Re: '93 Civic CX - DIED in parking lot?!?
 

When I pulled the plug wires to check for oil, the tubes looked clean.
The first mechanic did a quite thorough job cleaning out the oil.

I interrogated my mechanic today (in person) and was able to see a
very good reason for my engine woes.

Compression test: 105 / 80 / 60 / 60 which improved on the low
cylinders when a little oil was squirted in. Looks like a ring problem
- explains the sluggishness and hesitation too. He expects ~110 psi
across the board for an engine of my vintage.

The ignition circuitry does seem to be giving a good spark.

He agreed that just replacing the ICM (which the first mechanic did)
was something sort of odd. He would have opted to replace the whole
assembly for a remanufactured one.

Sigh ...

Re: '93 Civic CX - DIED in parking lot?!?
 

When I pulled the plug wires to check for oil, the tubes looked clean.
The first mechanic did a quite thorough job cleaning out the oil.

I interrogated my mechanic today (in person) and was able to see a
very good reason for my engine woes.

Compression test: 105 / 80 / 60 / 60 which improved on the low
cylinders when a little oil was squirted in. Looks like a ring problem
- explains the sluggishness and hesitation too. He expects ~110 psi
across the board for an engine of my vintage.

The ignition circuitry does seem to be giving a good spark.

He agreed that just replacing the ICM (which the first mechanic did)
was something sort of odd. He would have opted to replace the whole
assembly for a remanufactured one.

Sigh ...

Re: '93 Civic CX - DIED in parking lot?!?
 

madmanguruman@gmail.com wrote in news:1180536400.115161.192510
@q69g2000hsb.googlegroups.com:

> When I pulled the plug wires to check for oil, the tubes looked clean.
> The first mechanic did a quite thorough job cleaning out the oil.
>
> I interrogated my mechanic today (in person) and was able to see a
> very good reason for my engine woes.
>
> Compression test: 105 / 80 / 60 / 60



Oh. My. Gosh.

You are, not to put too fine a point on it, WAY, WAY LOW.



> which improved on the low
> cylinders when a little oil was squirted in. Looks like a ring problem
> - explains the sluggishness and hesitation too. He expects ~110 psi
> across the board for an engine of my vintage.


Wow. And you've only got 244,000km, which is a skimpy 151,000 miles.

While I considered the possibility of low compression as being the cause
of your woes, I did not expect that your compression could be that low
at this mileage.

You bought the car with 106K miles on it, and got a pretty good price.

I'm afraid the previous owner did not take care of the car quite the way
you might have hoped. At this point you should consider either selling
the car or replacing the engine.

A rebuild will likely not be economic. An engine with compression this
low has suffered severe neglect, and it is a guarantee the crankshaft is
scored.

What were your numbers when you passed DriveClean when you transferred
ownership? Do you still have the printout? Did the car start and run OK
when you bought it?



>
> The ignition circuitry does seem to be giving a good spark.
>
> He agreed that just replacing the ICM (which the first mechanic did)
> was something sort of odd. He would have opted to replace the whole
> assembly for a remanufactured one.
>
> Sigh ...
>


Sorry, Adam. Wish the news was better.



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

Re: '93 Civic CX - DIED in parking lot?!?
 

madmanguruman@gmail.com wrote in news:1180536400.115161.192510
@q69g2000hsb.googlegroups.com:

> When I pulled the plug wires to check for oil, the tubes looked clean.
> The first mechanic did a quite thorough job cleaning out the oil.
>
> I interrogated my mechanic today (in person) and was able to see a
> very good reason for my engine woes.
>
> Compression test: 105 / 80 / 60 / 60



Oh. My. Gosh.

You are, not to put too fine a point on it, WAY, WAY LOW.



> which improved on the low
> cylinders when a little oil was squirted in. Looks like a ring problem
> - explains the sluggishness and hesitation too. He expects ~110 psi
> across the board for an engine of my vintage.


Wow. And you've only got 244,000km, which is a skimpy 151,000 miles.

While I considered the possibility of low compression as being the cause
of your woes, I did not expect that your compression could be that low
at this mileage.

You bought the car with 106K miles on it, and got a pretty good price.

I'm afraid the previous owner did not take care of the car quite the way
you might have hoped. At this point you should consider either selling
the car or replacing the engine.

A rebuild will likely not be economic. An engine with compression this
low has suffered severe neglect, and it is a guarantee the crankshaft is
scored.

What were your numbers when you passed DriveClean when you transferred
ownership? Do you still have the printout? Did the car start and run OK
when you bought it?



>
> The ignition circuitry does seem to be giving a good spark.
>
> He agreed that just replacing the ICM (which the first mechanic did)
> was something sort of odd. He would have opted to replace the whole
> assembly for a remanufactured one.
>
> Sigh ...
>


Sorry, Adam. Wish the news was better.



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

Re: '93 Civic CX - DIED in parking lot?!?
 

<madmanguruman@gmail.com> wrote in message
news:1180536400.115161.192510@q69g2000hsb.googlegr oups.com...
> I interrogated my mechanic today (in person) and was able to see a
> very good reason for my engine woes.
>
> Compression test: 105 / 80 / 60 / 60 which improved on the low
> cylinders when a little oil was squirted in. Looks like a ring problem
> - explains the sluggishness and hesitation too. He expects ~110 psi
> across the board for an engine of my vintage.
>

OTOH, you have a heck of a doorstop there.

Mike

Re: '93 Civic CX - DIED in parking lot?!?
 

<madmanguruman@gmail.com> wrote in message
news:1180536400.115161.192510@q69g2000hsb.googlegr oups.com...
> I interrogated my mechanic today (in person) and was able to see a
> very good reason for my engine woes.
>
> Compression test: 105 / 80 / 60 / 60 which improved on the low
> cylinders when a little oil was squirted in. Looks like a ring problem
> - explains the sluggishness and hesitation too. He expects ~110 psi
> across the board for an engine of my vintage.
>

OTOH, you have a heck of a doorstop there.

Mike

Re: '93 Civic CX - DIED in parking lot?!?
 

> While I considered the possibility of low compression as being the cause
> of your woes, I did not expect that your compression could be that low
> at this mileage.

Of course. No one expects a reasonably-well-working D-series engine to
just fall apart like that. We certainly didn't!

We've been religious with our 5000 km oil and filter changes, usually
erring on the side of caution (and never going more than 100 km over).

We never bothered with premium gas since the owner's manual specifies 87
octane.

The previous owner indicated that the car did have an overheat problem
for a time, during which it was not used for long trips. The owner's
brother-in-law "fixed it" at which point they resumed using it both
short haul and good highway drives (i.e. Toronto to Montreal and back),
but I'd say that 75% of the car's use prior to my takeover of it was
strictly city.

> What were your numbers when you passed DriveClean when you transferred
> ownership? Do you still have the printout? Did the car start and run OK
> when you bought it?

March 2006 / August 2004 (when purchased)
40 km/h
HC PPM: 23 / 0
CO%: 0.02 / 0.03
NO PPM: 104 / 128
RPM: 1809 / 2122
Dilution: 14.62 / 14.73

Curb idle:
HC PPM: 15 / 0
CO %: 0 / 0
RPM: 751 / 751
Dilution 13.50 / 14.10

The shop that did both of these certifications (not our regular
mechanic, BTW) is currently under a 4-month DriveClean inspection
suspension, as per the MTO website.

The car ran OK even after purchase, but was sluggish getting up to
speed. The big tune-up done in early 2005 remedied that nicely (plugs,
wires, cap, rotor, PCV valve, rocker gaskets). The only "problem" that
was found during the one-and-only tune-up was that one of the vacuum
hoses had collapsed, which was MacGyvered by cutting out the stressed
portion and clamping the two pieces around a metal stent (since the
mechanic indicated that a new hose would have to come from the dealership)

Ever since that tune-up, the oil consumption has slowly been creeping
upwards, to the point where we needed to top up over a quart between
changes. I don't blame the workmanship.

> I'm afraid the previous owner did not take care of the car quite the way
> you might have hoped. At this point you should consider either selling
> the car or replacing the engine.
>
> A rebuild will likely not be economic. An engine with compression this
> low has suffered severe neglect, and it is a guarantee the crankshaft is
> scored.

Considering the money we've put into the drive train and body, our
mechanic is going to install a used JDM for us, most likely a D16Y.
$1200 plus taxes (plus $150 to replace the rotting radiator at the same
time - might as well with the engine out).

Is my understanding correct in that the D16 series doesn't suffer from
the oil-leak-around-the-plug problem?

If you want to update the gory details to the site, feel free ...

Six weeks ago: ICM and rocker gaskets (no spark)
Four weeks ago: Front passenger side tire sidewall failure (covered by
Cdn Tire warranty)
Three weeks ago: Passenger side balljoint separation while driving
(fortunately while driving out of a parking lot)
This week: Catastrophic compression failure - engine and radiator
replacement

Plus our cat needed surgery! Seven thousand big ones in seven weeks...

Re: '93 Civic CX - DIED in parking lot?!?
 

> While I considered the possibility of low compression as being the cause
> of your woes, I did not expect that your compression could be that low
> at this mileage.

Of course. No one expects a reasonably-well-working D-series engine to
just fall apart like that. We certainly didn't!

We've been religious with our 5000 km oil and filter changes, usually
erring on the side of caution (and never going more than 100 km over).

We never bothered with premium gas since the owner's manual specifies 87
octane.

The previous owner indicated that the car did have an overheat problem
for a time, during which it was not used for long trips. The owner's
brother-in-law "fixed it" at which point they resumed using it both
short haul and good highway drives (i.e. Toronto to Montreal and back),
but I'd say that 75% of the car's use prior to my takeover of it was
strictly city.

> What were your numbers when you passed DriveClean when you transferred
> ownership? Do you still have the printout? Did the car start and run OK
> when you bought it?

March 2006 / August 2004 (when purchased)
40 km/h
HC PPM: 23 / 0
CO%: 0.02 / 0.03
NO PPM: 104 / 128
RPM: 1809 / 2122
Dilution: 14.62 / 14.73

Curb idle:
HC PPM: 15 / 0
CO %: 0 / 0
RPM: 751 / 751
Dilution 13.50 / 14.10

The shop that did both of these certifications (not our regular
mechanic, BTW) is currently under a 4-month DriveClean inspection
suspension, as per the MTO website.

The car ran OK even after purchase, but was sluggish getting up to
speed. The big tune-up done in early 2005 remedied that nicely (plugs,
wires, cap, rotor, PCV valve, rocker gaskets). The only "problem" that
was found during the one-and-only tune-up was that one of the vacuum
hoses had collapsed, which was MacGyvered by cutting out the stressed
portion and clamping the two pieces around a metal stent (since the
mechanic indicated that a new hose would have to come from the dealership)

Ever since that tune-up, the oil consumption has slowly been creeping
upwards, to the point where we needed to top up over a quart between
changes. I don't blame the workmanship.

> I'm afraid the previous owner did not take care of the car quite the way
> you might have hoped. At this point you should consider either selling
> the car or replacing the engine.
>
> A rebuild will likely not be economic. An engine with compression this
> low has suffered severe neglect, and it is a guarantee the crankshaft is
> scored.

Considering the money we've put into the drive train and body, our
mechanic is going to install a used JDM for us, most likely a D16Y.
$1200 plus taxes (plus $150 to replace the rotting radiator at the same
time - might as well with the engine out).

Is my understanding correct in that the D16 series doesn't suffer from
the oil-leak-around-the-plug problem?

If you want to update the gory details to the site, feel free ...

Six weeks ago: ICM and rocker gaskets (no spark)
Four weeks ago: Front passenger side tire sidewall failure (covered by
Cdn Tire warranty)
Three weeks ago: Passenger side balljoint separation while driving
(fortunately while driving out of a parking lot)
This week: Catastrophic compression failure - engine and radiator
replacement

Plus our cat needed surgery! Seven thousand big ones in seven weeks...

Re: '93 Civic CX - DIED in parking lot?!?
 

Michael Pardee wrote:
> <madmanguruman@gmail.com> wrote in message
> news:1180536400.115161.192510@q69g2000hsb.googlegr oups.com...
>
>>I interrogated my mechanic today (in person) and was able to see a
>>very good reason for my engine woes.
>>
>>Compression test: 105 / 80 / 60 / 60 which improved on the low
>>cylinders when a little oil was squirted in. Looks like a ring problem
>>- explains the sluggishness and hesitation too. He expects ~110 psi
>>across the board for an engine of my vintage.
>>
>
>
> OTOH, you have a heck of a doorstop there.
>
> Mike
>
>


Yep... Anything under 100psi will probably not fire.

JT

Re: '93 Civic CX - DIED in parking lot?!?
 

Michael Pardee wrote:
> <madmanguruman@gmail.com> wrote in message
> news:1180536400.115161.192510@q69g2000hsb.googlegr oups.com...
>
>>I interrogated my mechanic today (in person) and was able to see a
>>very good reason for my engine woes.
>>
>>Compression test: 105 / 80 / 60 / 60 which improved on the low
>>cylinders when a little oil was squirted in. Looks like a ring problem
>>- explains the sluggishness and hesitation too. He expects ~110 psi
>>across the board for an engine of my vintage.
>>
>
>
> OTOH, you have a heck of a doorstop there.
>
> Mike
>
>


Yep... Anything under 100psi will probably not fire.

JT

Re: '93 Civic CX - DIED in parking lot?!?
 

Adam Christopher Lawrence <madmanguruman@gmail.com> wrote in
news:6d34b$465e2e4f$cf705650$9863@PRIMUS.CA:

>> While I considered the possibility of low compression as being the
>> cause of your woes, I did not expect that your compression could be
>> that low at this mileage.
>
> Of course. No one expects a reasonably-well-working D-series engine to
> just fall apart like that. We certainly didn't!



They don't. Only if neglected or abused!


>
> We've been religious with our 5000 km oil and filter changes, usually
> erring on the side of caution (and never going more than 100 km over).
>
> We never bothered with premium gas since the owner's manual specifies
> 87 octane.
>
> The previous owner indicated that the car did have an overheat problem
> for a time, during which it was not used for long trips. The owner's
> brother-in-law "fixed it" at which point they resumed using it both
> short haul and good highway drives (i.e. Toronto to Montreal and
> back), but I'd say that 75% of the car's use prior to my takeover of
> it was strictly city.



Overheating? Uh-oh. I wonder if it came to replacing the head gasket.

If the brother-in-law used sandpaper to clean the block face when
replacing the head gasket, you engine's days are numbered. Grit falls
into the bores and chews up the rings extremely hastily.

There is one more possibility for the low compression: A warped head, or
a burned valve. If the valve seats are not dead square to the valves,
they won't seal completely. If the clearances have not been maintained,
the exhaust valve can burn, also leading to leakage.

The test for this involves rotating the engine by hand until the valves
are closed, then blowing shop air into the cylinder through the spark
plug hole. If there is hissing through the throttle body or the exhaust,
a valve is not seating properly.

There is a (remote) chance that soft carbon buildup is propping one of
the valves open, something that can happen to cars that spend much of
their time doing short-hop, low-speed city driving. In that case, an
"Italian tuneup" will usually cure that.



>
>> What were your numbers when you passed DriveClean when you
>> transferred ownership? Do you still have the printout? Did the car
>> start and run OK when you bought it?
>
> March 2006 / August 2004 (when purchased)
> 40 km/h
> HC PPM: 23 / 0
> CO%: 0.02 / 0.03
> NO PPM: 104 / 128
> RPM: 1809 / 2122
> Dilution: 14.62 / 14.73
>
> Curb idle:
> HC PPM: 15 / 0
> CO %: 0 / 0
> RPM: 751 / 751
> Dilution 13.50 / 14.10



Amazing what a good cat will eat up. Those numbers are very good.



>
> The shop that did both of these certifications (not our regular
> mechanic, BTW) is currently under a 4-month DriveClean inspection
> suspension, as per the MTO website.
>
> The car ran OK even after purchase, but was sluggish getting up to
> speed. The big tune-up done in early 2005 remedied that nicely (plugs,
> wires, cap, rotor, PCV valve, rocker gaskets). The only "problem" that
> was found during the one-and-only tune-up was that one of the vacuum
> hoses had collapsed, which was MacGyvered by cutting out the stressed
> portion and clamping the two pieces around a metal stent (since the
> mechanic indicated that a new hose would have to come from the
> dealership)
>
> Ever since that tune-up, the oil consumption has slowly been creeping
> upwards, to the point where we needed to top up over a quart between
> changes. I don't blame the workmanship.



You also just might be paying more attention to oil consumption than you
were before. What you describe is about 3,000 miles per quart of oil.
That's somewhat high, but acceptable for an engine that's not had the
best of care.

Disastrous would be if you wewre having to dump in a quart with every
gas fillup.



>
>> I'm afraid the previous owner did not take care of the car quite the
>> way you might have hoped. At this point you should consider either
>> selling the car or replacing the engine.
>>
>> A rebuild will likely not be economic. An engine with compression
>> this low has suffered severe neglect, and it is a guarantee the
>> crankshaft is scored.
>
> Considering the money we've put into the drive train and body, our
> mechanic is going to install a used JDM for us, most likely a D16Y.
> $1200 plus taxes (plus $150 to replace the rotting radiator at the
> same time - might as well with the engine out).



JDM is a good idea. However, be prepared for possible glitches, such as
having to drill new holes or fabricate brackets. Non-North American
engines have some stuff in different places.


>
> Is my understanding correct in that the D16 series doesn't suffer from
> the oil-leak-around-the-plug problem?



All the D and B-series are prone to oil leakage if the gaskets are not
changed occasionally. Oil leakage is exacerbated if oil changes are
neglected, which I suspect was the case before you bought the car.


>
> If you want to update the gory details to the site, feel free ...
>
> Six weeks ago: ICM and rocker gaskets (no spark)
> Four weeks ago: Front passenger side tire sidewall failure (covered by
> Cdn Tire warranty)
> Three weeks ago: Passenger side balljoint separation while driving
> (fortunately while driving out of a parking lot)
> This week: Catastrophic compression failure - engine and radiator
> replacement
>
> Plus our cat needed surgery! Seven thousand big ones in seven weeks...



You're nothing if not persistent. I'll put this up soon.



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

Re: '93 Civic CX - DIED in parking lot?!?
 

Adam Christopher Lawrence <madmanguruman@gmail.com> wrote in
news:6d34b$465e2e4f$cf705650$9863@PRIMUS.CA:

>> While I considered the possibility of low compression as being the
>> cause of your woes, I did not expect that your compression could be
>> that low at this mileage.
>
> Of course. No one expects a reasonably-well-working D-series engine to
> just fall apart like that. We certainly didn't!



They don't. Only if neglected or abused!


>
> We've been religious with our 5000 km oil and filter changes, usually
> erring on the side of caution (and never going more than 100 km over).
>
> We never bothered with premium gas since the owner's manual specifies
> 87 octane.
>
> The previous owner indicated that the car did have an overheat problem
> for a time, during which it was not used for long trips. The owner's
> brother-in-law "fixed it" at which point they resumed using it both
> short haul and good highway drives (i.e. Toronto to Montreal and
> back), but I'd say that 75% of the car's use prior to my takeover of
> it was strictly city.



Overheating? Uh-oh. I wonder if it came to replacing the head gasket.

If the brother-in-law used sandpaper to clean the block face when
replacing the head gasket, you engine's days are numbered. Grit falls
into the bores and chews up the rings extremely hastily.

There is one more possibility for the low compression: A warped head, or
a burned valve. If the valve seats are not dead square to the valves,
they won't seal completely. If the clearances have not been maintained,
the exhaust valve can burn, also leading to leakage.

The test for this involves rotating the engine by hand until the valves
are closed, then blowing shop air into the cylinder through the spark
plug hole. If there is hissing through the throttle body or the exhaust,
a valve is not seating properly.

There is a (remote) chance that soft carbon buildup is propping one of
the valves open, something that can happen to cars that spend much of
their time doing short-hop, low-speed city driving. In that case, an
"Italian tuneup" will usually cure that.



>
>> What were your numbers when you passed DriveClean when you
>> transferred ownership? Do you still have the printout? Did the car
>> start and run OK when you bought it?
>
> March 2006 / August 2004 (when purchased)
> 40 km/h
> HC PPM: 23 / 0
> CO%: 0.02 / 0.03
> NO PPM: 104 / 128
> RPM: 1809 / 2122
> Dilution: 14.62 / 14.73
>
> Curb idle:
> HC PPM: 15 / 0
> CO %: 0 / 0
> RPM: 751 / 751
> Dilution 13.50 / 14.10



Amazing what a good cat will eat up. Those numbers are very good.



>
> The shop that did both of these certifications (not our regular
> mechanic, BTW) is currently under a 4-month DriveClean inspection
> suspension, as per the MTO website.
>
> The car ran OK even after purchase, but was sluggish getting up to
> speed. The big tune-up done in early 2005 remedied that nicely (plugs,
> wires, cap, rotor, PCV valve, rocker gaskets). The only "problem" that
> was found during the one-and-only tune-up was that one of the vacuum
> hoses had collapsed, which was MacGyvered by cutting out the stressed
> portion and clamping the two pieces around a metal stent (since the
> mechanic indicated that a new hose would have to come from the
> dealership)
>
> Ever since that tune-up, the oil consumption has slowly been creeping
> upwards, to the point where we needed to top up over a quart between
> changes. I don't blame the workmanship.



You also just might be paying more attention to oil consumption than you
were before. What you describe is about 3,000 miles per quart of oil.
That's somewhat high, but acceptable for an engine that's not had the
best of care.

Disastrous would be if you wewre having to dump in a quart with every
gas fillup.



>
>> I'm afraid the previous owner did not take care of the car quite the
>> way you might have hoped. At this point you should consider either
>> selling the car or replacing the engine.
>>
>> A rebuild will likely not be economic. An engine with compression
>> this low has suffered severe neglect, and it is a guarantee the
>> crankshaft is scored.
>
> Considering the money we've put into the drive train and body, our
> mechanic is going to install a used JDM for us, most likely a D16Y.
> $1200 plus taxes (plus $150 to replace the rotting radiator at the
> same time - might as well with the engine out).



JDM is a good idea. However, be prepared for possible glitches, such as
having to drill new holes or fabricate brackets. Non-North American
engines have some stuff in different places.


>
> Is my understanding correct in that the D16 series doesn't suffer from
> the oil-leak-around-the-plug problem?



All the D and B-series are prone to oil leakage if the gaskets are not
changed occasionally. Oil leakage is exacerbated if oil changes are
neglected, which I suspect was the case before you bought the car.


>
> If you want to update the gory details to the site, feel free ...
>
> Six weeks ago: ICM and rocker gaskets (no spark)
> Four weeks ago: Front passenger side tire sidewall failure (covered by
> Cdn Tire warranty)
> Three weeks ago: Passenger side balljoint separation while driving
> (fortunately while driving out of a parking lot)
> This week: Catastrophic compression failure - engine and radiator
> replacement
>
> Plus our cat needed surgery! Seven thousand big ones in seven weeks...



You're nothing if not persistent. I'll put this up soon.



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

Re: '93 Civic CX - DIED in parking lot?!?
 

Tegger <tegger@tegger.c0m> wrote in
news:Xns99416C31ABA1Ategger@207.14.116.130:


>
> The test for this involves rotating the engine by hand until the
> valves are closed, then blowing shop air into the cylinder through the
> spark plug hole. If there is hissing through the throttle body or the
> exhaust, a valve is not seating properly.



Disconnect the PCV system before doing this!

--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

Re: '93 Civic CX - DIED in parking lot?!?
 

Tegger <tegger@tegger.c0m> wrote in
news:Xns99416C31ABA1Ategger@207.14.116.130:


>
> The test for this involves rotating the engine by hand until the
> valves are closed, then blowing shop air into the cylinder through the
> spark plug hole. If there is hissing through the throttle body or the
> exhaust, a valve is not seating properly.



Disconnect the PCV system before doing this!

--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

Re: '93 Civic CX - DIED in parking lot?!?
 

> If the brother-in-law used sandpaper to clean the block face when
> replacing the head gasket, you engine's days are numbered. Grit falls
> into the bores and chews up the rings extremely hastily.

I would estimate this repair at somewhere around 2 years prior to my
purchase of the car, so we're talking 4-5 years. My mechanic doesn't
think that the head gasket is to blame.

> There is one more possibility for the low compression: A warped head, or
> a burned valve. If the valve seats are not dead square to the valves,
> they won't seal completely. If the clearances have not been maintained,
> the exhaust valve can burn, also leading to leakage.

> There is a (remote) chance that soft carbon buildup is propping one of
> the valves open, something that can happen to cars that spend much of
> their time doing short-hop, low-speed city driving. In that case, an
> "Italian tuneup" will usually cure that.

We consistently bring (brought, I suppose, is the correct term now)
the car up to 120-130 km/h during highway driving, which for us is at
least once per week (minimum). Good 300-400 km round trips would
happen at least monthly.

> JDM is a good idea. However, be prepared for possible glitches, such as
> having to drill new holes or fabricate brackets. Non-North American
> engines have some stuff in different places.

Good to know; I'll be sure to ask the mechanic once the car is ready.
Fortunately, I haven't yet done my annual rustproofing, so any new
holes/brackets/etc will get hit when I get the work done. (I use Krown
- no one that I know has had a bad experience with them.)

> All the D and B-series are prone to oil leakage if the gaskets are not
> changed occasionally. Oil leakage is exacerbated if oil changes are
> neglected, which I suspect was the case before you bought the car.

That's also good to know.

My car should be roadworthy again by Saturday - update to follow!