Pulling the motor in my M5- what to do while it's out.

Specific conversations and info for the BMW E28 M5 and M535i.
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Etip
Posts: 155
Joined: Sep 05, 2021 2:06 AM
Location: Seattle

Pulling the motor in my M5- what to do while it's out.

Post by Etip »

Hey all,
I'm having some major body work and repairs done to my M5. The body shop is going to pull the motor and trans, so it's a good opportunity to do some maintenance.

So far I'm thinking motor mounts and Clutch- what do people recommend?

What else while they're in there??

Thanks in advance.
milarsky
Posts: 515
Joined: Jan 26, 2013 11:19 AM
Location: NYC

Re: Pulling the motor in my M5- what to do while it's out.

Post by milarsky »

Depending on your mileage, I would refresh everything. Timing chain, all timing guides, crank nut, all gaskets on front and rear. Motor mounts, extensive cleaning, and lubrication of throttle body assembly. Maybe send fuel injectors out for deep cleaning, and replace every hose you see. All of this is pretty cheap. If you want to delve deeper, you could do connecting rod bearings, bolts, oil pump, etc. In addition, you could upgrade to S38b36/38 intake camshaft and s38B35 exhaust camshaft with new sprockets. Then valve and lash adjustments of course. Euro headers are also a possibility.

It is just a great opportunity to have access to everything without performing any gymnastics.

good luck,
Jeff
Randomg
Posts: 480
Joined: Jul 12, 2007 3:12 PM
Location: Seattle

Re: Pulling the motor in my M5- what to do while it's out.

Post by Randomg »

Seems like the answer would depend on your budget. The only thing that comes to mind as not doable with the engine in the car is crank removal. Cheap things that are much easier with the engine out would be freeze plugs, oil pan gasket, front and rear crank seals, that rear coolant pipe, cleaning/painting/corrosion removal, and some of the timing chain stuff. If you have access to an impact gun, the crank nut can come up much easier than when the engine's in the car. Throughout the years people have insisted that the plastic chain guide specifically should be replaced.

If the freeze plugs don't have any sign of corrosion and the rear pipe and oil pan gasket aren't leaking, I might leave them alone. Messing with stuff can often lead to other things. I replaced the freeze plugs and didn't install them carefully and they started rusting faster than the ones I replaced. I sent fuel injectors from an ok running engine out to VAC and they were returned with more than one no longer working... I spent a long time last winter cleaning the engine while it was out, only to have my oil pressure sensor start leaking and spew oil almost everywhere you can think of.

However, if you have the budget, I'd replace timing chain guides and chain (I've been told that the cam sprockets don't really wear) first, then the crank hub with an upgraded one if you can find one, then the oil pump and switch to the e34 chain and gear (which I believe increases idle oil pressure) and add the pump chain tensioner if it's not already there. Then probably rod and main bearings.
Etip
Posts: 155
Joined: Sep 05, 2021 2:06 AM
Location: Seattle

Re: Pulling the motor in my M5- what to do while it's out.

Post by Etip »

Randomg wrote: Feb 02, 2022 11:53 PM Seems like the answer would depend on your budget. The only thing that comes to mind as not doable with the engine in the car is crank removal. Cheap things that are much easier with the engine out would be freeze plugs, oil pan gasket, front and rear crank seals, that rear coolant pipe, cleaning/painting/corrosion removal, and some of the timing chain stuff. If you have access to an impact gun, the crank nut can come up much easier than when the engine's in the car. Throughout the years people have insisted that the plastic chain guide specifically should be replaced.

If the freeze plugs don't have any sign of corrosion and the rear pipe and oil pan gasket aren't leaking, I might leave them alone. Messing with stuff can often lead to other things. I replaced the freeze plugs and didn't install them carefully and they started rusting faster than the ones I replaced. I sent fuel injectors from an ok running engine out to VAC and they were returned with more than one no longer working... I spent a long time last winter cleaning the engine while it was out, only to have my oil pressure sensor start leaking and spew oil almost everywhere you can think of.

However, if you have the budget, I'd replace timing chain guides and chain (I've been told that the cam sprockets don't really wear) first, then the crank hub with an upgraded one if you can find one, then the oil pump and switch to the e34 chain and gear (which I believe increases idle oil pressure) and add the pump chain tensioner if it's not already there. Then probably rod and main bearings.
Hey, thanks for this input. My budget is actually pretty maxed out with doing the frame rail and structural repairs correctly.
As I realistically think about it, I'm probably not going to do any significant engine work.

I think I will do engine mounts as it's basically free to replace them while they're there. And I'm not going to worry about that.

Also going to do a clutch as mine is stuff and worn.


Any input on clutches? Car is all stock.
Basic Sachs?
Etip
Posts: 155
Joined: Sep 05, 2021 2:06 AM
Location: Seattle

Re: Pulling the motor in my M5- what to do while it's out.

Post by Etip »

Thanks,
Last edited by Etip on Feb 06, 2022 11:10 PM, edited 2 times in total.
Etip
Posts: 155
Joined: Sep 05, 2021 2:06 AM
Location: Seattle

Re: Pulling the motor in my M5- what to do while it's out.

Post by Etip »

Randomg wrote: Feb 02, 2022 11:53 PM Seems like the answer would depend on your budget. The only thing that comes to mind as not doable with the engine in the car is crank removal. Cheap things that are much easier with the engine out would be freeze plugs, oil pan gasket, front and rear crank seals, that rear coolant pipe, cleaning/painting/corrosion removal, and some of the timing chain stuff. If you have access to an impact gun, the crank nut can come up much easier than when the engine's in the car. Throughout the years people have insisted that the plastic chain guide specifically should be replaced.

If the freeze plugs don't have any sign of corrosion and the rear pipe and oil pan gasket aren't leaking, I might leave them alone. Messing with stuff can often lead to other things. I replaced the freeze plugs and didn't install them carefully and they started rusting faster than the ones I replaced. I sent fuel injectors from an ok running engine out to VAC and they were returned with more than one no longer working... I spent a long time last winter cleaning the engine while it was out, only to have my oil pressure sensor start leaking and spew oil almost everywhere you can think of.

However, if you have the budget, I'd replace timing chain guides and chain (I've been told that the cam sprockets don't really wear) first, then the crank hub with an upgraded one if you can find one, then the oil pump and switch to the e34 chain and gear (which I believe increases idle oil pressure) and add the pump chain tensioner if it's not already there. Then probably rod and main bearings.
Hey, thanks for this input. My budget is actually pretty maxed out with doing the frame rail and structural repairs correctly.
As I realistically think about it, I'm probably not going to do any significant engine work.

I think I will do engine mounts as it's basically free to replace them while they're there. And I'm not going to worry about that.

Also going to do a clutch as mine is stuff and worn.


Any input on clutches? Car is all stock.
Basic Sachs?
Bonebiz
Posts: 3
Joined: Jun 02, 2008 3:58 PM
Location: Manhattan Beach CA

Re: Pulling the motor in my M5- what to do while it's out.

Post by Bonebiz »

Get a fresh starter and replace the bolts with studs in the block. It's much easier to change with the engine out and the studs would make any necessary future R&R much easier too.
Etip
Posts: 155
Joined: Sep 05, 2021 2:06 AM
Location: Seattle

Re: Pulling the motor in my M5- what to do while it's out.

Post by Etip »

Bonebiz wrote: Mar 31, 2022 4:09 PM Get a fresh starter and replace the bolts with studs in the block. It's much easier to change with the engine out and the studs would make any necessary future R&R much easier too.
Thanks Bonebiz! Yup, got a new Bosch and doing studs.
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