HOW TO DO AN ADVANCED SEARCH.

Mon Jul 08, 2013 3:56 pm by Admin


For the benefit of 944Hybrids users there are two search functions available for you to use.
The purpose of this sticky is to explain the "Advanced Search" function because it is much more powerful and is the best choice when researching information.

When you log on to the site a list of options is shown in a line at the top of the page. One option is labelled "Search", use this option (NOT the search box lower down on the right).

After you click on the upper search option, a drop down box appears. At the bottom of this box is a radio button marked "Advanced …

Comments: 0

Latest topics
» Poly based strut mounts on exchange
Fri Aug 18, 2017 10:16 pm by xschop

» 18x10" Enkei wheels
Wed Aug 16, 2017 9:59 pm by Sterling Doc

» Around the block
Tue Aug 15, 2017 11:46 am by Red944ls1

» RX7 Caliper Swap
Mon Aug 14, 2017 8:13 am by osx86ftw

» Cooling solutions please!
Sun Aug 13, 2017 3:15 pm by yamamtx

» Holley intake, vacuum pump and cross member spacer
Sun Aug 13, 2017 12:33 am by zeusrotty

» Sparkydog's Abnormal Build - 944 With L67 + Ford Stuff & CARB Legal
Sat Aug 12, 2017 3:42 pm by sparkydog

» LSA Supercharged 86 Porsche 944
Sat Aug 12, 2017 7:41 am by haroldk

» Coolant / header tank cap
Wed Aug 09, 2017 7:56 pm by Arthropraxis

» Cadillac ATS Brembo Front Brake Swap
Tue Aug 08, 2017 6:43 pm by superman22x

August 2017
MonTueWedThuFriSatSun
 123456
78910111213
14151617181920
21222324252627
28293031   

Calendar Calendar

Log in

I forgot my password


Venting through dipstick tube, help!

View previous topic View next topic Go down

Venting through dipstick tube, help!

Post  docwyte on Sat Jan 18, 2014 5:06 pm

So I was blowing oil through the exhaust. Figured it was because of the way I had the breather setup.

So I cleaned all the oil out of the intake, put in new spark plugs and capped off the passenger valve cover vents.

Now I'm venting from the LS6 valley cover into my catch can, then to the PCV valve, then into the intake manifold.

Started the car up and I'm blowing oil through the dipstick tube.

WTF! How do I solve this?

docwyte

Posts : 1371
Join date : 2010-07-18

Back to top Go down

Re: Venting through dipstick tube, help!

Post  money pit 951 on Sun Jan 19, 2014 8:26 am

docwyte wrote:... and capped off the passenger valve cover vents.  

If you're having venting/pressure problems why did you cap the valve cover vent?

You have two issues - either a lack of venting or your rings are shot and the compression is getting by them (or both). I would start with pulling the cap off the valve cover and venting it. You don't want the pressure to blow out through the rear main seal or someplace else.
avatar
money pit 951

Posts : 99
Join date : 2013-01-07

Back to top Go down

Re: Venting through dipstick tube, help!

Post  Lemming on Sun Jan 19, 2014 8:39 am

My engine will also blow the diptick out if I do not vent the valve cover.  I put a better catch can on my valley cover and move it lower down hoping that it would not pull as much oil into the intake manifold.  I've not yet tested the new setup.

See: [You must be registered and logged in to see this link.]

avatar
Lemming

Posts : 855
Join date : 2011-05-30
Location : B'ham

Back to top Go down

Re: Venting through dipstick tube, help!

Post  docwyte on Sun Jan 19, 2014 9:08 am

Because with the valve cover vents hooked up to the catch can I was blowing oil out the exhaust on deceleration.

Compression tests (wet and dry) were fine. Doing a leak down on Tuesday.

docwyte

Posts : 1371
Join date : 2010-07-18

Back to top Go down

Re: Venting through dipstick tube, help!

Post  money pit 951 on Mon Jan 20, 2014 7:06 pm

docwyte wrote:I was blowing oil out the exhaust on deceleration.  
There's your answer. Your rings or ringland are shot. You can keep playing around with the breathers, but I think you have your answer (might not like it and I understand that)
avatar
money pit 951

Posts : 99
Join date : 2013-01-07

Back to top Go down

Re: Venting through dipstick tube, help!

Post  docwyte on Mon Jan 20, 2014 7:27 pm

Yeah, I don't wanna hear that, although I've been suspecting it. Hopefully the leakdown test confirms it. If so at least I can rebuild the motor this winter. I'll probably add a set of ported and decked 243 heads while I'm at it

docwyte

Posts : 1371
Join date : 2010-07-18

Back to top Go down

Re: Venting through dipstick tube, help!

Post  docwyte on Wed Jan 22, 2014 10:22 pm

Leakdown test confirmed a worn bottom end. Going to pull it out for a rebuild and will add a set of ported 243 heads while I'm at it.

docwyte

Posts : 1371
Join date : 2010-07-18

Back to top Go down

Re: Venting through dipstick tube, help!

Post  money pit 951 on Thu Jan 23, 2014 6:51 am

Sorry to hear. Was there last year with the same thing. Think about a cam also while' you're in there....
avatar
money pit 951

Posts : 99
Join date : 2013-01-07

Back to top Go down

Re: Venting through dipstick tube, help!

Post  docwyte on Thu Jan 23, 2014 8:59 am

Already have a cam, so I'm good there. I'm going to try to have a solid rebuild done, vs a race car motor being built. I want longevity measured in 10's of thousands of miles, not hours.

docwyte

Posts : 1371
Join date : 2010-07-18

Back to top Go down

Re: Venting through dipstick tube, help!

Post  skywalker01 on Thu Jan 23, 2014 9:32 am

I'm am in the market for a cam too. Which ones have you been looking at/used?
avatar
skywalker01

Posts : 477
Join date : 2009-07-22
Age : 54

Back to top Go down

Re: Venting through dipstick tube, help!

Post  docwyte on Thu Jan 23, 2014 9:35 am

I've got an EPS 226/230 cam. I made 400rwhp with it last spring and that was on my weak motor.

With the ported/decked 243's and a fresh bottom end I expect somewhere around 430-440rwhp with it.

It idles nicely, had good bottom end and pulls hard all the way to 7000 rpm.

I've also had a 224/224 cam, which I wasn't a fan of. It had no top end and couldn't make more than around 335rwhp.

docwyte

Posts : 1371
Join date : 2010-07-18

Back to top Go down

Re: Venting through dipstick tube, help!

Post  skywalker01 on Thu Jan 23, 2014 9:49 am

Interesting - may just give them a call.
avatar
skywalker01

Posts : 477
Join date : 2009-07-22
Age : 54

Back to top Go down

Re: Venting through dipstick tube, help!

Post  948 on Thu Jan 23, 2014 11:34 am

docwyte wrote:Leakdown test confirmed a worn bottom end.......
Could you post the numbers, cylinder position (TDC usually), twin or single gauge, engine temp....and how you determined the bottom end is to blame and not valves or head-gaskets?


Last edited by 948 on Thu Jan 23, 2014 11:42 am; edited 1 time in total (Reason for editing : Spelling)
avatar
948
Moderator
Moderator

Posts : 511
Join date : 2009-06-09
Age : 102
Location : East PA

Back to top Go down

Re: Venting through dipstick tube, help!

Post  acorad on Thu Jan 23, 2014 11:43 am

docwyte wrote:Leakdown test confirmed a worn bottom end.  Going to pull it out for a rebuild and will add a set of ported 243 heads while I'm at it.
How many miles on your motor?
avatar
acorad

Posts : 644
Join date : 2010-12-21
Location : Agoura Hills, CA

Back to top Go down

Re: Venting through dipstick tube, help!

Post  acorad on Thu Jan 23, 2014 11:46 am

fwiw (general info found on the interwebs, in case you're like me and are not up on what doc's doing):

"A leak down or "cylinder leakage" test is similar to a compression test in that it tells you how well your engine's cylinders are sealing. But instead of measuring pressure, it measures pressure loss.

A leak down test requires the removal of all the spark plugs. The crankshaft is then turned so that each piston is at top dead center (both valves closed) when each cylinder is tested. Most people start with cylinder number one and follow the engine's firing order.

A threaded coupling attached to a leakage gauge is screwed into a spark plug hole. Compressed air (80 to 90 psi) is then fed into the cylinder.

An engine in great condition should generally show only 5 to 10% leakage. An engine that's still in pretty good condition may show up to 20% leakage. But more than 30% leakage indicates trouble.

The neat thing about a leakage test (as opposed to a compression test) is that it's faster and easier to figure out where the pressure is going. If you hear air coming out of the tailpipe, it indicates a leaky exhaust valve. Air coming out of the throttle body or carburetor would point to a leaky intake valve. Air coming out of the breather vent or PCV valve fitting would tell you the rings and/or cylinders are worn.

A leakage test can also be used in conjunction with a compression test to diagnose other kinds of problems.

A cylinder that has poor compression, but minimal leakage, usually has a valvetrain problem such as a worn cam lobe, broken valve spring, collapsed lifter, bent push rod, etc.

If all the cylinders have low compression, but show minimal leakage, the most likely cause is incorrect valve timing. The timing belt or chain may be off a notch or two.

If compression is good and leakage is minimal, but a cylinder is misfiring or shows up weak in a power balance test, it indicates a fuel delivery (bad injector) or ignition problem (fouled spark plug or bad plug wire)."


Last edited by acorad on Thu Jan 23, 2014 12:02 pm; edited 2 times in total
avatar
acorad

Posts : 644
Join date : 2010-12-21
Location : Agoura Hills, CA

Back to top Go down

Re: Venting through dipstick tube, help!

Post  docwyte on Thu Jan 23, 2014 11:53 am

Motor has around 75k miles on it now.

I disagree with the percentages you've posted. In my experience, 5% or less is healthy, 5-10% is suspect, 15% or more isn't good.

docwyte

Posts : 1371
Join date : 2010-07-18

Back to top Go down

Re: Venting through dipstick tube, help!

Post  acorad on Thu Jan 23, 2014 12:01 pm

docwyte wrote:I disagree with the percentages you've posted.  In my experience, 5% or less is healthy, 5-10% is suspect, 15% or more isn't good.
Probably so. I just posted what I found on the internet, 'cuz I needed to learn about what you were doing. I posted it for general info in case others were in the same boat as me.
avatar
acorad

Posts : 644
Join date : 2010-12-21
Location : Agoura Hills, CA

Back to top Go down

Re: Venting through dipstick tube, help!

Post  docwyte on Thu Jan 23, 2014 12:04 pm

Bear in mind I was also throwing out a smoke screen out the exhaust on decel and running through 1.5qts of oil a day at the track.

So the leakdowns confirmed what I already suspected, worn rings.

What's ironic is that this is exactly why I pulled the factory turbo motor to begin with. Financially I would've been way ahead just having Chris White build me a 3 liter turbo motor, but hindsight is 20/20 and the LS is way cooler.  Twisted Evil 

docwyte

Posts : 1371
Join date : 2010-07-18

Back to top Go down

Re: Venting through dipstick tube, help!

Post  948 on Thu Jan 23, 2014 12:27 pm

docwyte wrote:Bear in mind I was also throwing out a smoke screen out the exhaust on decel and running through 1.5qts of oil a day at the track.   
Smoke on decel it typicaly worn valve guide seals but can also be a malfunctioning PCV system (Typical for LS motors even with the LS6 update) or worn rings.
Did you put oil in the suspect cylinders and re-run the leak-down? If there is no or little change in your results the leak is elsewhere.
In my limited experience 10-15 percent isn't unusual for a typical 100K mile engine.....a proper race engine would be considered done at around 10%, for power reasons only though.

Also, are your heads ported? Some port jobs cause the rocker arm bolt hole to open into the port. If not sealed oil will get sucked in.

Numbers?


avatar
948
Moderator
Moderator

Posts : 511
Join date : 2009-06-09
Age : 102
Location : East PA

Back to top Go down

Re: Venting through dipstick tube, help!

Post  docwyte on Thu Jan 23, 2014 12:31 pm

No, in my experience smoke on decel is rings, I've never had smoke out the back caused by the valve train. I've already replaced the valve stem seals as it was easy with no change, heads are stock 241's, not ported.

PCV system is a PITA on this car, but it's operating properly.

docwyte

Posts : 1371
Join date : 2010-07-18

Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum