Update on the $100 240D - not good - PeachParts Mercedes-Benz Forum

MikeTangas · #1 08-25-2004, 08:27 PM

Had the day off and figured what better way to spend it than getting the 240 running. I headed out early and was at the car by 10:45, figuring I had a lot of work to do and about 5 hours to do it.

First order of business was the new starter. Piece of cake from above on the 240, only thing I had to do was remove the battery tray and breather. I was able to reach both of the bolts from above too - only had to reach under the car to retreive dropped tools. Starter took me about 45 minutes to R&R.

Once the battery tray was back in I placed the battery, leaving it unconnected. Then I replaced a couple rusted hose clamps at the T-stat housing and headed for the glow plugs. I was able to R&R the glow plugs without having to remove the injector lines but that did require some contorting. Glow plugs too were a snap, no more than 15 minutes. Then I moved on to the fuel filters, got them changed and primed the system.

Only thing I didn't do was drain the old fuel from the IP, in fact I didn't even think about that. Hooked up the battery and was ready to hear the beast run.

Soon as I warmed the GP's and hit the key the engine was turning over nice and fast, much faster than with the old starter, but no joy. Tried it again for a little longer and soon I could hear one cylinder hitting with a "fwump". Tried many times and could only hear the one cylinder hitting.

Dejected I called Roy Hunter (hopefully during lunch) and talked a few things over, I tried a few "tricks" he had and started getting a second cylinder to hit - "fwump, fwump". Man this puppy is gonna start.

Next try I held the key and let her spin. Soon it sounded like it was trying to hit on all cylinders, even started getting smoke out of the tail pipe, but still didn't start. So I waited, then gave it another long spin, it was trying "fwump, fwump, fwump", man I just know it's gonna start. Then all of a sudden the starter quits. I hit the key and the starter just goes clunk.

Just abouyt this time Roy called me back, I explained was happed and told him the starter was too hot to touch. Because of the prolonged cranking it seemed likely the starter had been toasted. I ran into town and tried the local parts house - no they don't have one, but can order it and have it in a day or two. No thank you, that won't work.

I went back to the car with the intention of cleaning up and putting things away when something made me look at the valve cover.

Well, I knew right away that this wasn't good, so I pulled the valve cover. I fully expected to find a broken camshaft, like the many pictures we've seen here before but that wasn't the case.

cam is intact, but look at the chain.

The spocket seems to look okay

I was able to locate the cam timing marks, with the cam stopping where you see it in the picture

Alright, so the timing chain broke while trying to start. On the plus side - it happened when trying to start rather then while driving, it happened when the battery was getting tired and the starter getting hot. Maybe, just maybe damage is confined to the chain and guides. I guess I'll have to drag it down here and pull the front cover. Any ideas on a cause, or likely candidates to checkout?

The deal for the car included an extra MB diesel engine, I just don't know which one it is yet. I will finally see it when I go to trailer the car. Maybe I'll get lucky.

Anyways, I'm bummed.

rwthomas1 · #2 08-25-2004, 08:40 PM

I gotta bad feeling you are gonna find some bent valves. These things are interference engines aren't they? Rebuilt head at least.... Sorry, RT

psfred · #3 08-25-2004, 08:40 PM

Just fish the end of the chain up from the bottom and pull a new one in! You may have to pull the bottom pan to get to the end, but first take a look down past the tensioner rail and see if the chain is visible. If so, bend a tiny hook on the end of an unfolded coat hanger, you may get lucky!

Clamp the chain on the cam first...

Peter

MikeTangas · #4 08-25-2004, 09:11 PM

Funny you should mention hooking the chain Peter. Roy and I were just on the phone talking about trying that very thing.

While cranking I have to admit that I don't remember looking at the oil gauge so I can't say whether or not it was building pressure. There seems to be an absense of oil on the valve train, which may be a sign of a bad oil pump. Does anyone know if this pump is chain driven on the 240?

psfred · #5 08-25-2004, 09:50 PM

The oil pump is driven off the IP drive shaft, so if the chain was broken you didn't get any oil.

If you didn't break a cam tower, you are probably all right enginewise, but a valve clearance check will tell you -- bent valves won't come all the way up.

Peter

#6 08-25-2004, 10:21 PM

In the third picture the third cam lobe seems to
have a crack in it, unless it is oil but it is hard
to see.

Louis.

Mercedes Man · #7 08-25-2004, 11:25 PM

My guess:

I do not think the engine siezed because you were able to turn the engine with the starter.

Timing chain guide broke. The pieces fell between the gear and sproket, and broke the chain.

You can put on a new timing chain and see if the engine starts.

Benzcrusher · #8 08-25-2004, 11:18 PM

[QUOTE=MikeTangas]I guess I'll have to drag it down here and pull the front cover. Any ideas on a cause, or likely candidates to checkout?

QUOTE]
I'd guess that something else broke and that's why the chain snapped. It would take some inertia to snap a chain like that, cranking without engine damage wont snap a chain.. This may explain why the dude had and extra engine in the first place!....

These OM's are not like your M117, no front cover, just nasty pita countersunk pins which hold the rails in place.

I'd Drop the pan first and see what's in it.....