Blue Smoke - KV6
 

Hallo everybody!

i got a problem with my kv6, it started six months ago.
While accelerating i saw a big blue smoke cloud coming out of my exhaust.
Fun fact is that this just happend from time to time. Only about once per month, and i am driving around 1000km per month.
Now it happens more often.

I checked the PCV System and found a lot of oil sitting in the inlet/throttle.

I already searched in the forum. It seems that i dont have the known problem of a blocked PCV as i am getting a lot of oil through the system.

What would you suggest me to do?

Will an oil catcher solve the topic?
I dont think that it is normal to have that much oil in the PCV.
I checked my oil level like the forum explained it. It is more around "low" than to high.

As a next step i would check my compression. Perhaps i have a lot of blowby.

I am thankful for any advise or idea!:bowdown::shrug:

Have a nice day! :}

Have you checked the breathers in the cam covers? These are prone to blocking up and may cause pressurisation of the crankcase, forcing oil past the valve stem oil seals.

Thanks for the idea!
I used airpressure to blow throw the hole in the covers. For sure they are not completly blocked.
I cleaned the throttle area and will check again this week. If there is again a lot of oil then the breather system should work i guess.
But should be a good idea to clean the whole system.
And: I did only check the front cam cover. Perhaps the back one is blocked. But as far as i understand the system the overpressure should be "one" and not divided in front and back... :shrug:

All KV6s suffer from this Benni. The wire mesh filters in the camshaft covers don’t work properly. The oil is supposed to condense on them and remain in the head. Instead it is sucked into the throttle body where some trickles down the gradient into the air filter rubber outlet hose and some is sucked into the manifold chamber where it can interfere with the VIS actuators over time. This doesn’t normally result in blue smoke from the exhaust. You may have a damaged valve stem oil seal. Have you looked at all the sparking plugs for evidence of a less than perfect mixture?

Simon

As you have said , check your compressions . If nothing else , it will eliminate something ! How many miles has the engine done ?

Hi!

The engine has around 108.000 miles (175.000km).

I always thought that damaged valve stem oil seals are more a problem with high revving.
But sometimes the problem occurs right after cold engine start with idle rpm.
Then just one big smoke cloud comes out of the exhaust and not much more.

But at the moment my exhaust gas smells a little bit like burned oil without permanent heavy blue clouds...

This is vital evidence, thank you. It definitely points to a strong possibility that it’s a valve stem oil seal. What happens is that oil slowly seeps past the seal into the combustion chamber and is then burnt when the engine is started, producing the instantaneous blue cloud which you have seen. I experienced this years ago with a Mini which had been fitted with a poorly modified cylinder head.

Simon

The A series engines is a number of generations before the K engines were even thought about, materials and engineering have evolved so much over this time, therefore the A cannot be compared. To date I have never came across a Kseries or KV6 with damaged valve stem seals, and hence I believe unlikely in this case. The only reasons I have came across burning oil on the K engines is either broken/damaged/worn piston rings or liners, including gummed up piston rings due to neglect with fuels/oils or sometime overheated due to coolant leaks.

If the OP eliminates the well known breather issues on the KV6, and still has issues they should proceed with a leakdown or compression test, failing this a teardown of the top end will reveal all usually.

Thank you so far for all the input!
I will check the intake again next week and will do a compression test.
After that i will post again.

Have a nice week!

ElHocko , I would be interested to know how you got on with this ?
Out of the blue , so to speak , my kv6 car has started to do this :eek:
First sign was this Tuesday evening , then twice more including today . In each case it is a cloud of blue smoke from a cold start and then no more problem whilst running . Negligible (zero ) oil consumption and on the MOT last week emissions were excellent , and no sign of smoke when starting whilst still warm.
My own thoughts were initially worn valve stem oil seals , but this is not reported on the kv6 , and I don't see that this would happen so suddenly if that were the cause :shrug: The suddenness seems to suggest breakage rather than wear ?
As suggested , I will be following the routes of compression test and breather clean-out in the near future , plus a spark plug inspection ( oh , how I hate those back 3 plugs ! )
My car is a kv6 , 2001 reg with 113k miles on it , and is running beautifully otherwise .