Red Fuel Cap light, then next day Check engine light..?
Thread Starter
Super Member
Joined: Aug 2009
Posts: 685
Likes: 121
From: Palm Coast, Florida
2019 E-450 Wagon
Red Fuel Cap light, then next day Check engine light..?
Got the Check Engine light this morning. Never seen it in 3 years of owning the car.
About once a month I get a big red Check Fuel Cap light, but wrote it off as a loose microswitch or some such thing.
Did a search on the forum for similar problems, no cigar.
Any ideas, or does anybody have a list of what would cause the Check Engine light to illuminate..?
(All services and maintenance has been done, last trip to the MB dear 2 months ago)
About once a month I get a big red Check Fuel Cap light, but wrote it off as a loose microswitch or some such thing.
Did a search on the forum for similar problems, no cigar.
Any ideas, or does anybody have a list of what would cause the Check Engine light to illuminate..?
(All services and maintenance has been done, last trip to the MB dear 2 months ago)
Member
Joined: Jan 2012
Posts: 244
Likes: 4
From: PA, USA
2004 E320 4matic Sedan
The fuel cap is not sealing well, probably,....
you can buy a new one, or try spraying a little silicon spray or a small quantity of some other lubricant, on the seal ring on the cap. (light blue ring on mine).
The engine light / fuel cap warning is coming on because there is a leak in the EVAP system. That is probably caused by the fuel cap.
The most common cause of an EVAP leak, and hence pollution, is an incorrectly sealing fuel cap, that's why Mercedes give you the red warning because it is the best, simplest, bet. (It could still be something else.)
The engine light / fuel cap warning is coming on because there is a leak in the EVAP system. That is probably caused by the fuel cap.
The most common cause of an EVAP leak, and hence pollution, is an incorrectly sealing fuel cap, that's why Mercedes give you the red warning because it is the best, simplest, bet. (It could still be something else.)
Thread Starter
Super Member
Joined: Aug 2009
Posts: 685
Likes: 121
From: Palm Coast, Florida
2019 E-450 Wagon
Aha, there could be a connection then...?
If indeed the seal on the fuel cap is bad, then the light should be on every day, not just on for 2 minuttes, then go off, and only twice a month...?
Will take a close look at the cap, try the silicone trick and hook up a diagnostic code reader.
Thanks for chipping in.
If indeed the seal on the fuel cap is bad, then the light should be on every day, not just on for 2 minuttes, then go off, and only twice a month...?
Will take a close look at the cap, try the silicone trick and hook up a diagnostic code reader.
Thanks for chipping in.
Member
Joined: Jan 2012
Posts: 244
Likes: 4
From: PA, USA
2004 E320 4matic Sedan
actually, the red light will come and go....
the seal will be good enough one day, then not so good another. One day you'll refuel and it will seat just right. Next time it won't. Eventually the seal may go completely.
This happened on mine about 4 different times. I'd simply remove the cap and reseat it and it would be OK for a few weeks.
Eventually I got fed up and lubricated it with silicon. It hasn't happened for a year now.
The check engine light should go away after a few days of no red fuel cap warning. If it doesn't, the cause is something else.
This happened on mine about 4 different times. I'd simply remove the cap and reseat it and it would be OK for a few weeks.
Eventually I got fed up and lubricated it with silicon. It hasn't happened for a year now.
The check engine light should go away after a few days of no red fuel cap warning. If it doesn't, the cause is something else.
Thread Starter
Super Member
Joined: Aug 2009
Posts: 685
Likes: 121
From: Palm Coast, Florida
2019 E-450 Wagon
Good advice, thanks.
Will replace the fuel cap as soon as I can find a replacement and have a guy come to the house on Monday to read the error code.
Will report back.
Will replace the fuel cap as soon as I can find a replacement and have a guy come to the house on Monday to read the error code.
Will report back.
Trending Topics
MBWorld Fanatic!
Joined: Aug 2005
Posts: 3,085
Likes: 59
From: Los Angeles
2009 SL550 Roadster Diamond White, 2008 CLK550 Coupe Obsidian Black
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Thread Starter
Super Member
Joined: Aug 2009
Posts: 685
Likes: 121
From: Palm Coast, Florida
2019 E-450 Wagon
You could fall into this:
Bought a new fuel cap on ebay, $44 including tax and shipping.
Hopefully that will solve the problem..
The car ran out of warranty 2 months ago, hopefully it will behave for a while..
MBWorld Fanatic!
Joined: Aug 2005
Posts: 3,085
Likes: 59
From: Los Angeles
2009 SL550 Roadster Diamond White, 2008 CLK550 Coupe Obsidian Black
Aye, hope not..Been looking for fuel leaks over the years, but no cigar, fortunately.
Bought a new fuel cap on ebay, $44 including tax and shipping.
Hopefully that will solve the problem..
The car ran out of warranty 2 months ago, hopefully it will behave for a while..
Bought a new fuel cap on ebay, $44 including tax and shipping.
Hopefully that will solve the problem..
The car ran out of warranty 2 months ago, hopefully it will behave for a while..
MBWorld Fanatic!
Joined: Aug 2005
Posts: 3,085
Likes: 59
From: Los Angeles
2009 SL550 Roadster Diamond White, 2008 CLK550 Coupe Obsidian Black
Thread Starter
Super Member
Joined: Aug 2009
Posts: 685
Likes: 121
From: Palm Coast, Florida
2019 E-450 Wagon
I'd simply remove the cap and reseat it and it would be OK for a few weeks
MBWorld Fanatic!
Joined: Aug 2005
Posts: 3,085
Likes: 59
From: Los Angeles
2009 SL550 Roadster Diamond White, 2008 CLK550 Coupe Obsidian Black
Thread Starter
Super Member
Joined: Aug 2009
Posts: 685
Likes: 121
From: Palm Coast, Florida
2019 E-450 Wagon
how interesting. mine goes away when i'm stopped and comes up again once the car starts moving
Got my new gas cap today, OEM for sure, if I see that red fuel cap light again, followed by the check engine light, I just lost $44.00.
(Should have tried silicone grease first to lube the seal as mentioned above, but was trigger happy and just ordered the new cap.
)
Thread Starter
Super Member
Joined: Aug 2009
Posts: 685
Likes: 121
From: Palm Coast, Florida
2019 E-450 Wagon
Soo, the red Fuel Cap warning light is back, and it set of the Check Engine Light.
Guess I wasted $44.00 on a new fuel cap. Called my indy mech, he is going to check MB service bulletins for more info on the problem, still tempted to try silicon grease on the fuel cap seal: If that fixes it, it would be a "no-cost" item.
Any other ideas...?
Guess I wasted $44.00 on a new fuel cap. Called my indy mech, he is going to check MB service bulletins for more info on the problem, still tempted to try silicon grease on the fuel cap seal: If that fixes it, it would be a "no-cost" item.
Any other ideas...?
Out Of Control!!
Joined: Jan 2005
Posts: 11,266
Likes: 3
From: Texas
2005 E55
Add me to list of those with this exact problem. Red alert for gas cap and now check engine light. I am going to see if I can get the codes read and then I will post the results. Good luck.
MBWorld Fanatic!
Joined: Aug 2005
Posts: 3,085
Likes: 59
From: Los Angeles
2009 SL550 Roadster Diamond White, 2008 CLK550 Coupe Obsidian Black
Newbie
Joined: Sep 2024
Posts: 1
Likes: 0
Mercedes Benz c230 Kompressor sport
