[DeTomaso] Cylinder Heads leaking
JEFFREY COBB
jeffcobb1 at me.com
Mon Nov 23 06:24:34 EST 2015
Joseph,
Your thinking is pretty cool and right on, sometimes when we do a leak down test we will place our gloved hand over the tailpipes, throttle body and dipstick time an peal off the thin glove and tie strap down it for visual verification of our test.
While a leak down test is static knowledge, sometimes we need to rap the valve stem top with a small hammer so to see if it sits different and gives diff pressures. This hit can tell you if the valve was dirty and if a guide is worn and allows the valve to sit off center and leak.
Sean,
You can't do a compression test with valve gear not 100% functioning, it is a dynamic opera.
All of your air psi test so far mean nothing. Since rockers are off do a leak down test then if numbers are not right then a compression test. But remember to zone in for what problem you want to kill or are just wanting to play and learn. Both are beneficial.
Sounds like an oil control ring and or what Mike said about the intake gasket area sucking oil-air from valley.
Happy hunting,
Jeff Cobb- I pad
-------
On Nov 22, 2015, at 7:38 PM, "Joseph F. Byrd, Jr." <byrdjf at embarqmail.com> wrote:
> This is just the abstract thinking of someone not an automotive mechanic,
> but performed similar on other equipment.
>
> Think about this, Tape a thin plastic bathroom size trash bag over the carb,
> the tail pipe and oil fill cap.
> Then, with air being injected through the spark plug, see which bag
> inflates.
>
> I was thinking about using a trace gas in lieu of air injecting, but
> probably with the close proximities, it might not distinguish where the hit
> was coming from (besides that would require a gas and a sniffer to detect)
>
>
> -----Original Message-----
> From: DeTomaso [mailto:detomaso-bounces at poca.com] On Behalf Of sean mundy
> Sent: Sunday, November 22, 2015 19:43 PM
> To: Asa Jay Laughton
> Cc: mikeldrew at aol.com; detomaso at poca.com
> Subject: Re: [DeTomaso] Cylinder Heads leaking
>
> Compression test shows1= 1602= 1203= 2004= couldnt get the comp tester in
> the spark plug hole. Too tight with the coolant tank in the way.On 5-8 I
> was hooking up the comp tester and getting really bad readings but I didn't
> have the rockers arms installedand I think that is necessary. Not sure if
> the readings I did get show a piston ring problem or a valve leak. I will
> do a leak down test next when I pick up a tester.
> Date: Sat, 21 Nov 2015 07:00:21 -0800
> Subject: Re: [DeTomaso] Cylinder Heads leaking
> From: asajay at asajay.com
> To: seanmundy at hotmail.com
> CC: ehpantera at yahoo.com; mikeldrew at aol.com; detomaso at poca.com
>
> The air is probably leaking past the rings, which have a designed in gap.
> With the valves closed, the cylinder is NOT a hermetically sealed container.
> Asa Jay
> Sent using Jedi Mind Tricks
>
> sean mundy <seanmundy at hotmail.com> wrote:
>
> I tried pumping air into 7 and 8 spark plug holes and both I can hear air
> leaking. I have all my rockers removed on that side so all the valves
> should be closed. I've tried a few different types of gaskets but buying
> the CHI specific ones seemed to be the best approach. They fit perfect so I
> hoped my valve seals were the problem especially since there is a lot of
> blue smoke on startup after the car has been sitting awhile. I re torqued
> the heads thinking the air leak could only be either the valves or a leaking
> head gasket. I have no signs of coolant in my oil. Maybe I have multiple
> problems ?
>
> Date: Sat, 21 Nov 2015 00:52:12 +0000
> From: ehpantera at yahoo.com
> To: seanmundy at hotmail.com; mikeldrew at aol.com
> CC: detomaso at poca.com
> Subject: Re: [DeTomaso] Cylinder Heads leaking
>
> I just buy a roll of gasket material and cut my own. Never any leaks and
> easy to do.Mark
>
>
> On Friday, November 20, 2015 7:30 PM, sean mundy <seanmundy at hotmail.com>
> wrote:
>
>
> Thank you Mike. That explains a possible oil leak being sucked in via
> a leak but that wouldn't account for me hearing air leaking when pumping
> air into the cylinder with both valves closed? I have CHI heads and CHI
> intake and I'm using their specific intake gasket set. I don't think the
> stock gasket is going to match up all that well. > CC: detomaso at poca.com
>> From: MikeLDrew at aol.com > Subject: Re: [DeTomaso] Cylinder Heads leaking
>> Date: Fri, 20 Nov 2015 16:12:19 -0800 > To: seanmundy at hotmail.com >
>> Sean, > > This is a VERY common problem. Your intake manifold gasket
> has failed and is leaking on the bottom edge, allowing oil to be sucked
> from the valley under the intake into one or more cylinders. > > Many
> people have made the mistake of using Fel-Pro 'Print-o-seal' intake
> gaskets. These things are notorious for failing; so much so that you can
> find numerous references to them on Internet forums for all sorts of cars,
> where they are commonly called 'Print-o-leak' gaskets! > > I happen to
> favor the stock-style valley pan gasket, Fel pro MS96012. If you follow
> the installation instructions to the letter, these seal fine with the
> added advantage of cooling the underside of the intake by shielding it
> from oil splash. > > There is a story with photos about this chronic
> problem in a recent PCNC newsletter; you can read it by accessing the
> website at www.panteraclubnorcal.com > > I've helped repair two local
> cars with this problem in the past few months and know of a third that is
> awaiting repair.... > > Mike > > > > Sent from my iPhone > >
> On Nov 20, 2015, at 15:42, sean mundy <seanmundy at hotmail.com> wrote: > >
>> After a long hiatus, I am back working on my Pantera. Latest issue is
>>> the engine is burning oil at about a quart every 300 miles. > > My
> spark plugs don't look horrible but something is going on. I re > >
> torqued the cylinder heads and intake manifold and made sure my pc > >
> valve was working. I looked at my intake valves with an > > inspection
> camera and there is a lot of carbon buildup but I only have > > about 2k
> miles on the new aluminum heads. I thought my valve seals may > > be
> leaking so I started removing the rockers on one side and tried to > >
> replace the Teflon valve seals on #8cyl with new Comp Cam Viton seals. >
>> I connected compressed air to the #8 spark plug hole to hold the valve
>>> up so I could remove the spring. I don't think you are supposed to > >
> but I can hear air leaking from somewhere inside the engine. It seems >
>> like I can feel a little air coming out of the top of the intake > >
> manifold with my carb removed. I can't trace the air leak. > > Need some
> tips on what steps I should take at this point. Thanks, Sean > >
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>
>
> I tried pumping air into 7 and 8 spark plug holes and both I can hear
> air leaking. I have all my rockers removed on that side so all the
> valves should be closed. I've tried a few different types of gaskets
> but buying the CHI specific ones seemed to be the best approach. They
> fit perfect so I hoped my valve seals were the problem especially since
> there is a lot of blue smoke on startup after the car has been
> sitting awhile. I re torqued the heads thinking the air leak could
> only be either the valves or a leaking head gasket. I have no signs
> of coolant in my oil. Maybe I have multiple problems ?
> __________________________________________________________________
>
> Date: Sat, 21 Nov 2015 00:52:12 +0000
> From: ehpantera at yahoo.com
> To: seanmundy at hotmail.com; mikeldrew at aol.com
> CC: detomaso at poca.com
> Subject: Re: [DeTomaso] Cylinder Heads leaking
> I just buy a roll of gasket material and cut my own. Never any leaks
> and easy to do.
> Mark
> On Friday, November 20, 2015 7:30 PM, sean mundy
> <seanmundy at hotmail.com> wrote:
> Thank you Mike. That explains a possible oil leak being sucked in
> via
> a leak but that wouldn't account for me hearing air leaking when
> pumping air into the cylinder with both valves closed? I have CHI
> heads and CHI intake and I'm using their specific intake gasket set.
> I
> don't think the stock gasket is going to match up all that well.
>> CC: [1]detomaso at poca.com
>> From: [2]MikeLDrew at aol.com
>> Subject: Re: [DeTomaso] Cylinder Heads leaking
>> Date: Fri, 20 Nov 2015 16:12:19 -0800
>> To: [3]seanmundy at hotmail.com
>>
>> Sean,
>>
>> This is a VERY common problem. Your intake manifold gasket has
> failed
> and is leaking on the bottom edge, allowing oil to be sucked from the
> valley under the intake into one or more cylinders.
>>
>> Many people have made the mistake of using Fel-Pro 'Print-o-seal'
> intake gaskets. These things are notorious for failing; so much so
> that
> you can find numerous references to them on Internet forums for all
> sorts of cars, where they are commonly called 'Print-o-leak' gaskets!
>>
>> I happen to favor the stock-style valley pan gasket, Fel pro
> MS96012.
> If you follow the installation instructions to the letter, these seal
> fine with the added advantage of cooling the underside of the intake
> by
> shielding it from oil splash.
>>
>> There is a story with photos about this chronic problem in a recent
> PCNC newsletter; you can read it by accessing the website at
> www.panteraclubnorcal.com
>>
>> I've helped repair two local cars with this problem in the past few
> months and know of a third that is awaiting repair....
>>
>> Mike
>>
>>
>>
>> Sent from my iPhone
>>
>> On Nov 20, 2015, at 15:42, sean mundy <[4]seanmundy at hotmail.com>
> wrote:
>>
>>> After a long hiatus, I am back working on my Pantera. Latest
> issue
> is
>>> the engine is burning oil at about a quart every 300 miles.
>>> My spark plugs don't look horrible but something is going on. I
> re
>>> torqued the cylinder heads and intake manifold and made sure my
> pc
>>> valve was working. I looked at my intake valves with an
>>> inspection camera and there is a lot of carbon buildup but I only
> have
>>> about 2k miles on the new aluminum heads. I thought my valve
> seals
> may
>>> be leaking so I started removing the rockers on one side and
> tried
> to
>>> replace the Teflon valve seals on #8cyl with new Comp Cam Viton
> seals.
>>> I connected compressed air to the #8 spark plug hole to hold the
> valve
>>> up so I could remove the spring. I don't think you are supposed
> to
>>> but I can hear air leaking from somewhere inside the engine. It
> seems
>>> like I can feel a little air coming out of the top of the intake
>>> manifold with my carb removed. I can't trace the air leak.
>>> Need some tips on what steps I should take at this point. Thanks,
> Sean
>>> _______________________________________________
>>>
>>> Detomaso Forum Managed by POCA
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> References
>
> 1. mailto:detomaso at poca.com
> 2. mailto:MikeLDrew at aol.com
> 3. mailto:seanmundy at hotmail.com
> 4. mailto:seanmundy at hotmail.com
> 5. mailto:DeTomaso at poca.com
> 6. http://poca.com/mailman/listinfo/detomaso_poca.com
> 7. mailto:DeTomaso at poca.com
> 8. http://poca.com/mailman/listinfo/detomaso_poca.com
>
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