Losing coolant; no obvious leaks
Thread Starter
Junior Member
Joined: Jul 2021
Posts: 26
Likes: 5
From: Acworth, GA
2005 S500, 2013 E350 cab
Losing coolant; no obvious leaks
Hi all.
I'm losing coolant at the rate of about 32 oz every 300-400 miles. There are no obvious leaks, no puddles in the garage, nothing. I've never had a car do this, and it's worrying me. I can't believe this is normal for a Benz but this is my first one. I would appreciate any info/ thoughts/ suggestions on this issue. Thanks!
I'm losing coolant at the rate of about 32 oz every 300-400 miles. There are no obvious leaks, no puddles in the garage, nothing. I've never had a car do this, and it's worrying me. I can't believe this is normal for a Benz but this is my first one. I would appreciate any info/ thoughts/ suggestions on this issue. Thanks!
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Joined: Dec 2012
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From: Ball Ground, GA (N of Atlanta)
2003 S500 2007 GL450
One common cause for this is a plastic fitting that goes thru the forward "false" firewall, under the wiper system. The leak often only happens at speed, and sometimes doesn't make a visible leak in the garage.
This is a good write-up on the leak and the repair. https://w220.wiki/WIS_20.20_Radiator,_Coolant_Hoses
This is a good write-up on the leak and the repair. https://w220.wiki/WIS_20.20_Radiator,_Coolant_Hoses
Thread Starter
Junior Member
Joined: Jul 2021
Posts: 26
Likes: 5
From: Acworth, GA
2005 S500, 2013 E350 cab
Hopefully resolved!
Well, it's been a long time going back n forth with this coolant loss issue. The pipe in the false firewall was OK. In the summer my mechanic said the water pump was going bad (155k miles) so we replaced it and I was hoping that would fix the coolant issue but it did not. I kept track of how much I was losing and the milage, and it was getting worse. This week I took it to the dealership and they they said there was an incorrect fitting used on a water pump hose, and that's where the pressure test detected the leak. I believe the wrong fitting was not done by my current indy mechanic but by a prior guy who I no longer use. I'm really glad that's all it was as research indicated it could be the head gaskets.
Anyway, I know it's good to let the forum know the outcome, and I hope you never hear from me again on this issue! LOL!
Our next adventure is finding a good used E-class convertible as a daily driver so I can relegate the S500 to Sunday car status.
Anyway, I know it's good to let the forum know the outcome, and I hope you never hear from me again on this issue! LOL!
Our next adventure is finding a good used E-class convertible as a daily driver so I can relegate the S500 to Sunday car status.
Thread Starter
Junior Member
Joined: Jul 2021
Posts: 26
Likes: 5
From: Acworth, GA
2005 S500, 2013 E350 cab
The coolant saga continues....
After MB fixed the faulty clamp I had high hopes the problem was resolved, but no dice. She's back at the dealer and it's looking like either head gasket(s) or a motor crack. Hoping for the gaskets, obviously.
After MB fixed the faulty clamp I had high hopes the problem was resolved, but no dice. She's back at the dealer and it's looking like either head gasket(s) or a motor crack. Hoping for the gaskets, obviously.
Super Member
Joined: Dec 2007
Posts: 980
Likes: 224
2005 S500 Designo
The coolant saga continues....
After MB fixed the faulty clamp I had high hopes the problem was resolved, but no dice. She's back at the dealer and it's looking like either head gasket(s) or a motor crack. Hoping for the gaskets, obviously.
After MB fixed the faulty clamp I had high hopes the problem was resolved, but no dice. She's back at the dealer and it's looking like either head gasket(s) or a motor crack. Hoping for the gaskets, obviously.
Before you cry that your engine might be destroyed: consider a used replacement engine is like $500. Throw in another $1-2k for parts + labor and you should be golden.
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Thread Starter
Junior Member
Joined: Jul 2021
Posts: 26
Likes: 5
From: Acworth, GA
2005 S500, 2013 E350 cab
Hi all.
Thanks for all your advice and help. The 500's coolant lose issue turned out to be the head gaskets. The dealership had it for awhile, and they also did some other repairs while it was there.
We're glad to have her back and she's running great!
It took me a few days, but I recently finished a 4-step paint conditioning. (clay, correction, polish, sealant) I enjoy doing it and she looks awesome.
We have also recently purchased a 2013 E350 cab, and are enjoying the hell out of it. I've just started doing the same paint procedure on it.
Thanks for all your advice and help. The 500's coolant lose issue turned out to be the head gaskets. The dealership had it for awhile, and they also did some other repairs while it was there.
We're glad to have her back and she's running great!
It took me a few days, but I recently finished a 4-step paint conditioning. (clay, correction, polish, sealant) I enjoy doing it and she looks awesome.
We have also recently purchased a 2013 E350 cab, and are enjoying the hell out of it. I've just started doing the same paint procedure on it.
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Thread Starter
Junior Member
Joined: Jul 2021
Posts: 26
Likes: 5
From: Acworth, GA
2005 S500, 2013 E350 cab
Hi Wally, I used MB of Marietta, as the car has some repair history there. I thought they treated me well.
Regarding repairs, yes I like doing manageable repairs and maintenance. I have a lot to learn as I'm fairly new to taking ownership of the car.
Regarding repairs, yes I like doing manageable repairs and maintenance. I have a lot to learn as I'm fairly new to taking ownership of the car.
Super Member
Joined: Jun 2018
Posts: 533
Likes: 39
From: Northern Hemisphere - Chicago
fleet
how many thousands of dollars was it at the dealership for head gaskets x 2?
I was going to say while reading this thread, that coolant has to be going somewhere and if not a leak then clearly out the exhaust pipe. Did you ever notice the exhaust smoke being more white or thick?
I was going to say while reading this thread, that coolant has to be going somewhere and if not a leak then clearly out the exhaust pipe. Did you ever notice the exhaust smoke being more white or thick?
Thread Starter
Junior Member
Joined: Jul 2021
Posts: 26
Likes: 5
From: Acworth, GA
2005 S500, 2013 E350 cab
[QUOTE=e350forme;8756879]
Q: how many thousands of dollars was it at the dealership for head gaskets x 2?
A: Too many, lol! Plus other work was done.
Q: Did you ever notice the exhaust smoke being more white or thick?
A: No, that never happened.
Q: how many thousands of dollars was it at the dealership for head gaskets x 2?
A: Too many, lol! Plus other work was done.
Q: Did you ever notice the exhaust smoke being more white or thick?
A: No, that never happened.
Super Member
Joined: Dec 2007
Posts: 980
Likes: 224
2005 S500 Designo
There's something to be said for a serious job done right to keep a car running well for years to come. If your dealership is anything like my favorite mercedes dealership, I imagine they did a lot of "while you're in there" type work to keep things going strong and make it worth it.
Thread Starter
Junior Member
Joined: Jul 2021
Posts: 26
Likes: 5
From: Acworth, GA
2005 S500, 2013 E350 cab
There's something to be said for a serious job done right to keep a car running well for years to come. If your dealership is anything like my favorite mercedes dealership, I imagine they did a lot of "while you're in there" type work to keep things going strong and make it worth it.
