rhythmic hesitation in '93 SL1

I thought the older S-series used a vacuum, not a solenoid, to activate the
EGR. In any event, it sounds like the EGR is sticking so should be
replaced.

Bob

 

I would like to throw a silly idea, for which I apologize in advance
(but I have seen this happening several times):
Could you pls check if that (as a result of so much "work" done in the
car), the hoses have not been mistakenly reinstalled (swapped)?
Sorry again if it sounds ludicrous, but it was possible before.

Good luck.

 

I would like to throw a silly idea, for which I apologize in advance
(but I have seen this happening several times):
Could you pls check if that (as a result of so much "work" done in the
car), the hoses have not been mistakenly reinstalled (swapped)?
Sorry again if it sounds ludicrous, but it was possible before.

Good luck.

 

I would like to throw a silly idea, for which I apologize in advance
(but I have seen this happening several times):
Could you pls check if that (as a result of so much "work" done in the
car), the hoses have not been mistakenly reinstalled (swapped)?
Sorry again if it sounds ludicrous, but it was possible before.

Good luck.

 

I would like to throw a silly idea, for which I apologize in advance
(but I have seen this happening several times):
Could you pls check if that (as a result of so much "work" done in the
car), the hoses have not been mistakenly reinstalled (swapped)?
Sorry again if it sounds ludicrous, but it was possible before.

Good luck.

 

I would like to throw a silly idea, for which I apologize in advance
(but I have seen this happening several times):
Could you pls check if that (as a result of so much "work" done in the
car), the hoses have not been mistakenly reinstalled (swapped)?
Sorry again if it sounds ludicrous, but it was possible before.

Good luck.

 

I would like to throw a silly idea, for which I apologize in advance
(but I have seen this happening several times):
Could you pls check if that (as a result of so much "work" done in the
car), the hoses have not been mistakenly reinstalled (swapped)?
Sorry again if it sounds ludicrous, but it was possible before.

Good luck.

 

I really don't know how it works in this car, the mechanic said he had
to remove vacuum to get it to close (he actually has the valve closed
off with a screw right now). But something would need to switch
between vacuum and non-vacuum, and I figured that would be a solenoid
(and the trouble codes for this car indicate 'EGR solenoid' anyway).
Well, the car doesn't hesitate anymore, and it was ok for the several
minute drive home. I have it back today and he said to try it a few
days until they can come up with a permanent fix, but it seems that bad
things can also happen if it's permanently shut (and it probably
wouldn't pass emissions, fortunately it was just inspected in
September). All the work that's been done so far, including new spark
plugs and wires, test driving, and the temporary EGR fix has come to a
whopping $82. Sure beats the $1500-$2300 I was planning on dishing out
for a rebuilt transmission or major engine work. Maybe I'm just too
used to being scammed around here, where the DC area scam tax is about
300%.

 

A solenoid activated EGR is an electrically controlled valve, while the
vacuum activated EGR relies on a vacuum. I believe that Saturn changed from
the mechanical vacuum to the electrical solenoid around 1995 or 1996. The
EGR valve itself was basically unchanged and both experience similar
clogging so can get stuck in either the open or closed position. The vacuum
activated units also suffered from pinhole leakage in the diaphragm so would
not hold the vacuum or activate properly. It also was sensitive to leaks in
the lines that went to it from the manifold. The solenoid, on the other
hand, consisted of an electromagnet that when energized pulled a steel
plunger activating the valve. The solenoid is more reliable than the
diaphragm , but can go open circuit and cause failures as well. The code
is common to both types so that is why it contains the solenoid term. If
there is no electrical connection to the EGR valve and only a vacuum line,
then it has no solenoid.

Glad you found the problem.

Bob

 

You should be right about that. It would make the most since to do
changes like that at the same time the entire auto market had to change
to OBDII. Everything could get upgraded with less impact on R&D cost.