2LTE Blowby (1 Viewer)

[N88]

Has anyone had experience with blowby on there engines?

The truck was consuming quite some oil so I fitted a catch can. Found that fills woth oil pretty quick....200ml with about 150km of driving.

Found quite a bit of excessive pressure from the oil cap cover and dipstick when removed which suggests blowby.

Compession test results.

#1 - 340
#2 - 360
#3 - 300
#4 - 370

 

[Dprio34]

@N88 , I think we all get it to some degree until we either rebuild or replace our CT20 Turbos.

 

[N88]

@N88 , I think we all get it to some degree until we either rebuild or replace our CT20 Turbos.

You think its more likely the turbo than the rings?

 

[Dprio34]

@N88 , I"d say 99.9% sure. So that's good new, right?

 

[N88]

@N88 , I"d say 99.9% sure. So that's good new, right?

Replacing a turbo is cheaper than a rebuild however the turbo seems like its in good condition with no play in the shaft.

 

[Dprio34]

I"ve owned other turbo diesels with Garrett Turbos, and they get blow by as well... but the way you described it, it does seem a bit excessive.
I think shaft play (from feel), may not be a good indicator. I think it would be hard to gauge from feel. The oil in my hoses seems to have diminished since I've intercooler it, but I still get it a bit. Nothing I can't live with until it gets worse.

 

[N88]

I"ve owned other turbo diesels with Garrett Turbos, and they get blow by as well... but the way you described it, it does seem a bit excessive.
I think shaft play (from feel), may not be a good indicator. I think it would be hard to gauge from feel. The oil in my hoses seems to have diminished since I've intercooler it, but I still get it a bit. Nothing I can't live with until it gets worse.

Had my turbo looked at by a turbo shop and they think it's allgood. Changed the rings and honed the cylinders by hope without having the cylinders bored. Still no luck. Problem still exists. Can't see how it can be the turbo seals if its got excessive blowby under no boost.

 

[Waikato Willy]

Im using around 4 litres of oil per 10,000ks now, my engine breathes pretty heavy but still goes good, is your catch can higher than the rocker cover?
mine is so it acts as a drain back , Im sure id fill a catch can up really quickly if it was level or below, especially after a long hill, it kinda reminds me of an old steam train

 

[N88]

Im using around 4 litres of oil per 10,000ks now, my engine breathes pretty heavy but still goes good, is your catch can higher than the rocker cover?
mine is so it acts as a drain back , Im sure id fill a catch can up really quickly if it was level or below, especially after a long hill, it kinda reminds me of an old steam train

Hey mate. Thanks for the reference. I'll move my can up higher and see what happens. At the moment its filling 200ml pretty quick.

 

[N88]

Hey mate. Thanks for the reference. I'll move my can up higher and see what happens. At the moment its filling 200ml pretty quick.

 

[Waikato Willy]

oh and my catch can vents straight down the diff, you can see where its all oily from the fumes, any kind of restriction will definitely make it fill the catch can up

 

[N88]

oh and my catch can vents straight down the diff, you can see where its all oily from the fumes, any kind of restriction will definitely make it fill the catch can up

So what have you done to the return pipe on the inlet? Capped it off?

 

[Waikato Willy]

ha ha ive actually jammed a sparkplug in it, its just vented into the rubber joiner on the front of the turbo, so yer i just blocked it up, I actually got rid of my catch can altogether and ran a rubber breather pipe from the rocker cover looped up the firewall then back down under the vehicle, looping it up lets the oil drain back into the rocker cover, worked better than my catch can that just seemed to be always full of oil and it was a messy bastard of a thing to clean out
Ill get a pic tonight of my hose routing

 

[N88]

ha ha ive actually jammed a sparkplug in it, its just vented into the rubber joiner on the front of the turbo, so yer i just blocked it up, I actually got rid of my catch can altogether and ran a rubber breather pipe from the rocker cover looped up the firewall then back down under the vehicle, looping it up lets the oil drain back into the rocker cover, worked better than my catch can that just seemed to be always full of oil and it was a messy bastard of a thing to clean out
Ill get a pic tonight of my hose routing

Sweet. It'll be good to see. Seems like this is a common problem with these engines

 

[Copydoc]

Had my turbo looked at by a turbo shop and they think it's allgood. Changed the rings and honed the cylinders by hope without having the cylinders bored. Still no luck. Problem still exists. Can't see how it can be the turbo seals if its got excessive blowby under no boost.

Curious as to what your compression was after you re-ringed your pistons. I know on mine if I disconnect the oil return from the turbo (for testing purposes only) it stops oil from coming out of turbo which actually has no seals to speak of, just oil slingers to keep oil away from output shafts which means excessive pressure from crankcase back up oil return hose. Also, if I remove oil cap and try the idle test by setting it upside down on it dances a lot, barely stays on. I have around 400 from cylinders 1 and 4 but barely over 200 on 2 and 3. I am trying first to see if I just have a stuck ring by soaking the cylinders with seafoam and then doing another oil change.

 

[N88]

Curious as to what your compression was after you re-ringed your pistons. I know on mine if I disconnect the oil return from the turbo (for testing purposes only) it stops oil from coming out of turbo which actually has no seals to speak of, just oil slingers to keep oil away from output shafts which means excessive pressure from crankcase back up oil return hose. Also, if I remove oil cap and try the idle test by setting it upside down on it dances a lot, barely stays on. I have around 400 from cylinders 1 and 4 but barely over 200 on 2 and 3. I am trying first to see if I just have a stuck ring by soaking the cylinders with seafoam and then doing another oil change.

Turned out to be a bit of a piss around, I ended up getting better compression (400) and the same over all cylinders after changing the rings and honing the liners. My main problem turned out to be the ceramic filter in the rocker cover. It was caked in carbonised oil and wasn't allowing the filter to catch the oil in the vapour therfore looking like it was another issue. Sad thing is I was all told it was excessive blowby by 3 different mechanics and that I should just rebuild the whole engine until one suggested looking at the ceramic filter which he wasn't sold on the idea at the time.

 

[Copydoc]

Turned out to be a bit of a piss around, I ended up getting better compression (400) and the same over all cylinders after changing the rings and honing the liners. My main problem turned out to be the ceramic filter in the rocker cover. It was caked in carbonised oil and wasn't allowing the filter to catch the oil in the vapour therfore looking like it was another issue. Sad thing is I was all told it was excessive blowby by 3 different mechanics and that I should just rebuild the whole engine until one suggested looking at the ceramic filter which he wasn't sold on the idea at the time.

I am going to check mine tomorrow, I did an EGR delete and discovered a heavy buildup at the throttle body and #2 and #3 glow plugs electrodes were bound up and those are the same two cylinders with low compression and I’ll find out this weekend when I do another compression test if my fix worked.