# Oil blowing out of the dipstick



## mikelly2 (Nov 24, 2018)

I sure could sure use some advice.

I have the 400 ci engine in my ’68 GTO and I’m having an issue with oil blowing out through the dipstick. The car was a well started basket case project when I acquired it 20+ years ago. The engine was already installed so I don’t know much about it except that it runs strong. Since then I’ve put a lot of miles on it so I kinda thought my problem was blow by from worn rings. I just pulled the plugs and they were all cocoa brown with no sign of oil. I did a compression check and I’ve got 175-180 all around.

It really only does it when I get on it hard but it has covered the passenger side of the engine compartment with oil. I first noticed the problem a little while after I took it to a local lube and tune for an oil change. Thinking they had perhaps over filled it I pulled the dipstick and found the end of it broken off. I changed the oil and installed a WIX oil filter and replacement diptick. The new dipstick read full with 6 quarts in. This morning when I started working on it I checked the oil and found the end of the new dipstick broken off.

I run a pcv valve in each valve cover rather than a vent on one side and pcv on the other but it’s always been like that and both pcv valves are working. Four or five years ago I installed a Weiand manifold and FI Tech fuel injection. When I did I had to install a smooth valley pan and it has no PCV…but it’s been fine since then.

Oil pressure runs between 20 psi – 80 psi depending on conditions but that’s normal for this engine too.

I’m racking my brain trying think what’s changed.

Any thoughts?


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## PontiacJim (Dec 29, 2012)

Unknown as it could be several things, but oil blowing out the dipstick or blowing off the dipstick indicates excessive crankcase pressure - which can blow out valve cover gasket and rear main seals. You also need a breather to let airflow into the engine. Having 2 PCV valves, one on each cover, is only creating a vacuum. How does airflow enter your engine? Ditch one of the PCV valves and add a breather. This will let crankcase pressure out on higher RPM runs. Sometimes you actually need 2 depending on how high you spin the engine.

The Pontiac engine holds 5 qts in the pan and 1 in the filter for 6 quarts total. If you are putting 6 quarts in the pan and the 1 in the filter, you are over filling. This can be part of your problem - unless you have a custom pan made for more oil.

Seems to be a recent rash of broken off dipsticks. Read this recent post:









Oil dip stick cut off


Hi all I just changed the oil in my new 68 goat. When I pulled dip stick it does not show oil level. It looks to be cut off. Ordered and received correct dip stick and tube. When it was installed the crank started hitting the dip stick. Help!




www.gtoforum.com


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## Old Man Taylor (May 9, 2011)

You may have more than one problem. I've had a problem in the past with the valve cover bolts loosening up. Oil starts seeping out of the back of the gasket and ends up on the header. When it burns off of the header it looks like it is blowing oil out of the exhaust pipe. Try tightening up your valve cover bolts.


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## BLK69JUDGE (Jun 10, 2010)

hey guys
how about no lower dip stick elbow or the incorrect one
Im thinkin NO elbow along with incorrect pcv = crank case pressure pushes
dipstick up from the tube and the sealing is gone.. and w rpm oil creeps up the stick and tube and out ...
time for a bore scope ... down the tube and in thru the drain
peek aboo maybe 








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It's the newest waterproof Endoscope for Android, which can take photo, record video. You can also use the Endoscope with the computer through the USB adapter. How to use on Android phone Waterproof level: IP67.



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## PontiacJim (Dec 29, 2012)

BLK69JUDGE said:


> hey guys
> how about no lower dip stick elbow or the incorrect one
> Im thinkin NO elbow along with incorrect pcv = crank case pressure pushes
> dipstick up from the tube and the sealing is gone.. and w rpm oil creeps up the stick and tube and out ...
> ...


Is that a colonoscopy procedure for a Pontiac engine perhaps? Seems to ring a bell with me.


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## Old Man Taylor (May 9, 2011)

I don't believe the bore scope is going to do you any good. You can't fix a problem with the lower dip stick tube without removing the pan. So no matter what you see with the bore scope, you can't do anything about it. I think that is a separate issue from the dip stick blowing out and leaking oil.


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## Lemans guy (Oct 14, 2014)

PCV problem, you have 2, but they are likely both inadequate and you have no fresh air inlet for the crankcase.

as PJ said put a breather , a good breather on one valve cover, I use a K&N breather, has good air flow and keeps air clean. Those PCV’s may be clogged and not pulling much vac.

nice chrome & polished vale breather caps only have small holes around the bottom of the cap, not so g real. Best recommendation would be to get an ME Wagner dual flow PCV valve. On one valve cover. You dial it in with a vacumn gauge to your engine, for idle and cruise circuits.

It will pull a 1 to 3 hg vac on your crankcase 99% of the time...check out their website. I have no connection just use it and recommend it to my hot rod friends and they all rave about it.

Now listen to Mr. Taylor and bulk Judge as well you could ave a leaky valve cover gasket or something going on down in the pan. But your PCV system is definitively not right.
You will get it good luck!


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## BLK69JUDGE (Jun 10, 2010)

somethins bustin 2 of his dipsticks... sure sounds like the dipsticks end up in the wrong position...
with the second one reading correct after oil change is wierd if the elbow isnt installed tho...
I would think for 35.00 you could peek down the dipsticktube ...to make sure elbow was there
my buddy just bought one and it seemed small enuf to go down the tube we looked in the cylinders of his
56 lincoln to check out the rust and looked thru the drain pug of his 68 400 to see the timing gear plastic
all over the bottom of the pan ,,, Im sure if we looked around we could have seen the widage tray and dipstick and elbow ...
Im gettin one ,,,, it has an adjustable led ... takes pictures ,, and movies
the stuff thats available is mind boggling .... plugs right into his cellphone 3' 6' 10'cables ... zooms in too
seemed like a time saver idea to me ........ so many uses ,,,,

it seems to be 2 different issues tho ,,, pcv vacuum having no intake breather and chopped dipsticks


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## pontrc (Mar 18, 2020)

Agree with all of you on this,but judge has a point about the scope saves on wrenching chores and it works good tracing wires under the dash


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## mikelly2 (Nov 24, 2018)

Thanks for the suggestions. For lack of a better idea I think I’ll find a breather that will fit the grommet in the valve cover and ditch one of the PCV valves. I know it’s not normal to have two but that’s how it was when I got the car and it’s worked fine for over 20 years and 70K plus miles. Something changed recently and I’d sure like to know what.

I first thought I had a valve cover leak but because the oil was all over the place I wasn’t sure where it was coming from. I added die and used a UV light to see. It’s all from the dipstick.

The broken dipstick issue may be an unrelated coincidence. it’s an AC car so the dipstick is longer and a little tricky to get in and out. When the first one broke I thought either the lube and tune place was too rough or maybe the 52 year old dipstick was just past its life expectancy. I really don’t want to pull the pan to check on the lower tube. BTW, you can pull the pan with the engine in the car. I installed a one piece pan gasket years ago by disconnecting the mounts and lifting the engine a bit. A PITA but doable. I need to think on it but I may do as suggested and use the short stick while the engine is running and the long one to check the oil when the engine is not running.

The endoscope a good idea and just a nifty little gadget.

Again, thanks to all for taking the time to respond. All good suggestions but none explain what changed and that’s what worries me. I just keep thinking I’m missing something.


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## Lemans guy (Oct 14, 2014)

2 PCV’s are ok if you have a breather, the crankcase needs fresh air.....and it needs that blowby crud and condensation removed....fresh air in and bad crud out....


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## mikelly2 (Nov 24, 2018)

Just wanted to give an update. I had a suitable valve cover vent laying around so I installed it on one side and my problem went away. I may look into the tunable PCV later but for now I'm a happy camper. I should have known better but again the two PCV set up has been there for years and worked fine. I was so focused on the broken dipstick and finding out what changed that I missed the obvious and easy solution. 

Thanks for giving me a new perspective.

Still wondering about the dipstick. I plan to pick up an endoscope. I looked at them a little bit yesterday but didn't buy one. The smallest camera I saw was 8.5mm and I want to see if I can find one that's smaller.


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## Lemans guy (Oct 14, 2014)

We’re they both hooked to manifold vac?..one wasn’t run up to the air cleaner was it?...

PCV are Mostly closed with Vac at idle....once vac goes away,...like when throttle opens, the spring in PCV opens the valve and lets blowby crankcase fumes enter the intake...

there are different configurations but they all depend on vacumn.

If you had one PCV hooked to direct manifold vac, and another hooked to the air cleaner,
The one with the direct manifold vac would be closed at idle correctly...

but the one hooked to the air cleaner would see no vac from the manifold at idle and therefore be open by spring pressure essentially being a fresh air intake....

You asked how could it have worked, well this is one way it would have, not very good, but still had fresh air in and crud out.


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## mikelly2 (Nov 24, 2018)

Lemans guy said:


> We’re they both hooked to manifold vac?..one wasn’t run up to the air cleaner was it?...
> 
> PCV are Mostly closed with Vac at idle....once vac goes away,...like when throttle opens, the spring in PCV opens the valve and lets blowby crankcase fumes enter the intake...
> 
> ...


I don't recall how they were connected before I installed the fuel injection but from then until the other day they were connected to a Tee so they saw the same amount of vacuum from the manifold. How it worked and why it stopped working suddenly will remain a mystery. I've been asking myself why I left it that way even though I knew better and I suppose it was just because it was working so I didn't see the need to "fix" it. Lesson learned...the hard way of course because that's the way I roll. 🙂


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## Lemans guy (Oct 14, 2014)

Don’t be so hard on yourself!.....at least the way you roll..is to keep rolling!

you have the right attitude with these old cars, you have to deal with the things that come up.....that is part of the enjoyment.....!

every mechanical thing needs service and or will eventually malfunction, from wear, age abuse or just for no specific reason!

check out that ME Wagner website they have a ton of solid info there and for the price of that valve you can really help your engine run better, stronger, cleaner, more efficient...and you can do the work yourself in short order, a great return on investment!


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## BLK69JUDGE (Jun 10, 2010)

aside of the pcv issue ....
tonite I put together a 68 ac dipstick and windage tray assembly
kindof ... for a visual ,,, maybe you already get the idea/picture ..
the 68 ac dipsticks were very tender to start with ,,and MOODY ,
they had perforated dipsticks that like to often bend at the hole,,,
you can see all the snaking the dip stick needs to do ,,, in 69 the upper tube goes to
the valve cover bolt ,,, not the back of the ac compressor like 67 68,,, 70 it moved again
but the 69 n up had a smoother curve for the stick....
now it looks very possible "IF" the lower elbow thru the windage tray is missing,,,,
that the dip stick COULD hit the hole and read fairly correct,,, also if it missed and
deflects it could get wacked by the crank ....
IF your parts are all 68 still ,,,, oil pan windage tray etc they should look like this set up

Scott
its worth a peek thru the drain plug next oil change it will be easy tooo see ...

if a 70 n up pan was used ,,,, well ... we will save that for another day


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## mikelly2 (Nov 24, 2018)

BLK69JUDGE said:


> aside of the pcv issue ....
> tonite I put together a 68 ac dipstick and windage tray assembly
> kindof ... for a visual ,,, maybe you already get the idea/picture ..
> the 68 ac dipsticks were very tender to start with ,,and MOODY ,
> ...


Thanks for the pictures. Very enlightening. I have an AC car but I removed the AC long ago and haven't gotten around to reinstalling it. I was considering installing the shorter non AC dipstick until I do. I see from your pictures that if that lower tube is missing the shorter stick isn't going to help much. I ordered an endscope; when it arrives I'll check it out.


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## gtomike455 (May 24, 2020)

mikelly2 said:


> I sure could sure use some advice.
> 
> I have the 400 ci engine in my ’68 GTO and I’m having an issue with oil blowing out through the dipstick. The car was a well started basket case project when I acquired it 20+ years ago. The engine was already installed so I don’t know much about it except that it runs strong. Since then I’ve put a lot of miles on it so I kinda thought my problem was blow by from worn rings. I just pulled the plugs and they were all cocoa brown with no sign of oil. I did a compression check and I’ve got 175-180 all around.
> 
> ...


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## JohnCarnell. (Aug 11, 2019)

mikelly2 said:


> I sure could sure use some advice.
> 
> I have the 400 ci engine in my ’68 GTO and I’m having an issue with oil blowing out through the dipstick. The car was a well started basket case project when I acquired it 20+ years ago. The engine was already installed so I don’t know much about it except that it runs strong. Since then I’ve put a lot of miles on it so I kinda thought my problem was blow by from worn rings. I just pulled the plugs and they were all cocoa brown with no sign of oil. I did a compression check and I’ve got 175-180 all around.
> 
> ...


Take a look at the valley pan grommet which the PCV valve fits into. If it is worn or not correctly pushed into the grommet you can get oil blow by. I know because I had that problem . Replace the 
grommet and all is well. OPGI has replacements. Also Edelbrock has great looking and performing valve cover vents.


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## Miko66 (Jan 6, 2022)

PontiacJim said:


> Unknown as it could be several things, but oil blowing out the dipstick or blowing off the dipstick indicates excessive crankcase pressure - which can blow out valve cover gasket and rear main seals. You also need a breather to let airflow into the engine. Having 2 PCV valves, one on each cover, is only creating a vacuum. How does airflow enter your engine? Ditch one of the PCV valves and add a breather. This will let crankcase pressure out on higher RPM runs. Sometimes you actually need 2 depending on how high you spin the engine.
> 
> The Pontiac engine holds 5 qts in the pan and 1 in the filter for 6 quarts total. If you are putting 6 quarts in the pan and the 1 in the filter, you are over filling. This can be part of your problem - unless you have a custom pan made for more oil.
> 
> ...


I have a 1969 GTO and just purchased a set of Doug's D590 Headers and the dipstick tube is hitting the flange plate. Is there a good way to bend the dipstick tube out of the way, without tearing the engine apart? Thanks in advance.


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## PontiacJim (Dec 29, 2012)

Miko66 said:


> I have a 1969 GTO and just purchased a set of Doug's D590 Headers and the dipstick tube is hitting the flange plate. Is there a good way to bend the dipstick tube out of the way, without tearing the engine apart? Thanks in advance.


Hmmm, good question. Have not heard of any issues with the dipstick tube hitting the header flange. I was able to find a pic of my '68 Lemans when I was pulling the 400CI out and here is a shot of the dipstick/tube - looks about in the same location/height as yours is now. Maybe you have the wrong tube or an aftermarket "generic" tube?

If me, I would simply put a bend in the tube to get it tighter against the block and angled to clear the flange. I have Doug's headers myself.

I pulled a photo of an aftermarket tube for reference. Does your tube have a bend in it to hug the block like the 2nd pic? The 3rd pic is a RA IV engine and you can see how the tube is real close to the block side.

I don't know if there is a dipstick tube you could use from another year that would have a pre-bent curve in the tube. If it were taller, I would simply tighten the header down up against it and force it over.

*BLK69JUDGE* would be the person on the forum who would be able to clear this up and maybe has an oil tube that would take car of the fit.


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## Miko66 (Jan 6, 2022)

Thanks for the quick follow up. I'm hesitant about bending the dipstick tube, to get it into the position shown, in picture #3, without getting it good and warm. Pic #3 is exactly where I want it to be, so it won't interfere with the exhaust and still be accessible. Does you Doug's Header (on the passenger side) have a large loop, over the oil filter? Mine does and while the motor is still out of the car, I need to make some measurements before it goes in. Just asking because to me, mine looks like it will hit the firewall, when the motor is in the car. I reached out to Butler Performance, where I got them to also check with them. It may fit, but it seems really odd and I can't recall the make and model of the headers that were on the car 35 years ago. The drivers side is nicely tucked against the motor. Also, I'll reach out to BLK69JUDGE and ask the same question. Thanks again for the info and I post a follow up when I get it done. Thanks again.


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## PontiacJim (Dec 29, 2012)

Miko66 said:


> Thanks for the quick follow up. I'm hesitant about bending the dipstick tube, to get it into the position shown, in picture #3, without getting it good and warm. Pic #3 is exactly where I want it to be, so it won't interfere with the exhaust and still be accessible. Does you Doug's Header (on the passenger side) have a large loop, over the oil filter? Mine does and while the motor is still out of the car, I need to make some measurements before it goes in. Just asking because to me, mine looks like it will hit the firewall, when the motor is in the car. I reached out to Butler Performance, where I got them to also check with them. It may fit, but it seems really odd and I can't recall the make and model of the headers that were on the car 35 years ago. The drivers side is nicely tucked against the motor. Also, I'll reach out to BLK69JUDGE and ask the same question. Thanks again for the info and I post a follow up when I get it done. Thanks again.


I don't know if you could use a brake/gas line tubing bender on the dipstick tube - if you have one. Never did this, but the old trick to bend tubing is to pack it tight with sand so when you bend it, the sand inside the tube keeps the tubing from collapsing and retains its shape. A little heat would probably work too, just small tweaks at a time and I would not put my bend all in one place, work it up the tube and let the tube cool after each small bend creating more of an arc than bend.

That kick out over the oil filter does look excessive but may work as it may fit into the trans tunnel and the firewall tapers down and back about that point. I guess you won't know until you install them. My Doug's are still in the boxes so I can't tell you how they fit. My car is disassembled and I plan of installing the engine/trans in with the nose off and then fit the headers to make sure nothing hits as I have a manual shift car and can modify the Z-bar a lot easier when I can access it with the nose off.


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## geeteeohguy (Feb 2, 2008)

If you don't feel comfortable bending the tube, you could cut the header flange plate for clearance. Won't hurt a thing and your tube will remain as-is.


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## Baaad65 (Aug 29, 2019)

mikelly2 said:


> I sure could sure use some advice.
> 
> I have the 400 ci engine in my ’68 GTO and I’m having an issue with oil blowing out through the dipstick. The car was a well started basket case project when I acquired it 20+ years ago. The engine was already installed so I don’t know much about it except that it runs strong. Since then I’ve put a lot of miles on it so I kinda thought my problem was blow by from worn rings. I just pulled the plugs and they were all cocoa brown with no sign of oil. I did a compression check and I’ve got 175-180 all around.
> 
> ...


I had the same problem running a cheap pcv valve and inefficient breathers on my 461, got the Wagner and drilled out my breathers big time...problem solved. At wot there is no more vacuum so now all that crankcase pressure has to get out and if the breathers have little holes then it goes to the next path of least resistance ala dipstick, and your lucky it popped it otherwise like has been said next will be the seals on the motor. I would show you what I did to my breathers but everyone's seen enough of them here 😉


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## NYGTO2018 (Oct 1, 2018)

I tend to be late on threads but here goes. This is a vintage picture and 1 of many from back then showing a dipstick pushed up. I have 2 stock 1965 GTO'S and they both do this if taken to upper r.p.m. Just some FYI, thanks NOTE dipstick at arrow.


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## Picasso (6 mo ago)

just sort of came over this thread. I dont have the problems suggested above, I have the 400, 67 Grand Prix, but if putting in breathers on the valve covers were nothing but upside advantage, would it be worth putting them on? 

Sincerely
Kim


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## Jetzster (Jan 18, 2020)

Our resident breather xpert Baaad65 will help you with this and much more shortly😉😀!


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## geeteeohguy (Feb 2, 2008)

I would be more inclined to relieve the header flange with a die-grinder. Messing around with those tubes is asking for trouble. Believe me.


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## Baaad65 (Aug 29, 2019)

NYGTO2018 said:


> I tend to be late on threads but here goes. This is a vintage picture and 1 of many from back then showing a dipstick pushed up. I have 2 stock 1965 GTO'S and they both do this if taken to upper r.p.m. Just some FYI, thanks NOTE dipstick at arrow.


Why don't you put a breather in the drivers vc where the plug is, the crankcase has to inhale and exhale on these big motors. And you should look into a Wagner tunable pcv valve. Back by popular demand these are mine 😉


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## lust4speed (Jul 5, 2019)

Here is an old photo of the Doug's headers that were installed on the '67 GTO. Back tubes look identical.









The dipstick tubes from Inline Tube bend very easy and without problems. The tubes from either Butler or Ames are really hard and scary to get enough bend in place and act like spring steel. Most of the time I end up going to the outside of the flange because there just isn't room on the inside, but sometimes for some reason with certain heads the tube can stay up against the head. Only downside to having it outside is the header has to be lifted up and dropped over the tube when installing the engine in the car.

I just insert a very large Philips screwdriver in the tube and exert pressure until it locates where I want it.


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