1996 SL1 Difficulty Starting - Solenoid Location/Other Thoughts?

No.

Starter solenoid won't affect cranking speed. The starter *motor* may be wearing out, but if the starter cranks the engine at all, the solenoid is good.

You said he replaced the battery, and the problem recurred the following day. A new battery doesn't go bad overnight. My first thought is that the guy who checked the charging system is incompetent -- the alternator or voltage regulator is going south, or the belt is loose -- and you should have the charging system checked out again by a different shop.

If that checks out OK the second time around, look for something that's draining the battery overnight: interior light left on, sagging brake pedal turning on the brake lights, or who knows what. Maybe he has some sort of accessory plugged into the cig lighter socket that's draining current?

How long since the last oil change, and what type of oil was put in? You said the weather is getting "colder".. but that's a relative term. Where are you? "Cold" to you might be "balmy" to me, or vice versa. "Cold" to the *car* means freezing or below. It might help to change the oil with 5W30 -- but make sure to get that out of there, and put 10W30 in, before summer.

Doug,

Thanks for the response. Comments are inserted below. I've done a bit more research and see that the solenoid is attached to the starter motor assembly and is not a separate component. As such, if all the fuses, wires and connections check out good/clean/tight, then the most obvious thing to do would be to replace the starter with a rebuilt unit since this covers the situation regardless of whether it is being caused by the starter motor or the solenoid.

Thanks again for taking the time to respond with your thoughts.

Bob

I disagree with this statement and have seen resistive solenoid contacts (in other vehicles) cause a reduction in available cranking current resulting in reduced voltage at the starter motor causing the same symptoms he claims to be seeing.

I had thought the same thing, and he went back and re-tested the battery and charging system at a second service garage and they said both the battery and alternator looked good. This is why I don't suspect the new battery is bad and believe the alternator is in fact working properly as well. (I knew these are a common failure on Saturn's so had suspected that first.)

As expalined above, the new battery does not appear to being drained. (I had asked my son the same question when he first reported the symptoms, but since the battery was 4 years old, suggested he have it tested and replaced.) I'll hopefully get a chance to see this for myself if he drives home from school over the weekend. I plan to measure battery voltage with the vehicle off when he arrives and again when the car is running and the alternator is charging the battery. Based on his being able to drive it now for a couple days and running headlights at night, radio, heater blower, etc. I tend to believe the two independent diagnosis that the charging system and battery are now working correctly.

I do change the oil from 10W30 to 5W30 for the winter in all of our vehicles since temperatures can reach -20 degrees F here in the Chicago area during winter. Right now the temperature is about 40 degrees F so I doubt this is the issue. The oil was scheduled to be changed to 5W30 when he was home for Thanksgiving in a couple weeks. I've never seen a problem in any vehiclke with temperature above 0 degrees F, and would think that the Saturn's small

4 cylinder would make it even easier to turn. That said, we may change the oil sooner if he gets home to fix the starter.

Thanks.

Incorrect. You've explained that the new battery does appear to be getting charged -- but you haven't described any testing or investigation you've done to make sure that charge isn't getting drained off overnight by some load that shouldn't be there (interior light left on, for example).

Before replacing the starter, I think you should make three voltage measurements on the battery: just before starting the engine, just after shutting the engine off after driving the car for a while -- and after it's been sitting in the driveway overnight. If there's a substantial difference between the three, particularly if the last measurement is much lower than the other two, then it's time to start looking for whatever's draining the battery overnight.

As it is on ALL starter motors...

[snip]

Disagree all you like -- you're still mistaken. You've described a problem caused by corrosion, not a bad solenoid. The solenoid is nothing more than an electromagnet that moves the starter pinion gear into position where it contacts the flywheel. The symptom of a good starter motor and a bad solenoid is that the starter motor spins when you turn the ignition key -- but the engine does NOT; hence my statement that if the starter cranks the engine at all, the solenoid is good.

Additional comments inline below.

Bob

Again, I respectfully disagree with your statement that "the solenoid is nothing more than an electromagnet that moves the starter pinion gear into position where it contacts the flywheel." While it is indeed true that the solenoid is indeed an electromagnet that is energized by turning the ignition key, which in most cases closes the starter relay circuit, it actually serves as the final connection for the high amperage current directly from the 12V battery. This is accomplished when the solenoid gets energized and pulls down a conductive copper plunger that shorts across two copper contacts and energizes the circuit to the starter motor armature, thereby turning the engine.

Here is a URL with a site that includes photos for a Nippondenso starter/solenoid for which I have removed and replaced worn out contacts on four separate occassions and 4 separate Chrysler vehicles:

With regard to your comment that you feel this is caused by corrosion, this could in fact be very true. My point is that the solenoid plunger and contact surfaces wear and eventually can lead to intermittant starting problems like my son is seeing. If the contacts become resistive (this only requires it be tenths of an ohm), then the reduced current and accompanying voltage drop can produce symptoms that emulate dirty/corroded battery or ground contacts. In addition, just like with the dirty battery contacts, the high current drawn through the resistive connection can "burn through" the source of the resistance which coupled with this being an physical contact of the conductive surfaces, leads to the intermittant and unpredictable nature of this beast.

That all said, I do agree with your recommendations on the battery measurements in a previous post and appreciate that input. Given that my son has been driving the vehicle now several days/nights and using his electrical accessories (headlights, stereo, heater blower, rear defroster) normally since the 4-year old battery was replaced, I am inclined to believe the two separate service garages that gave their Ok to the alternator/charging system and the second one that verified the charge on the new battery was also good.

My plan at this point is to verify the following in the order given and if all look good, then I'll go ahead and replace the starter (which has the solenoid attached - by the way, on a side note this was not true of all vehciles I've worked on over the years) :

1. Make recommended battery measurements to assure system is charging battery properly
2. Verify all connections at battery and starter are clean and tight
3. Verify chasis and engine block ground cable connection clean and tight
4. Verify there is no internal cable corrosion and measure cable resistance
5. Remove starter, open and examine starter solenoid contacts (Replace unit w/rebuilt)

Thanks again.

With all due respect, yes, it is true of all vehicles you've ever worked on. You appear to be confusing the starter solenoid with the starter *relay*, which often *is* a separate unit, particularly on Chrysler vehicles such as you referred to -- and is frequently referred to, albeit mistakenly, by many auto parts store employees, mechanics, and DIYers as the solenoid. The solenoid is *always* integrated with the starter. It has to be, because it's the part that moves the pinion gear into position. It's impossible for the solenoid to not be part of the starter.

And is not being drained overnight!

Post again when you've found the problem. It may well be the starter motor (although I'm betting on something that's draining the battery). But it is

*not* the starter solenoid.

I do know the difference between a starter relay and a starter solenoid. On Chryslers, the relay energizes the solenoid which makes the final high amperage contact for the starter motor. Look at the site I provided. The pictures show the copper contact surfaces and how they get degraded with use.

The Saturn uses a Valeo PMGR starter. If you care to do a google search, you will find similar pictures of the solenoid plunger and contactor for that starter as well.

I will let you know the outcome. I think I have what I need at this point.

Bob

As promised, here is what I believe is the final outcome for this posting.

My son brought the car home on Saturday morning. Since we suspected battery/charging problems, I measured the battery voltage after he arrived (12.8V) and again with the engine running and the alternator charging the battery (14.8V). My son tried to duplicate the starting problems that evening with the engine warm, but could not. I did notice though that the car seemed to be idling a bit fast (~1000RPM) so we cleaned out the throttle body to see if that would have any impact, but did not appear to help.

The next morning before the car had been started, I re-measured the battery voltage with the engine off and it was still 12.8V. I then concluded the problem wasn't the battery draining or alternator related for that matter either. When we started the car, it took a while to start, but the starter turned over the engine at what appeared to me to be normal speed. My son then said that this symptom of not starting was exactly the problem he was seeing. He pushed the accelerator to the floor and the car started up, but the idle jumped to 1500RPM. Even after running for 10 minutes, the temperature gauge still showed Cold and the RPM was still hovering around

1050 and when I gave it gas we saw a slight hesitation.

Based on what I have read in this newsgroup over the years and the symptoms, I immediately suspected the Coolant Temperature Sensor. We visited the local auto parts store and bought a brass replacement unit and some high temp thread sealant.

We did the replacement and for good measure I sprayed electrical contact cleaner into the connector. When done, we topped off the antifreeze/coolant since a small amount was lost during the swap. When done, we re-started the engine and all seemed good and it ran well. The gauge was working again and the engine idled around 850 with the engine is warm. I am hoping that this is what was causing the problem and he just left to drive back to school.

After he left, I looked a the part we removed and see that the plastic sealed part that sits inside the engine head was cracked so this must have caused the failure.

I also noticed that his gas purchase/miles traveled per tank showed a 25% decrease in mileage over the last month. This further supported that this has been an issue for some time. Lastly, when we removed and looked at the spark plugs, they were carbon fouled indicating it was running rich.

Doug, thanks again for your input. I'm betting this was the issue and hopefully he will be better able to convey symptoms in the future now that he knows what to look for.

Bob