hot air box+ ticking sound

[pepe256]

i started my 86 740 gle and i idled it for around 30 min and i put hand on
the air box and it was extremely hot is the air box thermostat bad and if
it is could it be causing poor mileage? and also when the car is running i
am getting a clicking sound its extrememly fast not extremely loud but
still lud enough to hear over a running engine

 

[James Sweet]

i started my 86 740 gle and i idled it for around 30 min and i put hand on
the air box and it was extremely hot is the air box thermostat bad and if
it is could it be causing poor mileage? and also when the car is running i
am getting a clicking sound its extrememly fast not extremely loud but
still lud enough to hear over a running engine

Hot airbox is bad, that could certainly be the problem, or at least part of
it, and it will kill the air mass meter fairly quickly. For now disconnect
the corrugated aluminum hose that goes from it to the exhaust manifold, if
you live in a mild climate you can throw that part away and wedge the airbox
thermostat so it always sucks in outside air.

The clicking you hear is probably the valves closing, it's normal unless
it's loud or irregular.

 

[Randy G.]

i started my 86 740 gle and i idled it for around 30 min and i put hand on
the air box and it was extremely hot is the air box thermostat bad and if
it is could it be causing poor mileage? and also when the car is running i
am getting a clicking sound its extrememly fast not extremely loud but
still lud enough to hear over a running engine

As James said, the air box should not be hot. In normal operating
tmperatures just shut off the motor and open the box. You will see a
flapper in it that is controlled byt a thermostatic device. The
flapper should be covering the hot air intake hole.

And again, it can ruin the air mass meter (expensive part!). It can
also be a factor in lowering teh gas mileage as well... like he said.

If there is a smog check program in your area it could be illegal to
defeat or disconnect any portion of the air intake system as it is
part of the pollution cntrols designed into the car. Just a heads
up...

Also, if a car is equipped with a catalytic convertor it should not be
allowed to sit, idling for that long without some forced air over it
(like a ventilation fan) becasue it can create a fire hazard.


__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"

 

[pepe256]

i have already removed the hose and it still does it

 

[pepe256]

So could this have somehting to do with my 14mpg and how owuld i know?

 

[Randy G.]

i have already removed the hose and it still does it

You removed the silver, metal'ish' corrugated hose, right? The one
that goes to the heat riser on teh exhaust manifold?

We are NOT talking about the black, plastic hose that goes to the Air
mass Meter and then to the throttle body..

If you removed the correct hose then when you drive the car that box
should be at about he same temp as the outside air. if you are sitting
at idle it can get warm from the ambient heat in the engine
compartment.


__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"

 

[Randy G.]

So could this have somehting to do with my 14mpg and how owuld i know?

Se the other response in this thread, but basically, the hot air is
less dense and expands less when the fuel is ignited in the combustion
chamber. it also will throw off the readings that the air mass meter
gets which will mess up the enmtire fuel metering system.

And as mentioned before, unless you are getting accurate odometer
readings and doing accurate math when figuring teh mileage, AND you
have a locking gas cap, then there is really no way to tell what is
going on.

My advice at this point would be to seek the help of a knowledgeable
mechanic or a prefessional. Continuing to drive the car when it
getting such poor mileage will ruin the rings, damage the AMM, and
possibly necessitate a new catalytic convetor. If you continue to run
the car at idle for 30 minutes at a time it will most likely
eventually catch fire.

I don't what to sound discouraging, but to save $10-200 in mechanics
time you are risking that much in the air mass meter alone, and that
is the price for a cheap rebuilt unit!

__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"

 

[John Robertson]

Unless your in a very cold area the pipe from the exhaust to the air intake
might just fall off or disconnect so you dont cook the air mass meter .My
wifes did ,mine was not fitted from the factory .My inlet was blocked from
the factory so I removed the bung and piped in cool air from beside the
radiator .Did the same with my wifes and sons cars .