Correct way to replace a PCV hose on Buick Century

buick
century

#1

I hope somebody on here has experience with the Buick Century with 3100 3.1 L V6. I have a cracked PCV hose, and I’ll need to remove it, but part of the hose cannot be removed without moving an obstruction, as you can see in this image. I think the only real obstructions I have are the metal bracket and a fresh air breather hose connected to the air intake hose, but I do not think that the fresh air breather hose will be in my way. I could manage I believe without moving it out of the way. Can somebody let me know if this will work? I’ll just remove the 2 bolts on the metal bracket and lift it just enough to remove the old hose, without disturbing the throttle cables on the bracket. Then I’ll install the new hose by slipping it on underneath the bracket and just bolt the bracket back on. Hopefully it will be enough to install the hose. If I need to remove the fresh air breather hose to push it out of the way, I can just pull it out very carefully right? And if I need to remove them, how do the throttle cables (I think that is what they are called) come out of the bracket? Hopefully I won’t need to remove them. Thank you.


#2

Just unbolt the bracket, and feed the hose thru to connect it.

Tester


#3

Will it move enough to let me just lift the hose out?


#4

I have a 2000 Buick Century 3.1L engine, and I have not had to remove my metal bracket, I was able to pull the plastic nipple out of the rubber air duct.grommet. But it was tough to get back in, so I lubed it and it slid in easily. But I’m sure you had planned to do that already if necessary…On a 1996 Buick Regal 3.1L I used to have, the hard part of this job was getting the nipple for where the plastic tubing fits into the rear bank valve cover under the ignition coil pack in it’s rubber grommet and having it stay in there. Didn’t seem to be aligned properly. I didn’t have this trouble with the Century though, did you? And if I remember right from when I removed my throttle cables, they have a little lug on the end of them that slip into a slot in the pulley segments when you release the tension on the cables.


#5

Are you talking about the PCV hose when you are talking about how it can be removed without removing the metal bracket or are you talking about the hose that goes from the air intake duct to the rear valve cover? Just want to make sure. And I took a look at the throttle cables and saw what you are talking about, so I’ll be able to remove them if necessary. Thank you for the help there. The only big problem is the hidden third bolt on the bracket or removing the hose elbow that connects to the purge solenoid (???) in the back. It seems a little tight but with a screwdriver it might come off hopefully without breaking anything. But if you were talking about squeezing the PCV hose from under the bracket, I’ll definitely try that if I can’t loosen the bracket enough. Maybe this won’t be too difficult. I just don’t want to destroy any fragile things in this 18 year old car! I’m not sure about the hose not fitting into the valve cover yet, hopefully I won’t have to remove that hose.


#6

I’m sorry intermittentspeakers, I did get the PCV tubing confused with the air intake tubing from air intake to rear valve cover. I don’t see how I could get my PCV tubing out of it’s grommet without removing that metal bracket that holds it into place under that tab. The bottom bolt looks very hard to get a wrench onto for sure. But no doubt you have got the bracket off and the tubing replaced by now…


#7

Haha no worries. And I haven’t gotten to it yet. I think I will wait until it warms up a bit to do it outside. I am feeling a bit more confident, the only real challenge might be the metal bracket. Maybe I’ll make a video about it if I complete it successfully. I’ve watched a few “intake manifold gasket” videos and some show them removing the PCV hose, so that’s given me some idea of how to do it. Thanks though for the advice guys, and wish me luck! And a few more degrees outside if you don’t mind! :slight_smile:


#8

If you were where I am, Toledo Ohio, it would take a heated garage to work on your engine, we are having a colder than usual winter.


#9

(I’m so sorry about this long read)
Really? :open_mouth: Now I’m glad about my temperature. It was slightly warmer today so I decided to do the hose replacement. Good news: I replaced it. Bad news: car won’t start and I do not know what’s wrong.

When I replaced the hose, it looked pretty close to the original just the U shaped end connector going to “purge solenoid” was smaller but I did not think it would matter too much. So I removed the bolts on the bracket and there was just enough wiggle room (just a little) that I was able to squeeze the hose connection to the intake manifold (the metal part of the engine with “3100 SFI” on it) out from underneath, although the grommet (a ribbed grommet) came off of the hose connection point (the connection point is just a cylinder that the grommet was covering so it was two separate pieces if that makes sense) and fell where I couldn’t reach it - outside of the engine thankfully.

I double checked that there was no debris left in the hole, but the flashlight seemed to be shining into a pitch black hole, so I had to assume that none of the grommet had fallen in (the majority came out at the very least, it wasn’t exactly brittle but just a gooey, soft mess). The walls in there are just so dark that it looks like a black hole. I’m 99% sure that no grommet fell in. (I really apologize for my vocabulary) But I continued on, and the hose I bought had the same grommet anyway.

I installed the new hose. The U shaped connector that connects the hose to the “purge solenoid” barely fit on but seemed to fit tightly once I got it on (it was smaller and narrower than the original but seemed fine otherwise). After installing the middle connection point, I installed the bolts, and installed the PCV valve in the other end of the hose (the valve has the same number stamped on it as the original and is ACDELCO branded), and inserted the valve into the engine. I started the car and it seemed to run fine. I could hear no hiss like the cracked hose made. I felt around the hose and didn’t feel a vacuum so I assume the hose is securely installed.

One other thing I messed with during the installation of the PCV hose (I tried to disturb as little as possible) is the fresh air breather hose (the yellow hose in the picture in first post). I removed it from the air intake duct which was easy enough, but it’s connection to the valve cover (?) in the back was so loose it just came out, and when I reinstalled the fresh air hose, the back did not want to seal fully (if it was ever sealed in first place). It was just kept in place by the stiffness of the hose. I am not sure if there is a grommet back there or if there was. I should have checked I guess in case it got sucked it or not. The car started fine. I removed the PCV valve from the engine while it was running to test the valve, and sure enough it had a vacuum so the valve had to be working properly. Then I reinstalled it. I don’t think any dirt entered the valve, but it could be a possibility. Not a lot at all if any entered if it happened, because I did not see any. The car was running for a few minutes, and I smelled gas, although it had done that before so I just assumed it was a normal “old car” problem. It never ran particularly well, it would sometimes knock, or sometimes have a harder time starting than usual, or just idle badly and shake sometimes. But only sometimes. This time around, the hiss from the vacuum leak was gone, but it still idled badly. The engine sounded like it was going up and down and up and down in speed while idling.

I turned off the car eventually, and when I went to turn it on later, it had a hard time starting. I would turn the key, and it would sound like it was starting, but the instant I let go, it would run for less than a second or a second and stall out. It had done this before I messed with the engine maybe once in 50 times starting the car, but not to this extent. Before, it would start if I persisted on the ignition for a few extra seconds. And I do not think that it was ever the case where the car was able to run for it a second before stalling out. It just never started before so maybe it was a different problem. But now it sounds like it was starting to run before stalling out. It does this after several attempts to start the car. It also shakes trying to start it, although I’m pretty sure it did before.

Eventually after a few tries I get it to run again, thinking it was maybe just one of those days it feels like not starting but worse since it had been sitting out for a week. (Also: the hose was broken and was open for that week and it snowed, rained and sleeted, maybe that played a role?) It seemed to run fine again, so I took it for a spin around the neighborhood. It idled fine (like before the repair) and drove like it did before, so there certainly couldn’t be a major vacuum leak again right? The whole event that got myself into this mess was trying to replace the elbow of the hose that the PCV valve was installed in because it was cracked. It seemed to have an okay vacuum seal despite it being cracked which is why the car even ran at all, but after fiddling with the cracked elbow I ruined it’s vacuum seal and the car idled horribly, shaking and everything. Then I cracked the hose trying to replace the elbow. That’s how I got to the point where I needed to replace the whole hose. But this can’t possibly be a vacuum leak, right? It’s not shaking like an earthquake like it did when it had the huge vacuum leak. When I got home (it seemed to drive normally), I turned off the car, but tried starting it again and it wouldn’t start even after a few tries, so I knew something was wrong and stopped trying. I undid the bolts on the bracket and removed/reinstalled the middle connection on the hose, just in case, and tried to push the fresh air breather hose connection to the back valve cover in case it was loose (didn’t look like it made a difference). The car still won’t start reliably, and I haven’t tried to get it running a third time in case I am damaging the engine by cranking it. Now I’ll have to hire an actual mechanic to solve the problem I created somehow, but does anyone have an idea of what happened? Thanks guys.


#10

My dad thinks I flooded the engine and the car started again with no problem an hour later. Assuming I have the hoses all connected properly, do you guys know what the problem could be? If it isn’t bad connections, it’s a lack of oxygen right? If I’m smelling gas/flooding the engine.


#11

The PCV system is a controlled vacuum leak into the intake manifold. Fresh air (cleaned by the air filter first) is drawn into the crankcase, then pulled back out into the intake manifold via the PCV valve. If something isn’t working w/the PCV system correctly, it can cause the symptoms you are having. The rpms going up and down at idle sounds like some kind of air leak into the intake manifold. If I had that problem I’d see if there was a way to block off all flow to the PCV system temporarily, and see if that made the problem go away. If so, you’d know at least the problem was in that area. It’s possible that your PCV valve isn’t working, so you might try replacing that on a flier since they are usually pretty inexpensive. I had a similar problem on my truck a while ago, and soaking the PCV valve in gasoline helped quite a bit, so I replace the valve and that fixed it completely.


#12

I’ll try sticking my hand over the PCV valve to block it up to see if there’s a difference in idle (thanks for the suggestion), but the car has never had a great idle when we bought it from my grandpa (he is second owner, so there’s no telling how the first owner treated the car). The car also has trouble climbing hills and was slow, even before I tried to fix the PCV hose and possibly caused or unearthed this problem. I’m not so sure if it is a vacuum leak. I am not a professional and I don’t want to doubt your knowledge, but let me know if this reasoning is sound for thinking a vacuum leak isn’t the problem: It certainly doesn’t idle well and that could be a sign of a vacuum leak, but when I had a huge vacuum leak the engine shook. It doesn’t shake but just idles strangely, and floods the engine with fuel. Before I definitely had a small vacuum leak through cracks in the hose, and it idled badly, but never flooded the engine (although it smelled like gas). Now it either has no or at least less of a vacuum leak because I fixed the small vacuum leak in the hose, but floods the engine for some reason because the leak is lesser. So if the flooding/rough idle is caused by a vacuum leak, shouldn’t it have gotten better not worse? I’ve read that the intake manifold gaskets can fail on this car, but if so it was running “alright” with that vacuum leak before I replaced the hose, so replacing the hose to fix that small vacuum leak shouldn’t have exacerbated the problem because it should have decreased the leak. I’m sorry if I’m totally wrong, and I’m not doubting your knowledge, but could you let me know if this could be true? I realize I did not summarize all of the possible details of how this car runs in my posts, which could make all the difference in you guys figuring out the problem. My fault if that is the case.


#13

Could you guys give your opinion on my (probably wrong) theory? So the car has never ever run like it should. I haven’t driven a Buick Century in good condition before, but this one has to be too slow and it also idles roughly and occasionally misfires. It has trouble keeping highway speeds, too, emits gas smells and is bad on gas mileage. It also has a check engine light that my dad hasn’t checked before, but it can’t be good (it’s a very old and weathered car so I guess that is the reasoning). So something’s wrong with the combustion, and the fuel isn’t being totally consumed, right? So what if the air filter is clogged and preventing adequate oxygen from reaching the combustion chambers and burning up the fuel? I have read online that the engine computer should lower the amount of fuel reaching the combustion chambers to compensate for the lack of oxygen, but I don’t know why this car doesn’t do that. Maybe it’s too old to have that technology? But the car did have an additional source of oxygen, which is the vacuum leak, maybe enough to keep it from totally stalling out from unburned fuel. But when I repaired the vacuum leak, it only had the air intake’s supply of oxygen, and stalled out because it is clogged and needs replacement so it isn’t letting as much air in as it should. And when I accidentally worsened the vacuum leak before by fiddling with the old cracked hose and breaking a seal, the car seemed to have more power because it was sucking in more oxygen from the vacuum leak, possibly. It idled extremely roughly because it’s uncontrolled, right? But it seemed to have more acceleration power. So it seemed maybe the cracked PCV hose was its main source of oxygen. Could you guys let me know if this is possible? There are a million possible problems for these symptoms, but considering that the car started doing this after fixing a vacuum leak, maybe it narrows the problem list down. I could try taking out the PCV valve and blocking only portions of the hose with my thumb, as crazy as that sounds, and maybe modulate the amount of oxygen coming in through the vacuum leak to see if it smooths out the idle, but replacing the air filter is something I should do anyway. My grandpa’s mechanic dropped a pencil in the engine bay and just left it there, so maybe he wasn’t the best mechanic. :stuck_out_tongue_winking_eye: But I’d better take it to a real mechanic to see if he could figure it out.


#14

It could also be the O2 or MAF sensor or some other problem, as I just replaced the air filter and the old one wasn’t too dirty (or at least less dirty than filters in some internet pictures I’ve seen). I have yet to reattach the hose, because it is really difficult to push back on fully. Will update on the situation and if it doesn’t solve the problem I guess I will take it to our mechanic to scan the codes and see what sensor has failed or what the problem is (vacuum leak, spark plugs, leaking fuel injector, whatever it may be). Hopefully not too expensive! :fearful:

Also we should clone the DNA from that feather and replicate the bird it fell from years ago.


#15

That can often be the best plan for difficult to solve drivability problems. You can always just ask for a diagnosis, then you fix the problem yourself. It might take a few iterations but eventually you’ll get it fixed.


#16

I took it to a mechanic and it ended up being a dirty throttle body. Now it starts up fine, but it probably still needs a tune-up.


#17

Glad you got it fixed. Good for you. Bring all the routine maintenance up to date, and you’ll be good to go.