Wonderful day for the automobile, till I parked!

[harper.castillocp]

Hot day, drove twenty miles to the grocery shop; engine temperature was in the center of the gauge; running well.

Parked, shopped, and then emerged to find that starting was a challenge; but, it did start. but, the idle speed dropped to 250 and, after revving the engine, which was quite laborious to run, my voltmeter gauge only showed 12V. Would the engine's performance be impacted by low voltage?


Should I be staring at the regulator? I can't tell if it's heat-induced or not. What's the best way to check the regulator? Lastly, I saw that there is a certain brand of regulator available. Has anyone had positive experience with this particular brand?

I am thankful.

[owencastilloss]

In most cases, the Accumulator requires a hot restart.
Assuming it started up and ran smoothly until you switched off the engine, but then you had trouble starting it after, say, 30 minutes of sitting, the accumulator is probably to blame.
My 560SL and 380SL both required me to change the accumulator. There was a Bosch on one side and a URO on the other; the former was more costly, but the latter was functional and aesthetically pleasing. With simple wrenches, it's not hard to swap out.

[harper.castillocp]

The accumulation is a novel innovation.

because the charging problem is very recent and began at the same time as the idle/rough running problem...It seemed to me that they must be connected.


Checking the alternator...When the engine is operating, the voltage at the battery terminals should be greater than 13.6 volts; if it's less than 13, it's safe to presume the regulator is at fault and replace it; however, is this part of the system easily testable?

I am thankful.

[emma.brooksoi]

See the battery indicator light? When you initially shift into run, does it turn on?

[harper.castillocp]

The light doesn't turn on.

This afternoon, I will inspect the connections and posts of the battery at the alternator.


Do you think that low idle is caused by low voltage? Once it gets going, it's great, but I take it that the low voltage is just being overcome by increasing gas and rpms, as the idle goes back down to 250 when the engine is stopped.

[emma.brooksoi]

It is probable that the bulb has blown if the battery light remains off while the engine is turned off and the key is in the run position. The alternator field is able to begin operating at a reduced speed thanks to the current drawn by the bulb. The normal operation is for it to self-energize when the rpm increases significantly.

There shouldn't be any damage to the electronics if you still have about 12V.