2001 S40 1.9 Turbo automatic. I have read that these engines should have vacuum at crankcase. When I take off oil fill cap with engine running I feel air blowing out not sucking in. I cleaned pcv system (some gunk but no real blockage), and still the same condition. Is there anything else that would cause no vacuum at oil fill cap?
Thanks

 

When you cleaned the PCV system, did you replace the oil trap? If not, that might be the problem.

 

Thanks for the reply. Yep, I put a brand new oil trap in.

 

Another possible issue is a clogged cat converter. The old school test is to remove the top O2 sensor and run the car to see if the condition changes. Don't run it long like this if you try it.

 

Thanks Hudini. I will try that. The car still runs good. I thought a with a clogged cat the car would lose power. Can you tell me if I am checking this condition correctly? With the engine running I remove oil fill cap and put a paper towel over the opening. I expected the paper towel to stay on the opening but it slightly gets blown off. Is there a better way to check this?

 

use a rubber/latex glove. if it inflates you have pressure. it should get sucked down. i hold it and then have someone else start the engine bc my gloves dont fit snug.


did you clean the ptc when you did the pcv?

 

Ah...thanks teekay, another good idea. You guys are coming up with great suggestions. This is my son's car and he has it now. When I get a chance I will try both yours and Hudini;s ideas.What is the ptc?

 

I mentioned the cat convertor because someone recently had this problem. It caused quite a bit of blowback through the oil fill. Personally I've had a clogged cat one time. The car was down on power like you said. The test I mentioned is a quick and dirty test to see if anything changes with the O2 sensor removed. If the crankcase suddenly has vacuum again then you know you are on the right track. If nothing changes then keep looking.

 

I think it is a good test. Just did not have a chance to try it. I changed the O2 sensor about a year ago so hopefully it will come out easy. And I'm not really sure if there is pressure there or not. If i lay a paper tower over the oil fill opening it seems to slightly blow it a little, but if I cover the opening with my hand it kind of feels like a slight vacuum. I'm not sure how much vacuum should be there. You know if you take a line off the intake you can really feel the vacuum. This seems different. I wish there was a way to test how much vacuum is present. Thanks for your help.

 

The glove test worked for me but the glove did not immediately get sucked inwards so the negative pressure is not huge. However after a few seconds the glove did crumple right up.

 

The dingle dange on your intake pipe that has vacuum and is connected to the PCV (I think it is at least). You can see it here on this removed pipe. Follow your airbox and you'll find it. https://i.imgur.com/OJCjCQX.jpg

Here's a blurb on it (Engine: Fuel Injection)

Here's a very good thread on MVS that has images of it being dirty http://www.matthewsvolvosite.com/for...c.php?p=226269

 

Sorry I didn't get back sooner. Thank you for all the replies. I'm at a point where I am going to assume all is normal. The glove test worked. The fingers never inflated, but after I gave it some throttle the glove slightly crinkled. There is not a lot of vacuum there, but there is some.Thanks pierremcalpine, Hudini, and TEEKAY.

 

After reading this thread and checking my 2001 I found the air/oil separator for the PCV system to be clogged causing excessive pressure. I removed the intake manifold and cleaned the air/oil separator of this nasty oily mess. Now my car has a nice suction when I place my hand over the open oil fill hole.

 

Good deal. I got another question for you. When you took off the intake, you had to remove 2 coolant lines. Why are they hooked up to the intake?

 

I think it's some kind of anti-icing feature. The rubber lines connect to a metal line that runs around a vacuum port. After the intake one coolant line runs all the way back to the turbo.

The vacuum port has a rubber 90* elbow, then a 3/16" hard line down to a rubber T above the air/oil separator. I cleaned out the vacuum port with a coat hanger as the hole is quite small.

Maybe the vacuum port can freeze up from condensation from the air/oil separator? My air/oil separator was clogged with a milky white oily mess at the bottom where the oil should flow back to the engine. That suggests to me that oil and water were mixing somehow.

 

The milky mess can happen in the winter without issues and be a false positive. You might see that where you're in a super cold climate and only doing very short travel, it's just condensation. You'll see a lot of this concern with people who have added an oil catch can and it milks up in the winter. That aside it's recommended to do the PCV every 100,000 miles anyway (to my knowledge I'm at ~170k and it's never been changed and have had it on my todo list for the last few months).

 

Hudini, thanks for the info. That makes sense. TEEKAY. I bet Hudini is relieved to hear that.