Long Starting Time

[greenphant]

My C280 always starts right up first thing in the morning, but then when I go out again at about 10:30 it takes a long time to start. It's cranking fast, so it's not battery/starter, but it just takes a long time. It always does start though. After the prolonged start time, if I shut it off and restart it, it starts right up with one crank. I was thinking possible fuel issue?

The thing that throws me off is that it always starts right up after sitting all night. Anyone experience the same thing? Any thoughts?

[iwhocorrupts]

Fuel filter?

[matt09]

My car got towed while I was out of the country due to a misunderstanding and sat in a lot for almost a month. When I came back and claimed my car, the guy that towed it followed me to the car, I sat inside and with the turn of the key, the car started instantly!. The towing guy laughed and then asked me if I wanted to sell the car... lol.

[kropsch]

You could be loosing pressure somewhere between the gas pump and engine. This pressure should remain for some time after ignition is turned off. You will need a pressure gauge to find where is the loss.. Possibly it could be the filter or the fuel pressure regulator.

[trymonlam]

well, mine always starts, but my problem is that usually, the car's on in 3 clicks of the ignition. but these days on a cold start in the morning, it takes about 10 clicks and the clicking sound changes in tone. the pitches rises for the first 4 clicks or so, then the pitch get so high that the 5-6 clicks are almost not audible, then the pitch drops for about 2-3 more clicks and the car's on fine...
what do u guys think this is?

[Sulaco]

Originally posted by trymonlam
well, mine always starts, but my problem is that usually, the car's on in 3 clicks of the ignition. but these days on a cold start in the morning, it takes about 10 clicks and the clicking sound changes in tone. the pitches rises for the first 4 clicks or so, then the pitch get so high that the 5-6 clicks are almost not audible, then the pitch drops for about 2-3 more clicks and the car's on fine...
what do u guys think this is?

Exact same thing happened to me. If it's not starting. Get inside the car, turn the key to the ON position but do not try to crank it.

Pop the hood.

Get out of car.

Raise hood.

Remove protective plastic panel on passenger side near the windshield that covers/protects alot of wiring.

Look for a shiny, long, rectangular box sticking up with a clear-plastic door on top that protects a fuse.

Tap that piece with your hand.

If you hear a bunch of clicks underneath the hood, you need to replace that part. It's a very common thing on our old 202's. It's called the OVP (Overvolt Protection Relay). About $130 for me, i think.

www.importeccatalog.com is about the cheapest you'll find it.

As for the original owner of this thread:
If it's an m104 engine (1994-1997 C280 with the I-6) then it's almost CERTAINLY the crank position sensor. Another very common problem on the m104.

I've suffered both of them. And the head gasket. And the wiring harness.

Headed home this weekend to replace the head gasket and hopefully I won't need a new engine.

[greenphant]

If it's an m104 engine (1994-1997 C280 with the I-6) then it's almost CERTAINLY the crank position sensor. Another very common problem on the m104.

Yes, I have the I-6, were there different varieties of it in the C280?

If so, how do I go about replacing/repairing the crank position sensor?
-G

[Sulaco]

There's an I-6 version and a V6 version. Every C280 from 1994 to 1997 came with the I-6 engine designated as the "M104" by Mercedes Benz. It's the same design as in the "320" badged cars (ie the E320 or the S280/S320's that were sold outside the U.S.). It's the last I-6 engine Mercedes released and, except for a few HUGE production flaws that have nothing to do with the design of the engine, many believe it's the best, most bullet-proof I-6 one can find.

But these flaws are what's killing these engines today. First is the engine wiring harness and throttle body actuators. They were manufactured using "bio-degradable" insulation on all the wiring. Needless to say, after 100+thousand miles, these harnesses/wires begin to fail and make the car run EXTREMELY poorly. In some cases the cars can't even be driven due to their handicap. The wiring harness (sold online) is between $500-700 and takes a do-it-yourself'er about 3 hours to install alone. But if you're NOT the kind to do it yourself, you can hand the dealer about $3-500 of your money to install it for you. Most dealers won't install a part you purchased elsewhere, so they'd likely make you pay $7-1200 for their own wiring harness and THEN charge you labor.

And the biggest shortcoming of all is the design of the head gasket. The head gaskets begin to weaken and shrink over the years. This problem has been recognized by the manufacturers; seeing as how when you order a replacement gasket, it comes "reinforced" in all the specific areas the original gasket failed. First symptoms are mysterious oil-leak that cannot be fixed without replacing the head gasket. Some cases (such as mine) an accidental over-heat of the engine can cause the head gasket to fail completely and allows the engine coolant and oil to become mixed. Pressurized water/antifreeze finds a way into the firing chamber and this can result in COMPLETE engine failure in some cases. It can also slowly begin to happen without an overheat. Try draining your radiator a tad. If it's milky-white then it has oil mixed with it at high pressure.

Replacing the head gasket is about as extreme as DIY jobs get on these cars. To pay the dealership you're looking at $2,000 at the bare minimum. I found a local mom-pop shop that quoted me $1,000. I'm an incredibly broke, jobless college student. I'm doing it myself. No choice.

I won't go into any more detail about other known issues, because I'm basically just venting. I'm very angry about what's happened with my car. I'd like to help you prevent this from happening to you.

As for the crank position sensor, I haven't done the job myself. I chose to just ignore the hesitating start and leave it alone. Doesn't really hurt the car. Just hurts that three-point star on the hood when passengers and passerby's see a Mercedes having trouble cranking.

But if you search this forum, I'm sure there's SOMETHING on it.

[trymonlam]

Originally posted by Sulaco
Exact same thing happened to me. If it's not starting. Get inside the car, turn the key to the ON position but do not try to crank it.

Pop the hood.

Get out of car.

Raise hood.

Remove protective plastic panel on passenger side near the windshield that covers/protects alot of wiring.

Look for a shiny, long, rectangular box sticking up with a clear-plastic door on top that protects a fuse.

Tap that piece with your hand.

If you hear a bunch of clicks underneath the hood, you need to replace that part. It's a very common thing on our old 202's. It's called the OVP (Overvolt Protection Relay). About $130 for me, i think.

www.importeccatalog.com is about the cheapest you'll find it.

As for the original owner of this thread:
If it's an m104 engine (1994-1997 C280 with the I-6) then it's almost CERTAINLY the crank position sensor. Another very common problem on the m104.

I've suffered both of them. And the head gasket. And the wiring harness.

Headed home this weekend to replace the head gasket and hopefully I won't need a new engine.

hmm...
i will give that a try tomorrow. however, mine's the v6. would this inherent fault apply to me?

[Sulaco]

If you're hearing the "clicking" sound phenomena, then yes, it could still be the OVP.

If it's hesitating on start all the time, then yes, it could be the crank position sensor. It happens on alot of Mercedes'. I just read a thread from a C43 owner who had this same problem.

[94benZo]

mines a 94 c280 and i have the same problem sometime, but most of the time, i just give it a little gas when cranking and it starts right up, is that bad??

[jnenad16]

Originally posted by 94benZo
mines a 94 c280 and i have the same problem sometime, but most of the time, i just give it a little gas when cranking and it starts right up, is that bad??

that might be a clogged fuel filter.

nenad

[trymonlam]

Originally posted by 94benZo
mines a 94 c280 and i have the same problem sometime, but most of the time, i just give it a little gas when cranking and it starts right up, is that bad??

would this be the sign of a failing fuel pump? used to have the same issue on me 94 jag.

[94benZo]

fuel filter was replaced about a year ago...

[jnenad16]

Originally posted by 94benZo
fuel filter was replaced about a year ago...

and its probably that time of the year again...

nenad

[jnenad16]

Originally posted by trymonlam
would this be the sign of a failing fuel pump? used to have the same issue on me 94 jag.

I know what you mean with the jags. I have seen this problem on jags about 20 times by now, its very common. the tank gets filled with sand and other crap because the filler neck and the gas lid are straight up. so you have to replace the pump, the modulator, and remove and flush the tank. however, this situation will cause the car to stall and die, unless his car is doing that, this is most likely not the case.

nenad