Did I trash my PTC valve

azureblue · Post by **azureblue** » 27 May 2016, 22:03

While trying to track down the source of excess CC pressure, I pulled my PTC valve and cleaned it, and the intake pipe down to the turbo. Before I removed and cleaned it, I did a latex glove test on the oil filler port- it would inflate for a bit at idle, then inflate a little more, then it would collapse when the idle was raised to maybe 2K. When i pulled it, I could not blow through it at ambient temp. The valve was dirty and i sprayed it with carb cleaner and cleaned it with a drill bit to scrape the gunk out of the valve hole. I could blow through with some resistance after cleaning it. I put it all back together, but now I have little to no CC pressure at idle, but at 2K + it will practically blow a loosened oil filler cap off. Oil vapor is now coming out of the dipstick tube when the dipstick is out and it's dripping oil like crazy.

So did I mess up the PTC valve? Or, since it was cleaned, it's working properly and the PCV system is effed up? The PCV system was replaced 6 years ago, BTW.

Thanks in advance...

Sommerfeldt · Post by **Sommerfeldt** » 28 May 2016, 03:16

Strange development, really... But, the PTC is basically just a couple of holes and a disc that heats up when it's told do do so, and in essence, there's not much that can go wrong with it, except that it plugs up over time. If it's clear, then it's working (well, aside from the heating, which you won't know w/o testing, but the main thing is that flow through it is unhindered).

If your pressure is that high, you shouldn't drive the car until it's taken care of. You'll blow out seals here, there and everywhere if you do. To me, it sounds like the PCV is blocked somewhere, probably gunk in the ports to the block. So yeah, the PCV system is effed up.

- S

azureblue · Post by **azureblue** » 28 May 2016, 07:52

Thanks for the great input - yeah, it is odd.. I gather the heater is just to close the valve when the car is cold,and it is supposed to be open I can go to parts yard and snag another pipe and PTC valve assembly, if needed.

I pulled the dipstick out a bit to take the pressure off the already weak rear main seal, which is how this saga began. I guess I won't know what is messed up withe the PCV system until I get in there. Which leads to - do I need to by all the PCV parts, like the can? I'm not cheap but no use replacing parts that are 50,000 miles old. Of course, the intake manifold gasket will be replaced..

I dug up some articles on putting in a larger 5/8" hose to improve breathing. Anything else for improvements or things I need to watch for? I found some articles and vids on the job and it's no problem for me to do. But if hehre is someone in my area that could supervise, it would be appreciated..

Sommerfeldt · Post by **Sommerfeldt** » 28 May 2016, 08:27

I think you misunderstood me - the PTC is always open - it's never closed. The disc in there just heats up, nothing more. Take a look at this: https://www.matthewsvolvosite.com/forums ... =1&t=68898 where JReed tears one open to see what exactly is in those things.

If you can blow through your PTC, then that's not your problem.

Usually, the main problems in the PCV system is the ports from the block, and the hoses. Pull your manifold, take off the can and inspect the ports to the block. Be thorough - if these are clogged, then nothing but a good reaming out will help you, no matter the condition of the rest of the system. Inspect the can - in many, many cases, it can be reused. Be wary of reusing any hoses, long or short. the 5/8" hose mod is a good way to go when you've got all the stuff off anyway.

- S

azureblue · Post by **azureblue** » 28 May 2016, 08:37

Thanks - no, I got it - the point being is that it should be open when I blew through it after cleaning it.. It was totally clogged when I removed it for cleaning. I don't think it could have gotten that clogged in 50K miles

I read something about that small plastic pipe being a problem because it will get brittle - is there are upgrade for that?

I will probably just get the entire rebuild kit minus the can, and some 5/8" heater hose, too.

I was looking at catch cans as a replacement for a stock PCV system, but that seems to be inadvisable.. The fact that the RMS leaks a bit already (PO ran the car with a clogged PCV system) is making me think of getting another wagon. I think mine has had its day...

Sommerfeldt · Post by **Sommerfeldt** » 28 May 2016, 10:49

Ah, yes - I gotcha. No, 50k is a little quick for a full clogging of it, especially if it's had regular oil changes.

The small, hard plastic line can be a problem. I've used 5mm silicone line, routed from the port on the manifold and on the outside of the manifold and under the TB and distributor to join in the holders with the other vac lines there and down to the side port. Seems to work swimmingly. If you're having the manifold off, you can route it under it instead, if you want.

A few other people here know what happens when people talk about ditching their wagons over minor issues around me...so I'll try and let that pass... but suffice to say that a clogged PCV system is a very, very minor issue if you actually do something about it. Letting that pressure pass to where it's supposed to go instead of having it push on seals here and there will often also nix a minor leak that it's been causing. So keep that in mind.

These are 20 year old cars by now, and there will always be things that need fixing, maintaining, etc - the absolutely superb thing about these older Volvos is that you can actually do everything yourself. Yes, the parts will cost you some dollars, but you never need to pay hundreds of bucks in labor anymore. With MVS and the repair database at your back, there's nothing you can't do with your own Volvo. And a PCV job is peanuts.

- S

azureblue · Post by **azureblue** » 28 May 2016, 13:12

Thanks for the encouragement and advice..... I like the 5mm silicone line idea.

So what parts do i actually have to buy, if I am going to clean out the old trap?
- 8653339...Short hose to engine block...$5.85
- 1271653..Short hose to engine block... qty = 1; $8.76
- 9146266...Intake manifold gasket... $13.86

I would also love to use a catch can to stop routing the vapors into the turbo......

I would love to keep it, but a leaky Rear main seal is the deciding issue. I hope that with a new PCV system and hose upsizing, it will stop leaking or at least slow way down.. I mean, everything works great in the car and, with new seats and headliner, I'd love to see 400K in it.

Sommerfeldt · Post by **Sommerfeldt** » 28 May 2016, 15:05

If you go with the silicone instead of the tiny hard plastic line, and the 5/8, then that's all you need, except the hose to the top, but if that's in good shape, you can reuse it. You have to make sure you clean out the ports to the block - squeaky clean.

An additional catch can is usually not necessary with a PCV system that works, but it certainly won't do any harm. Just remember to empty it out once in a blue moon or so.

A clean 850T with a good interior can be hard to find, and remember that even an RMS is a DIY job if you've got the guts and time to go through it. (I've never had to try it. Yet.) A new RMS from Volvo is about 150 bucks, I guess, but can be had from an OEM for a third of that.

- S

Post by **erikv11** » 28 May 2016, 16:58

A couple comments in addition to Sommerfeldt's great advice:

- For sure you will need Volvo hose 1271654 from the trap to the valve cover, it gets rock hard and can clog. About $25.

- I prefer rubber over silicone for that small hose. Over time the oil vapor saturates the silicone hose and then oozes through the walls, the whole hose gets slimy and it is messy.

- If you go with 5/8 hose then be sure to get a quality hose not a cheapo, or better yet fuel line or a pre-formed hose. The problem is a cheap hose can easily kink and get blocked and sabotage your PCV efforts, so be very careful about how you route it. In my opinion the easiest and best way to go is something like Gates 28471 with a pre-formed 90 degree elbow, see https://www.matthewsvolvosite.com/forums ... =1&t=75631 for pics.

- PTC is not a valve it's better if we never call it that, it is just a hole, it neither opens nor closes it just is clogged or not clogged. I know this was said a couple times but tons of people don't know it or get misled when it is called a valve, worth repeating.

Post by **MadeInJapan** » 28 May 2016, 22:32

I agree it's just a hole, but it does get clogged. I've drilled mine out twice now. So, from the original post, what you did to it didn't ruin it unless you drilled another hole somehow.