[DMCForum] Re: damnit to hell (my poor engine)
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[DMCForum] Re: damnit to hell (my poor engine)
- From: "cartermartin" <cartermartin@xxxxxxxxx>
- Date: Mon, 18 Apr 2005 01:38:16 -0000
Bummer dude,
I may be in the same boat at this point. I will change the oil next
and do more checking which is difficult since i have several coolant
leaks i'm still chasing.
Have you been able to get your De Lorean back on the road yet?
When I'm spending a wonderful spring day under or over my car I
pretend i'm restoring my De Lorean.
Carter
--- In DMCForum@xxxxxxxxxxxxxxx, "Matt Spittle" <mds328@xxxx> wrote:
>
> I had chocolate milkshake in the oil filler, and also in the oil pan
> (along with lime green milkshake). When I finally pulled the heads,
> Rob Grady confirmed I had a cracked passenger side head.
>
> Matt
> #1604
>
>
> --- In DMCForum@xxxxxxxxxxxxxxx, "cartermartin" <cartermartin@xxxx>
wrote:
> >
> > This was a most interesting thread (the subject line right out of
my
> > lips).
> >
> > I am reasonably sure at this point I will have to reassess the
> > condition of my engine (PRV/B280f in a...umm...Volvo...).
> >
> > I have some more questions:
> >
> > 1. How does one properly bleed the cooling system on one of these?
> >
> > 2. Would a compression test reveal a faulty head gasket? I have
good
> > compression on all 6 cylinders (180-185psi, maybe too good?).
> >
> > 3. Would a head gasket that is bad or heading that way cause
excess
> > pressure in the cooling system?
> >
> > The engine is running strong but I have had a couple high
> > temp 'incidents'. And chocolate milkshake in the oil filler which
was
> > there before though.
> >
> > Carter
> >
> > --- In DMCForum@xxxxxxxxxxxxxxx, "therealdmcvegas"
<dmcvegas@xxxx>
> > wrote:
> > >
> > > --- In DMCForum@xxxxxxxxxxxxxxx, "Matt Spittle" <mds328@xxxx>
wrote:
> > > <SNIP>
> > > > Will running a coolant pressure test verify if I have a blown
> > head
> > > > gasket?
> > > >
> > > > thanks,
> > > >
> > > > Matt
> > > > #1604
> > >
> > > Most definetly. You'll be pressurizing the cooling system, and
> > forcing
> > > water out of any leaks that you have. I had lots of coolant in
the
> > > "Valley of Deat" too, when one of the O-Rings on the Y-Pipe
finally
> > > rotted away, and allowed fluid to flow out freely. So you'll
want to
> > > snag a couple of new rings down at the local autoparts store
when
> > you
> > > pick up the pressure testing kit. BTW, don't bother looking for
the
> > > rings in the aisle. They're in a box behind the counter.
> > >
> > > But first, let's talk about what causes a head gasket to
prematurely
> > > fail. Heat is the enemy here. And you know that if you severely
> > > overheated an engine, the cylinder heads warp and seperate
> > themselves
> > > from the headgasket. Obviously at that point you need to
replace
> > both
> > > the cyliner head, and the head gasket. But, there is also
another
> > > silent killer of headgaskets, and it too is caused by heat.
> > >
> > > Improperly bled cooling system: That's right. If you've got air
in
> > the
> > > engine, you're gonna SEVERLY shorten the life of the
headgasket. It
> > > works like this. Cast Iron cylinder sleeves will heat up and
expand
> > > and a far slower rate than the Aluminium cylinder heads.
However,
> > when
> > > we have coolant flowing across them both, the heat is gently
> > > transfered between the two, and they both heat and expand at a
much
> > > more syncronized rate.
> > >
> > > But air inside the cooling system negates all this. Water
doesn't
> > flow
> > > across the surfaces evenly, and pockets of air them become steam
> > > pockets. Now keep this in mind: Steam is a gas so it rises, and
it's
> > > the aluminum cylinder heads up that are on the top. The water
below
> > > may only be like 120°F during the warm up, but the steam
pockets
> > have
> > > already hit 260°F+! So the Aluminum expands much more quickly
than
> > the
> > > Cast Iron below. What happens here is that the head gaskets are
> > slowly
> > > torn, because the two sides between it are shifting in different
> > > directions.
> > >
> > > And DeLoreans are tricky to the average mechanic, when it comes
to
> > > diagnosing bad headgaskets just by sight.
> > >
> > > Because of that damn valley under the intake manifold, it's
easy to
> > > believe that the car has a bad head gasket. You leak out fluid,
but
> > it
> > > never drips below the car. Instead, it collects up above, and
gets
> > > boiled off. And then when a car isn't always run up to
temperature,
> > > the condensation inside is easily mistaken for coolant in the
oil.
> > > Although I too have concerns about that crap in the oil filler
cap
> > for
> > > your engine.
> > >
> > > Do this:
> > > Step 1. Pressure test a FULL cooling system. 14½ PSI for 15
minutes,
> > > and the fluctuation should be minimal, if at all.
> > >
> > > If no leaks detected, move on to step 2. If leaks are found,
repair
> > > them before proceeding. Remeber, you're dealing with coolant
hoses,
> > a
> > > radiator, engine block, AND the heater core inside. So check
all
> > these
> > > areas IF the pressure isn't able to maintain itself.
> > >
> > > Remove the rocker covers, and pull the oil drain plug. See if
any
> > > water sprays, or otherwise visably drips out of any of these
places.
> > > That'll find out what's going on with the engine.
> > >
> > > Step 2: If/when no leaks are present, reassemble the top end
with
> > new
> > > seals, hoses, etc. Use silicone hoses for the water pump, new
rubber
> > > tubes for the vacuum lines, new orings for the intake manifold,
new
> > > oil resistant hoses for the breather tubes, etc. SEAL
EVERYTHING!
> > Make
> > > certain that there are no vacuum leaks.
> > >
> > > Step 3: Disconnect the Oxygen sensor from the ECU wire, so that
the
> > > engine will stay in "limp mode", and won't fiddle with the O2
> > mixture
> > > on you. Start the engine, and see how she runs. Since you had
vacuum
> > > leaks before, you're prolly gonna need to adjust the CO mixture
to
> > get
> > > the car running right. So if you need to fiddle with it right
now to
> > > get the car running right, that's OK.
> > >
> > > Step 4: Once the engine is cool, flush it with this (2nd from
the
> > bottom):
> > > http://www.berrymanproducts.com/Default.aspx?tabid=139
> > > This is POWERFUL stuff. It dissolves anything (including
styrofoam),
> > > and will clean out your motor. You'll only need about ⅔
of
> > the bottle.
> > > Pour it directing into the crankcase, and idle the motor for
about 7
> > > minutes. Then shut the motor off, and drain the oil & cleaner
out
> > ASAP.
> > >
> > > After that you can drive the car to your local old skool Volvo
> > > mechanic where you can reattach the O2 sensor, and get the CO
> > balanced
> > > on the motor. But I would first add that you pour some Techron
into
> > > the tank, and burn out the old gasoline first, and refill with
fresh
> > > before tuning the CO on the car.
> > >
> > > -Robert
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