Buying used M44B19 engine - what to look for?

[bernard]

I am looking to buy a used M44B19, and am going to inspect 3 motors in the next week.  I have no experience with this particular engine, and would like to ask you all for advice on what to look for when inspecting these engines - common weak failure points or signs that can tell me to walk away from a certain engine.  Any advice on how to choose one engine over another would also be appreciated.

Background:  I have been a lurker here for quite some time, trying to look for ways to improve my M43B16 - it would run rough when cold and idle would dip on run-off.  There was a small oil leak in the profile gasket as well, so I decided to pull the head to replace the gasket, only to find out my problems were coming from leaking valves.  A top end rebuild would cost me about 80% of what I could get an M44B19 for, so I have more or less decided to just get an M44B19 and swap the whole engine for the additional power.  I'm thinking I would just be throwing good money after bad if I try to keep my M43B16 and still left wanting for more power.

Thanks.

[Darky]

Hi and welcome

Will the engines you inspect be running or palletised? Running would be so much less of a gamble!

Cheers Rohan

[bernard]

The engine would be palletized, and I would have 3 engines to choose from in a used parts yard.  They should be able to crank the engines so I can check compression numbers, but I know that doesn't say a lot.  I would also be looking for any leaking oil and water, as well as turn the crankshaft to see if there is any unwanted movement. 

I'm just not familiar with the M44 to know of any common problem areas that I should pay more attention to.  Also, I would appreciate any tips on choosing one over the other.

[Darky]

Compression will be good start
But being from the same yard asking the owner is not a bad idea either
One thing does occur to me is the plastic thermostat housing, check its condition and try to figure out what coolant was used.

[bernard]

Thanks for the tip, I hadn't thought of the thermostat housing, I'll make sure to check that when I inspect the engines.

Any other thins I should look at wih these engines?

[benz-tech]

The heads are probably cracked on all of them. Mine was a perfect, 'never overheated' motor with 180k on it. Head was cracked in 3 places. But, Pull the oil cap, look inside,  get the cleanest one. As long as the compression checks out. If it starts loosing coolant, find an m42 head to put on.

[1998ccc]

Check crankshaft endplay.  A rubber mallet will work in that setting.  If u feel a major clunk, move onto the next one.  Good luck.