Mercedes-Benz Forum banner

1 - 20 of 33 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter #1 (Edited)
Full Engine Repair M119 97 E420 (Replacing all gaskets)

Hey guys, been a long time lurker around here. Posted a few times here and there, but now I am turning to my fellow W210'ers for help and advice. I have a 97 E420 w/ AMG Sports Package, she has 238,000km and is my DD. Body is in perfect shape, interior is like new and transmission is original but perfectly maintained. The problem I noticed today after swapping out my old windshield washer bottle, I noticed there was some oil pooling on the skid plate. Then I backed the car up and saw a small pool of oil on the ground. It also had a strong smell of burning oil when I started her up.

Now, here is a small background on it. I have had it since it was 100,000km old, always run done my oil change at 5000km and used full synthetic with K&N high performance oil filters, transmission was dropped and rebuilt at 210,000km, this August my fiancee was driving it to work as her car was broken down. While on the highway she looked down and saw the engine temp was redlined, pulled over and the engine was smoking. When I got there the coolant had all drained out the overflow and the rad was bone dry. I swapped out the thermostat and waterpump and all was good.

I do drive her hard from time to time as I do like my speed, but 90% of the time drive her like I should. Anyway, now why I have posted. I am going to pull the engine and and replace all gaskets and clean the lifters. I am NOT a mechanic but do all my work on my car. I replaced the thermostat, waterpump and replaced the valve cover gaskets myself. I have however NEVER lifted an engine out of the car and done a full gasket replace. I understand that it is a large undertaking and I have ALL of the tools. What I am asking for is for tips and tricks from those who have done an engine rebuild. Also if there is anyone in the Windsor Ontario are who has done it before reads this, PM me and we can swap numbers.

Thanks in advance.

Here is a few pics, she is in perfect condition. Which is why I doing everything I can to keep her running smooth.





 

·
Registered
Joined
·
35,797 Posts
I admire you devotion to the car, but what gasket require pulling the engine out of the car?
As far as I can read you never checked where is the oil leak?
BTW "engine overhaul" would be new pistons, rings, hone, valve job and new bearings.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #3
Well I have taken a flashlight in to see what I can see and have gone under her to see what I could see. The problem is that she is an old girl and the valve gasket was leaking before so there is oil all over the engine below the valve covers making it rather hard to see where the new leak is. What I have gathered from first look is that it isn't the oil pan, it isn't the valve covers. I can't see the head gasket very well so I can't really tell. However I have gone from slightly dirty 8.8L of oil to about 4.4L of black oil in two days.
 

·
Registered
Joined
·
35,797 Posts
Oil changing the color might be unrelated issue, but so far I understand that the only confirmed issue is leaky valve cover gasket(s). No need to pull the engine to replace those.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #5
Oil changing the color might be unrelated issue, but so far I understand that the only confirmed issue is leaky valve cover gasket(s). No need to pull the engine to replace those.
No no, I just replaced the valve cover gaskets with high temp silicon. They are not leaking, I made sure to clean around them so that I could see if the seal was good, there is no oil around the valve cover gaskets. Also losing half of my oil in two days is a big deal.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #7
still .. pulling the engine out without knowing what is wrong with it makes no sense.
No, I am not hauling it out yet. But if I cannot figure out where the leak is coming from I am going too. For two reasons, one to figure out what is wrong and two so that I can do a full tear down and replace all gaskets, rebuild the lifters and inspect the pistons/arms.
 

·
Registered
Joined
·
31,633 Posts
You are correct when you say you're not a mechanic, if for no other reason than because no mechanic would consider removing an engine and replacing gaskets to be any kind of overhaul, much less a "full" one.

Rebuilding an engine is an arduous task. It requires special tools, meticulous attention to detail, thorough organization, a proper shop manual, and a pristine work environment.

Moreover, a mechanic would actually find the source of the leak and repair it, rather than going off half-cocked on some quest that has little to do with fixing a problem.

My guess is that if you actually remove the engine and completely disassemble it, it will never run properly again, and it's probable that after countless hours, expense and frustration you'll abandon this project and end up buying another engine or selling the whole thing and finding another car.

I don't mean to dissuade you entirely. Indeed, it sounds as though your engine had been seriously abused and perhaps the argument could be made that it's a smoking pile of junk, so you can't do much more to it anyway. But if that's the case, it will cost you many thousands of dollars to fix it. Engine parts aren't cheap, and the tools to test and reassemble it properly aren't either. And simply tearing it all apart and putting it back together truly is an arduous task. Good Lord, man, simply replacing the timing chain and guides is ridiculously complicated, and it's just a small part of the task.

If you think there is life left in the engine and you really want to repair it, I'd respectfully suggest you take the car to a real mechanic and have him/her diagnose your leak. That won't cost an awful lot (and surely less than the cost of a rebuild gasket set!!). Depending on its nature and location, you can then determine whether to fix it yourself or have it fixed.

Or if you think your engine is too far gone, then buy a used one and swap them out. Then if you wish you can tear into the old one at your leisure, wasting nothing other than some spare time and gaining at least some basic understanding of what all is lurking behind all those bolts, gaskets and covers.

Good luck.
 

·
Registered
Joined
·
35,797 Posts
You got it pontiac. Ever done it before?
Did overhaul twice on Skoda, but it had wet sleeves and the kit had them included. I have been replacing head gaskets and valves in the past as well.
One of the reasons I drive Mercedes is that I didn't enjoy that part ;)
Than even when I could replace head gasket in 2 hr (no power wrenches) on 4-banger VW, the modern engines are way more complicated. Your V8 is not having much clearance in the engine bay, so lifting alone will be a major job. Remembering all sensors and cable connections will be another story.
Find older ohlord's topic with picture of engine removed. You don't see how huge the drivetrain in those cars is, till you pull them out. Hope you can gather 2-3 helpers for the job, who know how to not scratch and dent your fenders.
Another story is parts cost. About 15 years ago I bought gasket set for my old Ford. About 100 pieces cost me less than $50 what included head and manifold gaskets. Try to figure out today's gasket cost for your engine?
 

·
Registered
Joined
·
13 Posts
Discussion Starter #12
You are correct when you say you're not a mechanic, if for no other reason than because no mechanic would consider removing an engine and replacing gaskets to be any kind of overhaul, much less a "full" one.

Rebuilding an engine is an arduous task. It requires special tools, meticulous attention to detail, thorough organization, a proper shop manual, and a pristine work environment.

Moreover, a mechanic would actually find the source of the leak and repair it, rather than going off half-cocked on some quest that has little to do with fixing a problem.

My guess is that if you actually remove the engine and completely disassemble it, it will never run properly again, and it's probable that after countless hours, expense and frustration you'll abandon this project and end up buying another engine or selling the whole thing and finding another car.

I don't mean to dissuade you entirely. Indeed, it sounds as though your engine had been seriously abused and perhaps the argument could be made that it's a smoking pile of junk, so you can't do much more to it anyway. But if that's the case, it will cost you many thousands of dollars to fix it. Engine parts aren't cheap, and the tools to test and reassemble it properly aren't either. And simply tearing it all apart and putting it back together truly is an arduous task. Good Lord, man, simply replacing the timing chain and guides is ridiculously complicated, and it's just a small part of the task.

If you think there is life left in the engine and you really want to repair it, I'd respectfully suggest you take the car to a real mechanic and have him/her diagnose your leak. That won't cost an awful lot (and surely less than the cost of a rebuild gasket set!!). Depending on its nature and location, you can then determine whether to fix it yourself or have it fixed.

Or if you think your engine is too far gone, then buy a used one and swap them out. Then if you wish you can tear into the old one at your leisure, wasting nothing other than some spare time and gaining at least some basic understanding of what all is lurking behind all those bolts, gaskets and covers.

Good luck.

You see it is funny because I have rebuilt two engines, triple the size of my Mercs, One from a CASE 440 and another from a CASE 190. Sure they are tractors but engines none the less. I also have a literal BARN full of tools. I may not know fancy terms such or know correct procedures, but living and working on a farm my whole life, I have never once used a mechanic to fix anything, and my last two cars last above and beyond expectations. I may be knew to smaller engine repair but all the same applications apply. Thanks for your vote of confidence, I will be sure to show you videos of my progress and keep you updated on the goings on, if nothing more than to simply prove you wrong.

I do enjoy being underestimated, kinda fuels me.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #13
Did overhaul twice on Skoda, but it had wet sleeves and the kit had them included. I have been replacing head gaskets and valves in the past as well.
One of the reasons I drive Mercedes is that I didn't enjoy that part ;)
Than even when I could replace head gasket in 2 hr (no power wrenches) on 4-banger VW, the modern engines are way more complicated. Your V8 is not having much clearance in the engine bay, so lifting alone will be a major job. Remembering all sensors and cable connections will be another story.
Find older ohlord's topic with picture of engine removed. You don't see how huge the drivetrain in those cars is, till you pull them out. Hope you can gather 2-3 helpers for the job, who know how to not scratch and dent your fenders.
Another story is parts cost. About 15 years ago I bought gasket set for my old Ford. About 100 pieces cost me less than $50 what included head and manifold gaskets. Try to figure out today's gasket cost for your engine?
I have my father in law who is an electrical journeyman and has rebuilt more farm equipment than myself. We also have a lift that can lift two ton motors. As I said in my above post, I have more tools than I can shake a stick at. I may be a redneck backyard "mechanic", which makes some people doubt my abilities, but what some people seem to think is that I am pulling the motor simply to fix some leaks. However, what I really should have mentioned, is this is sort of my hobby. I love taking things apart and putting them back together, if nothing more than to learn their inner workings. I will check that link out. Thanks.
 

·
Registered
Joined
·
35,797 Posts
I can fully understand your drive as I at least used to be the same. I was taking the oldfashion alarm clock apart when I was 7. Put them back and (some of them) worked with same gears left over.
But as I indicated above, the modern engines are far from CATs and CASE you see on bulldozers. I deal with Detroit 8V72 on my vacations and it is totally different animal.
So I mostly agree with CC that at one point you might run into electronic glitches that will overwhelm you.
Still would love to see pictorial :)
The car is beautiful BTW
 

·
Registered
Joined
·
7,035 Posts
Well, just so you know you might want to consider your eagerness may just outshine your effectiveness, and cause you more problems down the road.

It would have to be a major-major valve cover leak to lose that qty of oil - but since you were not more specific about the "silcone sealant" you used on the valve covers, frankly you might have already screwed the pooch so to speak.

Thorough and proper cleaning of the valve covers is critically essential, and a "Chevy/Ford" type gasket sealant, or even too much of the correct sealant can quite quickly brittle up/break off, and start plugging the very small oil galleys in the system.

Even the most referenced "stickie" on the valve cover job here shows way too much sealant (and in that case it's Permatex Ultra Grey which is "wrong" but at least OK, me, I would buy the MB sealant anyway for the job). DIY'rs almost always use 3-4 times more sealant than is recommened...

That to the side, if your engine is so dirty that you can't tell where 4 qts have gone - and you report "blackness" then I might start assuming a bot of overheating, and for that if you have internal in my opinion you need to pull the heads (which does not necessarily mean pulling the motor).

If you really want to fix the car - my recommendation is to hold back the sassyness, and start asking better questions..
 

·
Registered
Joined
·
138 Posts
You've lost 4 quarts in two days. if it's a leak there should be a small lake under where it is parked, and a big puddle on the bottom engine cover/shield. And if it was leaking when you were down the freeway, there would be enough oil on the bottom trailing back and via the "draft" the backend of the car would have more oil on it than a grill in a diner. My guess is that if the engine was driven without coolant until it was smoking you've probably cooked the tension out of the rings. Check and see if you have any blue smoke coming out of the tailpipe. And check the color of the coolant, you probably fried the head casket and combusion gases and oil are probably getting into the coolant.

You say you have "all the tools", pardon me but -no way!!! Get a "workshop manual" for your model of MB and read through the engine dismantle/assembly section and make note of all of the special tools that are required for - installing seals, setting up the timing on OH cams, pulling damper pulleys, oil seals and one and one. Chances are the only tool that you can use on your MB that you used on the tractors will be the "breaker bar". I'd bet that you're looking at buying well over a $grand worth of special tools required for the MB engine work.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #17
You've lost 4 quarts in two days. if it's a leak there should be a small lake under where it is parked, and a big puddle on the bottom engine cover/shield. And if it was leaking when you were down the freeway, there would be enough oil on the bottom trailing back and via the "draft" the backend of the car would have more oil on it than a grill in a diner. My guess is that if the engine was driven without coolant until it was smoking you've probably cooked the tension out of the rings. Check and see if you have any blue smoke coming out of the tailpipe. And check the color of the coolant, you probably fried the head casket and combusion gases and oil are probably getting into the coolant.

You say you have "all the tools", pardon me but -no way!!! Get a "workshop manual" for your model of MB and read through the engine dismantle/assembly section and make note of all of the special tools that are required for - installing seals, setting up the timing on OH cams, pulling damper pulleys, oil seals and one and one. Chances are the only tool that you can use on your MB that you used on the tractors will be the "breaker bar". I'd bet that you're looking at buying well over a $grand worth of special tools required for the MB engine work.
You may very well be right, I may not have every tool. However have you ever worked on a tractor? If not than you may not know what kind of tools we use. Anyway that is beside the fact. I have not noticed any bluish smoke coming out the pipe, however the smoke is very white, as if to be burning to much oxygen. Also when I started it up today it smelt like burning oil. I also flushed the coolant system of any old coolant once I swapped out the thermostat and waterpump. I just checked the back end and my rear right rim has oil on it and the underside on the right has traces of oil all over.

I will however take your advice and look up the manual and see what I may need.
 

·
Registered
Joined
·
138 Posts
White smoke from the tailpipe is water vapor. (All cars will do it when you first start them up on a cold day, evaporating moisture in the exhaust pipes. If it smokes white after the engine and exhaust sysstem is warmed up - then---) Your coolant is making it into the cylinders. Check it, I'll bet it's going down. Here's where I show my ignorance on a MB. With cars that I'm more familiar with, a check for that is to remove the radiator cap and see if the coolant is bubbling - that's a sign of combustion gases being forced into the cooling circuit. Not sure if a MB will be able to see that or not.
So, I'm pretty sure you fried your head gasket. The white vapor makes it highly likely, and if the radiator is bubbling, then its a sure thing.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #19
Well, just so you know you might want to consider your eagerness may just outshine your effectiveness, and cause you more problems down the road.

It would have to be a major-major valve cover leak to lose that qty of oil - but since you were not more specific about the "silcone sealant" you used on the valve covers, frankly you might have already screwed the pooch so to speak.

Thorough and proper cleaning of the valve covers is critically essential, and a "Chevy/Ford" type gasket sealant, or even too much of the correct sealant can quite quickly brittle up/break off, and start plugging the very small oil galleys in the system.

Even the most referenced "stickie" on the valve cover job here shows way too much sealant (and in that case it's Permatex Ultra Grey which is "wrong" but at least OK, me, I would buy the MB sealant anyway for the job). DIY'rs almost always use 3-4 times more sealant than is recommened...

That to the side, if your engine is so dirty that you can't tell where 4 qts have gone - and you report "blackness" then I might start assuming a bot of overheating, and for that if you have internal in my opinion you need to pull the heads (which does not necessarily mean pulling the motor).

If you really want to fix the car - my recommendation is to hold back the sassyness, and start asking better questions..

I used MB high temp silicon, I used a scotch brite wheel on both the cover and engine block around where the silicon was going to be applied. I used what I thought was almost not enough, however if I have to give an amount, it was about a pencil leads worth of bead around the seal... if that makes sense. I do apologize for sound a bit of an sassy git, just I don't like when people just assume you shouldn't be touching an engine because I don't know everything there is to know. That is why I am here, to ask questions.

I really can't get any more specific about the leak. Here is a quick notes on what I know.

- Lost about 4L of oil in 2 days
- Smells of burning oil when I start it
- Engine overheated due to faulty thermostat three months ago
- Thermostat and water pump replaced
- White consistent smoke out the pipe
- Valve cover gasket replaced on both sides last month
- Oil change two months ago and oil is already BLACK
- Oil on the underside all the way to the back mostly on the passenger side
- Oil pooling in the skid plate
- No knocking, rough idle or loss of power
- Between 20kph-80kph every 10 seconds or she drops about 200 rpm then returns to normal rpm
- Already tried no leak to try and swell the oil pan seals


Next step: Leakdown test.
 
1 - 20 of 33 Posts
Top