Do I Really Need New Cylinder Head?
Thread Starter
Member
Joined: Jul 2012
Posts: 90
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From: San Francisco, CA
2003 C230 Sedan Manual
Do I Really Need New Cylinder Head?
My 2003 C230 with 150,000 miles shakes at idle. It will not stall, but struggles to accelerate back to cruising speed. Feels like it lost 75% of the power. If I turn off the engine and restart everything is normal again. This does happen at about every other stop, with varying frequency depending on the day.
Took it to an independent shop. Found misfire code on cylinder 2. Checked the air intake hoses for leaks and replaced the coils. Then did compression test and was borderline for cylinder 2. Explanation given was exhaust valve probably elongated, and need to replace with re-designed cylinder head from MB. Estimate $5,000.
Went to the local MB dealership for a second opinion without telling them about the first technician. Same misfire code for cylinder 2, but they found oil leaking from valve cover gasket into cylinder 1 spark plug boot area. Estimate $500.
Not sure which diagnostic to trust now. I would hate to spend $500 and then find out what I really needed was the cylinder head. Any suggestions?
Took it to an independent shop. Found misfire code on cylinder 2. Checked the air intake hoses for leaks and replaced the coils. Then did compression test and was borderline for cylinder 2. Explanation given was exhaust valve probably elongated, and need to replace with re-designed cylinder head from MB. Estimate $5,000.
Went to the local MB dealership for a second opinion without telling them about the first technician. Same misfire code for cylinder 2, but they found oil leaking from valve cover gasket into cylinder 1 spark plug boot area. Estimate $500.
Not sure which diagnostic to trust now. I would hate to spend $500 and then find out what I really needed was the cylinder head. Any suggestions?
Last edited by wanderlust360; Mar 28, 2014 at 09:46 PM.
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Early M271 heads were known to foul & give trouble in poor fuel areas. They were designed to run on Euro fuel. The heads were redesigned. The best thing you can do is a boroscope examination to see if there is heavy fouling of the inlet manifold & valve tulips that is preventing a valve from closing properly.
Last edited by Glyn M Ruck; Mar 28, 2014 at 09:56 PM.
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From: 1 hours drive north of Sydney Australia
2007 W204 220CDI Classic Sedan
I am having trouble here about understanding why the misfire on #2 can be fixed by stopping the gasket oil leak on #1.
Also by resetting your engine management all runs well for a time. This does not sound like a severe mechanical problem. More of a sensor or electrical gremlin.
Did the MB shop do a compression test ?
Also by resetting your engine management all runs well for a time. This does not sound like a severe mechanical problem. More of a sensor or electrical gremlin.
Did the MB shop do a compression test ?
Thread Starter
Member
Joined: Jul 2012
Posts: 90
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From: San Francisco, CA
2003 C230 Sedan Manual
The independent shop did a compression test and all cylinder were fine except for #2 which was much lower (I do not have the actual numbers.) What I have trouble understanding is why the shaking and loss of power only gets triggered at idle, and never when at cruising speed. Note that if I keep my foot on the gas pedal just a bit to raise the RPM at idle, everything stays fine.
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
The throttle body might be troublesome or dirty.
If the ECU detects a problem on #2 it could be shutting down the injector at idle.
If the ECU detects a problem on #2 it could be shutting down the injector at idle.
Senior Member
Joined: Jun 2011
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From: Lumberton, TX
2009 ML350, 2007 GL450, 1963 GMC, BMW 325i
$5K. Ouch. I replaced my head a couple years ago. It was a reman with updated springs and valves. It was about $750 from Metric Motors in Cali.
Not a hard job to do yourself if you have a little mechanical aptitude.
Not a hard job to do yourself if you have a little mechanical aptitude.
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C240 4MATIC
Hmph. My car now does the same thing sometimes with cylinder six. If I abuse it, I will get a cylinder 6 misfire & it'll run with less power unless I restart the car. I'm aiming towards replacing the coil pack/spark plug wires & fuel injector for that particular cylinder.
But if I were you, I'd start doing little things by myself. @ 150k, I'd definitely clean the throttle body since that has a lot to do with idling. Idk how many shops I've been to & they gave me crap solutions on why my car was doing somethings. I had to use this forum to fix my own car.
Work your way to the big repairs by starting with the small repairs. There's plenty of DIY guides on here relating to idle issues.
But if I were you, I'd start doing little things by myself. @ 150k, I'd definitely clean the throttle body since that has a lot to do with idling. Idk how many shops I've been to & they gave me crap solutions on why my car was doing somethings. I had to use this forum to fix my own car.
Work your way to the big repairs by starting with the small repairs. There's plenty of DIY guides on here relating to idle issues.
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Junior Member
Joined: Jan 2011
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C230 2003
Hi Wanderlust, i saw this post about a week ago and i got curious about the updated head. I'm currently in the Army and stationed in Germany so I went to the MB dealer that has been doing some work on and off for the last 3 years. I asked my service rep about the price and he quoted 1,700 Euro (roughly 2400 dollars).
Thread Starter
Member
Joined: Jul 2012
Posts: 90
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From: San Francisco, CA
2003 C230 Sedan Manual
Thanks for all the replies. This seems to only be an issue only when the weather is cold. Once the temperature reaches the 80s and above here in FL, the check engine light comes off and the car runs just fine. As soon as the temperature drops, the problem reappears. Does this support the theory of fouled heads/throttle body? Would any fuel additive help clean-up the engine at this point or is it too late?
