rhythmic hesitation in '93 SL1

I have a '93 SL1 with 145k miles. It seems to have a worsening problem
with hesitation when going between 25-40 mph (2nd/3rd gear? it's
automatic transmission), and feels like it could stall. Yesterday was
noticeably bad, so I revved it up while idling and it has a regular
rhythmic hesitation between about 1800 and 3000 rpm. I changed the
oil, which was extremely black and dirty (it takes 5W30 which is very
light-colored, haven't been changing as frequently as I should, it had
been about 4 months with low miles). More disturbing was this thick
cream-consistency light brown crud all over the inside of the oil cap
and around the cap hole, but couldn't see further down than that. I
had never seen anything like that before, almost like dirty foamed oil.
The hesitation seemed to disappear immediately after the oil change,
but this morning it's back again when revving in idle, not quite as bad
as yesterday yet.

Other than changing the spark plugs and dumping some fuel injection
fluid, any other suggestions? Does a regular hesitation suggest
something in particular?

By the way, it's also had a 'check engine light' come on with code 32
only (quad driver module, no code 28) but only when going 65 mph or
higher, which I very rarely have an opportunity to do anymore. I
haven't seen the light in months...

The code 32 is a defective EGR. It should be replaced. A fairly simple 30
minute job if you have metric sockets and are mechanically inclined. The
brown crud on the inside of the oil cap is probably condensation/water that
has mixed with the oil. You need to keep your eye on this since it could be
early sign of a head gasket problem. How did the oil that you drained look?
Did it too have water in it as well?

When was the vehicle last tuned with new plugs? Are they correctly gapped?
Have you removed them to see if they are oil or carbon fouled? When were
your wires last changed?

Post what you eventually learn and good luck.

Bob

> wrote in message
ups.com...
> I have a '93 SL1 with 145k miles. Yesterday was
> noticeably bad, so I revved it up while idling and it has a regular
> rhythmic hesitation between about 1800 and 3000 rpm. I changed the
> oil, which was extremely black and dirty (it takes 5W30 which is very
> light-colored, haven't been changing as frequently as I should, it had
> been about 4 months with low miles). More disturbing was this thick
> cream-consistency light brown crud all over the inside of the oil cap
> and around the cap hole, but couldn't see further down than that. I
> had never seen anything like that before, almost like dirty foamed oil.
>
> Other than changing the spark plugs and dumping some fuel injection
> fluid, any other suggestions? Does a regular hesitation suggest
> something in particular?
>
> By the way, it's also had a 'check engine light' come on with code 32
> only (quad driver module, no code 28) but only when going 65 mph or
> higher, which I very rarely have an opportunity to do anymore. I
> haven't seen the light in months...

Wait...I think I have those code numbers reversed in my head...the code
was NOT the EGR valve code, it was whatever the one was for quad driver
module. It looks like EGR valve normally requires the combination of
28 and 32, this was just 28.

The car was bought used in 2000 with 94k and I've never had the car
tuned, so when it last had anything done with the spark plugs is a
mystery to me. I actually don't know how to remove the plugs, we tried
pulling on them since that's how they pop out in my husband's car (his
car's manual actually tells you how to do this!), but they wouldn't
budge, and we were afraid to bust something. It's run so reliably, I
guess I've just been waiting for something bad to start happening
before getting anything done other than oil changes (I know...bad idea,
but I buy cheap used junk cars, if it makes it 5 years then I'm already
ahead...)

I didn't see any evidence of water in the drained oil, but could have
missed it. I definitely wouldn't have seen a small amount of water
emulsified in the blackness. Is there anything you can do to remove
water from the engine? The first thing I thought when seeing the brown
cream was a head gasket leak, but there isn't really any other evidence
of this, at least no excessive white smoke. I did have to add some
coolant for the first time ever recently (it probably badly needs a
coolant flush, add that to the list) fairly recently after the add
coolant light flashed at me. It was pretty full but not quite to the
fill bar. But still, this was the first time in 5 years that there was
a change in the level. Before refilling, the car had almost overheated
in traffic. The gauge always goes just above the mark before the red
zone before the fan kicks in, and this is normal operating temperature,
however this time it went further than I ever saw it go before, seemed
like the fan couldn't keep up. Since starting a new job right down the
street from where I live, it's hard to get in enough driving in this
traffic-clogged area to follow-up on or reproduce problems, and it's
now a lot colder outside.

From your response, I think it would be best to take the vehicle to a
trusted service center/garage and have it tuned up, replace the plugs,
wires, gas filter, air filter, PCV, and thoroughly clean the throttle body.
Techron fuel injector cleaner in the tank wouldn't hurt either ... And then
see what happens with the hesitation and codes. I'd bet this is a fouled
plug or bad wire.

The coolant is supposed to be flushed and changed every two years. You are
long overdue. These engines are temperamental to overheating and the
corrosion additives only last 24 months or so ... you obviously don't take
care of your vehicle ... so bad things will happen and you are living on
borrowed time. By the way, if you have an automatic transmission, that too
needs an occasional drain, filter and oil change. I'd suggest doing that
every 30K miles.

On the EGR, if it is still original, consider yourself lucky ... it is
probably bad as well.

I'd also strongly suggest you keep an eye on the oil and coolant levels to
make sure you have not blown the head gasket or cracked the head when it
"came close to overheating". (It probably did overheat ... keep in mid the
gauge will not read accurately if you don't have enough coolant.) The
mechanic can do a compression test, but this will not guarantee finding a
coolant to oil passage leak.

Good luck.

Bob

> wrote in message
ups.com...
> The car was bought used in 2000 with 94k and I've never had the car
> tuned, so when it last had anything done with the spark plugs is a
> mystery to me. I actually don't know how to remove the plugs, we tried
> pulling on them since that's how they pop out in my husband's car (his
> car's manual actually tells you how to do this!), but they wouldn't
> budge, and we were afraid to bust something. It's run so reliably, I
> guess I've just been waiting for something bad to start happening
> before getting anything done other than oil changes (I know...bad idea,
> but I buy cheap used junk cars, if it makes it 5 years then I'm already
> ahead...)

> I didn't see any evidence of water in the drained oil, but could have
> missed it. I definitely wouldn't have seen a small amount of water
> emulsified in the blackness. Is there anything you can do to remove
> water from the engine? The first thing I thought when seeing the brown
> cream was a head gasket leak, but there isn't really any other evidence
> of this, at least no excessive white smoke. I did have to add some
> coolant for the first time ever recently (it probably badly needs a
> coolant flush, add that to the list) fairly recently after the add
> coolant light flashed at me. It was pretty full but not quite to the
> fill bar. But still, this was the first time in 5 years that there was
> a change in the level. Before refilling, the car had almost overheated
> in traffic. The gauge always goes just above the mark before the red
> zone before the fan kicks in, and this is normal operating temperature,
> however this time it went further than I ever saw it go before, seemed
> like the fan couldn't keep up. Since starting a new job right down the
> street from where I live, it's hard to get in enough driving in this
> traffic-clogged area to follow-up on or reproduce problems, and it's
> now a lot colder outside.

> From your response, I think it would be best to take the vehicle to a
> trusted service center/garage and have it tuned up, replace the plugs,
> wires, gas filter, air filter, PCV, and thoroughly clean the throttle body.
> Techron fuel injector cleaner in the tank wouldn't hurt either ... And then
> see what happens with the hesitation and codes. I'd bet this is a fouled
> plug or bad wire.

I'm going to have it looked at on Friday by a good mechanic (aka not at
dealership). Crossing my fingers it's something to do with the plugs.
It's really had this almost unnoticeable slight hesitation going about
30-40 mph for quite a long time, but suddenly it's hesitating and
lunging (today felt like it was going to stall out again) much worse.

> The coolant is supposed to be flushed and changed every two years. You are
> long overdue. These engines are temperamental to overheating and the
> corrosion additives only last 24 months or so ... you obviously don't take
> care of your vehicle ... so bad things will happen and you are living on
> borrowed time. By the way, if you have an automatic transmission, that too
> needs an occasional drain, filter and oil change. I'd suggest doing that
> every 30K miles.

Yeah, with this new dose of fear I'll definitely get it done. The
coolant has stayed amazingly clean looking all these years though.
Transmission flush has also been on the list, this stuff adds up $$$.
The engine temp gauge on these things is weird, there must be a really
fine line between "normal" temperature (and a mechanic verified the
engine temperature was well within operating range while the gauge read
above the white mark just before red, on any other car this would
indicate the verge of disaster) and overheating.

> On the EGR, if it is still original, consider yourself lucky ... it is
> probably bad as well.

I got the EGR valve replaced the first week I had the car at 94k miles,
so I'm just taking a guess that it's not the second one to go.

> I'd also strongly suggest you keep an eye on the oil and coolant levels to
> make sure you have not blown the head gasket or cracked the head when it
> "came close to overheating". (It probably did overheat ... keep in mid the
> gauge will not read accurately if you don't have enough coolant.) The
> mechanic can do a compression test, but this will not guarantee finding a
> coolant to oil passage leak.

I'm really concerned reading about the light brown gunk in the oil cap.
There was no sign of this coloration on the dipstick before or after
the oil change, so far I've only seen it in and around the cap area.
It's driven on really short trips almost exclusively lately, so I'm
hoping this is just condensation causing an oil/water emulsion around
the cap without the ability to boil off, since the engine rarely warms
up. It had been unusually bitter cold most of this month. I can't
detect any sign of glycol smell in the engine, but if it's still a tiny
leak without noticeable change in coolant level, you wouldn't expect to
smell it anyway. At any rate, if it's a gasket leak, hopefully this is
still early sign and not too much damage has been done. My 87 Nova
made it nearly 6 years after a bad blown head gasket (plumes of white
smoke out the exhaust, car not starting) before the engine died on the
interstate, which was probably due to a bad job with the gasket seal.
It was having weird problems for months with overheating and coolant
literally erupting out of the overflow tank while the radiator was
empty. Blew $1200 on that and nothing fixed it (thanks Chevy dealer!).
None of that with the Saturn yet... Thanks for your suggestions.

The brown "sludge" you are seeing is just condensation coming to a rest up
there. It is normal if the car doesnt reach operating temperature often.
Aka you make alot of short trips with it.

Your hesitation sounds like a bad plug and wire. Have it checked it out.

Your code is probably 26, Quad driver fault, which is often the EGR
control solenoid, but could be the purge solenoid.

And about the temp gauge, it is normal operation for the fan to come on at
the 3/4 mark on saturns from 91-94. They changed the operation in 95 due to
scared customers. It then is normal operation to be around halfway when
fans come on....

Hope it helps.... I see saturns everyday!

> The brown "sludge" you are seeing is just condensation coming to a rest up
> there. It is normal if the car doesnt reach operating temperature often.
> Aka you make alot of short trips with it.

That's definitely what I want to hear and what makes sense, but I have
a friend who insists it's minor head gasket leaking. I'll let the
mechanic decide.

> Your hesitation sounds like a bad plug and wire. Have it checked it out.

Really hoping that's all it is, or else no New Year's Eve party for me.

> Your code is probably 26, Quad driver fault, which is often the EGR
> control solenoid, but could be the purge solenoid.

Yeah, that's it...I took a guess it was the canister purge solenoid out
of the 4 possible options, since the coolant fan was working and there
was no EGR fault code. No idea what that is, supposedly a cheap part
that's impossible to get to. I haven't even seen the light come on for
months, since it requires speeding on an interstate before it comes on
(only above 60-65 mph). Usually you have to make it up to 70-75 mph
before it firsts come on, and it fades out when you slow down below 65
(maybe this is the cops' new trick).

> And about the temp gauge, it is normal operation for the fan to come on at
> the 3/4 mark on saturns from 91-94. They changed the operation in 95 due to
> scared customers. It then is normal operation to be around halfway when
> fans come on....

I was fine with it once a mechanic told me this was normal. It seems
like the fan has been kicking in higher and higher up the gauge, it
used to kick it precisely on the 3/4 mark, then it started a little
above the 3/4 mark. And this last time when the engine almost or did
overheat, it was at the verge of red before it kicked in. I was ready
to turn off the car and leave it on the side of the road. Maybe this
was just evidence of the dropping coolant level? You'd think that'd be
independent of the temp gauge and electronics controlling the fan.
It'll get hotter with less coolant but the fan should still kick in at
the programmed temp, right? Maybe this gauge is not as sophisticated
as a thermocouple...or is there another sensor independent of the gauge
that kicks the fan on? That would be the only thing that makes sense,
but I shudder as a chemical engineer...

> Hope it helps.... I see saturns everyday!

Thanks for your suggestions!

>Yeah, that's it...I took a guess it was the canister purge solenoid out
>Yeah, that's it...I took a guess it was the canister purge solenoid out
>of the 4 possible options, since the coolant fan was working and there
>was no EGR fault code. No idea what that is, supposedly a cheap part

Well, mine cost me about 50 bux Canadian at a dealership. Replaced it,
ran OK for a while and
I'm still getting code 26. However, it only happens in the fall and
spring....go figure. I'm guessing
it has something to do with a bad connection between the PCM and the
solenoid.

>that's impossible to get to. I haven't even seen the light come on for

Don't bother with the purge canister solenoid. It only gets activated
when your car is idling and it closes
when the car is in motion. It has nothing to do with your car's
hesitation.
I would look at the EGR solenoid instead and make sure it opens up when
the car is moving.

>I was fine with it once a mechanic told me this was normal. It seems
>like the fan has been kicking in higher and higher up the gauge, it
>used to kick it precisely on the 3/4 mark, then it started a little
>above the 3/4 mark. And this last time when the engine almost or did
>overheat, it was at the verge of red before it kicked in. I was ready

Do you have A/C in your car? If you're really concerned about the fan
not kicking early enough,
switch your A/C for a couple of minutes. The fan will come on
automatically and will stay on
for few minutes after you switch A/C off.

>to turn off the car and leave it on the side of the road. Maybe this
>was just evidence of the dropping coolant level?

There is an idiot light on your dash informing you that your coolant is
low.

>You'd think that'd be
>independent of the temp gauge and electronics controlling the fan.

I'm pretty sure it is. There are two temp sensors in your car, one
sends the information
to your front dash, while the other sends the information to the PCM.
The PCM then
decides on the mixture, fan on/off commands, etc.

>It'll get hotter with less coolant but the fan should still kick in at
>the programmed temp, right? Maybe this gauge is not as sophisticated
>as a thermocouple...or is there another sensor independent of the gauge
>that kicks the fan on?

Oops....I should have read the whole thing. as per above.... yes

good luck!

Alex

> wrote in message
ups.com...
> It seems
> like the fan has been kicking in higher and higher up the gauge, it
> used to kick it precisely on the 3/4 mark, then it started a little
> above the 3/4 mark. And this last time when the engine almost or did
> overheat, it was at the verge of red before it kicked in. I was ready
> to turn off the car and leave it on the side of the road.

If it makes you nervous, you can always force the fan in by turning on the
A/C for a few seconds, then shut it off. This will trigger the fan to
engage and it'll shut off automatically (as normal) when it reaches the low
temp.

Scott

Nope no AC, the compressor was busted when I bought it, and it didn't
seem worth it at the time to get it replaced (the longer the car lasts,
the more I wish I replaced it at the start). I've really, really
regretted this in 2 hour traffic jams in my former commute, next to
fuming tractor trailers, in 98 degree humidity here in DC area.

The coolant light flashed at me for a split second before this
incident, and for several seconds after the overheating incident. It
was below the fill bar but not by a whole lot. Hopefully that explains
the overheating, knowing there's a separate sensor.