Volvo Penta 2003 oil leak/ fizzing from rocker cover studs

[Pickard Corsair]

Whilst sailing back from Conwy to Hightown this week and keeping the engine under frequent scrutiny for leaks ( following heat exchanger service and refit with slightly variable fresh water seal success) I noticed that the three stud bolts along the top of the rocker cover next to the injectors were "fizzing" with what I assume to be oil and air, not at great volumes or enough to deplete the engine of any serious amount of oil but still not great and slightly offsetting my water seal success satisfaction!

Will that just be the stud seals going or a sign of something more serious, can the stud seals be replaced by simply removing the studs and replacing the seals and bolting down again or does the rocker cover have to come off and disturb the main rocker cover gaskett?

Thanks in advance for any advice

Rohan

 

[VicS]

Just remove the screws (they are not studs, they appear to be set screws) one at a time and refit with new sealing washers.



BUT

I am wondering if you have an excessively high crankcase pressure causing the "fizzing"

Has the rocker cover gasket been fitted incorrectly?

 

[scottie]

Has head been off recently .

 

[Boater Sam]

Is there a crankcase breather that is blocked?

 

[Pickard Corsair]

Hi thanks for replies,. excessive pressure sounds likely now you mention it , there was some blow back from the oil dipstick and oil cap when I was checking oil levels underway, I have also been unable to get a good seal on new water pump at the back oil end which starts to drip when the engine has been running for a while (but I have seen others have had that problem separately).

Head has not been off for years.

I think I may have mis described the fizzing bolts, I attach a picture of the offending parts, if the breather is blocked where is it and is there a recommended unblocking process? Thanks in advance.

 

[VicS]

Hi thanks for replies,. excessive pressure sounds likely now you mention it , there was some blow back from the oil dipstick and oil cap when I was checking oil levels underway, I have also been unable to get a good seal on new water pump at the back oil end which starts to drip when the engine has been running for a while (but I have seen others have had that problem separately).
Head has not been off for years.
I think I may have mis described the fizzing bolts, I attach a picture of the offending parts, if the breather is blocked where is it and is there a recommended unblocking process? Thanks in advance.

Not rocker cover screws at all

You appear to be pointing in the direction of 3 of the cylinder head bolts. Is that correct ? ( there are 14 of them altogether but half are under the rocker cover)

Marked with a X in this picture

 

[scottie]

Very near the injectors which are a known place for leaking (or fizzing?) you could try nipping down the injector clamp bolts
drip at water pump may be connected although there are slots on the pump rather than just a telltale hole the can block up with crud
I would suggest checking oil for level rising and of contamination fro water out fuel

 

[Pickard Corsair]

Not rocker cover screws at all

You appear to be pointing in the direction of 3 of the cylinder head bolts. Is that correct ? ( there are 14 of them altogether but half are under the rocker cover)

Marked with a X in this picture

View attachment 125851

Yes my mis description, they are the cylinder head bolts shown above, I only observed the three next to the injectors leaking/' fizzing (I say fizzing as there appeared to be air bubbling with the oil), It definitely wasn't fuel from the injectors and the engine starts easily and sounds like it is running well.

 

[Pickard Corsair]

UPDATE just in case anyone else has this problem, I bought a new rocker cover seal and thoroughly cleaned out the built in breather hole (no separate pipe on the Volvo 2003) which seems to have cured the pressure issues/ symptoms.

 

[Bilgediver]

The first thing to check is if you have excessive blow by pressurising the crank case. This can be identified by removing the oil filler cap with the engine running and then seeing what flows out. If you hold your hand palm up over the filler with the cap off and engine running can you feel pulses? The fact that you are seeing problems at the dip stick suggests that you have excessive crankcase pressure.. If this pressure is not being released under normal conditions then the crank case breather would appear to be the problem. I have seen questions before regarding the location of the breather on these engine but not seen the answer. There maybe a crankcase breather strainer/filter that is blocked.

 

[Pickard Corsair]

The first thing to check is if you have excessive blow by pressurising the crank case. This can be identified by removing the oil filler cap with the engine running and then seeing what flows out. If you hold your hand palm up over the filler with the cap off and engine running can you feel pulses? The fact that you are seeing problems at the dip stick suggests that you have excessive crankcase pressure.. If this pressure is not being released under normal conditions then the crank case breather would appear to be the problem. I have seen questions before regarding the location of the breather on these engine but not seen the answer. There maybe a crankcase breather strainer/filter that is blocked.

Hi I did initially have what I believe to be high crank case pressure with excessive blow by from the oil filler and the dipstick that had not previously been present when I had checked or topped up the oil underway but having eventually found and cleaned out the breather arrangement on the the Volvo 2003 (no mention of it in the manual that I could find) and changing the rocker gasket at the same time (which has a hole for the built in breather) the pressure issues (or at least the observable ones in terms of blow by have totally resolved. I will get some pics up of the breather location for future reference.

Cheers

 

[Bilgediver]

Hi I did initially have what I believe to be high crank case pressure with excessive blow by from the oil filler and the dipstick that had not previously been present when I had checked or topped up the oil underway but having eventually found and cleaned out the breather arrangement on the the Volvo 2003 (no mention of it in the manual that I could find) and changing the rocker gasket at the same time (which has a hole for the built in breather) the pressure issues (or at least the observable ones in terms of blow by have totally resolved. I will get some pics up of the breather location for future reference.

Cheers

Thanks. I have heard about the hole near the rocker cover joint but not heard where it goes. Be interesting to hear what you found out.