No compression dilemma
Thread Starter
Super Member
Joined: Jun 2016
Posts: 589
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From: Snowville, ID
W212 E350; W166 GLC300; W164 ML550; W164 ML63; W221 S65; W220 S430; Escalade ESV
No compression dilemma
Background:
Car was shaking in idle. Indy shop replaced plugs, distributor and wires. It's still shaking after parts replacements and the shop pointed to no compression on V8 cylinder #4. All other cylinders read 140.
Took to another dealer for diagnostic and dealer said car needs a new engine.
Car runs fine and no CEL but shakes violently in idle. Coolant reservoir showed low fluid but no leaks were found. Muddy sludges were found at the oil filling cap. Oil drained and no metal dust were found.
Question:
Assuming passenger side head gasket is blowed. Can it caused no compression on 1 cylinder? Should it be low and not zero compression?
Car was shaking in idle. Indy shop replaced plugs, distributor and wires. It's still shaking after parts replacements and the shop pointed to no compression on V8 cylinder #4. All other cylinders read 140.
Took to another dealer for diagnostic and dealer said car needs a new engine.
Car runs fine and no CEL but shakes violently in idle. Coolant reservoir showed low fluid but no leaks were found. Muddy sludges were found at the oil filling cap. Oil drained and no metal dust were found.
Question:
Assuming passenger side head gasket is blowed. Can it caused no compression on 1 cylinder? Should it be low and not zero compression?
Senior Member
Joined: Dec 2010
Posts: 282
Likes: 66
From: Virginia Beach
2005 S600 2005 SL600
Coolant leak won't cause zero compression.
Blown head gasket will cause a coolant and/or oil leak and may cause a compression drop, but doubtful that it will go to zero.
Broken valve, broken piston, completely worn bore...the things that cause a zero reading are mechanical, and expensive to fix.
And it doesn't run fine with zero compression on one dead cylinder. It runs. And that's a testament to a Mercedes engine, but it doesn't run fine.
A compression test isn't hard to do. You might want to verify the readings. I would like more detail from the dealer on "Needs new engine" - how did they conclude that, exactly?
Sludge on the oil cap is a sign of moisture in the oil. Could be coolant. Could be lots of short trips leading to moisture. Doesn't prove anything. No metal particles in the oil proves nothing as well. You could have a broken valve where the pieces went out the exhaust. Or a broken chunk of piston in the oil pan that won't fit out the drain plug.
Only time I've ever seen zero PSI, there were big broken parts in the engine. Big, broken, parts.
Blown head gasket will cause a coolant and/or oil leak and may cause a compression drop, but doubtful that it will go to zero.
Broken valve, broken piston, completely worn bore...the things that cause a zero reading are mechanical, and expensive to fix.
And it doesn't run fine with zero compression on one dead cylinder. It runs. And that's a testament to a Mercedes engine, but it doesn't run fine.
A compression test isn't hard to do. You might want to verify the readings. I would like more detail from the dealer on "Needs new engine" - how did they conclude that, exactly?
Sludge on the oil cap is a sign of moisture in the oil. Could be coolant. Could be lots of short trips leading to moisture. Doesn't prove anything. No metal particles in the oil proves nothing as well. You could have a broken valve where the pieces went out the exhaust. Or a broken chunk of piston in the oil pan that won't fit out the drain plug.
Only time I've ever seen zero PSI, there were big broken parts in the engine. Big, broken, parts.
Last edited by Astro14; Jun 19, 2017 at 06:38 PM.
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Joined: May 2004
Posts: 432
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From: Albuquerque, NM
09' E350, 01' Maxima SE, 93 Nissan Maxima SE, 1987 Nissan Maxima SE
anytime a zero compression in one of the cylinder, is essentially a dead cylinder, which either your valve broke or stuck, or blown piston. SO yes, you will need a new engine. It sucks, but it's ultimately up to you what you're gonna do, scrap the car, or get a new engine.
Thread Starter
Super Member
Joined: Jun 2016
Posts: 589
Likes: 60
From: Snowville, ID
W212 E350; W166 GLC300; W164 ML550; W164 ML63; W221 S65; W220 S430; Escalade ESV
I thought so about the relationship between the coolant leak and no compression. Thanks for the confirmation.
Questions:
1. The distributor, plug and wire were replaced but if any one of those was defective then it would still give no compression right?
2. Can bad seal or blown piston be replaced by removing the cylinder head? Why can't the engine be rebuild?
Questions:
1. The distributor, plug and wire were replaced but if any one of those was defective then it would still give no compression right?
2. Can bad seal or blown piston be replaced by removing the cylinder head? Why can't the engine be rebuild?
MBWorld Fanatic!
Joined: Jan 2008
Posts: 6,151
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Mercedes
I thought so about the relationship between the coolant leak and no compression. Thanks for the confirmation.
Questions:
1. The distributor, plug and wire were replaced but if any one of those was defective then it would still give no compression right?
2. Can bad seal or blown piston be replaced by removing the cylinder head? Why can't the engine be rebuild?
Questions:
1. The distributor, plug and wire were replaced but if any one of those was defective then it would still give no compression right?
2. Can bad seal or blown piston be replaced by removing the cylinder head? Why can't the engine be rebuild?
a good used engine will cost $400
there are so many good used engines out there it makes no sense to spend labor time to rebuild . Just swap in a used engine
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MBWorld Fanatic!
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From: Ball Ground, GA (N of Atlanta)
2003 S500 2007 GL450
A leak-down test will tell you immediately what the problem is. A tester is installed in a spark plug hole in the affected cylinder, and compressed air is blown thru the tester into the cylinder. A gauge on the tester tells the amount of leakage, and the hiss of escaping air tells where the leak is. Hissing at the oil filler port on the cam cover shows damaged piston or cylinder wall. Hissing at the MAF or throttle body shows a damaged intake valve. Hissing at the exhaust pipe shows a damaged exhaust valve.
Zero compression is more often a valve problem. A head crack or failed head gasket bad enough to show zero compression would be blowing huge quantities of coolant out of the system. A broken piston would usually make a lot of noise, and would cause heavy smoke from the exhaust.
It is possible that you could fix a failed valve by pulling only the affected cylinder head, but the labor and parts cost would be close to the same as installing a used engine.
Zero compression is more often a valve problem. A head crack or failed head gasket bad enough to show zero compression would be blowing huge quantities of coolant out of the system. A broken piston would usually make a lot of noise, and would cause heavy smoke from the exhaust.
It is possible that you could fix a failed valve by pulling only the affected cylinder head, but the labor and parts cost would be close to the same as installing a used engine.
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Thread Starter
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Joined: Jun 2016
Posts: 589
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From: Snowville, ID
W212 E350; W166 GLC300; W164 ML550; W164 ML63; W221 S65; W220 S430; Escalade ESV
I wish that I could do a compression test right now but I can't. Head cover is off. Upper intake manifold is off. Fuel rail is about ready to come off. Then lower intake manifold and the head.
I'm almost there.
I'm pausing because of couple suspicious issues:
1. Plug on the problem chamber can be removed by hand.
2. Ignition wire to the problem chamber had corrosion. Perhaps no contact?
Do I put things back or do I go all the way and remove the head? What would you do?
I'm almost there.
I'm pausing because of couple suspicious issues:
1. Plug on the problem chamber can be removed by hand.
2. Ignition wire to the problem chamber had corrosion. Perhaps no contact?
Do I put things back or do I go all the way and remove the head? What would you do?
Thread Starter
Super Member
Joined: Jun 2016
Posts: 589
Likes: 60
From: Snowville, ID
W212 E350; W166 GLC300; W164 ML550; W164 ML63; W221 S65; W220 S430; Escalade ESV
Indy shop said no compression in one cylinder and all others are good. I wish I do compression test myself before taking things apart but I didn't.
Engine is shaking in idle mode and it could be from ignition source from the evidence. I stick a camera into the trouble cylinder and the pistol looks fine. Cylinder walls also look fine with no vertical scratches. Trying to look at the valves but the camera angle isn't co-operating...
Engine is shaking in idle mode and it could be from ignition source from the evidence. I stick a camera into the trouble cylinder and the pistol looks fine. Cylinder walls also look fine with no vertical scratches. Trying to look at the valves but the camera angle isn't co-operating...
Thread Starter
Super Member
Joined: Jun 2016
Posts: 589
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From: Snowville, ID
W212 E350; W166 GLC300; W164 ML550; W164 ML63; W221 S65; W220 S430; Escalade ESV
I got some images of the head valves finally. I don't see any burnt marks
Wall and piston images
I think I'm going to put things back to see if it's still shaking or not
Wall and piston images
I think I'm going to put things back to see if it's still shaking or not
Super Member
Joined: Sep 2012
Posts: 690
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From: Montreal, Quebec
2009 E350 4M Avantgarde;mistress 2002 S600; wife 2014 C300 4M
stick a finger into the plug hole and have somebody crank it for a few turns.
Might be wise to make sure the engine does not actually start.
You will know if there is compression or not.
Good luck!
Alternate: Buy a cheap compression gauge.
If you get more involved, crank the engine without ignition, and listen: if there is no compression you will hear the engine speed up momentarily in a steady rhythm.
... of course there is always DAS, if you can get it.
Might be wise to make sure the engine does not actually start.
You will know if there is compression or not.
Good luck!
Alternate: Buy a cheap compression gauge.
If you get more involved, crank the engine without ignition, and listen: if there is no compression you will hear the engine speed up momentarily in a steady rhythm.
... of course there is always DAS, if you can get it.
Last edited by kraut56; Jun 23, 2017 at 09:36 AM.
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From: Sarasota, Florida
2023 E450 Cabriolet, 2019 F150 Platinum, 2014 Dodge Challenger R/T
If you've torn it down this far, then your mechanically inclined and I would buy a decent compression gauge and check it myself 
Thread Starter
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Joined: Jun 2016
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From: Snowville, ID
W212 E350; W166 GLC300; W164 ML550; W164 ML63; W221 S65; W220 S430; Escalade ESV
I'm learning. The passenger valve cover is back on but the upper intake manifold and the throttle valve body are still out. Is it safe to do the compression test at this point?
Thread Starter
Super Member
Joined: Jun 2016
Posts: 589
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From: Snowville, ID
W212 E350; W166 GLC300; W164 ML550; W164 ML63; W221 S65; W220 S430; Escalade ESV
In the last couple of weeks, I put everything back together and had hard time with timing. It would crank but won't turn over.
Finding the TDC was easy but positioning the distributor was quite a challenge. I nailed it today and the engine is back to life.
It wasn't shaking at all and the compression all 8 cylinders are good. Disconnected distributor wire was the culprit.
This is the case of dishonest professional at the indy shop and a lousy diagnostic job at the dealer.
Finding the TDC was easy but positioning the distributor was quite a challenge. I nailed it today and the engine is back to life.
It wasn't shaking at all and the compression all 8 cylinders are good. Disconnected distributor wire was the culprit.
This is the case of dishonest professional at the indy shop and a lousy diagnostic job at the dealer.
Senior Member
Joined: Aug 2014
Posts: 370
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S55 AMG
This is why I never trust my car with anyone.
Always do repairs yourself, and you will never go through any bs problems, because if you disconnected something you would reconnect it right on the spot. Instead of some lousy tech not caring about anything and the stealership trying to throw as much bs at you as they possibly can just to make the most money out of you.
Always do repairs yourself, and you will never go through any bs problems, because if you disconnected something you would reconnect it right on the spot. Instead of some lousy tech not caring about anything and the stealership trying to throw as much bs at you as they possibly can just to make the most money out of you.
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Joined: Nov 2010
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From: Welwyn, Herts, UK
2006 S600
Background:
Car was shaking in idle. Indy shop replaced plugs, distributor and wires. It's still shaking after parts replacements and the shop pointed to no compression on V8 cylinder #4. All other cylinders read 140.
Took to another dealer for diagnostic and dealer said car needs a new engine.
Car runs fine and no CEL but shakes violently in idle. Coolant reservoir showed low fluid but no leaks were found. Muddy sludges were found at the oil filling cap. Oil drained and no metal dust were found.
Question:
Assuming passenger side head gasket is blowed. Can it caused no compression on 1 cylinder? Should it be low and not zero compression?
Car was shaking in idle. Indy shop replaced plugs, distributor and wires. It's still shaking after parts replacements and the shop pointed to no compression on V8 cylinder #4. All other cylinders read 140.
Took to another dealer for diagnostic and dealer said car needs a new engine.
Car runs fine and no CEL but shakes violently in idle. Coolant reservoir showed low fluid but no leaks were found. Muddy sludges were found at the oil filling cap. Oil drained and no metal dust were found.
Question:
Assuming passenger side head gasket is blowed. Can it caused no compression on 1 cylinder? Should it be low and not zero compression?
With a mis-firing engine, it's easy to jump to the worst conclusion, but the cause is often much more benign.
Nick
Member
Joined: Mar 2007
Posts: 95
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From: Sydney, Australia
220SE Coupe, ML250, E320
In the last couple of weeks, I put everything back together and had hard time with timing. It would crank but won't turn over.
Finding the TDC was easy but positioning the distributor was quite a challenge. I nailed it today and the engine is back to life.
It wasn't shaking at all and the compression all 8 cylinders are good. Disconnected distributor wire was the culprit.
This is the case of dishonest professional at the indy shop and a lousy diagnostic job at the dealer.
Finding the TDC was easy but positioning the distributor was quite a challenge. I nailed it today and the engine is back to life.
It wasn't shaking at all and the compression all 8 cylinders are good. Disconnected distributor wire was the culprit.
This is the case of dishonest professional at the indy shop and a lousy diagnostic job at the dealer.
Thread Starter
Super Member
Joined: Jun 2016
Posts: 589
Likes: 60
From: Snowville, ID
W212 E350; W166 GLC300; W164 ML550; W164 ML63; W221 S65; W220 S430; Escalade ESV
Well, let's me filled in some of the blank:
First, this wasn't my car, it was my brother in-law and he lives 200miles from me. The guy asked me for an opinion after he took it in and the problem got worse. Take a note here: The Indy shop had their hands all over this car.
This was my advice. I told him to go to the dealer for a 2nd opinion.
This was my observation when he stopped by for a quick visit. I didn't know the seriousness of no compression issue at this point.
Now the rest of the story:
He was facing with a large repair so he decided to trade in. The dealer gave him nothing for it because of the violent shaking.
He had a business and the Indy shop guy came multiple times asking to buy the broken car from him. The offer price was higher than the market value of a broken car.
I wanted to learn about the engine rebuild so I offered to buy it. I drove it 200miles, it ran fine but it wanted to die at all intersection stops.
I posted multiple forums and I got scared from the responses so I told the guy that I changed my mind and wanted to return the car. He wasn't happy. So I tear the engine apart...
Originally Posted by DrDoe
Car was shaking in idle. Indy shop replaced plugs, distributor and wires. It's still shaking after parts replacements and the shop pointed to no compression on V8 cylinder #4. All other cylinders read 140.
Originally Posted by DrDoe
Took to another dealer for diagnostic and dealer said car needs a new engine.
Originally Posted by DrDoe
Car runs fine and no CEL but shakes violently in idle. Coolant reservoir showed low fluid but no leaks were found. Muddy sludges were found at the oil filling cap. Oil drained and no metal dust were found.
Now the rest of the story:
He was facing with a large repair so he decided to trade in. The dealer gave him nothing for it because of the violent shaking.
He had a business and the Indy shop guy came multiple times asking to buy the broken car from him. The offer price was higher than the market value of a broken car.
I wanted to learn about the engine rebuild so I offered to buy it. I drove it 200miles, it ran fine but it wanted to die at all intersection stops.
I posted multiple forums and I got scared from the responses so I told the guy that I changed my mind and wanted to return the car. He wasn't happy. So I tear the engine apart...
