5.0 swap on 400E

[GusBus]

Hello all,
This is my first post, although I've lurked for the past 3-4 years. I appreciate the immense knowledge I've come across on here for our beloved W124s.

I've come across a SL500 93-95 engine locally for sale, with 83k. $500.

I've had plans to swap the 4.2 on my 92 400e for the 5.0 M119 and here is my opportunity kickstart that project for a great deal on the motor.
(motor has been listed for over a year at $1k and has recently been reduced to half the price, I feel like I can't walk away from this)

I wanted to receive input on what I should replace on the motor or what to look out for upon inspection? Also what components I will need from the SL500 and what are crucial components to keep from the 400e?

From a bit of research, I know I'll need the 5.0 LH module + EZL. Best to look at the timing guide rails, bottom/top harness will be changed, hoses, mounts.

What else would be best to change while the motor is out?

Thank you

 

[gsxr]

$500 is a great deal on that .972 engine. Sounds like you've done your homework and know basically what is needed. This swap is plug+play. More info here. If your 400E does not have ASR you'll need to use the ETA from your 400E, the SL500 ETA is for ASR only. Definitely replace all external seals while the engine is on the stand, along with a new oil level sender (or at least a new O-ring at the side of the block). For most parts you'll need to shell out for OE/Genuine from an online dealer (like this one), as most of the aftermarket stuff is junk (PCV hoses up top, engine mounts, valve cover gaskets, hoses, etc).

Since the engine is coming out, I'd also pull the transmission and do a complete external re-seal. If it's never been rebuilt, also install new reverse clutches while it's apart, along with reducing the number of reverse piston springs from 20 --> 15.

BTW, welcome to the forum!

 

[kubasz]

I came across an issue with 5.0 to 400E swap where transmission stopped upshifting at the usuall speeds and only upshifted at very high RPMs. That was bc 400Es from US are equipped with K29/1 relay (1st gear start relay module) which is operated by the 4.2LH pin 40. The 4.2LH switches relays coil to ground based on RPM signal. 5.0 LH modules put out ground on pin 40 and activate relays coil pernamently which makes the kickdown valve turned on all the time and then tranny misbehaves. Pulling the relay is the easy way out of this drama.

 

[gsxr]

@kubasz is correct! With the 5.0L LH module installed in a USA- or Japan-spec 034, the K29/1 relay must be removed.

 

[winmutt]

The 129 fan clutch won't fit, keep the 400e fan setup.

 

[ssaliaj]

I have the same swap some months ago with a m119.970 engine, 5.0 LH module, transferring all headers, oil pump, etc. I am facing a problem withe the ignition control module. With the 400E module the car starts and runs lets say good (i think there is space for better, the spark plugs seem to have unburned fuel when removed ) . When i tried to swap a 500E ignition control module it doesnt start at all. Any idea on which module code would be better, diagram how the ignition module is conected internaly? Any help would be more than appreciated.
Below the first photo is the 500E module and the second one the 400E module from the original engine 4.2.
Thanks in advance, Saimir

 

[ssaliaj]

@kubasz is correct! With the 5.0L LH module installed in a USA- or Japan-spec 034, the K29/1 relay must be removed.

Which is the simplest way to remove it from circuit ?

 

[gsxr]

I have the same swap some months ago with a m119.970 engine, 5.0 LH module, transferring all headers, oil pump, etc. I am facing a problem withe the ignition control module. With the 400E module the car starts and runs lets say good (i think there is space for better, the spark plugs seem to have unburned fuel when removed ).

If the car runs ok with the 400E EZL, just use that. If the spark plug insulators are tan color and look like the photos below, it's fine. Make sure you are using non-resistor plugs, set the gap to 1.0-1.1mm (not 0.8mm).

When i tried to swap a 500E ignition control module it doesnt start at all. Any idea on which module code would be better, diagram how the ignition module is conected internaly? Any help would be more than appreciated.

Sounds like your 5.0L EZL is dead / defective. Where did you get it, and was it removed from a running vehicle?

Which is the simplest way to remove it from circuit ?

Unplug / remove the relay completely.

 

[ssaliaj]

If the car runs ok with the 400E EZL, just use that. If the spark plug insulators are tan color and look like the photos below, it's fine. Make sure you are using non-resistor plugs, set the gap to 1.0-1.1mm (not 0.8mm).



Sounds like your 5.0L EZL is dead / defective. Where did you get it, and was it removed from a running vehicle?




Unplug / remove the relay completely.
View attachment 202325 View attachment 202326

I bought the relay on Ebay and didnt try it on time, now i cant return it any more .

I had the bosch plugs and replaced them with new NGK spark plugs.

Sorry for my lack of knowledge, do you have any photo of the relay location ?

 

[gsxr]

Relays are located in the compartment directly behind the fuses, you need to remove several screws first, then remove the cover, to access the relay compartment.