Check Engine Light
Thread Starter
Newbie
Joined: Oct 2011
Posts: 6
Likes: 0
From: Chalfont, PA
C230
Check Engine Light
I have a 2005 C230 Kompressor and a few days ago someone had put in 89 fuel instead of 93. Then yesterday the check engine light went on and the code that is showing is:
P0128 Coolant Thermostat Coolant Temp Below Thermostat Regulating Temperature
Is this a fluke thing because the fuel may have shocked the engine or how else do I fix this issue?
P0128 Coolant Thermostat Coolant Temp Below Thermostat Regulating Temperature
Is this a fluke thing because the fuel may have shocked the engine or how else do I fix this issue?
MBWorld Fanatic!
Joined: Jul 2008
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2019 G70 6MT & 2022 Ford Maverick XL
No it's not fuel related. The thermostat is stuck open and the car is not reaching normal operating temp. You need a new thermostat.. part is about $25-30 and labor might be $100. Don't take it to dealer.
Out Of Control!!
Joined: Nov 2001
Posts: 10,067
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From: Westwood, NJ
2004 Civic Si. FWD for the Win!
My guess would be bad thermostat, and that the bad gas has nothing to do with it.
Judging by your post, the best thing to do would be to have a MB specialist in your area look at everything and fix what needs to be fixed.
Judging by your post, the best thing to do would be to have a MB specialist in your area look at everything and fix what needs to be fixed.
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MBWorld Fanatic!
Joined: Dec 2005
Posts: 1,055
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From: SoCal. Desert
'16 E350, gone: '03 c230k
Mine started with staying ~80 when I first had this come up (and I got the CEL), then after a couple weeks it had a hard time getting over ~60. After replacing it heats up to ~85 and stays there. Cheap, easy fix - shouldn't be more than an hour in labor and $50 in parts. 
MBWorld Fanatic!
Joined: Dec 2006
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From: Toronto, Canada
2019 C300 Wagon; '75 Triumph TR6; previous: 2004 C230 6spd sold after 17 years of driving
All M271 engines seem to need a thermo after about 5years. I also changed a temp sensor that was throwing codes only when it was cold out side listed the error as 'Coolant' the sensor is on the exhaust side of the engine right near the plastic part (the nipple that attaches to the metal coolant pipe) that always breaks on this engine and is a 5 min job to replace the sensor and plug it in and costs about $20
Super Moderator
Joined: Jun 2008
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Old thermostats opened between 87 & 89. New thermostats open at 90 in NA. They appear to have ceased to sell both.
MBWorld Fanatic!
Joined: Jul 2008
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2019 G70 6MT & 2022 Ford Maverick XL
Thread Starter
Newbie
Joined: Oct 2011
Posts: 6
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From: Chalfont, PA
C230
MBWorld Fanatic!
Joined: Jul 2008
Posts: 8,384
Likes: 800
2019 G70 6MT & 2022 Ford Maverick XL
That's too expensive. Let me help:
http://www.rmeuropean.com/Part-Numbe..._91DEFFEE.aspx
Or even cheaper:
https://www.getmercedesparts.com/mer...***-parts.html
http://www.rmeuropean.com/Part-Numbe..._91DEFFEE.aspx
Or even cheaper:
https://www.getmercedesparts.com/mer...***-parts.html
Super Member
Joined: Jun 2009
Posts: 506
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From: Argyle, TX
10 Tahoe LT, 07 Silverado Z71, 99 BMW R1100RT
50 bucks for a thremostat? No way.
Like LILBENZ230 already pointed out, low-30 buck range is where it should be. AutohausAZ has them for $33.xx. Then add $17 worth of other stuff and you'll get free shipping.
Like LILBENZ230 already pointed out, low-30 buck range is where it should be. AutohausAZ has them for $33.xx. Then add $17 worth of other stuff and you'll get free shipping.
Super Moderator
Joined: Jun 2008
Posts: 19,942
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Looks like ill have to replace the thermostat. . . anyone have the part number?
