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?

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90 190 E 2.6 162K
91 300 E 117K
90 Laser RS turbo 169K
"The one who dies with the most toys wins"

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!

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90 190 E 2.6 162K
91 300 E 117K
90 Laser RS turbo 169K
"The one who dies with the most toys wins"

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.

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Jim

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.

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Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

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

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-Paul-
'01 E430, Sport 72,000 mi
'98 C280, 126,500 mi

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.

__________________
90 190 E 2.6 162K
91 300 E 117K
90 Laser RS turbo 169K
"The one who dies with the most toys wins"

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.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

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.

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90 190 E 2.6 162K
91 300 E 117K
90 Laser RS turbo 169K
"The one who dies with the most toys wins"

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

__________________
90 190 E 2.6 162K
91 300 E 117K
90 Laser RS turbo 169K
"The one who dies with the most toys wins"

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,