Pcv Valve

rattler1968 · May 31, 2015

Does any one know where it is? On a is220d 2009 ? Is it easy to replace?

steve2006 · May 31, 2015

They're normally located on the valve cover.

rattler1968 · May 31, 2015

Hi Steve , yes there is a pipe coming off the top going into the air intake , but there is no valve in there?? Have looked all around the web , its mentioned .. But its not clear where it actually is ...

Jules PF · February 5, 2016

The diesel doesn't have a pcv, it has an egr valve. The is250 has a pcv valve have just cleaned mine whilst I wait for a replacement. Lexus and Toyota charge £27 for this part in the UK. I ordered it from the states for a mere $5......shipping of £9 !!

jackcramerr · March 2, 2016

What symptoms lead to.cleaning / replacing of the PCV valve ?

normski2 · March 2, 2016

Might be wrong ... but I think it can relate to a somewhat smokey exhaust on the 250. Not hugely smokey but just a bit more than usual.

Verbout · March 2, 2016

On 5 February 2016 at 3:14 AM, Jules PF said:

The diesel doesn't have a pcv, it has an egr valve. The is250 has a pcv valve have just cleaned mine whilst I wait for a replacement. Lexus and Toyota charge £27 for this part in the UK. I ordered it from the states for a mere $5......shipping of £9 !!

Are you saying all diesels don't have a PCV? Or just Lexus? Because other makes of diesel definitely have them.

rattler1968 · March 2, 2016

7 hours ago, jackcramerr said:

What symptoms lead to.cleaning / replacing of the PCV valve ?

Well having the usual problems, smoking exhaust .. Cleaned the ERG, which does calm it down , use additives for pdf ... And thought if it was easy to replace , would do the valve? There is a lot of pressure out the top of the engine? Is this normal?

jackcramerr · March 2, 2016

rattler

what do you mean by pressure and from where exactly ?

rattler1968 · March 2, 2016

39 minutes ago, jackcramerr said:

rattler

what do you mean by pressure and from where exactly ?

Take the oil fill top off and it blows? A lot of pressure ...

jackcramerr · March 2, 2016

That's funny. I am diagnosing the exact issue on another car and have been thinking of PCV valve as culprit.

In my case I have to take the intake manifold off and many other parts to get access to it.

Any oil consumption you have there ?

If there is a pipe coming off from the crank case area and terminating just before the throttle body, that's the PCV pipe. Disconnect the PCV pipe and see if it is blowing air out at idle. If not replace the PCV without a second thought.

Out of curiosity what oil did you use last time ? The exact spec of it? And how many miles ha's the car done ?

rattler1968 · March 2, 2016

2 minutes ago, jackcramerr said:

That's funny. I am diagnosing the exact issue on another car and have been thinking of PCV valve as culprit.

In my case I have to take the intake manifold off and many other parts to get access to it.

Any oil consumption you have there ?

If there is a pipe coming off from the crank case area and terminating just before the throttle body, that's the PCV pipe. Disconnect the PCV pipe and see if it is blowing air out at idle. If not replace the PCV without a second thought.

Out of curiosity what oil did you use last time ? The exact spec of it? And how many miles ha's the car done ?

No oil consumption .. The car has done over a hundred thousand , as for the oil type I can't be sure , I had serviced by a garage , and I have looked everywhere to find the valve , but nothing .. The car has no warning lights up, and when it first started to smoke, had it wired up , and it showed nothing, just had a MOT , and it flew through the emissions test.. But still smokes ..

jackcramerr · March 2, 2016

What color is the smoke and any smell to it ? Are you sure it's not condensation.

I can say blowing air out of the cap doesn't sound right and that's the reason I am looking into it.

My theory is that instead of air circulating through the PCV, PCV being blocked, it's forcing it's way out from the cap. Can't prove it yet though.

Also the blow by is due to gap between the piston so worn out rings is also a possibility. Hence I am to do a compression test as well.

I will be surprised if there isn't a PCV or eqvalent system. But could be they have designed the system differently. Theoretically every car will have some blow by and to reduce emissions it really circulated.

The reason I asked about oil is, lower viscosity oil can result in blow by. And in oil.consumption.

rattler1968 · March 2, 2016

4 minutes ago, jackcramerr said:

What color is the smoke and any smell to it ? Are you sure it's not condensation.

I can say blowing air out of the cap doesn't sound right and that's the reason I am looking into it.

My theory is that instead of air circulating through the PCV, PCV being blocked, it's forcing it's way out from the cap. Can't prove it yet though.

Also the blow by is due to gap between the piston so worn out rings is also a possibility. Hence I am to do a compression test as well.

I will be surprised if there isn't a PCV or eqvalent system. But could be they have designed the system differently. Theoretically every car will have some blow by and to reduce emissions it really circulated.

The reason I asked about oil is, lower viscosity oil can result in blow by. And in oil.consumption.

No it's not condensation, it does have a blue tint to the smoke? But I have had the car almost 2 yrs , never topped up the oil,or the water, it smokes just as the ERG valve opens, the temperature gauge hits a cleaner of the way round , sometimes you cant even see behind you? And yes it does smell , like fuel ,sweet , smell? Like I said , I do clean the ERG , and use additives to clean ,unblock, the dfp ? Filter in the exhaust . that does stop it , for a while , but it returns every 2000 miles ..

I do , do only short trips ..... ? Apart from this smoke problem ... The car is great

The air isn't as actually blowing out from the cap , just when u take it off ... The reason I thought it could be a problem, a friend had Volvo, that had problems with his valve, his engine should have zero pressure coming from it? Though other cars do ...... A new Honda I looked at could blow up a bouncy castle !!

rattler1968 · March 2, 2016

Just now, rattler1968 said:

No it's not condensation, it does have a blue tint to the smoke? But I have had the car almost 2 yrs , never topped up the oil,or the water, it smokes just as the ERG valve opens, the temperature gauge hits a cleaner of the way round , sometimes you cant even see behind you? And yes it does smell , like fuel ,sweet , smell? Like I said , I do clean the ERG , and use additives to clean ,unblock, the dfp ? Filter in the exhaust . that does stop it , for a while , but it returns every 2000 miles ..

I do , do only short trips ..... ? Apart from this smoke problem ... The car is great

The air isn't as actually blowing out from the cap , just when u take it off ... The reason I thought it could be a problem, a friend had Volvo, that had problems with his valve, his engine should have zero pressure coming from it? Though other cars do ...... A new Honda I looked at could blow up a bouncy castle !!

Sorry that should of said "temperature gauge a quarter of the way round"

jackcramerr · March 2, 2016

make a video of it. . Might be rich diesel. I wouldn't worry about it if it is not consuming oil. But can someone here confirm there is no airbeing blown out of the oil cap when idle? I know is250 doesn't.

jackcramerr · March 3, 2016

talked to.a few people. They suggested drain the oil.and use the correct spec oil. it will.free up the pcv and make it work again...

rattler1968 · March 4, 2016

11 hours ago, jackcramerr said:

talked to.a few people. They suggested drain the oil.and use the correct spec oil. it will.free up the pcv and make it work again...

Ok cheers , thanks for your help

jackcramerr · March 26, 2016

An update. I did compression test. it looked ok. So I went ahead and strip down half the car to get to PCV valve... strip injectors, throttle body, intake manifold, brake lines and lots of connectors.

Only to find PCV is in perfect working order. To be honest looking at it, I doubt it ever needs replacing. Had to replace a lot of seals as I went so not cheap job. Takes a lot of time.

While I was there, I replaced the PCV anyway. The oil fill cap is still a bouncy castle so I now thing this is how it is...

Jules PF · March 26, 2016

After replacing my PCV now covered 1,600 miles and have lost 250ml approx of oil, the dipstick has gone from full to 3/4 marker. previously I was losing a minimum of 750ml per 1,000 miles. I have no doubt the change to a low noak oil has helped. However the difference was most noticeably be seen from the exhaust, or rather lack of plumes of smoke. I actually did this before I changed the oil and it was very clear the pcv was the main culprit. Its a cheap part, no loss in simply changing it.

Jules PF · March 26, 2016

On 3/3/2016 at 7:31 PM, jackcramerr said:

talked to.a few people. They suggested drain the oil.and use the correct spec oil. it will.free up the pcv and make it work again...

As discussed use a good top end cleaner, several times if necessary. Then oil flush, change or clean pcv (carb cleaner), drain oil, refill with Mobil 1 esp.

jackcramerr · March 26, 2016

In some cases it might help someone but in my case the PCV is perfectly working. I will sell the one I removed on eBay. Before PCV I had top up with C3 oil. I hadnt seen any oil loss since then. So in my case it is the oil. It was eating A5 oil. Checked on Castrol website and the recomendation was C3. So I guess wrong oil. Checking the sepcs, A5 is has much lower viscosity and C3 has much higher.

But I didnt replace PCV due to oil. I never saw any smoke and no smell. And after compression test I was confident engine is solid. I did it for bouncy castle.

madasahatter · March 26, 2016

On Vw group cars when the pcv is on the way out, revs rise upto 2000 rpm when stood still and go down. It does not affect running as such just the looks

from passers by. They normally rattle if you take them off, and are made of plastic.