Blown head gasket and still run good?????

[Amelio]

Well I had an ignition issue and a smoking issue with the car...the ignition problem is fixed and now I am tracking a smoking problem.

Here is the deal The engine is new maybe 1k or just over miles, I noticed the car starting to smoke at idle and it has progressively gotten worse. I checked and made sure it was not the turbo (which is brand new) and it is not. I then pulled the rocker covers and found that all the valve stem seals were off the guides and at the top of the valves. I also had an oil residue build up on cylinder #6 and a tiny bit on #4. I replaced the valve stem seals and plugs...

The car runs real good and will only smoke at idle....it does not smoke when revving and from as best as I can tell it does not smoke when getting on the throttle.

A few weeks back I had a boosting problem which the car saw 26-28 psi a few time on 93oct....I noticed the smoking shortly after that.

I have done a compression test and all cyl were about 180psi except #6 was about 160psi.

Is it possible to have hurt a head gasket and the car still run real good but let oil in at idle?????

 

[Amelio]

with these cars and blown head gaskets I thought I may get some kind of response....LMAO:biggrin:

 

[84BuickGNYorkPA]

Well at 26-28 psi on 93 octane fuel, I'm sure you had major knock. But with the compression comming back ok.... gaskets, rings must be decent, maybe you got lucky on the overboost. How does the pcv line look? If you take off the vaccuum block, should be able to see if the pcv line is spewing oil into the intake. And what did you do to keep your valve seals on this time? Maybe they came back off?
Good Luck,

Chuck

 

[RmvBfrFlght]

The car runs real good and will only smoke at idle....it does not smoke when revving and from as best as I can tell it does not smoke when getting on the throttle.

If I had to guess, which is all I can do from where I am sitting, I'd venture that you broke some rings. At boost the 2-3 piece rings still get pushed out against the bores for a tight seal.

But at idle with no real pressure behind them they let the oil past.

RemoveBeforeFlight

 

[JDSfastGN]

I didn't have smoking but recently had a tapping that i thought was a lifter. After pulling the intake it was a blown headgasket and the tapping was a tiny bit of compression going into the valley. I had driven the car hundreds of miles for a couple weeks before that (the tapping was faint) and even that day had seen 26 psi and speeds up to 120+ with no signs of a blown headgasket. The firing rings were still intact but the graphite part of the gasket was blown away. So yes its not always a milkshake and may not show obvious signs.

 

[Amelio]

Well at 26-28 psi on 93 octane fuel, I'm sure you had major knock. But with the compression comming back ok.... gaskets, rings must be decent, maybe you got lucky on the overboost. How does the pcv line look? If you take off the vaccuum block, should be able to see if the pcv line is spewing oil into the intake. And what did you do to keep your valve seals on this time? Maybe they came back off?
Good Luck,

Chuck

I have the PCV blocked off and breathes on both valve covers so I know it is not pulling from there. I did not do anything different to the valve seals this time and when I was putting on the new ones they seemed to go on the valve guides easier than I would think.....I have been thinking of ways to make them a tighter fit but have not come up with anything yet. I need to pull the valve cover back off and see if they are stil on the guides or if they came off.

 

[Amelio]

I didn't have smoking but recently had a tapping that i thought was a lifter. After pulling the intake it was a blown headgasket and the tapping was a tiny bit of compression going into the valley. I had driven the car hundreds of miles for a couple weeks before that (the tapping was faint) and even that day had seen 26 psi and speeds up to 120+ with no signs of a blown headgasket. The firing rings were still intact but the graphite part of the gasket was blown away. So yes its not always a milkshake and may not show obvious signs.

Ok thanks that is exactly what I was looking for....I curious to know if I could have a slightly blown head gasket that held the water and compression but would allow a little oil in the cylinder. As I said the car runs real good and there are no typical signs of a head gasket....I have new plugs in it so I am going to drive it for a few miles to see if the plugs will point me to the correct cylinder. If it points back to number 6 then it may be the gasket.

I will also pull the plenum and look in the intake for signs of oil.

Thanks again guys....sometimes when you hammer on these cars for a while you need some ides to check the simple stuff cause you get flustered.

I will post my findings

 

[Procharge]

some signs of a blown head gasket is water vapors coming thru the exhaust