bad engine

[hardl;abor]

hi, My 91 740 has lost compression in number 4 cyl, problems started when I
parked the car and came back hours later, wouldnt start, it started up the
next day.Mechanic changed plug,wire, cap and rotor. He thought bad coil,
not, replaced timing belt, because when it did start, it didnt seem to fire
right and than he ran a compression test and said that the # 4 cylinder has
no compression. The mechanic is a friend, I know he is not trying to make
more money on me. I don't know if I should pull the engine apart or just
replace it.I have a 1989 240 with a good engine, but bad body, will a 240
engine swapp into a 740 car? Thank you guys, If anyone has any thoughts on
my problem I would love to hear them. thank hardlabor

 

[Mr. V]

Are the distributors both mounted on the rear of the cam, against the
firewall?

Assuming both are normally aspirated, you should be fine.

But, having said that, why not swap heads, as opposed to engines?

Assuming that is that the compression loss is valve related (in the
head).

It is a PITA to swap engines, and is easier to swap heads.

 

[James Sweet]

hi, My 91 740 has lost compression in number 4 cyl, problems started when
I parked the car and came back hours later, wouldnt start, it started up
the next day.Mechanic changed plug,wire, cap and rotor. He thought bad
coil, not, replaced timing belt, because when it did start, it didnt seem
to fire right and than he ran a compression test and said that the # 4
cylinder has no compression. The mechanic is a friend, I know he is not
trying to make more money on me. I don't know if I should pull the engine
apart or just replace it.I have a 1989 240 with a good engine, but bad
body, will a 240 engine swapp into a 740 car? Thank you guys, If anyone
has any thoughts on my problem I would love to hear them. thank hardlabor

The motors are identical, but you will have to swap some of the accessories
around. The 240 motor will have a gear on the aux shaft to drive the block
mounted distributor while the 740 motor probably will not, but you can
ignore that and plug the hole or you can use a block mounted distributor on
the 740, but the head mounted one will not fit on a 240.

I would pull the head on the bad motor first and see what happened, if it's
just a burned valve it will be easier to replace that, but you will also
need to find out why it burned, bad injector can cause that.

 

[Niels Bengaard]

hi, My 91 740 has lost compression in number 4 cyl, problems started when

I parked the car and came back hours later, wouldnt start, it started up
the next day.Mechanic changed plug,wire, cap and rotor. He thought bad
coil, not, replaced timing belt, because when it did start, it didnt seem
to fire right and than he ran a compression test and said that the # 4
cylinder has no compression. The mechanic is a friend, I know he is not
trying to make more money on me. I don't know if I should pull the engine
apart or just replace it.I have a 1989 240 with a good engine, but bad
body, will a 240 engine swapp into a 740 car? Thank you guys, If anyone
has any thoughts on my problem I would love to hear them. thank hardlabor

Take the head off to have a look first, might only be a bad head gasket.

Greetings Niels