumbling idle.
I can see that happening. It's hard to get the rpms high since the engine is pretty strong (at the cost of mpgs 🥲). I have to actually try to get the rpms to 4k when I'm accelerating.
 
I can see that happening. It's hard to get the rpms high since the engine is pretty strong (at the cost of mpgs 🥲). I have to actually try to get the rpms to 4k when I'm accelerating.

Astro14 is on-point. An "Italian-tune up" is a thing. Google that expression if you aren't familiar.

This car should pull like a train from 1,500 rpm to around 5.5k rpm or all the way to 6k. The torque curve is very flat and around 240 ft/lbs. Is that what you are saying (that it's strong and you don't rev it high for that reason)? If the car does not feel that way, then it's worth investigating the small things that can get it out of tune.
 
Astro14 is on-point. An "Italian-tune up" is a thing. Google that expression if you aren't familiar.

This car should pull like a train from 1,500 rpm to around 5.5k rpm or all the way to 6k. The torque curve is very flat and around 240 ft/lbs. Is that what you are saying (that it's strong and you don't rev it high for that reason)? If the car does not feel that way, then it's worth investigating the small things that can get it out of tune.
Yes, it doesn't rev high because it "pulls like a train". I'm up to 80mph very quickly. I have to take to 90mph to get it to kiss 4k rpm
 
Yes, it doesn't rev high because it "pulls like a train". I'm up to 80mph very quickly. I have to take to 90mph to get it to kiss 4k rpm
Ok, then that's what it should do so your TCV is working ok, most objective things are likely a-ok. So something like what astro mentioned is likely the culprit.
 
Yeah, I reckoned it would be back.

With your miles, it’s probably time for a PCV system replacement. All new parts, cleaning doesn’t work. No shortcuts. Do it right or you’ll be doing it over.

Make certain to clean the block to sump oil passages, as they get plugged up, too. Took me about six hours to DIY this the first time. I could likely do it in three now, but budget the time.

Here is a good kit: https://www.ipdusa.com/products/216...o-5-Cylinder-for-Volvo-IPD-Kit-Builder-K21637

If you own a Volvo, you should get to know IPD.

You need to do this, regardless if it’s affecting starting by pooling oil. Reason: PCV system failure leads to increase crankcase pressure. This leads to cam seal failure - and it’s catastrophic, when a seal blows, the engine is puking out about a quart a minute. You’ll blow up the engine in short order if you don’t notice the smoke screen behind you.

Yes, I’ve done this four times. See my signature.

With PCV sorted, get someone with a copy of VIDA. Scan the engine for stored position sensor codes.

What you describe sounds most like a sensor. Italian tuneup won’t hurt, but sort the PCV system and then go after sensors. Fuel pump is another possibility- but don’t just fire up the parts cannon. My wife’s XC has 200,000 miles on a replacement pump. They last a long time.
 
Yeah, I reckoned it would be back.

With your miles, it’s probably time for a PCV system replacement. All new parts, cleaning doesn’t work. No shortcuts. Do it right or you’ll be doing it over.

Make certain to clean the block to sump oil passages, as they get plugged up, too. Took me about six hours to DIY this the first time. I could likely do it in three now, but budget the time.

Here is a good kit: https://www.ipdusa.com/products/216...o-5-Cylinder-for-Volvo-IPD-Kit-Builder-K21637

If you own a Volvo, you should get to know IPD.

You need to do this, regardless if it’s affecting starting by pooling oil. Reason: PCV system failure leads to increase crankcase pressure. This leads to cam seal failure - and it’s catastrophic, when a seal blows, the engine is puking out about a quart a minute. You’ll blow up the engine in short order if you don’t notice the smoke screen behind you.

Yes, I’ve done this four times. See my signature.

With PCV sorted, get someone with a copy of VIDA. Scan the engine for stored position sensor codes.

What you describe sounds most like a sensor. Italian tuneup won’t hurt, but sort the PCV system and then go after sensors. Fuel pump is another possibility- but don’t just fire up the parts cannon. My wife’s XC has 200,000 miles on a replacement pump. They last a long time.
I did the glove test to check the PCV system and there was vacuum. It was sucking the glove down. I don't think it's the PCV system. It's probably a crank or cam sensor (like you're saying) or dirty throttle body (like others have said) or a starter that's puking too many amps and interfering with the sensor signals (from what I read on forums).
 
Not to knock Astro14 at all because he knows elements of these cars much better than I - but have you asked at swedespeed.com? You will get some same suggestions as him, but also maybe a few others or a more direct necking-down of the problem. I have not encountered the dreaded PCV issue yet on four cars, and am doing all I can to avoid it. The P2 sub-forum at swedespeed has some great people (Astro14 is there also).

Also 2nd the iPd rec; O am helping a friend order some parts for a coolant issue on a P1 right now (07 S40), actually going over to check the car over again very shortly before placing the order. FCP Euro is also good and I find RME (Rocky Mountain European) very helpful also but not as user-friendly or Volvo-specific knowledgeable.
 
Not to knock Astro14 at all because he knows elements of these cars much better than I - but have you asked at swedespeed.com? You will get some same suggestions as him, but also maybe a few others or a more direct necking-down of the problem. I have not encountered the dreaded PCV issue yet on four cars, and am doing all I can to avoid it. The P2 sub-forum at swedespeed has some great people (Astro14 is there also).

Also 2nd the iPd rec; O am helping a friend order some parts for a coolant issue on a P1 right now (07 S40), actually going over to check the car over again very shortly before placing the order. FCP Euro is also good and I find RME (Rocky Mountain European) very helpful also but not as user-friendly or Volvo-specific knowledgeable.
SwedeSpeed website isn't as active as this one. I started the same topic and received only one reply.
 
no.

Something else is going on. Oil doesnt cause hard starts or cure them.

The only engines I could see where this could apply are those diesels that use engine oil as part of the fuel system, for example the Ford power stroke, some Cat engines, or stationary engines with a hydraulic governor.

Poor oil quality can cause a variety of symptoms on those.
 
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