New to Board - 99 ML320 air pump problem
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Member
Joined: Mar 2005
Posts: 173
Likes: 34
From: Friendswood, TX
99 C43, 73 911 targa
New to Board - 99 ML320 air pump problem
Hi Everyone here! I have been lurking here for a few weeks as I try in vain to troubleshoot a stranger problem with my wife's ML320.
I hope that someone here can guide me to a inexpensive solution, as money is pretty tight around here right now.
Here's what happened: Car is running fine (apparently) then one day a week ago wife exits work at 6PM to find car with battery STONE DEAD!
I went over there to help start the car. When I first put the jumper 12V onto the dead car, there was a constant whining noise under the hood - popped cover to discover the air pump was running even with the ignition off. pulled wire connector off and jump started the car replaced connector got in and it drove home fine.
I charged the battery for a day, and kept the car while wife drove my car for rest of week. I drove 6 times or so no worries.
Yesterday, wife is leaving work, as she starts car the Check Engine light comes on - car drives fine. Had a mech friend clear codes, and we discover that the 40 AMP fuse for the pump is blown! Replaced fuse, bought two more, and headed home, all okay again.
This AM, I went out and started car, put a stopwatch on the pump. It ran for about 1 min 10 sec then stopped. (supposed to be about 2 minutes from cold only, I am told). Shut down and checked fuse - it was BLOWN again!!
Here is my question - What all neeeds to be replaced, pump relay, fuse(of course) and can a fairly competent home mech do this and save a bunch of labor?? If so where is the cheapest place to buy MB partslike these, other than dealership - have had very bad luck with those guys here..
Anyway, thanks for listening to my looooong story, any of the pros out there that can advise me, I would be very grateful.
I hope that someone here can guide me to a inexpensive solution, as money is pretty tight around here right now.
Here's what happened: Car is running fine (apparently) then one day a week ago wife exits work at 6PM to find car with battery STONE DEAD!
I went over there to help start the car. When I first put the jumper 12V onto the dead car, there was a constant whining noise under the hood - popped cover to discover the air pump was running even with the ignition off. pulled wire connector off and jump started the car replaced connector got in and it drove home fine.
I charged the battery for a day, and kept the car while wife drove my car for rest of week. I drove 6 times or so no worries.
Yesterday, wife is leaving work, as she starts car the Check Engine light comes on - car drives fine. Had a mech friend clear codes, and we discover that the 40 AMP fuse for the pump is blown! Replaced fuse, bought two more, and headed home, all okay again.
This AM, I went out and started car, put a stopwatch on the pump. It ran for about 1 min 10 sec then stopped. (supposed to be about 2 minutes from cold only, I am told). Shut down and checked fuse - it was BLOWN again!!
Here is my question - What all neeeds to be replaced, pump relay, fuse(of course) and can a fairly competent home mech do this and save a bunch of labor?? If so where is the cheapest place to buy MB partslike these, other than dealership - have had very bad luck with those guys here..
Anyway, thanks for listening to my looooong story, any of the pros out there that can advise me, I would be very grateful.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 5,640
Likes: 11
From: GMT -8 hours
Mercedes-Benz
Yes, all MBs in the US at least are equipped with the air injection pump. It makes a whining noise for the first 30-40 seconds of startup... louder when it is cold out. Not sure how to fix your problem tho. Could be a bad switch or relay maybe?
MBWorld Fanatic!
Joined: Nov 2001
Posts: 4,260
Likes: 6
From: Philadelphia area
2010 ML550, 2010 E350 4M, 1966 Corvette Convt C2
Originally Posted by AlBoston
Yes, all MBs in the US at least are equipped with the air injection pump. It makes a whining noise for the first 30-40 seconds of startup... louder when it is cold out. Not sure how to fix your problem tho. Could be a bad switch or relay maybe?
Newbie
Joined: Sep 2004
Posts: 12
Likes: 0
From: North Texas
It's an electric pump. It's on top of the engine, under the plastic cladding and it sounds like a vacuum cleaner. It typically only runs when the engine is cold, but I have heard it cycling off and on as the engine is warming up on the ML and a C I owned. It sounds as if the motor in it is drawing too much current. I can't imagine it blowing a 40 amp fuse, but I guess it's possible. I've never heard of one going out, though. Sounds like you need somebody with a good diagnostic tool. Do you have a dealer/independent you trust? Good luck.
Of course money is tight. This problem wouldn't have appeared if you had plenty of cash on hand, right? There is a sensor in the seat of every Benz that measures the thickness of your wallet. When it gets thin, it forces a Check Engine Light on.
Of course money is tight. This problem wouldn't have appeared if you had plenty of cash on hand, right? There is a sensor in the seat of every Benz that measures the thickness of your wallet. When it gets thin, it forces a Check Engine Light on.
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MBWorld Fanatic!
Joined: Nov 2001
Posts: 5,640
Likes: 11
From: GMT -8 hours
Mercedes-Benz
Originally Posted by mlmoose
It's an electric pump. It's on top of the engine, under the plastic cladding and it sounds like a vacuum cleaner. It typically only runs when the engine is cold, but I have heard it cycling off and on as the engine is warming up on the ML and a C I owned. It sounds as if the motor in it is drawing too much current. I can't imagine it blowing a 40 amp fuse, but I guess it's possible. I've never heard of one going out, though. Sounds like you need somebody with a good diagnostic tool. Do you have a dealer/independent you trust? Good luck.
Of course money is tight. This problem wouldn't have appeared if you had plenty of cash on hand, right? There is a sensor in the seat of every Benz that measures the thickness of your wallet. When it gets thin, it forces a Check Engine Light on.
Of course money is tight. This problem wouldn't have appeared if you had plenty of cash on hand, right? There is a sensor in the seat of every Benz that measures the thickness of your wallet. When it gets thin, it forces a Check Engine Light on.
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