retna7

Intermittently - car cranks but but does not start. On the way to work in the morning - got off the highway & came to a stop and car died. Started right up after about 5 minutes.

So far -

New battery
Checked for codes - none
No warning on display

Ran a/c diagnostic and 24 showed only rose to 10.5 when car wouldnt start. Rose to 13.5 when running. Dropped to 13 when all accessories running.

Belt feels tight no cracks. Hear humming from rear of engine when key is in position 2.

Thinking either...

CPS
Voltage Regulator
Alternator

Is there any way to be 100% sure without taking the alternator out or taking it to the stealer? I read Bosch alternators shouldnt be bench tested like an AC Delco for instance as it would maybe cause damage?

Reason I ask is because I dont read over 13.5 when engine is running using ac diagnostic...

http://www.ehow.com/how_4601849_veri...r-working.html

Also - I disconnected negative battery terminal while engine was running and engine didnt die. (Later I read this is quite dangerous on a benz with all these electronics.)

http://www.ehow.com/how_4519042_chec...lternator.html

These facts seem to contradict each other to me.

How do I know which one is the culprit?

ohlord

would indicate cps.Autohausaz.com has them cheap.Alternator ,you would have your battery(misnomer)light lit up.
Cranks over,not the battery.If it is to low you will have lights but she won't turn over even slowly like olden day cars.
Take a cps and call the doctor when replaced.
diy on benzworld.org and http://www.peachparts.com/
in the diy resource section.
E8 torx sold in a set at www.harborfreight.com for about 8 bucks.
Use the hood release latch to make the hood go beyond the normal range,so you can put a blanket on the fender,remove your belt and watch and climb on in there.

watch out for the sharp heat shield down there

retna7

As always - thanks Ohlord!

Glad youre back!!!

ohlord

how wild the ride was
Going on another 3600 mile rt this week picked up a beauty of a 91 300E and sold it the next day.Driving to deliver it.
It is so nice,I gotta get me anuther My 17 yo daughter wants one now.
She follows in my foot steps,wants to race and loves the smell of a good burnout in the bleach box.

retna7

3600 miles

The driving distance between Los Angeles and New York is only 2,778 mi...how do you do it?

"She follows in my foot steps,wants to race and loves the smell of a good burnout in the bleach box."

Now THAT is something to be very proud of! For better or worse - I dont know who / what I'd be without my mom and dad. Some folks are naturally gifted at family life, some have to work really hard at it, and others have no business at all making babies!

BTW that is a nice ride - love the classy two tone & headlight wipers!

what_boost

I agree with Ohlord. My e430 would crank but not fire when the car was warm. Buy a CPS (part # 003-153-28-28) and install. Easy as 1-2-3! (it took me 10 minutes to remove and install). You not only need an E8 torx socket but you also need an extension and a swivel joint attachment. Raise the hood to vertical and remove the plastic engine cover. Then once you locate the sensor (between firewall and driver-side cylinder bank) detach sensor wire and remove torx bolt and pull sensor out.

retna7

Thanks What_Boost ~

I wish I would have checked with you guys BEFORE buying a new battery but hey - live and learn right? I dont feel too bad about it - there was no evidence that my battery had ever been changed by the original owner and I got the new one for 10% off ~ so it was around $117. You guys dont even want to know how much they'd have charged me for installation

I ordered the CPS from Autohauz AZ for around $50 including priority shipping. The Stealership wanted $161.50 plus tax!

I already knew how much it was at Autohauz but wanted to see if it was worth it to get it sooner so I called the stealer.

I thought the parts guy was refering to the CPS part number when he quoted me the price - as in "part number 16150."

Jeez, talk about a mark-up

I'm sure I've saved myself at least a few thousand dollars by joining these forums and DIY'ing!

Thanks again Guys! I will post the results ASAP.

ohlord

Seattle to ames,iowa and 1825miles back.3650 total miles
Seattle to nyc would be 5712 miles Round trip.
I need to get home ya know

Just did Seattle to butte,Montana in 9hours.621 miles with stops for gas,food,and a isit to the mb dealer in Spokane.This 300E flies
Needs to have the wheels balanced,slight shake at 120plus

retna7

120mph is only a dream here in the DC area - youd have to be a Jedi to get around the waves of 3 cars, driving side by side, blocking the fast, middle, and slow lanes, simultaneously, and probably talking to each other 3 - way on cell phones...

I got the CPS from Autohauz AZ yesterday. It took all of 20 minutes to put it in. Took her for a drive and couldnt duplicate the problem so I think I'm good (so far). Voltage never dropped below 13.5 but I heard that was low. I was suprised to see grit on the old CPS because it looks to sit pretty tight in the hole. Is that normal?

Anyway - thanks a million guys! No telling how much money I've saved!!! I sometimes get the itch to sell my W210 and buy a CLS but she always gives me (and my pockets) more reason to keep her! I might not be able to say the same if not for forums like these and guys like you.

tristarblue

On my 97 E320, I noticed lately all the lights in the car start flickering or sort of vibrating in a fast mode sometime. But when I turn on the A/C the flickering gets stronger and the transmission does hard shifting as if it's not getting enough electric power. Does anyone know or had this kind of problem? Is it my alternator going bad or the regulator isn't working properly?