Head Gasket help on a 190 E 2.6
 

I have a post up about my 1990 190 E 2.6 not starting. One day of troubleshooting and this is what I have found. Oil in my overflow tank and Zero Compression in the #3 cylinder.

http://www.peachparts.com/shopforum/tech-help/49295-190-e-2-6-wont-start.html

Has anyone ever had a head gasket go out that caused a sudden engine stop? I mean my Benz just died and wouldn't restart. I would have never thought head gasket, but I went over the ignition, gas deliver and relays (OVP and MAS) And they all checked out.

I am pretty sure this is the head gasket. I have the gasket kit and have lined up a machine shop to do the valves. What am I looking at as a do it yourself job, difficulty wise?

Is there any special tools needed to do this job or make it easier? My torque wrench is terrible. Anyone have any recommendations on a decent European torque wrench. Also do I need a special Head bolt socket and that tool I've seen for the serpentine belt (holding tool that keep the clutch from rotating)

Any help would be greatly appreciated!!!

I guess a blown head gasket could keep it from running but it would have to be severely blown. I would have figured it would have at least run - kinda scratching my head on this one. I'm sitting here wondering if there may be a head "warpage" issue. The story will be told when you get the head off. It is a diyer job as long as you take your time and "mark" wire/vacuum hose connectors and such. Study the books/manuals and take your time pulling those slide rail pins and such. Put the engine at #1 at TDC prior to taking everything apart. It is my experience it just makes it a little easer during reassembly.

Does the intake manafold have to come off like the CD shows. I saw a post w/ images that showed the IM undisturbed. The cd shows it being hoisted with the IM connected. Below is the picture I saw.

I found it easier to pull the intake manifold out of the way on the E320. I did not have to worry about the fuel distributor.

Benzmac stated that it could be a broken valve spring. This would explain the sudden stop. But why would the oil show up in the coolant tank. I'll pull the valve cover off in the morning and report the findings.

Broken valve spring, in my opinion, will not make oil show up in the coolant. A bad head gasket will make oil show up in the coolant though.

Been there, done that!

I thoght the head gasket had blown on my 103 engine. I still thought so after pulling the head and taking it to the shop. Luckily the shop I took it to was capable of welding up an aluminum head.

The problem turned out to be corrosion between the water jacket and the combustion chamber. He welded it up, did a valve job, checked the straightness. I put it back on about 55,000 miles ago and the engine has been flawless since except for ignition problems which have nothing to do with the guts of the engine.

Note! engatworks cylinder head job was on a 320 which has an M104 engine instead. On that engine, it is indeed easiest to disconnect everything from the intake manifold and remove it with the head.

On the M103, however, I found it much easier to leave the manifold in place and pull only the head. You will have to get to a few manifold bolts from underneath, but with a few extensions it is absolutely no problem. I think this method is superior because you don't risk breaking all the old brittle electrical and vacuum connections.

It really does sound as if you have a situation like mine. I would recommend that you move the car into place where you plan on doing the work and draining the oil and cooling system as soon as possible.

When mine blew, it was only a couple of days before I had to go to Europe for a 3 week business trip. It sat there, unbeknownst to me, with water in the oil. When I started it back up a number of weeks later, the oil already had looked like chocolate milk. I ran the engine only a minute or so and drained the oil and changed the filter. I then ran it down the road and back and changed it again. After that, I ran it to the office and back and drained it hot and overnight. The next oil and filter change was only about 1,000 miles later which put me back on my normal schedule and it was finally clean. The rust in the cylinders did no harm at all, but it sure did worry me.

The engine now goes 3,300 miles between oil changes and the oil barely goes down on the stick in that time.

So, pull the head and take it to a machine shop that can pressure test it and weld it up if necessary.

If you have never done this on an M103, and it sounds like you haven't, keep posting your questions here and we will get you through it.

There are several little tricks you will need to know such as how to seal the upper timing cover, beware of the small valve lifter cups and how to deal with the ratcheting timing chain tensioner without breaking something.

Once you start taking it apart, post here often and let us know how it is going.

Good luck,

Thanks Larry and to everone else helping in advance. I'm going to pull the head, weather permitting on Monday.

Will a 3/8 torque wrench get me through this job? I haven’t gone through all the torques yet, 70 Nm/ 51.85ft/lbs on the head bolts seem to be the highest.

Second question is I don't have an impact extractor, to take out the slide rail pin. Any thing else I can use to get it out.

Third I've seen a special head bolt tool. What size is it? Does craftsman make anything similar? Due to shipping time, I would rather pick it up if I could.

Thanks
Neil

The guide rail pins can be pulled using a bolt and a socket or large nut. You put the bolt through a washer, then a socket or nut larger than the pin, thread the bolt into the pin and tighten down to extract the pin. You may have to experiment with bolt lengths, etc.

I bought the special star tool for the head bolts. The gas engines are 10MM and the diesels are 12MM, but I don't know what this is called. I bought the Benz tools. A friend of mine bought a set of them made by Lisle. They were inexpensive and worked well for him. I don't think Craftsman can supply this tool.

I would really want to have a good wrench for this job due to the way you torque these heads. You torque them to the value in the book following the pattern. Then you turn them all 1/4 turn following the pattern, and then, I think another 1/4 turn following the pattern. If you don't have a book, I will look it up for you. You basically stretch the daylights out of the head bolts. If the engine has never been apart, the head bolts should be in good shape. After a few stretches, they need to be measured for length before reuse.

BTW Don't overlook checking the valve springs as suggested earlier in the thread. You can do this quickly by just pulling the valve cover. If you do find a broken spring, don't expect to simply replace the spring and everything be finished. There will probably be other damage as a result. But, you should check them.

Good luck,

you'll need a few special tools to complete this job. pulling the head shouldnt take "you" more than a few hours. But do this...determine if your # 3 valves are bent, if so, you have jumped time and need to replace your chain, tensioner and rails.

Torque specs come with the head gasket. you will need 14 new stretch blots for the head. have a friend help you lower the head onto the block.....that is do not tear the new headgasket with the sharp edges. replace your timing chain cover and seal while you are there.

You don't need to replace the bolts unless they are over length. I don't have a factory manual to offer the exact length, but it should not be difficult to come up with here on the site.

If you pull the head ONLY, without the intake manifold attached, it was next to nothing, you will not need a helper to lower it in place. I think the previous poster was thinking of an iron head engine.

These engines have a ratcheting timing chain tensioner and give very few timing chain problems. They probably have the most reliable timing chain and associated components of ANY MB engine to date.

The previous poster is, of course, correct about looking for bent valves, but if there is one or more bent, I would suspect a broken valve spring as the cause, rather than a timing chain problem. It will be obvious when start taking it apart.

When you start back together with it, let us know and we will coach you on how to get the upper timing cover in place such that it does not leak.

Good luck,

Oh my blood pressure!!! I’m finally getting around to pulling the head off today. I just got my 300e back out of the sick bed with a new water pump. Now it's got a chirping sound coming from the belt tensioner. I'm kicking myself for not changing it.

Is it just me or do others here find that they severely start talking to themselves or have an on slot of temporary turrets syndrome while working on their Benz. Soon as my hood goes up on my Benz’s, the windows of my neighbors house slowing slide shut. I really do like fixing my own cars, it’s just when that socket wrench gets that awful feeling just before a bolt head snaps off or it just won’t budge. Drives me a tad crazy.

I just want to get this post back up for all you willing to help me through this head gasket. I'll post back around lunch 12:00est to let you know my whereabouts and progress. Wish me luck.

When you take the head bolts off, use the installation bolt torque tightning sequence in reverse. It may help prevent warpage.

I got the valve cover off and didn't see any broken springs. What's weird is that the head bolts are M12 and my special socket that took a week to get here is M10. Do some 2.6 eng. have M12 head bolts. I was able to pick up a set of metric internal star sockets. So far so good.

Need a little help. Does the engine have to be TDC on the # 1 cylinder when taking the head off. I've got the front cover off, and the pin out. I was getting ready to pull the chain cam off when I got a little worried about the position of the engine.

How do I get the engine TDC by myself (working alone). And I don't have one of those TDC whistles. Any tricks out there.

Well, Benzmac/Donnie was right. The # 3 intake spring was broken. How much further/other damage could this have done? Do I keep going with the head gasket job?

Hurray the heads off but, I'm confused a bit on the install
 

Well I went ahead with removing the head vs. just changing the spring, because I was about half way into the job. I got the head off yesterday. I noticed heavy carbon build up on top of the piston. Is their something I can do to clean the top of the piston while the heads off getting a valve job?

Also my neighbor has got me worried about the position of the cam and crankshaft. The MB cd shows that first you mark the cam and chain, but then during the install section it tells ya that the cam should be reset to TDC Ref. mark and the crankshaft to the 0 TDC Mark. Why in the removal would they have you mark the chain and cam if during the install they have you rotate cam and crank back to TDC? It's kind of got me confused.

When I get the head back I know the cam won't be in the same position, so why mark it in ref. to the chain. Also doesn't the chain fall from the timing gear/crank shaft while slack?

The EGR valve that’s on the front exhaust manifold will not come off the tubing. I was able to rotate it enough to get the manifold out but it may cause some problems of being in the way during the install. I am afraid to force it; the tube is kind of fragile looking. Any suggestions!

To remove the carbon, simply carefully rotate the crankshaft to position that piston at the very top, then scrape the carbon off with a piece of sharp wood. This is the safest way. Any scratches that a metal tool might leave will weaken the piston.

Don't worry about the timing. The gas engines are super simple to time. You will simply rotate the crankshaft to the TDC mark and line up the cam sprocket mark. They probably told you to mark it, because for some operations you might not have to turn the cam or the engine. For a head removal you only need to align everything when going back together.

After getting the head back on, be very careful in tightening down the camshaft. First of all, get the cam in proper timing position, so valves will not contact pistons. If you tighten a bolt or bolts at one cam bearing journal, you can easily strip the aluminum bolt holes and even break the cam. Lay the cam in place, time it and get all the bolts started, then tighten down evenly by tightening each bolt only about one turn at a time.

My engine does not have an EGR valve on the exhaust manifolds, so I have no experience with that, sorry.

When you start back together, think things through and take your time. As an example, not tightening the cam bolts down gradually as I talked about above could cause damage, also tightening them without the engine and cam timed could cause damage. Use your head and be patient while putting it back together.

Also, have you found out how you're supposed to "angle torque" the head bolts? Make sure you know the drill and have a really good breakover bar. You will think you are damaging the bolts when you do this. Also, when you get ready to torque the head bolts, make sure you don't have a time constraint and your head is in the job. You have to torque in sequence, then go around and angle torque in sequence. This is not a good time for an interruption. You should plan on doing this all in one session.

Good luck,

Very good points by Larry as always - specifically concerning covering torquing the head bolts/ sequence and having your mind in it. It is very important to stay focused and in sequence during this time. Also, for future reference try to get into the habit of putting the engine at TDC #1 piston prior to disassembly. This way you always always know where it was when you started.

Aren't you supposed to to do the first set of 90 degree torques, then wait before completing the second set? Of course, I read this AFTER I torqued my head down. I don't remember what the wait time was though.

mplafluer reminds me of a good point. I can't remember if it was the diesels or the M103 that I read about a ten minute wait between torquing stage. Since mp said this and I don't think he has done a diesel, then I expect it is the 103. I remember his work from six months or a year ago, and as I recall, he had great success. In any event it wouldn't hurt anything.

You still need to do all this torquing in one session though. Specifically don't stop in the middle of one of the sequences. If you get out of sequence and put an extra 90 degrees on one or more bolts, that would be a bad thing.

Good luck,

PS. mplafluer, is your car still running well? LB

Adding a dab of oil, as the head gasket instructions state, between the head bolt and washer (or washer and head; forgot which) makes it easier to do the final 90deg torques.

ALSO

Make sure all head bolt holes are free of oil, especially the front two. Blow 'em out or if you have a top sider you can suck 'em free of oil. If not, you'll experience hydrolock and might not be able to fully torque down the bolts.

Good Luck :D

I'll second what Larry said about how tight you have to torque the head bolts... Everytime I do this job while on the second 90 sequence I'm just sure I'm going to break something. Its really, really tight. Make sure you have a GOOD breaker bar at least 18 inches long - and make sure you are not tired because I can assure you when you finish the second 90 degree torque sequence you will be!!

Tim

When I dropped off the head at the machine shop he stated that I would have to readjust all the valves once I finished torquing the head bolts. He's putting the cam back on for me.

Is he correct and if so, how hard is it to adjust the valves. I've never messed with it.

Are 12 MM head bolts normal for a 103 engine? Performance Auto sold me a 10mm head bolt socket, stating that’s what all gas models use. Luckily I found a 12mm star tool at the local auto store.

As far as the final torquing of the head bolts I think I got it. My break bar has a little play in it. It's about 24" long. It was 14 nasty sounds when taking them off (creek and popping) I assume it sounds the same in reverse.

I was 10 minutes as I remember, and it was for an M103 engine in my 190 2.6. The one diesel I did was more than 10 years ago and I don't remember anything of it. That was for a '75 300D.

I would think that the wait between 90deg torques would be a characteristic of the stretch bolt more than anything else.

Good memory Larry! The car was runnning well when I got rid of it and replaced it with the 190D 2.5.

DIYBenzer,

It's a good thing your machinist is a machinest because he knows nothing about the valve train on these engines. They are hydraulic and require no adjustment. Don't worry, you will have plenty of other details to keep your mind occupied.

There was a comment about oiling the threads because of the stretch bolts. ALL head bolt holes should be cleaned, preferrably with a tap and the threads oiled whether they are stretch or not. It's the only way you can get an accurate torque.

Good luck,

One thing I did notice is that ATF fluid is dripping from the rear of the transmission. The car is sitting on a pretty steep grade driveway with the tail pipe down hill. With the head off why would this happen? I didn't remove anything on the trans. except for the dipstick bolt off the head. It is a sizable puddle, so I am a bit concerned.

My car does not have an automatic transmission, so I did not have to remove the dipstick tube. I expect, however, that it is indeed where the ATF is coming from. I wouldn't worry too much about it. Take things one at a time and get the engine back together and running well first.

Oh yes, did you remove the radiator. The cooling lines that connect to the radiator may be your leak. I'm sure you can work it out without too much trouble.

I have not mentioned that the rocker arm stands should go back into the same positions from where you took them apart. This is so that the cam followers will be on their original lobes. I'm sorry I did not mention this before you took everything apart.

Good luck,

LarryB. you wrote a while back

"There are several little tricks you will need to know such as how to seal the upper timing cover, beware of the small valve lifter cups and how to deal with the ratcheting timing chain tensioner without breaking something. "

I'm just about there. My main question is about how to get the ratcheting timing chain tensioner correctlly installed. And I'm not sure what you mean about the small valve lifter cups.

Thanks
Neil

The timing chain tensioner has a plunger in the center. You need to start taking apart the tensioner until you can push this plunger toward the engine end and out. You then take the plunger with the ratchet teeth and start it through from the "away from engine side. Since it ratchets, once the oil pressure builds up it will ratchet into its proper place.

To put on the upper timing cover, get the correct sealant fromt the dealer. This sealant is very slick when wet, so that you can push the cover in place without disturbing the u shaped seal at the bottom. Put the new seal in the cover, dob this sealant on the u seal and around the cover mating vertical surfaces. Then, put the timing cover down against the u seal and start moving it rearward. Use your fingernail around the shaft while putting slight pressure rearward. The fingernail is used to see that the shaft seal goes over the shaft without folding the seal. There is a special tool for this, but your fingernail will work fine. Once the seal is over the shaft push the cover rearward into place and start all bolts, then after they are all started, snug them in place.

Hopefully you noticed the small cups in the ends of the valves. Be careful not to lose any and put them carefully in place.

When laying the cam in place, put the rocker arm sets in place and start the bolts, then tighten each bolt a turn or so all the way down the line, then turn one turn or so again all the way down the line until they are all tight. If you just throw one rocker arm set in place and tighten down, you will strip the bolt holes in the head and/or break the camshaft.

Good luck,

I can't for the life of me get the Timing Chain Tensioner bolt to tread. The spring is to much for my little fingers to overcome. Please does anyone have a trick to this. I don't want to take off the smog pump.

I have struggled with this a time or two on the 617 engines. The way I do it is to back out the plug behind the spring until it is down to the last 4-5 threads then start the tensioner mounting bolts. I use a socket on the plug to PUSH hard until I can get the mounting bolts started then tighten everything down. You can do it this way but it will wear you out.

Have you taken the tensioner mechanism out and "recycled" the plunger? If not, do not try to force anything.

I believe it would be really helpful to get your hands on a diagram of the tensioner. You need to thoroughly understand how it works to prevent any damage. If you have restarted the plunger, it should go in easily.

Good luck,

I am happy to say that my 190 E is back up and running well. Thanks to all who helped. Hope this thread can help others. Larry thanks for your detailed responses and time, it made a world of difference.

I still have one problem with the car. It still has a sight vibration on heavy acceleration between 25-34 mph. It only happens on acceleration. It's got me stumped. I replaced the rt, lt, and center tie rods, damper, idler arm, front shocks, and mounts. Had the car aligned and wheels balanced. Very little change.

Thanks again
Neil M