cracked head....ouch!

Got a 1990 325i (E30/M20) that was overheating, but with no apparent
pressure loss in the cooling system and no obvious leaks. Took it to H&B
in Berkeley, CA and they took the cylinder head off.

The head gasket itself looked ok, although it looked as if the head itself
might have slid around a bit w/ respect to the block. We (meaning the
mechanic and I) thought that encouraging, as a crappy gasket was the best
(or least expensive) of the possible scenarios. However, looking closer
at the cylinder head, between cylinders 4 and 5, the mechanic finds what he
calls a 'crack' in the head. I look at it too (picture us there,
flashlight in hand, peering past the camshafts and rockers), and true
enough, I see what looks like a smudged discoloration at the base of where
the valve spring rests. If I squint, I can sort of see what looks like a
possible hairline fissure connecting two of the discolored spots. Frankly,
it doesn't look like real crack (could easily have been a particularly
stubborn oil smudge) and it hardly seemed like the sort of thing that
would have terrorized my cooling system. However I trust the mechanic (I
have it from trustable sources that H&B is among the best BMW shops in the
Bay Area...perhaps some here would disagree). When I questioned his
judgement, the mechanic graciously offered to do a dye test whereby they
actually leak some dye from the oil compartment to the coolant compartment
on the other side. The downside: an hour plus more labor (at $90/hr) to
remove the camshaft and valves and do the test.

I would usually trust him,
but replacing the head is going to cost a very painful $3K or so
(parts and labor included) while just replacing the gasket is about $1.3K.
Should I have him do it, or am I paranoid? I have never seen a cracked
head so I don't even know what to look for...only have a paltry
former machinist's intuition to go on. Does my description sound typical
of a 'crack'?

Also, what should I expect to pay for a head replacement, assuming the use
of aftermarket parts of course? The mechanics estimate, as stated, was
about $3K all told. Am I being had? Is that too rich?

Thanks in advance,

A.

"Antonio Garcia" > wrote in message
keley.EDU...
>
> Got a 1990 325i (E30/M20) that was overheating, but with no apparent
> pressure loss in the cooling system and no obvious leaks. Took it to H&B
> in Berkeley, CA and they took the cylinder head off.
>
> The head gasket itself looked ok, although it looked as if the head itself
> might have slid around a bit w/ respect to the block. We (meaning the
> mechanic and I) thought that encouraging, as a crappy gasket was the best
> (or least expensive) of the possible scenarios. However, looking closer
> at the cylinder head, between cylinders 4 and 5, the mechanic finds what
he
> calls a 'crack' in the head. I look at it too (picture us there,
> flashlight in hand, peering past the camshafts and rockers), and true
> enough, I see what looks like a smudged discoloration at the base of where
> the valve spring rests. If I squint, I can sort of see what looks like a
> possible hairline fissure connecting two of the discolored spots. Frankly,
> it doesn't look like real crack (could easily have been a particularly
> stubborn oil smudge) and it hardly seemed like the sort of thing that
> would have terrorized my cooling system. However I trust the mechanic (I
> have it from trustable sources that H&B is among the best BMW shops in the
> Bay Area...perhaps some here would disagree). When I questioned his
> judgement, the mechanic graciously offered to do a dye test whereby they
> actually leak some dye from the oil compartment to the coolant compartment
> on the other side. The downside: an hour plus more labor (at $90/hr) to
> remove the camshaft and valves and do the test.
>
> I would usually trust him,
> but replacing the head is going to cost a very painful $3K or so
> (parts and labor included) while just replacing the gasket is about $1.3K.
> Should I have him do it, or am I paranoid? I have never seen a cracked
> head so I don't even know what to look for...only have a paltry
> former machinist's intuition to go on. Does my description sound typical
> of a 'crack'?
>
> Also, what should I expect to pay for a head replacement, assuming the use
> of aftermarket parts of course? The mechanics estimate, as stated, was
> about $3K all told. Am I being had? Is that too rich?

It's all well and good that your mechanic is the trustworthy sort, but a
judgement call on what may or may not be a crack is going to potentially
cost you $3k. Why not spend an hour of labor and do the test.

Also, 3K sounds a bit steep. Why not price out a rebuilt head yourself and
see?

-Fred W

"Fred W." <Fred.Wills@'remove this to reply to' myrealbox.com> wrote in
message ...
>
> "Antonio Garcia" > wrote in message
> keley.EDU...
> >
> > Got a 1990 325i (E30/M20) that was overheating, but with no apparent
> > pressure loss in the cooling system and no obvious leaks. Took it to H&B
> > in Berkeley, CA and they took the cylinder head off.
> >
> > The head gasket itself looked ok, although it looked as if the head
itself
> > might have slid around a bit w/ respect to the block. We (meaning the
> > mechanic and I) thought that encouraging, as a crappy gasket was the
best
> > (or least expensive) of the possible scenarios. However, looking closer
> > at the cylinder head, between cylinders 4 and 5, the mechanic finds what
> he
> > calls a 'crack' in the head. I look at it too (picture us there,
> > flashlight in hand, peering past the camshafts and rockers), and true
> > enough, I see what looks like a smudged discoloration at the base of
where
> > the valve spring rests. If I squint, I can sort of see what looks like a
> > possible hairline fissure connecting two of the discolored spots.
Frankly,
> > it doesn't look like real crack (could easily have been a particularly
> > stubborn oil smudge) and it hardly seemed like the sort of thing that
> > would have terrorized my cooling system. However I trust the mechanic (I
> > have it from trustable sources that H&B is among the best BMW shops in
the
> > Bay Area...perhaps some here would disagree). When I questioned his
> > judgement, the mechanic graciously offered to do a dye test whereby they
> > actually leak some dye from the oil compartment to the coolant
compartment
> > on the other side. The downside: an hour plus more labor (at $90/hr) to
> > remove the camshaft and valves and do the test.
> >
> > I would usually trust him,
> > but replacing the head is going to cost a very painful $3K or so
> > (parts and labor included) while just replacing the gasket is about
$1.3K.
> > Should I have him do it, or am I paranoid? I have never seen a cracked
> > head so I don't even know what to look for...only have a paltry
> > former machinist's intuition to go on. Does my description sound typical
> > of a 'crack'?
> >
> > Also, what should I expect to pay for a head replacement, assuming the
use
> > of aftermarket parts of course? The mechanics estimate, as stated, was
> > about $3K all told. Am I being had? Is that too rich?
>
> It's all well and good that your mechanic is the trustworthy sort, but a
> judgement call on what may or may not be a crack is going to potentially
> cost you $3k. Why not spend an hour of labor and do the test.
>
> Also, 3K sounds a bit steep. Why not price out a rebuilt head yourself
and
> see?
>
> -Fred W
> Since your bimmer is 14 yrs young, why not look into a salvaged head take
it to a machine shop have it cleaned up.

On Sat, 18 Sep 2004 10:11:39 -0700, Antonio Garcia wrote:

>
> Got a 1990 325i (E30/M20) that was overheating, but with no apparent
> pressure loss in the cooling system and no obvious leaks. Took it to H&B
> in Berkeley, CA and they took the cylinder head off.
>
> The head gasket itself looked ok, although it looked as if the head itself
> might have slid around a bit w/ respect to the block. We (meaning the
> mechanic and I) thought that encouraging, as a crappy gasket was the best
> (or least expensive) of the possible scenarios. However, looking closer at
> the cylinder head, between cylinders 4 and 5, the mechanic finds what he
> calls a 'crack' in the head. I look at it too (picture us there,
> flashlight in hand, peering past the camshafts and rockers), and true
> enough, I see what looks like a smudged discoloration at the base of where
> the valve spring rests. If I squint, I can sort of see what looks like a
> possible hairline fissure connecting two of the discolored spots. Frankly,
> it doesn't look like real crack (could easily have been a particularly
> stubborn oil smudge) and it hardly seemed like the sort of thing that
> would have terrorized my cooling system. However I trust the mechanic (I
> have it from trustable sources that H&B is among the best BMW shops in the
> Bay Area...perhaps some here would disagree). When I questioned his
> judgement, the mechanic graciously offered to do a dye test whereby they
> actually leak some dye from the oil compartment to the coolant compartment
> on the other side. The downside: an hour plus more labor (at $90/hr) to
> remove the camshaft and valves and do the test.
>
> I would usually trust him,
> but replacing the head is going to cost a very painful $3K or so (parts
> and labor included) while just replacing the gasket is about $1.3K. Should
> I have him do it, or am I paranoid? I have never seen a cracked head so I
> don't even know what to look for...only have a paltry former machinist's
> intuition to go on. Does my description sound typical of a 'crack'?
>
> Also, what should I expect to pay for a head replacement, assuming the use
> of aftermarket parts of course? The mechanics estimate, as stated, was
> about $3K all told. Am I being had? Is that too rich?
>
I'd say the money spent on a dye penetratation test would be well spent if
there's any evidence that the head might be cracked. If it is cracked and
you simply replace the head gasket the problem is sure to re-surface and
you'll have spent 1.3k for nothing.

--
The instructions said to use Windows 98 or better, so I installed RedHat.

Well, the default at this point is to go ahead and replace the head. The
dye test is just a gamble to see if it isn't a crack, and can hence get
out of paying for a head replacement. No way I'm going to have the gasket
changed and have what looks like a crack stay in the head without checking
it out.

Even if the dye test fails though (i.e. no leak) I would probably change
it. Even if the crack hasn't split yet, even to my eye I could see what
looked like a hairline fracture. The more I think about it the more I
think I should just replace the head.

I am already about $400-500 in the
hole for opening up the engine, and putting it back together (with the
same old head) will cost about $1.3K (mechanics' teardown and
back-together estimate).


Snooping around, I see an unassembled original BMW head on
bavautosports.com for $1250. On ebay, retooled heads go for as low at $550
(!). Mechanic's off-the-cuff quote: $1900 for new (which is about right).
You can find anything on ebay, looks like.

At this point, the only
additional expense is the about $600 for the new head. I'll have to just
bite the bullet I guess...

A.


On Sat, 18 Sep 2004, Jim Levie wrote:

> On Sat, 18 Sep 2004 10:11:39 -0700, Antonio Garcia wrote:
>
> >
> > Got a 1990 325i (E30/M20) that was overheating, but with no apparent
> > pressure loss in the cooling system and no obvious leaks. Took it to H&B
> > in Berkeley, CA and they took the cylinder head off.
> >
> > The head gasket itself looked ok, although it looked as if the head itself
> > might have slid around a bit w/ respect to the block. We (meaning the
> > mechanic and I) thought that encouraging, as a crappy gasket was the best
> > (or least expensive) of the possible scenarios. However, looking closer at
> > the cylinder head, between cylinders 4 and 5, the mechanic finds what he
> > calls a 'crack' in the head. I look at it too (picture us there,
> > flashlight in hand, peering past the camshafts and rockers), and true
> > enough, I see what looks like a smudged discoloration at the base of where
> > the valve spring rests. If I squint, I can sort of see what looks like a
> > possible hairline fissure connecting two of the discolored spots. Frankly,
> > it doesn't look like real crack (could easily have been a particularly
> > stubborn oil smudge) and it hardly seemed like the sort of thing that
> > would have terrorized my cooling system. However I trust the mechanic (I
> > have it from trustable sources that H&B is among the best BMW shops in the
> > Bay Area...perhaps some here would disagree). When I questioned his
> > judgement, the mechanic graciously offered to do a dye test whereby they
> > actually leak some dye from the oil compartment to the coolant compartment
> > on the other side. The downside: an hour plus more labor (at $90/hr) to
> > remove the camshaft and valves and do the test.
> >
> > I would usually trust him,
> > but replacing the head is going to cost a very painful $3K or so (parts
> > and labor included) while just replacing the gasket is about $1.3K. Should
> > I have him do it, or am I paranoid? I have never seen a cracked head so I
> > don't even know what to look for...only have a paltry former machinist's
> > intuition to go on. Does my description sound typical of a 'crack'?
> >
> > Also, what should I expect to pay for a head replacement, assuming the use
> > of aftermarket parts of course? The mechanics estimate, as stated, was
> > about $3K all told. Am I being had? Is that too rich?
> >
> I'd say the money spent on a dye penetratation test would be well spent if
> there's any evidence that the head might be cracked. If it is cracked and
> you simply replace the head gasket the problem is sure to re-surface and
> you'll have spent 1.3k for nothing.
>
> --
> The instructions said to use Windows 98 or better, so I installed RedHat.
>
>

On Sat, 18 Sep 2004 16:14:25 -0700, Antonio Garcia wrote:

>
> Well, the default at this point is to go ahead and replace the head. The
> dye test is just a gamble to see if it isn't a crack, and can hence get
> out of paying for a head replacement. No way I'm going to have the gasket
> changed and have what looks like a crack stay in the head without checking
> it out.
>
> Even if the dye test fails though (i.e. no leak) I would probably change
> it. Even if the crack hasn't split yet, even to my eye I could see what
> looked like a hairline fracture. The more I think about it the more I
> think I should just replace the head.
>
I think you might be confused about what a dye penetration test reveals.
Done properly it will find the smallest of hairline cracks that can't be
seen even with a magnifier. If you did have the test done and it didn't
show any cracks I'd have no hesitation in using that head and would be
looking elsewhere for the cause of overheating.

FWIW: The usual head related cause of overheating is leakage of cylinder
gases into the water jacket. I've never seen a case when that was the
cause that there was not also an inexplicable loss of coolant. What
happens is that cooling system pressure rises above the limit and coolant
is vented out of the overflow. Unless the gas leak is really bad this will
only occur when driving and that leaves no evidence of what's happening.
And the reason that one looses coolant is that a gas bubble will form in
the block and force coolant out to the tank.

--
The instructions said to use Windows 98 or better, so I installed RedHat.

> I think you might be confused about what a dye penetration test reveals.
> Done properly it will find the smallest of hairline cracks that can't be
> seen even with a magnifier. If you did have the test done and it didn't
> show any cracks I'd have no hesitation in using that head and would be
> looking elsewhere for the cause of overheating.

Even if visual inspection showed what looked like a developing crack? If
the crack doesn't leak now, it'll probably leak later. The thing's
already taken apart. Having found a replacement head on ebay for $550, I
am now more inclined to just change heads rather than make the error of
putting an old, possibly cracked one back in, having it bust at some later
date (even if it isn't leaking now) and then have to pay another $1.3K
just to take down the engine again.


>
> FWIW: The usual head related cause of overheating is leakage of cylinder
> gases into the water jacket. I've never seen a case when that was the
> cause that there was not also an inexplicable loss of coolant. What
> happens is that cooling system pressure rises above the limit and coolant
> is vented out of the overflow. Unless the gas leak is really bad this will
> only occur when driving and that leaves no evidence of what's happening.
> And the reason that one looses coolant is that a gas bubble will form in
> the block and force coolant out to the tank.

We're finding coolant in the oil...it's forming that gooey yellowish mix.
So there must be coolant getting into the oil somehow...and not just
venting out to the overflow tank.

A.

Antonio Garcia wrote:
>> I think you might be confused about what a dye penetration test
>> reveals. Done properly it will find the smallest of hairline cracks
>> that can't be seen even with a magnifier. If you did have the test
>> done and it didn't show any cracks I'd have no hesitation in using
>> that head and would be looking elsewhere for the cause of
>> overheating.
>
> Even if visual inspection showed what looked like a developing
crack?
> If the crack doesn't leak now, it'll probably leak later. The
thing's
> already taken apart. Having found a replacement head on ebay for
> $550, I am now more inclined to just change heads rather than make
> the error of putting an old, possibly cracked one back in, having it
> bust at some later date (even if it isn't leaking now) and then have
> to pay another $1.3K just to take down the engine again.
>

Don't be surprised to see your old head advertised as a replacement on
ebay before long ;-)

Huw


---
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Checked by AVG anti-virus system (http://www.grisoft.com).
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On Sat, 18 Sep 2004 21:09:00 -0700, Antonio Garcia wrote:

> Even if visual inspection showed what looked like a developing crack? If
> the crack doesn't leak now, it'll probably leak later. The thing's already
> taken apart. Having found a replacement head on ebay for $550, I am now
> more inclined to just change heads rather than make the error of putting
> an old, possibly cracked one back in, having it bust at some later date
> (even if it isn't leaking now) and then have to pay another $1.3K just to
> take down the engine again.
>
If you can get a new or re-man head for $550, then I'd tend to agree that
it's not worthwhile to test the head.
>
>> FWIW: The usual head related cause of overheating is leakage of
>> cylinder gases into the water jacket. I've never seen a case when that
>> was the cause that there was not also an inexplicable loss of coolant.
>> What happens is that cooling system pressure rises above the limit and
>> coolant is vented out of the overflow. Unless the gas leak is really
>> bad this will only occur when driving and that leaves no evidence of
>> what's happening. And the reason that one looses coolant is that a gas
>> bubble will form in the block and force coolant out to the tank.
>
> We're finding coolant in the oil...it's forming that gooey yellowish
> mix. So there must be coolant getting into the oil somehow...and not
> just venting out to the overflow tank.
>
That's almost certainly a gasket failure, but it wouldn't cause
overheating. So perhaps you had both of the classic gasket failure
problems.

--
The instructions said to use Windows 98 or better, so I installed RedHat.

"Antonio Garcia" > wrote in message
keley.EDU...
> > I think you might be confused about what a dye penetration test reveals.
> > Done properly it will find the smallest of hairline cracks that can't be
> > seen even with a magnifier. If you did have the test done and it didn't
> > show any cracks I'd have no hesitation in using that head and would be
> > looking elsewhere for the cause of overheating.
>
> Even if visual inspection showed what looked like a developing crack? If
> the crack doesn't leak now, it'll probably leak later. The thing's
> already taken apart. Having found a replacement head on ebay for $550, I
> am now more inclined to just change heads rather than make the error of
> putting an old, possibly cracked one back in, having it bust at some later
> date (even if it isn't leaking now) and then have to pay another $1.3K
> just to take down the engine again.

Unless the one you're thinking of buying is guaranteed to be in good
condition, I would prefer using a tried and trusted head that had been
checked, crack tested and found to be OK.
As Jim Levie said. If it's properly crack tested, and found to be OK, it has
no cracks. Period.
Mike.