300D 2.5T OM602 Engine Replacement - PeachParts Mercedes-Benz Forum

mbolton1990 · #1 11-05-2017, 06:39 PM

Howdy!

So after buying my '91 with a overheated engine and replacing the head with a straight head and changing the HG, the motor has low compression on a few cylinders still and the motor knocks a little bit.. (PO left coolant in the cylinders for roughly a year) anyways, I've been on the lookout for a cheap 2.5t and finally came across a good donor car for $400. It does run and drive, and the motor sounds good.
I've done a couple of engine swaps before, but never a MB. Anything to be aware of before I dive in? (I know to take the motor+trans out together) The donor car has a crack in the oil pan that the PO put JB weld on

but it doesn't leak somehow.. I'm gonna swap my good oil pan on of course, and really clean it out. I know to torque all the bolts to spec and make sure it's clean,clean,clean and use a little RTV.. not a novice I've done a few repair jobs before but wouldn't call myself a Master mechanic. Gonna swap my rebuilt turbo on and do the wastegate actuator mod and delete that huge rats nest of vacuum lines near the coolant reservoir..

My car has 300k and the donor has 352k, also the donor has the old style vacuum pump while mine has the newer style with the allen bolts on the outside.. would just like to hear from someone who has done something like this before. I know it's pretty straight forward all in all, but it can be easy to miss something.. Hope to make one solid car out of the two!

Thanks for any pointers/tips.

My car:

Donor car:

jake12tech · #2 11-05-2017, 06:45 PM

I did the removal twice and installation once on the same car. Nothing to worry about, label everything where it goes and especially the vacuum lines! Label them! They're very easy to confuse and if something is mixed up everything works wrong. Other than that don't forget to disconnect the torque converter bolts before separating rhe motor and transmission. You can't go wrong on this. I'd you have any questions I've done this like I said and remember all of my mistakes. On the parts car just saw off the front end so you can slide it right out.

mbolton1990 · #3 11-05-2017, 06:53 PM

Quote:

Originally Posted by jake12tech

I did the removal twice and installation once on the same car. Nothing to worry about, label everything where it goes and especially the vacuum lines! Label them! They're very easy to confuse and if something is mixed up everything works wrong. Other than that don't forget to disconnect the torque converter bolts before separating rhe motor and transmission. You can't go wrong on this. I'd you have any questions I've done this like I said and remember all of my mistakes. On the parts car just saw off the front end so you can slide it right out.

Ah, thanks Jake for the tips. That's exactly the kind of thing I was wanting to hear! Definitely gonna saw out the front clip on the donor car, that should help get her out of there. And label my vacuum lines

I'm also gonna grab whatever good parts are left on the donor car, window regulators, sending unit, fuel tank, nuts/bolts, relays, computers, gauge cluster, etc etc it's also got a mint dash.. Idk if that would be worth pulling though.

So is there a access window where you take each bolt out for the TC? Like on a Volvo B230? Just did the RMS on my 240 not long ago and had to do that.

jake12tech · #4 11-05-2017, 07:13 PM

That dash board is worth saving. What color is the interior? There should be a plastic access plate on the front of the trans iirc

mbolton1990 · #5 11-05-2017, 07:37 PM

Cool, just like the Volvo then.
It's got a grey interior, interior is decent. Was gonna put the smaller steering wheel on my 190d, that big W123 wheel hits my knees!!

jake12tech · #6 11-06-2017, 10:48 AM

Hey let me know how the lifters are and cam on your scrap motor. I may be interested.

moon161 · #7 11-06-2017, 11:05 AM

Don't forget the oil sender. If it's anything like a W123 (and the filter can looks the same) the sender line will break if you try to loosen it at the filter can. Remove it from the back side of the instrument cluster instead.

If you do happen to break this as described, you can swap the tapped plate that the sender line is attached to with one that has an intact sender attached.

dieselbenz1 · #8 11-06-2017, 11:12 AM

You may wish to reseal a few things such as rear seal and bottom of IP pump come to mind. Just have a close look when it's out.