1978 Volvo 242 mystery

Hi

I bought this car a few months ago and although its a 4 speed manual, there
seems to be no overdrive. The engine seems fairly powerful, and it
excellerates fast but I dont feel comfortable driving it above 75-80 mph as
it get really loud. I don't know if this seems excessive but I live in the
deep south and sometimes the flow of traffic is even faster. My confusion
is compounded by the lack of a tachometer, so I don't know if I'm even
harming the engine by going that fast. I just want to be able to drive on
the interstate and listen to myself think. Why is it so loud? Why would
they have made a car not designed to go any faster than that as late as
1978? Thanks for any insight you can give.

-Jonas

 

You can easily add a tach, they drop right in where the blank spot is in the
cluster, often you have to run one wire from the tach to the ignition coil
on the older cars. At 80 mph you're probably running close to 4000 RPM, it
won't hurt the engine, it's just noisy. An overdrive was available as an
option but not everyone got it, perhaps they didn't live near a highway at
the time or did very little driving on it. You can swap out the transmission
and front driveshaft for one with an overdrive, it's not particularly
difficult.

 

Right. Most of the tachs on late 1970s B21 engined 240s were redlined at
6500rpm , with a yellow arc at 6000rpm. As long as the timing belt (and
it's tensioner) have been maintained properly, about all that running the
engine at 4000rpm all day (or slightly higher) might result in is burning
more fuel and probably using up a little more oil. The engine may run
hotter too if the radiator is a little old.

But right, there is nothing inherently harmful in running that engine that
hard.

 

You have a real problem! The 240's are designed to do more than 110MPH without
overdrive and no real mechanical noise. Let me guess the used car dealer told
you it had low miles,driven by a little old lady only to church Bill

 

It depends what you mean by loud. If it's just the revs, that's the way it
is. If it an exhaust blowing, or mechanical noise off the tappets for
instance, get under the hood and see whats up. Volvos like yours will travel
all day at 4000 revs with no complaint from the engine.

 

Hi:
I have a 79 with 3 speed auto that also gets loud at about 55 - 60 miles an
hour. Mine is quite quick around town for a 2100 cc engine and I think it is
all in the gearing. I think they may have used a different rear end on my
car compared to my other two 240s I've owned, a 81 and a 89. Those cars
cruised better, but did not have the off the line jump of my 79. As said in
other emails, the tach should read about 4000 RPM at 70. Mine does and I
have driven long distances at that speed with no problem, just a need to
turn up the radio and a little higher gas usage.
bill