Excessive blowby, help needed

[sammyecoboost]

Hey! Nice to have a forum for the ecoboost to ask questions like this and hoping to find a solution. Someone might have some experience on this issue.

Built 2L bored out to 2.3L
Cammed stg 3
Bigger turbo
CNC ported head.

I have a radium baffle plate, PCV catch can with 100 PSI check valve (although the PCV from radium can handle the boost without checkvalve) and a valve cover breather catch can.

What i noticed is that at high boost I get blow by from the valve cover breather. 1 WOT pull, gives an ounce of oil in the can!! :( BUT drive around city and highway and stay out of high boost, no issue. So at WOT i do like 29 psi and when i tested lower boost i stayed below 20 psi.

Engine builder says ""Never seen rings seal at low boost and not at high boost without their being another cause""

I did a leak downtest

cyl 1 > 12%
cyl 2 > 46%
cyl 3 > 16%
cyl 4 > 9%

On Cyl 2, it caused coolant tank to go up and some bubbles so that means head gasket caput and will be changing very soon. Waiting on parts.

I am thinking just Maaaaaaaaaaaaaaaaaaybe.... that is what is causing combustion gases to get into the crankcase? What are the chances of that? I did drop in a borescope and could see damage to the gasket but on the exhaust side. Oil passage is on the intake side. Who know, maybe it is seeping their too.

Cyl 3 leak ... could perhaps be from rings or between cyl 2/3 gasket too.

Assuming the gasket has nothing to do with blowby, I was thinking of taking advantage of the 2nd port on the radium baffle plate and add a checkvalve to open under boost and vent to atm with a can to reduce valve cover pressure under boost.... less blow by via breather. Or maybe i should try vented oil cap with check valve first? I used to have one then i ditched it thinking pointless. I think that is when my problem started, not 100% sure though.

The other option is to change oil rings while head is off and just pull the oil pan but also i don't want to fix what is not broken....

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[Matti777]

When you do a leak down test you should be able to tell where it is leaking to especially at high leakage rates ie crankcase (rings), exhaust (exhaust valves), cooling system (head gasket),

 

[sammyecoboost]

I could here it from PCV valve and oil filler cap. The thing is, hearing it at those locations is inevitable since you will always have leak past the rings.

3000 miles on engine

 

[Jaymar]

If your source of vacuum for the catch can is only vacuum at idle/part throttle and boost at WOT you may still be getting the blowby at WOT but the pressure is venting elsewhere as the path through the catch can is blocked or reduced by the manifold pressure.

I don't know if I'd trust the advice of the engine builder too heavily if he delivered the anchor to you that has that much blowby and a blown head gasket at 3000 miles.

 

[sammyecoboost]

I contacted JE Pistons, they agree with "Never seen rings seal at low boost and not at high boost without their being another cause"

 

[Jaymar]

I contacted JE Pistons, they agree with "Never seen rings seal at low boost and not at high boost without their being another cause"

Fair enough, and that would be strange albeit not impossible. But perhaps you are also getting blowby at low boost but it manifests differently. If your indication of blowby is at the breather your blowby at vacuum may be going through the PCV system and venting into the manifold via the catchcan while at high boost that avenue is cut off via boost sealing the check valve. If that is the case then you have two problems to fix, the biggest being the blowby but a smaller problem being the lack of functionality of the PCV system at high boost. I don't think the second is much of a problem though given that even the OEM system performs that way.

The other scenario is your check valve is in backwards and you are leaking manifold boost into your crankcase via the PCV and it is venting through the crankcase vent above the head and blocking oil return/sloshing it into the crankcase breather. Given your leakdown numbers though I think this is least likely.

 

[sammyecoboost]

Fair enough, and that would be strange albeit not impossible. But perhaps you are also getting blowby at low boost but it manifests differently. If your indication of blowby is at the breather your blowby at vacuum may be going through the PCV system and venting into the manifold via the catchcan while at high boost that avenue is cut off via boost sealing the check valve. If that is the case then you have two problems to fix, the biggest being the blowby but a smaller problem being the lack of functionality of the PCV system at high boost. I don't think the second is much of a problem though given that even the OEM system performs that way.

The other scenario is your check valve is in backwards and you are leaking manifold boost into your crankcase via the PCV and it is venting through the crankcase vent above the head and blocking oil return/sloshing it into the crankcase breather. Given your leakdown numbers though I think this is least likely.

The radium pcv valve is heavy duty, the more you try to pass boost the tighter it seals.. Not sure if you have seen one physically but with one of those a check valve is not needed really.

My PCV catch can catches almost nothing.

What i had tried when i was testing before finding the blown head gasket is that i removed the check valve and also detached from intake manifold and capped the intake manifold to prevent boost leak. I then drove around and had no oil in catch can and no oil in the bottle in which i put the hose end that exits the catch can.

I also did a WOT with boost.... got oil in breather catch can but nothing in the pcv can nor out the hose into the temporary bottle.

 

[Jaymar]

Disconnecting your PCV system only proves that the vent cap became the path of least resistance for your crankcase gasses, not surprising given that the system contains the condenser path of the PCV plate, the positive spring pressure of the PCV valve and the condenser element of the catchcan when it was connected. Given the leakdown rate and the gasses escaping into the coolant system I'd say your conclusion of a blown head gasket is very likely. As for the ring blow by, I'd say there isn't concrete evidence to know that for sure until you can do the leakdown test with a repaired head gasket but given the circumstantial evidence I'd say you would be warranted in stripping the pistons out for an inspection at the least while you have the top end off. Your crankcase pressure sounds excessive even by pre-PCV motor standards and I'd be concerned about the high likelihood that a motor that can blow a head gasket in 3000 miles may also have done damage to the pistons at the same time. You'll want to inspect the ring land for damage from the same excessive pressure events that could blow a head gasket.

 

[FreePenguin]

I think the engine builder messed up.

 

[sammyecoboost]

Disconnecting your PCV system only proves that the vent cap became the path of least resistance for your crankcase gasses, not surprising given that the system contains the condenser path of the PCV plate, the positive spring pressure of the PCV valve and the condenser element of the catchcan when it was connected. Given the leakdown rate and the gasses escaping into the coolant system I'd say your conclusion of a blown head gasket is very likely. As for the ring blow by, I'd say there isn't concrete evidence to know that for sure until you can do the leakdown test with a repaired head gasket but given the circumstantial evidence I'd say you would be warranted in stripping the pistons out for an inspection at the least while you have the top end off. Your crankcase pressure sounds excessive even by pre-PCV motor standards and I'd be concerned about the high likelihood that a motor that can blow a head gasket in 3000 miles may also have done damage to the pistons at the same time. You'll want to inspect the ring land for damage from the same excessive pressure events that could blow a head gasket.

You think the tune could have caused this ?

 

[FreePenguin]

You think the tune could have caused this ?

Tunes blow shit up. Too much this to little that. Timings not right etc

 

[Jaymar]

You think the tune could have caused this ?

Not enough information to conclusively blame a tune but there is something drastically wrong that won't be fixed by replacing the defective parts. 3000 mile motors don't blow headgaskets plus whatever else you may find when you get in there, that takes something big going very wrong. My first suspicion would be a detonation given that level of damage but that isn't assured, you'll have to start by doing some investigation when you tear it down.

 

[sammyecoboost]

On my build my tune has been ongoing for a dam year :(!

About 2 weeks between each revision sometimes a bit more. Then i had downtime as i waited on some parts before resuming tune. then parts then resume.

We ran into an issue since early on in which i would have an annoying hesitation at part throttle and tuner would change strategies to counter it. Not sure if any of those might have affected it plus the fact that i drive 2 weeks on a tune while i wait for a revision not knowing if their was an issue. (nothing noticeable other than part throttle hesitation) It would improve and then come back.

Have had contact with others that got it sorted by going to another tuner that does not use COBB AP so it is believed that the way COBB AP writes the data is what was causing the issue. Didn't get a chance since i have a blown gasket now. (I believe it is early stage)

I have aux fuel rail so not sure what to check exactly that caused the issue if it was not tune related.

Tuner has me at 27 PSI on 91 oct

 

[Scootsmcgreggor]

Damn that’s a lot of boost for 91.

 

[FreePenguin]

Damn that’s a lot of boost for 91.

my thoughts as well. 93 would be safer for pre detonation right?

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