UK 1989 740 Estate Auto B200E

Hi again everybody

Many thanks for all your helpful replies of a couple of weeks ago to the
firing on 3 cylinders immediatly on startup issue.

Trawled through most of the ideas and not got rid of the annoying problem.
The engine fires on four if you blip the throttle a couple of times after
starting.

However I have just noticed something else which may be connected.

The coolant level in the header tank slowly drops from the high to low fill
marks over about a 500 mile period. I have checked for rad and pipe leaks,
core plugs are good and no leaking from the heater control valve, in fact no
obvious leaks anywhere. My thoughts is that the loss of water and the
initial firing on 3 might be connected - a marginally leaking cylinder head
gasket perhaps? Sept 1989 B200E engine, pre Cat
Not sure how to set about checking this or even if I am barking up the
right tree so ance again any help and your thoughts would be much
appreciated.

Thanks

Andy

 

Your reasoning is plausible. The head gasket of red-block engines does
seem to get a lot of mentions on this NG, mine included.

What may be happening is, when you turn the engine off, a little water
is squeezed into the combustion chamber by the pressure within the
cooling system. This may be soaking the plug and stopping it working
when you first start up. When the engine is running, the higher
pressure of combustion is forcing it way into the cooling system and
pushing water out.

In bad cases you can get what is known as hydraulic lock, when there
is enough water in the cylinder to stop the starter motor being able
to turn the engine.

Just before you next stop the engine, undo the coolant cap (be careful
- do it slowly) and leave it loose until you next start the car. This
should stop the pressure pushing the water into the combustion
chamber. If this solves the mis-fire, it suggests the head gasket has
failed, but also check the plug for wetness, and see if the plug
smells of antifreeze (if you can get your nose near he plug hole, have
a sniff here, also). Check your oil filler cap for mayonnaise-type
emulsion.

If the gasket shows signs of failure like this, I would attend to it
soon. I have seen ally heads from engines where this is a problem,
where the tiny flow of water under pressure has started to etch a
miniature version of the Grand Canyon in the head. If this has
happened, it can often be filled with a blob of weld, prior to the
head being machined flat
--

TSH


For email, replace 'SpamOnlyToHere' with my initials

 

What may be happening is, when you turn the engine off, a little water

I'm going to hijack this thread, sorry Andy!

How easy is the B200E's head gasket to change for an amateur mechanic such
as myself? I've done old fashioned pushrod engine head gaskets before
(Triumph Heralds), but the overhead camshaft in the B200E scares me.

Will I need any special tools, patience, luck etc? How long should I allow
for a such a task the first time round (assume the head is actually ok and
doesn't need re-machining)?

Thanks,

David

 

No more difficult than the Herald. The only special tool needed is a
good torque wrench, but while you are at it, change the timing belt
too (unless it is nearly new).

You need to take care and be diligent at every stage, to make sure
that it is right before proceeding further, but a head job is really
just nuts and bolts. You will be diconnecting the radiator hoses,
taking off the valve cover, both manifolds, the distributor, and the
timing belt. Make sure you have the right tools, take your time over
it, but don't be scared.

There are two difficult(-ish) parts to the job. One is loosening the
crankshaft pulley bolt, the other is retrieving the nuts that you keep
dropping when you try and refit the inlet manifold (IME swearing seems
to help here).

Make sure you know the relevant torques, and the order that the head
bolts should be tightened in.

Be sure that you get all the relevant timing marks lined up correctly
when refitting the timing belt.

You need to be accurate when checking the head for flatness - I
usually take it to the nearest machine shop to get them to check it
with a dial test indicator, or similar.


--

TSH


For email, replace 'SpamOnlyToHere' with my initials

 

I think your greatest concern is to make sure the camshaft timing is
not altered.

Whether you remove the manifolds or leave them on is your choice.
Which is more difficult? Getting that one last stuck exhaust nut, or
hoisting all that extra weight and getting the head gasket in place
undamaged, and meanwhile not damaging the intake and exhaust
plumbing? In some ways the Volvo OHC head is easier, since there are
no pushrods or rocker arms to deal with (you can leave the cam in place).

Just throwing out some food for thought, I myself haven't owned or
looked at one of the OHC red engines in almost ten years.

 

Before any removal, look at the spark plugs - one spotlessly clean
indicated the leaking cylinder.

I find it easier to leave most things still connected to the intake
manifold and leave it (intake manifold) in the car about 2" from it's
normal position.

You'll also have to take the exhaust manifold off to get the head
machined. I always take the head off with the exhaust manifold
attached, then remove it, putting it back on after the head is in
place. Heat each exhaust nut cherry red before putting a socket to them
and you won't break any studs.

And you need a decent 10 mm allen key socket for the head bolts - I had
a cheap one the first time and it broke on the 3rd bolt!

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

A bungee cord from manifold to front wheel holds it out of the way.
--

TSH


For email, replace 'SpamOnlyToHere' with my initials

 

It's about as difficult as changing the Herald head _plus_ changing
the Volvo timing belt _plus_ re-adjusting the tappets on an old Fiat
twincam.

You need to change timing belts att intervals anyway. The tappets
need some annoying tooling (which most people forge from old
screwdrivers) and a supply of shims to set them. But none of it's
really _hard_, there's just a bit more of it.

The black Haynes manual (not the blue one) tells all.