Xen0

Engine Removal / Replacement - Best method?

7 posts in this topic

Recently, my 06 Cabrio with 220,000kms suffered an oil pump / chain / etc failure and I believe it ran for ~3-4 mins with zero oil pressure.  When I started pricing chains, pump, things I should do when it's apart, and whatever else may have been damaged, I believe it'd be just better to replace the engine with a lower mileage engine.  I've found an engine at a local salvage yard with ~86,000km with a year warranty for $500. 

 

There seems to be two procedures for removing the engine, one by removing the rear subframe complete, and the other by removing engine/transaxle by lowering and removing engine mounts leaving subframe in place.  Any reason one is better then the other?  For those of you who've done it, any tips before I jump into this?

 

Thanks!

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Subframe with engine first then engine from the subframe.

 

Dropping the rear end complete only take half an hour and you can get at absolutely everything once you do.

 

I do not know anyone that has taken the engine out and left the subframe in. I have done three myself dropping the complete thing.

 

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3 hours ago, Mjolinor said:

Subframe with engine first then engine from the subframe.

 

Dropping the rear end complete only take half an hour and you can get at absolutely everything once you do.

 

I do not know anyone that has taken the engine out and left the subframe in. I have done three myself dropping the complete thing.

 

Same for me, never thought struggling under the car lifting and humping the engine etc was a better way...lol.   But to each their own.   

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i agree with the above ,  remove the subframe/engine as a complete unit.  its much easier.

you will have to disconnect the fuel, coolant, vacuum, and brake lines but it is not really that big of a deal.

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Spent the weekend swapping the engine in a friends garage.  Raised the car on ramps and jackstands, and used his motorcycle lift table to lower the drive unit, which worked very well for that purpose!  We disconnected the brake lines at the subframe, and the abs connectors at the plastic holder.  I saw a post from tolsen that mentioned to have the brake pedal wedged between 1/4-1/2 so it won't leak fluid, that worked perfectly!  Spent far too long trying to remove the 3 coolant hoses since they seemed to set inside the plastic housing.  Ended up heating a bit with a heat gun to eventually get them them off.  Instructions I had found online said to remove the parking brake cables from the cup, but actually the whole bar assembly seemed to come out.  The single power cable that connects to the starter and alternator was jammed under the starter, so we had to pull it through further and cut the fabric sheath off to get it back through (WHY didn't Smart put a disconnect under the belly pan?  I might if I ever have to lower it again).  Once free I removed the x-frame, airbox, egr, turbo, intercooler, starter, alternator and ac compressor (discovered broken wire from the green connector to the ac clutch, hoping to try charging that again and see if I have AC).  Removed axles, then unbolted the motor mounts and moved the subframe away.  Unbolted transmission and flywheel/clutch.  Lined up with flywheel with stud on new engine and installed everything in reverse. 

 

From start to finish took 18 hours, which I think is rather good for an amateur that's only changed oil, brakes, resoldered SAM, fixed headlights, etc.   Now that I know what I'm doing, I'm sure I could halve that time at least.  All the things I was worried about, such as the exhaust manifold studs/nuts, turbo oil feed and return were no problem.  I had been spraying them with Mr. Wrench for a few days before.  Installed a blocking plate on the EGR exhaust feed while in there.  Only broke two rusty bolts, one on the intercooler shroud, and the other on the block heater.

 

I do wonder how you could ever remove that starter without removing the subframe, we had a hard enough time getting it in with the engine on the floor.  Granted we should have done it before remounting the ac compressor.

 

I did bleed the coolant with the subframe still lowered a bit.  Removing the temp sensor seemed to work well and seemed to be fine at first, but after reassembly and a short drive to test, more air seemed to move and lost heat.  Topped up with coolant and left it overnight with coolant cover loose and it had dropped level a bit more by morning.  Topped up again and now it seems to work perfectly.  Lots of heat and no adverse temperature changes on my half hour drive from his garage to home tonight. 

 

New engine is much quieter, runs smoother and better power!  It's all thanks to the members on this forum, I never would dream of tackling a project like this without all the helpful posts of the wonderful people here.  You guys are amazing. 

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I don't know where you read that you had to do something with the handbrake. It comes out when you drop the subframe, the only thing you have to do is to make sure the handbrake is off when you drop it. When putting it back you have to make sure the tab goes into the right place, it can fall to one side and you have to drop the subframe again to get it right if it does that.

 

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2 hours ago, Mjolinor said:

I don't know where you read that you had to do something with the handbrake. It comes out when you drop the subframe, the only thing you have to do is to make sure the handbrake is off when you drop it. When putting it back you have to make sure the tab goes into the right place, it can fall to one side and you have to drop the subframe again to get it right if it does that.

 

It was from the FQ101 guide for engine removal: https://www.fq101.co.uk/how-to-guides/fortwo-450/engine/178-engine-replacement

 

When we raised the subframe I made sure the tab did go up in the plastic hole but didn't end up in right spot, a bit of fiddling with the carpet pulled forward and we were able to guide it in the proper spot by applying and releasing the handbrake without having to drop the subframe again. 

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