Red Hot Exhaust Manifold

[Niccko]

The thing with most head gaskets is that on many engines, you
*can* put them on upside down (flipped left to right) and the bolt
holes still line up, but the coolant passages don't, so you have
partially blocked passages and an overheated head.

The idle is a bit high (s.b. 750±100) . Does it refuse to idle at
lower speeds?

I couldn't find the online manual for your Excel at
www.hmaservice.com/webtech , the closest I could get is 1988.
Do you have a feedback carb and an O2 sensor? If you do and
your O2 sensor is dead, the ECU might think that it needs to
increase the O2 by leaning out the mixture as much as it can,
but not so much that you'd notice a performance problem at
highway speeds.

Looking at the 1988 manual, your secondary air control valve is
supposed to let air into the exhaust manfold when the engine is
warming up, then it switches to sending air downstream to the
2nd cat under the car. If this valve is burnt out or always open,
air would always be going into the manifold and causing the
red-hot condition. Try plugging the hose from the valve to the
manifold and see if things improve. There should also be some
sort of check valve where the hose meets the manifold to
prevent hot exhaust from going back thru the hose and burning
up the valve.

The cliff is starting to sound much better.

Bob

Im having somewhat the same problem with my chevy cavalier 85, 2.0
liter. The exhaust manifold lights up bright red after running for a
few moments. My friend had told me to un-hook the catalytic converter
from the pipe and see if it would get hot. When i looked under the car
i didnt see the catalytic converter. I looked up a picture to make
sure i knew what i was looking for, but found nothing. Timing was
right on and everything, it doesnt seem that the timing chain could
have slipped at all either. Im still stuck on this whole thing.

 

[Bob Bailin]

Im having somewhat the same problem with my chevy cavalier 85, 2.0
liter. The exhaust manifold lights up bright red after running for a
few moments. My friend had told me to un-hook the catalytic converter
from the pipe and see if it would get hot. When i looked under the car
i didnt see the catalytic converter. I looked up a picture to make
sure i knew what i was looking for, but found nothing. Timing was
right on and everything, it doesnt seem that the timing chain could
have slipped at all either. Im still stuck on this whole thing.

The cat is a muffler-shaped device located on the exhaust pipe towards
the front of the car, usually about where the driver sits. If you follow
the exhaust pipe from the engine to the back of the car, you should
see something muffler-like before you get to the actual muffler at the
back of the car. But removing the cat won't solve your problem, and
it's not easily removed on most cars.

If you've been following this thread, you'll see that the red glow is the
result of continued combustion in the manifold. This can be caused by
many things, such as base timing being off, not enough advance at
higher rpms, too rich a mixture, or an air leak into the manifold. If the
glow is that obvious and you really don't know what to do, take it to
your favorite mechanic and let him have a go at it.

 

[Niccko]

The cat is a muffler-shaped device located on the exhaust pipe towards
the front of the car, usually about where the driver sits. If you follow
the exhaust pipe from the engine to the back of the car, you should
see something muffler-like before you get to the actual muffler at the
back of the car. But removing the cat won't solve your problem, and
it's not easily removed on most cars.

If you've been following this thread, you'll see that the red glow is the
result of continued combustion in the manifold. This can be caused by
many things, such as base timing being off, not enough advance at
higher rpms, too rich a mixture, or an air leak into the manifold. If the
glow is that obvious and you really don't know what to do, take it to
your favorite mechanic and let him have a go at it.

Awesome advice there, i think that you have shinned the light upon me!
i veleive the problem happend after i did a tune up, but i changed it
back to where everything was set before the tune up (including putting
the old cables, cap and rotor on) seems to be really sluggish, i cant
get it to go over 15 mph in first, and it gets up to 25 in a five mile
stretch. ive noticed that it could just possibly be a leak then. ill
take a look at everything again, Possibly check if im runnin too rich.

 

[Mike W]

Hi Bob
Hope you had a nice Christmas, I did. Sorry I haven't gotten back to you
until now, it's been nutzzzz around here, I haven't had much time to myself
lately. I'm not even sure if you're even looking at this post anymore.
Anyhooooo, thanks for all the help, I'm going to leave the car the way it
is, it's not perfect, but at least I know that the exhaust manifold won't
get so hot that it will melt off!!!! LOL
As I mentioned before the problem has all but gone away. The remaining,
slight red glow (only when the car is driven faster then 110Kph) isn't that
bad at all. The remainder of the problem might be the Thermo to ERG valve,
but for now I'm going to leave er alone until I find out for sure.

Talk to you soon
Mike
PS funny story about your brother's doomed car. Funny thing is that the
Excell doesn't handle that badly, I know because I drive down, gravel back
roads, here in the country. Sure it's not a Porche, but it handles ok for a
small car : )

I'll check from time to time to see if you

I agree it could be a design flaw, however Hyundai would have taken care of
the problem by now (1986-91)
I'll research the problem, check to see if the dis has enough vacuum as you
are suggesting.
BTW, the dis timing is around 6% BTDC, I left the dis timing like this
becacause I knew it to be correct. When I said that I changed the dis timing
to 12% BTDC, and got a posiative result, I changed it back to the
recommended specs 4 BTDC +-1
I found 4 degrees to be a little sluggish and 6 degrees to be right on the
money.
With the setup the way I have it right now, releasing my foot from the gas
pedal sharply doesn't produce any back fire, however I think you ment if I
had the engine set to 12 degrees BTDC. That is a good theory that you have,
I'll give it a shot. One thing I forgot to mention in my last post...I has
some white deposits on #1 and #2 spark plugs, after readjusting the valve
lash with the engine hot, the plugs are fine, funny...when I lived in
Ottawa, I worked as an auto mechanic for 7 years and have known lots of
mechnics to add a couple of thou to the specs so the can adjust valves (over
head cam) on a cold engine. This methiod has always worked great, I gess in
my case I have valve margins that are warn unevenly producing a little bit
of a gap. I'll definatly plug the air injection system and see if that makes
a difference, however it may be a few days before I get back to you as I
have to reinstall Windows XP having a internet problem and did everything
that is humanly possiable to fix the problem and no go, so gots to reinstall
the OS. BTW if you have any computer, hardware, software, networking
problems, I'm the man. My specility is operating system trouble shooting. I
worked for Compaq for 4+ years in the commercial divsion and have 10 years
of combined trouble shooting experience.
Anyhoo I'll do a few tests on the car and let ya know.

Mike

Thanks for the update. I've never driven my brother's 91 Fuel Inj
Excel at that high a speed for an extended period, but I did notice
that the exhaust manifold heat shield that I replaced a couple of
years ago looks pretty beat up for such a relatively young part,
which may mean that this may just be a design flaw with this
engine.

As I've said before, if you're pushing the engine to keep it going
at 130Kph, you may not be supplying it with enough ported
vacuum to keep the dist at its maximum advance. If you have a
vacuum gauge, try putting it inline using a tee with the hose going
to the dist advance, and see what the readings are at 100 vs 130.

You can always advance the base timing from 12 to, say, 14 BTDC
as long as the engine doesn't knock and performance doesn't
suffer.

I doubt there's a carb problem, but if it was running too rich at full
throttle, it should backfire a bit when you let up sharply on the gas.
Other than a weak power valve spring or slightly clogged secondary
air bleeds, there's not a whole lot to adjust on a carb.

And once again, check out the air injection hose to the exhaust
manifold. Block it off, plug it, whatever, to stop any air from entering
the manifold.

And for what it's worth, I won't have a 91 Excel to work on anymore.
My brother managed to effectively total his on a slippery interstate
last week during that New England storm. Fishtailing and bouncing
from an adjacent car to a jersey barrier and back, even at a really
low speed, will tend to do that. And damn, I just got it to pass a
state emissions test for the first time in 6 years thanks to a new
catalytic converter I installed over Thanksgiving. The new part just
messed up the car's karma, and it was doomed.

Bob

thousand until for
the tomorrow
I'm way took be
red, the
car has the
wife that
the manifold).
You floor. pedal,
I'll at
100 when
the into
the

(pedal

to One
of problem
was looked After cold, for
the on
Red for
10 right that vacuum,
it's reverse
the separate
part junkyard
for

lots

of from
your

idle.

 

[Bob Bailin]

You're quite welcome. I'm glad to hear things worked out well
enough with the Excel. The fact that it's such a reliable little car
once you've gotten all the kinks worked out makes it difficult for
my brother to simply junk his doomed one when all it seems to
need is (just!) 2 fenders, a front bumper and a passenger door
and a hood. In other words, with all the damage, it still runs and
drives great. FWIW, the first body shop he took it to didn't even
want to give an estimate.

Regarding your car, you might want to eventually buy a heat
shield for the exhaust manifold for about $20-30, just to protect
the hood and any nearby hoses and wiring when summer comes
around.

But right now, I have to figure out what to do on this balmy, zero
degree (F) day here in CT. Balmy for you, that is.

Later,
Bob

Hi Bob
Hope you had a nice Christmas, I did. Sorry I haven't gotten back to you
until now, it's been nutzzzz around here, I haven't had much time to myself
lately. I'm not even sure if you're even looking at this post anymore.
Anyhooooo, thanks for all the help, I'm going to leave the car the way it
is, it's not perfect, but at least I know that the exhaust manifold won't
get so hot that it will melt off!!!! LOL
As I mentioned before the problem has all but gone away. The remaining,
slight red glow (only when the car is driven faster then 110Kph) isn't that
bad at all. The remainder of the problem might be the Thermo to ERG valve,
but for now I'm going to leave er alone until I find out for sure.

Talk to you soon
Mike
PS funny story about your brother's doomed car. Funny thing is that the
Excell doesn't handle that badly, I know because I drive down, gravel back
roads, here in the country. Sure it's not a Porche, but it handles ok for a
small car : )

I'll check from time to time to see if you

I agree it could be a design flaw, however Hyundai would have taken care of
the problem by now (1986-91)
I'll research the problem, check to see if the dis has enough vacuum as you
are suggesting.
BTW, the dis timing is around 6% BTDC, I left the dis timing like this
becacause I knew it to be correct. When I said that I changed the dis timing
to 12% BTDC, and got a posiative result, I changed it back to the
recommended specs 4 BTDC +-1
I found 4 degrees to be a little sluggish and 6 degrees to be right on the
money.
With the setup the way I have it right now, releasing my foot from the gas
pedal sharply doesn't produce any back fire, however I think you ment if I
had the engine set to 12 degrees BTDC. That is a good theory that you have,
I'll give it a shot. One thing I forgot to mention in my last post...I has
some white deposits on #1 and #2 spark plugs, after readjusting the valve
lash with the engine hot, the plugs are fine, funny...when I lived in
Ottawa, I worked as an auto mechanic for 7 years and have known lots of
mechnics to add a couple of thou to the specs so the can adjust valves (over
head cam) on a cold engine. This methiod has always worked great, I gess in
my case I have valve margins that are warn unevenly producing a little bit
of a gap. I'll definatly plug the air injection system and see if that makes
a difference, however it may be a few days before I get back to you as I
have to reinstall Windows XP having a internet problem and did everything
that is humanly possiable to fix the problem and no go, so gots to reinstall
the OS. BTW if you have any computer, hardware, software, networking
problems, I'm the man. My specility is operating system trouble

shooting.

I
worked for Compaq for 4+ years in the commercial divsion and have 10 years
of combined trouble shooting experience.
Anyhoo I'll do a few tests on the car and let ya know.

Mike

20
min, still
the Tomorrow
I'm for
the a
way min,
took problem
has am?
LOL in
it.

also,

I back
to the
car

drive

at

100
plus
from
time to time without the worry of something catching on
fire.

I'll get back to you tomorrow

Mike AKA Deefer Dog
"Never pet a burning dog!"

Here's a test for you:

You said that the manifold glows at 130Kph, but not at
100Kph.
I feel it's because you have enough advance with a
defective
dist
at whatever the rpm's are at 100Kph, but not enough when
the
engine is running faster at 130Kph (the faster the engine
turns,
the more advance is required because the burn speed

of
the

gas
remains constant).

So, what happens when you run the car at 100Kph in a lower
gear?
The rpms should be the same or higher as when you're at
130Kph,
but the load on the engine is less. If it's indeed the
timing,
your
manifold should glow in the lower gear at the lower speed
simply

because of lack of advance is dumping unburned HC's into
the
manifold, where they continue to burn.

Try it and let me know.

One other q: Are you truly at wide open throttle

(pedal

to
the
floor)
at 130Kph once you hit that speed (not just when you're
accelerating)?
If you are, you're asking too much from your engine. One
of
those
google posts (regarding the motor home going uphill at
WOT)
mentioned
that a glowing manifold is often the result of

running
at

WOT
for
extended periods of time. ost carbs have a power circuit
that
enriches the mixture at WOT (as a result of manifold
vacuum
dropping
to near zero) for better acceleration. But the rich
mixture
results
in
the glow after a period of time, but how often does one
actually
floor it for more than a minute or two, even? Hardly ever
(you're
supposed to downshift instead).

Bob

message
Ya I also did a Google search for my problem and found
various
reason
why
this is happening. More often then not, the

problem
was

timing.
But
what's
got me concerned is the fact that, the problem doesn't
happen
when
I
drive
around 100Kph, Surely it could be that I do have a
defective
vacuum
advance
module, but why at full throttle? Today I'll be checking
out
a
local
wrecker
for another distributor or engine. I wish the problem
was
burnt
or
leaky
valves because the car would perform quite badly

and
the

solution
is
obvious. When I installed the new head gasket, I looked
at
the
valves,
there
was quite a bit left on the valve margins, so I assumed
that
the
valves
were
ok. Again the mixture cannot be too rich as the spark
plugs
are
a
tan
colour. As far as the valve clearances go, I originally
set
them
loose,
because I thought that the valves weren't closing. After
I
determined
that
wasn't the problem, I set them when the engine was cold,
I
just
added
another thousand to the measurement to compensate for
the
engine
being
cold.
Not sure of the condition of the valve springs. If I
don't
have
any
luck
with the distributor, I'll try setting the valves

to
the

hot
clearances,
if
no go, I'm going to bring the car to a friend's heated
garage
so
I
can
tear
the whole thing down. I did mention that the car is
running
better
now?
LOL

Mike


message
Just for my own curiosity, I did a google search on
Red
Hot
Exhaust
Manifold, and was sort of surprised to see this thread
near
the
top.
But further down, there's a variety of opinions

as
to

 

[Mike W]

Seems to be working good so far. Car runs like shit when it's cold, just
have to wait until the car heats up a little bit to the cold mark on the
gage and it's fine. Pretty sure the problem is the thermo valve, as the ERG
opens when the car is cold (- 20 weather) going to wait until the summer to
work on that problem, but by then it won't be a problem. LOL
I was thinking about getting a new heat shield for the exhaust manifold, but
I can't, for the life of me loosen that snakey pipe that's attached at the
top, I had to cut the heat shield to get it off, when I replaced the head
gasket, what a pain!!!!
Anyhoo, I hope the repairs, turn out for the best with your brother's car,
good luck!!!

Mike

You're quite welcome. I'm glad to hear things worked out well
enough with the Excel. The fact that it's such a reliable little car
once you've gotten all the kinks worked out makes it difficult for
my brother to simply junk his doomed one when all it seems to
need is (just!) 2 fenders, a front bumper and a passenger door
and a hood. In other words, with all the damage, it still runs and
drives great. FWIW, the first body shop he took it to didn't even
want to give an estimate.

Regarding your car, you might want to eventually buy a heat
shield for the exhaust manifold for about $20-30, just to protect
the hood and any nearby hoses and wiring when summer comes
around.

But right now, I have to figure out what to do on this balmy, zero
degree (F) day here in CT. Balmy for you, that is.

Later,
Bob

Hi Bob
Hope you had a nice Christmas, I did. Sorry I haven't gotten back to you
until now, it's been nutzzzz around here, I haven't had much time to myself
lately. I'm not even sure if you're even looking at this post anymore.
Anyhooooo, thanks for all the help, I'm going to leave the car the way it
is, it's not perfect, but at least I know that the exhaust manifold won't
get so hot that it will melt off!!!! LOL
As I mentioned before the problem has all but gone away. The remaining,
slight red glow (only when the car is driven faster then 110Kph) isn't that
bad at all. The remainder of the problem might be the Thermo to ERG valve,
but for now I'm going to leave er alone until I find out for sure.

Talk to you soon
Mike
PS funny story about your brother's doomed car. Funny thing is that the
Excell doesn't handle that badly, I know because I drive down, gravel back
roads, here in the country. Sure it's not a Porche, but it handles ok

for

a
small car : )

I'll check from time to time to see if you
care
of as
you

if

I gess
in shooting. along
with

fine

IE the
for

in

a the
key. wouldn't
be on
my when
the bring
the

engine

in also, drive

not

at enough
when

speed

of you're
at HC's
into engine.
One

uphill

at does
one compensate
for

If

I

valves

to search
on

opinions

as

together?

If were
in

because

 

[Bob Bailin]

Do yourself a favor and pull off the vacuum hose to the EGR
and plug it, and see if there's any improvement. Those
thermal switches are a pain to remove because they can
snap off if you force them too much.

If there's a hot air door in the snorkel of the air cleaner, make
sure it works. And make sure that you're getting that extra
vacuum advance when the engine is cold.

I was going to suggest that you check out all the vacuum hoses
for leaks, but then I saw a picture of the vac hose assy. What
a nightmare! I just hope everything is connected to where it
should be.

Bob