Removing PCT Valve and Cleaning [1997 Volvo GLT Turbo]

Post by **1997volvo850** » 03 Apr 2010, 17:34

There are dozens of topics and posts that come up when you type PCT cleaning. Most posts are
asking for help. I've read the nice tutorial on replacing the PCV system and when it gets to the
PCT valve it says to remove and clean it. I guess this is so obvious that I shouldn't have to ask
but my mechanic's Hippocratic oath is to do no more damage than I need to in order to complete
a task.

The original symptoms that led me here were smoke coming out my oil dipstick and white smoke in
the exhaust. Oil disappears from my car but I'm not sure where it's going. I suspect a clogged PCV
system is sending it everywhere. Never find it on the garage floor.

So the task is to remove, clean the PCT valve, and reinstall it. If there is a tutorial "Volvo 850 PCT for Dummies"
please direct me to it. I working on a 1997 Volvo GLT Low-Pressure Turbo. I've read the lakeside tutorial and will
use it shortly to replace my PCV system.

So here are two pictures of what I'm dealing with:

: This is a wide angle view looking down on the air intake where the PCT valve is.

Here's a close up of the PCT / Air Intake connection. I noted that there is a lot of oil around this connection.

: This is the actual location where the PCT attaches to the air intake. There is a hose in the foreground that I believe is not associated with the PCT valve.

1) Removal

My understanding is that I need to first disconnect the hose (to the right on the PCT valve) and then disconnect
the connector (with a wire on the connection to the left). There does not appear to be a clamp on the hose so I guess
this just comes off when I pull hard enough. The other I suppose I need to hire someone with small enough hands to
disconnect the wire connector (is this for the heater component),

Do folks normally remove this leaving the air intake in place? Do you normally remove other stuff to clear space?

Please correct any misstatements above.

2) Cleaning

In one post they talked about a vinegar / lemon / degreasing solution. is there some magical spray that will dissolve
all of this coagulated oil?

3) Re-installation

Looks tricky to do this in place. But looks like real men can get their hands into tough places.

Any help is appreciated. One more question: How long does a PCV system replacement last? Mine was done at 150K.
I now have ~230K. Is it safe to suspect the PCV system at 80K?

Any ideas on how to keep this PCV system from clogging?

If they can design a self-cleaning oven for my wife I sure bet they could design a self-cleaning PCV system for my
Volvo 850. It's only fair.

Does the oil separator fill up first? Is this what starts the downward slide towards PCV system replacement? Why put
the oil separator in such a terrible location?

What would happen if you added a valve to the hose that goes to the PCT valve and periodically sprayed carb cleaner
into it while the engine was running? Would this result in a clean PCT valve and a seized engine? Seems like Volvo wasn't
expecting me to keep my car for 230K. Or they were thinking more about the dealer than the customer. Not sure which.

Thanks

3)

wjhandy850 · Post by **wjhandy850** » 03 Apr 2010, 23:05

I ran across the PCV/PCT issue the hard way. I was spewing oil for sometime, and never could figure out where it was coming from. I didn't pursue it quick enough. I did replaced the separator hoses cleaned PTC, but never really saw it reduce the oil leak all the way, but it did calm down quite a bit. Then, I blew the head gasket. I don't know if it was related, but I don't know. I got a rebuilt head put on, and the smoking dipstick and a smell of oil was happening from the start. In the meantime I had become more aware of the issue with the PCV and cleaned out the PTC, which wasn’t completely block, but the opening was restricted. I used a pipecleaner, which I dipped into seafoam. It really worked great at breaking down the gunk, which brake cleaner didn't. I haven't completely gotten rid of the oil leak, but figured out where it was coming from. It is the cam seals, either because of pressure, or not being installed correctly. It may also be because of the low-pressure turbo, and its near constant boost. I plan to replace those seals soon. The oil leak, and use is very low. I can tell the PCV is being worked by the similar appearance of my PTC to yours. I may end up replacing that hose. I also pour Seafoam down the hose connecting head to separator at oil changes with the oil being drained on a warm engine. This has kept my dipstick from smoking.

Post by **tailor** » 03 Apr 2010, 23:32

The original symptoms that led me here were smoke coming out my oil dipstick and white smoke in
the exhaust.

White smoke may be head gasket, or just condensation at start up. Smoke at the dipstick , usually a sign of Pcv replacement is needed.
I working on a 1997 Volvo GLT Low-Pressure Turbo. I've read the lakeside tutorial and will
use it shortly to replace my PCV system.
This is the best that I have seen, it will make it things much easier.

1) Removal
My understanding is that I need to first disconnect the hose (to the right on the PCT valve) and then disconnect
the connector (with a wire on the connection to the left).
Correct!
There does not appear to be a clamp on the hose so I guess this just comes off when I pull hard enough.
Wrong assessment, there are clamps, 2 of them, make sure you find them, they are likely covered in gunk.
The use of a hair dryer or heat gun to aid seating or removal is a valuable tool ,that is if the temps outside are frigid.

The other I suppose I need to hire someone with small enough hands to disconnect the wire connector (is this for the heater component),
Short stubby fingers will do!

Do folks normally remove this leaving the air intake in place?
It can be left]
Do you normally remove other stuff to clear space?
Yes , airbox , battery

2) Cleaning
In one post they talked about a vinegar / lemon / degreasing solution. is there some magical spray that will dissolve
all of this coagulated oil?
Some have used petrol, carb cleaner, try not saturate the electrical connection.

3) Re-installation
Looks tricky to do this in place. But looks like real men can get their hands into tough places.
Remove the turbo hose.

Any help is appreciated. One more question: How long does a PCV system replacement last? Mine was done at 150K.
I now have ~230K. Is it safe to suspect the PCV system at 80K?

Some say every 4 years, it will vary from driver to driver, most of the build up is from short hops..
Any ideas on how to keep this PCV system from clogging?
Keep oil changes regular. It is a semi regular service item.

If they can design a self-cleaning oven for my wife I sure bet they could design a self-cleaning PCV system for my
Volvo 850. It's only fair.
Its you!

Does the oil separator fill up first? Is this what starts the downward slide towards PCV system replacement? Why put
the oil separator in such a terrible location?
It is more the build up of gunk in the pipes than a filling up of the separator

What would happen if you added a valve to the hose that goes to the PCT valve and periodically sprayed carb cleaner
into it while the engine was running? Would this result in a clean PCT valve and a seized engine? Seems like Volvo wasn't
expecting me to keep my car for 230K. Or they were thinking more about the dealer than the customer. Not sure which.

I do not like the above suggestion, you may just kill the engine.

In the pictures below, the PTC has come out with ease due to the rubber seal deteriorating so much that unmetered air was getting into the system and giving me error codes. Not a good idea to remove the PTC in this fashion
The second picture is the turbo hose, sans PTC, but with the clamp attached, the third shows the top and side hole and the electrical connection.

: Ptc.jpg (65.75 KiB) Viewed 9731 times

: turbohosesansptc.jpg (75.53 KiB) Viewed 9731 times

: Ptctopview.jpg (129.2 KiB) Viewed 9731 times

Post by **1997volvo850** » 04 Apr 2010, 19:12

Houston we have a problem...

I managed to get the PCT off. Actually the entire thing came off the air intake hose. It looks
like the PCT should come out without the mount to the air intake hose.

The rubber seal has deteriorated on my unit. Do I need to replace the seal? I haven't seen then for
sale but given the deterioration I would expect someone must sell them.

: Surprised at how much oil is all over the PCT valve and everything around the point where it connects to the air intake.

The bottom opening is almost completely clogged with oil sludge. I guess this means my PCV system
is not doing a heck of a lot with the PCT in this condition.

: The bottom of the PCT looks clogged up pretty good.

I tried to get a good shot of the large tube at the top. There are very hard deposits on the inside of this
tube.

: The PCT right after removal. The large tube at top has significant deposits.

Started cleaning the PCT and an amazing amount of oil deposits material is coming off. Haven't completed cleaning
the hard deposits out of the larger tube. Need to get a better tool, like a test tube cleaning brush, to really to at this.

More after I finish cleaning and reinstall the PCT valve.

wjhandy850 · Post by **wjhandy850** » 04 Apr 2010, 19:25

Try Seafoam, it wll dissolve the hard stuff.

Post by **tailor** » 04 Apr 2010, 19:29

Do not bother cleaning it, you need a new turbo hose ! There are no replacement rubbers. Fcp or Darrel Trip or any other parts suppliers will have it. Ask for extra caps for the new Turbo hose as you may have extra nipples (newer version)that need to be closed.

whoa · Post by **whoa** » 04 Apr 2010, 20:49

http://volvospeed.com/vs_forum/index.ph ... take-pipe/

Post by **1997volvo850** » 05 Apr 2010, 22:31

First an update and then I will respond to recent posts in the next message.

I cleaned the PCT valve. A small toothbrush works pretty well. Used a combination of degreasers
and sea foam to clean off a lot of the oil deposits. I suspect the deposits may be due to the valve's
function of heating the gas coming from the oil separator.

There were no hose clamps on either of the two hoses going to PCT on my 1997 Volvo 850 GTL. Someone
mentioned there would be clamps. The hoses do not appear as though a clamp had ever been there. Is it
the case that the intake hose has a vacuum such that the tendency is to pull the hoses instead of blow them off?

Here are a few pictures:

: You are now able to see through the cleaned
valve passage.

Note the clear passage:

: Cleaned up quite nicely. Some deterioration
in lower seal but most of it still intact.

The PCT valve was in reasonable shape so I decided to use it instead of purchase a new hose. I discuss my thoughts
on whether a new hose is needed in the next post. The downward pressure applied from the two hose coming from
the oil separator also convinced me that this downward pressure would help keep the valve in place.

I reattached the three hoses to the PCT, a few hoses on the air intake, and plugged in the MAF connector.

I started my car and less smoke appeared to be coming from the dip stick. Actually I didn't notice any smoke until maybe
10 minutes of idling. There is less white smoke coming from the tail pipe but then the temperature is 20-30 warmer from the
last time I checked. I will check again during the morning.

It is my understanding that any smoke coming from the dip stick indicates the PCV system needs servicing. I have the PCV
system kit from FCP Groton. I may wait for the new writeup that jablackburn is working on. His pain is my gain I guess.

The white smoke from the tail pipe indicates what? Some have said this is a problem with the head gasket and others
have said this white smoke is due to the PCV system. One video shows white smoke coming out the tail pipe before the
PCV job and none after the job. I'm hoping it is PCV related.

How much are we talking to repair a "blown" head gasket, if this is what it is? Is the goop you pour in the oil/radiator effective
in plugging the leak? I'll have to find a good topic on head gaskets.

Post by **jblackburn** » 05 Apr 2010, 22:39

There were no hose clamps on either of the two hoses going to PCT on my 1997 Volvo 850 GTL. Someone
mentioned there would be clamps. The hoses do not appear as though a clamp had ever been there. Is it
the case that the intake hose has a vacuum such that the tendency is to pull the hoses instead of blow them off?

No clamps on this end; the other end of the hoses almost certainly need clamping, as the darn things pull off and are darn near impossible to get back. There is one clamp on the plastic end of the hose itself holding it to the turbo.

I'll add this to the write-up, you've actually got good pictures of it that I'll probably end up stealing (with your consent of course

). My hands were covered in grease and my camera died around this time

I'm starting it as we speak, but it may be a few more days before I've got the whole thing done.

The white smoke from the tail pipe indicates what? Some have said this is a problem with the head gasket and others
have said this white smoke is due to the PCV system. One video shows white smoke coming out the tail pipe before the
PCV job and none after the job. I'm hoping it is PCV related.

If you're not losing any coolant from the reservoir, you do not have a head gasket problem. My PCV blew blue smoke at startup after my car sat for a couple days, but that could just be old turbo seals too, I'm not sure. There's a couple good topics on head gaskets out there, just do a couple searches.

Hopefully, though, I'll mention the 2 bolts that will prevent you from doing this and feeling stupid when you realize there's a virtually invisible bolt you missed underneath the manifold still holding it in (though it did make for a funny picture)

Post by **1997volvo850** » 05 Apr 2010, 23:13

Here is my take on whether a new hose is needed. I also have some questions that might be good for
any PCV / PCT tutorial to cover.

First: New hose.

A new hose it $89. I believe most of this cost is due to the fact that the air intake hose includes the
PCT valve. I don't see the PCT valve sold separately (why) nor do I see the rubber seal that deteriorates
available. Someone posted a link with a hose (without PCT valve) and someone else said I needed to replace
the hose (implying the PCT valve could not be salvaged.

My air intake hose is perfectly fine. Therefore I am resistant to buying a new one because the rubber seal
on the PCT has started to deteriorate. If someone buys one for this job please take pictures demonstrating how
to get the PCT valve out for cleaning without removing the PCT mount. I'm assuming you are supposed to be
able to remove this and clean it without having to buy a new air intake hose. I may eventually need a new hose
but I'll put on my MacGyver hat before I shell out $89 for a new air intake hose.

What types of sealing material will hold up under these high temperatures? The upper portion of my PCT rubber
seal is perfectly fine. If I could remove the air intake (which I wasn't able to do using reasonable force) then I would
seat the PCT valve on the air intake hose and seal it in place. What has the consistency of silicone but will hold up
in this application? I'm assuming silicone won't work.

If a more secure mechanism is necessary it doesn't look difficult to build a custom PCT clamp using two hose clamps
and something to hold the PCT in place.

If my PCT valve falls off I will try one of these first. It is my understanding that the PCT valve is vary reliable. It's
just the hose companies who design the rubber seal to disintegrate so people have to buy hoses.

: Air Intake Hose $89 - Looks a bit redesigned
compared to the host in my 850.; AirIntakeHose.jpg (73.98 KiB) Viewed 9665 times

Two: Issues/Questions

Whoever writes a tutorial will hopefully address some of these issues and answer some of these questions.

It sounds like a neglected PCV system can cause MAJOR damage to our 850's, oil leaks, seal failures, head gasket
failures. Are there others? The PCV system failure sounds nearly as lethal as a timing belt going.

My 1997 Volvo 850 manual ONLY talks about cleaning the PCT valve every 60,000 miles. It never mentions anything
about the PCV system needing to be replaced. Maybe Volvo didn't realize how poorly designed the system was when they
put it in my 850. Or maybe Volvo dealers got together and actually designed it this way on purpose.

So, for a timing belt, you replace it every 70K miles. Is there a similar schedule replacement for the PCV system?
Replace every XXK miles? What is your experience? What would you DIY recommend as the schedule replacement
period for the PCV system?

Does the demise of the PCV system depend on cleaning the PCT valve? Someone else mentioned frequent oil changes
helping keep the PCV system clean. I suppose old oil tends to become a gas more easily and clogs the PCV system.

Is there a case where the PCV system does not need to be replaced? Or is it inevitable?

I guess my last question is why not clean instead of replace everything?

Most people here buy the kit and replace everything. But the main problem seems to be clogs at certain
points (from pictures I've seen) like the lower block ports and the PCT valve.

Is the main factor that the parts are $100 and the labor is worth $700? Just wondering.

Enough for tonight. I hope jablackburn is working hard on answering these questions as he write his
new PCV system tutorial.

More to come...I'll dump it all in this thread for now.