Looking at a Rod-Bender - PeachParts Mercedes-Benz Forum

mcguirjf · #1 10-10-2008, 02:32 PM

Greetings,
Well I've decided to try my luck on a rod-bender. Its a 1995 S350 that the owner overheated. Supposedly the car idles now and doesn't overheat, but did say that something is wrong. He has suggested that it may need a head gasket. I'm going to go look at it today after work.

Here is my list of what I'm going to check out...
1) Oil Cap Puff
2) Oil Color
3) Pressure in Coolant tank
4) Climate Control
5) Windows and Sun roof
6) Cruise Control if driveable
7) Check for Rust
8) Ask if it uses oil
9) Start cold

VIN #'s 12 and 13 are "20"

Are these engines prone to cracked cylinder heads like my old 1987 300TDT?
The bent rod would just be cause for high oil consumption right?
Anything else I should inspect for on W140?
Thanks for the help and wish me luck

TMAllison · #2 10-10-2008, 04:12 PM

Quote:

Originally Posted by mcguirjf

The bent rod would just be cause for high oil consumption right?

Would be cause for a new 3.5L engine. Biggest problem is not knowing if the new one would do the same thing.

CSchmidt · #3 10-10-2008, 05:02 PM

Look at the junction of the head and block around cylinder #1 (front of engine). Oil leaks around there seem pretty common and may have something to do with either head gasket issues or the potential of the rod bender syndrom.

FWIW, mine in its current state of burning a quart every 300 miles still starts and runs perfectly. No misses, pulls hard, never overheats, and doesn't lose any antifreeze.

Also, let it idle for 2-3 minutes, then rev it up in neutral for 20-30 seconds. I get a cloud of blue smoke out the back.

The other, easier problem to fix is the wiring harness. Look to see if you can get at the individual wires in any of the engine harness bundles. The original ones had insulation that breaks down. You may see numerous cracks and breaks in the insulation, or it may be fine.

Getting more fussy.... try the auto door closers. Lightly close a door (not completly) and see if it is automatically pulled closed.

Of course check the AC function and coldness.

The later ones are not as bad, but drive at about 55 and see if there feels like a wheel out of balance. This can be the lower control arm bushing ( fluid filled) that goes bad.

Very nice cars when they run right.

Chuck

Jadavis · #4 10-10-2008, 06:46 PM

I didn't know they made the S350 in 1995. I thought 1994 was the last year.

-Jim

JimmyL · #5 10-10-2008, 10:32 PM

Quote:

Originally Posted by Jadavis

I didn't know they made the S350 in 1995. I thought 1994 was the last year.

-Jim

You have one in your signature........

Jadavis · #6 10-10-2008, 11:48 PM

Holy Crap! I've been telling everyone it was a 1994! I guess I wrote the sig right after I bought it, when I remembered it was a 1995. Then I eventually convinced myself I had a 1994.

I true sign that I have been working too much!

-Jim

Jim B. · #7 10-11-2008, 02:52 AM

It's often said the most expensive used Mercedes Benz is the cheapest one.

That said, I would personally run away from this one even if it was offered to me for free.

chetwesley · #8 10-11-2008, 03:30 AM

Quote:

Originally Posted by Jadavis

Holy Crap! I've been telling everyone it was a 1994! I guess I wrote the sig right after I bought it, when I remembered it was a 1995. Then I eventually convinced myself I had a 1994.

I true sign that I have been working too much!

-Jim

LOL... pretty funny.

t walgamuth · #9 10-11-2008, 06:48 AM

If you buy it cheaply enough to replace the motor and you do so with the 3 liter short block you will be ok.

any other plan is a plan for financial disaster or at least an expensive lesson.

Maxbumpo · #10 10-11-2008, 08:57 AM

"Here is my list of what I'm going to check out..."
1) Oil Cap Puff Useless
2) Oil Color Useless
3) Pressure in Coolant tank Valid if the car has not been run for 12 hours or so, and then you want to check the upper radiator hose (you should be able to squeeze it so that your fingers meet or come very close)
4) Climate Control OK
5) Windows and Sun roof OK
6) Cruise Control if driveable OK
7) Check for Rust OK
8) Ask if it uses oil BINGO!
9) Start cold OK

Ask to see documentation of the maintenance and repair history.

Look at the color of the brake fluid; if it is dark or black, you know that the required maintenance has not ALL been done.

Look at the color of the coolant - it should be gold. If green or some other color, you know that improper maintenance has been done.

The replacement engines from MB did NOT suffer bent rods / increased oil consumption like the original.

There are other causes for increased oil consumption (failed turbos are not unheard of on this car, unlike the 123 and 124 series).

I like the idea of swapping in an OM603 3.0 liter from the 124 series; others have done it and are quite satisfied with their results.

JimmyL · #11 10-11-2008, 09:07 AM

Quote:

Originally Posted by Maxbumpo

The replacement engines from MB did NOT suffer bent rods / increased oil consumption like the original.

I have read on this forum before of new 3.5 liters from MB suffering the same fate......
No first hand knowledge of course, but have seen it here.
Take that for what it's worth.......

SwampYankee · #12 10-11-2008, 09:13 AM

Quote:

Originally Posted by JimmyL

You have one in your signature........

I thought I read that correctly.

mcguirjf · #13 10-13-2008, 10:57 AM

The battery was dead so I'm going back today to hear it run. The front bumper cover has a crack. The headliner on the sliding roof is torn. One headlight lens cracked with the wiper arm stuck in the wrong position. Missing rear muffler. The rest of the car just needs a good cleaning.

A bent rod wouldn't be a cause for over heating? I'm trying to see if it just needs a head gasket or an engine? Worst case maybe a cracked cylinder head? The cylinder head casting # is 20.

Anyone know what the numeric wheel on the side of the front seats do?
Thanks

compu_85 · #14 10-13-2008, 11:02 AM

The wheel adjusts the lumbar in the seats.

Shouldn't this car have door close assist?

-Jasno

mcguirjf · #15 10-13-2008, 11:42 AM

Lumbar support, thanks!

Are the door assists vaccum assist from the engine or a separate vaccum motor?

I did notice all the small vaccum lines disconnected at the vaccum pump. I had to ask him if he was able to shut the engine off with the key.

Where would the heated seat controls be located?