seized engine on my SDL ? - Page 2 - PeachParts Mercedes-Benz Forum

surfblau · #16 06-12-2003, 11:38 AM

It will be weekend before I can make any more progress.

surfblau · #17 06-16-2003, 12:36 PM

So I got my 27mm short socket and tried turning (the crankshaft) by hand. No dice. Turning clockwise with a socket and then a breaker bar, the crankshaft will not rotate a single mm. I was able to rotate it ccw slightly (like 3-5 degrees, really almost nothing, I really didn't want to push it, but it was able to move in that direction) with a normal amount of force.

Before I did all of this, I pulled the injectors, though the valve cover is still on.

Tonight, I will remove the vacuum pump and check to see if it looks intact. If time and daylight permit, the radiator and the serpentince belt tensioner will be coming out tonight too.

Thanks for all your guys support, I will let you know what I find.

Let me know if you have any other ideas.

alec

gsxr · #18 06-16-2003, 12:46 PM

Did you have the serp belt loose, or off, when you tried turning the engine with the socket? Sometimes a frozen accessory can make it seem like the crank is locked up when it really isn't. If you DID have the belt off/loose and it only turned CCW a little, well, that's really not good...

ned2683 · #19 06-16-2003, 12:50 PM

your descrition sounds a lot like what my car went through. it was a 78 300SD, and it ran out of oil on the highway (leak). the oil pressure dipped below 1 bar for about 5 seconds before i could shut it off and pull it over. when i added more oil it had that clanking noise (even at idle), which became louder and louder.

not saying your engine is ruined like mine was. just that it sounds similar. good luck on finding the problem

surfblau · #20 06-16-2003, 12:54 PM

Currently the serp belt is on the engine and tight.

I will probably remove it tonight.

alec

airfoill · #21 06-16-2003, 01:37 PM

Alec,

I certainly hope it isn't catastrophic. These are very special cars indeed.

Herb
'82 240D
'87 300SDL
'92 300D 2.5 Turbo

#22 06-16-2003, 01:41 PM

Only thing I can think of is that your vacuum pump grenaded. You're at the right mileage.. I can't forsee anything else failing like that.

surfblau · #23 06-16-2003, 01:54 PM

but I replaced the vac pump with new one only 10K ago, and it was the updated style with sealed bearing.

alec

rickg · #24 06-16-2003, 05:39 PM

I asked on here a year or so a go about slamming a 617 5cyl engine in a SDL. Didn't get too many answers, but someone said the couple they've seen didn't fit very well. I guess it's not a real simple swap as you'd think.
But I do still like the idea

Heck, if guys can dump a Chev 350 V8 in these things......

gsxr · #25 06-16-2003, 06:50 PM

The OM603.96x engine is very robust as long as you don't let it overheat. Let it get too hot, and quite likely the head will crack. The new head is updated and stronger and won't crack again, but it's not cheap to fix that first time. Buy a good SDL with a good head in the first place and you won't have these problems. Sticking an iron-head OM617 into an SDL would ruin the car, IMO. The 603 is a tremendously better engine. Only the 3.5L engines had serious problems. I've owned both 617 and 603 and believe me, I'll take the 603 any day! I can't wait to get rid of my current 617-engined car, to be replaced with an OM60x of some vintage (190D or later 300D).

Regards,

surfblau · #26 06-16-2003, 06:50 PM

For starters, the transmission is different (designed for a different engine, probably has a different legnth as well).

That would be the main one, but I am sure that there are other reasons. Most of the rest of the systems on look similar.

alec

DslBnz · #27 06-16-2003, 06:59 PM

I do not think the 300SDL engines are problematic. Maybe the 350, but not the 300. I have seen these cars with 450K + miles on them, still running on the road.

During the early years MB had problems with their diesels' aluminum heads cracking. Mercedes made several upgrades to their aluminum heads when they were replaced making them more durable. Kinda like the new Behr radiators with a steel-reinforced neck instead of pure plastic.

They can be just as tough as the old 5, but they are more sensitive to heat. Keep your oil changed, and an eye on the temperature gauge and you should be alright.

The only strike I have against the older diesels is having to adjust the valves every 30K miles. When you do a lot of driving, this gets to be a real annoyance.

I do think the 5 is a bit easier to work on though.

rdanz · #28 06-16-2003, 11:02 PM

Have you pulled the valve cover and checked the camshaft and timing chain?

surfblau · #29 06-17-2003, 01:02 PM

Everything is in order with the valves and chain- at least what can be seen from the top.

alec

surfblau · #30 06-17-2003, 11:36 PM

It looks like it is a seized alternator, stopping the whole engine.

I removed the serp belt and low and behold, I could crank the engine by hand clockwise the way I figured you should be able to. Some resistance, but with the plugs out, not too much.

The alternator looks suspicious. The main pulley won't turn, and the brushes look real short.

So, tomorrow, I order a rebuilt (bosch), sorry autozone.

Here is a pic of the suspect.