Engine repair/rebuild

mrscalex

mrscalex

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I'm still deliberating whether to buy a replacement low mileage engine from a salvage yard or try and get mine fixed. It's a 2.2 in the latest project car I've bought. Either way I'm happy doing the swap itself but I would be clueless opening up an engine.

Being a project car bought from a salvage dealer I don't know the history of the engine (other than it's got 92k miles on it). What I do know is what I can see. The engine is seized and there is no oil. On closer inspection I see a hole in the sump that appears to have been made from the inside out. My best guess is a bolt got thrown off the con rod.

I like to keep things original so I'd much rather the current engine was repaired. But such services seem to be thin on the ground these days, at least in Swindon/Wiltshire. I don't really want to go to a full rebuild as my budget is up to £500 - set as I know I can get a replacement for this.

So does anyone know of an engine specialist who could take a look for me? Preferably where you've had work done yourself? Are there any engine experts on the forum who fancy taking the job on? Am I wasting my time trying to get it fixed and I should just go for the replacement?
 
I would say with your budget. And the damage thats been done. The only coarse of action would be to bin the engine and start with a new one.

Engine parts alone rods bearings gaskets new sump. Possible new crank or regrind if bearings have spun. The bores will probably be damaged so either new liners or honing and at least new rings possibly pistons. That is just the bottom end. I would expect the cams to be knakerd if its been run dry so 2 new cams and valve train. Paying someone to do all that and buy the bits would be more than the cars value i would think.

If i where you I would swap the engine get it going. Then strip down the old engine asses the damage. Have some fun reading and learning taking it apart. Its trashed anyway. If it goes well and the damage looks minimal rebuild and refresh the engine and swap it back.
 
I think that's very sensible advice machine monkey. And yes, I would certainly take the opportunity to strip the current one down and learn.
 
mrscalex said:
I think that's very sensible advice machine monkey. And yes, I would certainly take the opportunity to strip the current one down and learn.
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I have not taken an engine apart for years. And i am no expert but if you need a hand when you do i am not that far away in Witney Oxfordshire.
 
machine monkey said:
I have not taken an engine apart for years. And i am no expert but if you need a hand when you do i am not that far away in Witney Oxfordshire.
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Sounds like an offer I may well take you up on - thanks. Probably more for putting it back together if it gets that far ;)

I did several engine swaps 30 years ago on MK 1/2 Escorts. As long as I'm methodical I expect that bit to be no more complicated than the front end rebuild I've just done on my first Z3.

I'm curious though. I've got a bit of an aversion for taking out gearboxes. But pulling off the front end of a Z3 for access no problem. Can I leave the gearbox in situ and pull the engine out through the gap where the front panel was?
 
mrscalex said:
Sounds like an offer I may well take you up on - thanks. Probably more for putting it back together if it gets that far ;)

I did several engine swaps 30 years ago on MK 1/2 Escorts. As long as I'm methodical I expect that bit to be no more complicated than the front end rebuild I've just done on my first Z3.

I'm curious though. I've got a bit of an aversion for taking out gearboxes. But pulling off the front end of a Z3 for access no problem. Can I leave the gearbox in situ and pull the engine out through the gap where the front panel was?
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I have never taken an engine out of a BMW but i cant see why not as long as you can get access to all the bolts holding the gearbox to the engine. Maybe difficult without a lift to get accesses. But once the prop is off and clutch lines and gaerbox linkage and mounts are undone it maybe easier taking out the whole lot?
 
It's the access to the gearbox/engine bolts I'm not sure about. But I take your point, even with the front panel off it may be easier to take the gearbox out with the engine.
 
Well i am doing a clutch on mine in about a months time. Its a z4 not a z3 but I hope you can get accesses I am sure you can its just going to be a PITA on jack stands off the floor. I have accesses to a 2 post lift. But if i where you and it sounds like you wont have a lift? I would take it out as one lump and change it over out of the car.
 
No lift no. Which is why I don't want to go b*ggering around under the car to remove the gearbox first or frankly even the propshaft. I have unhappy memories of doing so on old 4-speed Escort boxes and they would be light in comparison. Mind you the Escorts were a bit tricky as you had to put longer subframe bolts in and drop the subframe on the bolts to get 2" of clearance to reach the bolts as they hid up under the transmission tunnel. Funnily enough in one of this month's classic car mechanic mags a so called expert was moaning about how difficult it was to change an old Escort gearbox. I was wondering why. Then he said thank goodness for so and so person he knew who did the job in no time by dropping the subframe and what a great trick that was! You'd struggle without dropping the subframe!

If I can't take the engine out on it's own (and I'm happy to buy a transmission stand/prop) then the gearbox coming out with the engine is a good compromise. With the front panel off I'd expect no aggravation with that. Again on an old Escort engine/gearbox that was a tricky business as you used to have to swing the whole lot up at a rather frightening angle to get it in/out.
 
Done many an engine change on RWD cars/vans in the past and I'd definitely agree on taking the engine and gearbox out in one lump if at all possible, you'll be needing some sort of hoist anyway so the extra weight of the gearbox won't be an issue. It saves the hassle of trying to get the input shaft to line-up with the clutch splines (major PITA sometimes, been there done that), much easier out of the car. And just to be a PITA myself, if/when you get round to it would you consider standing the gearbox on a big bit of paper/card and drawing round it, marking the bolt holes as well? Reason being I feel the need to fit a 6-speed box but I'm not too sure which of the many boxes BMW use would actually fit.
 
Brian4 said:
@mrscalex here is a good guide on stripping the M54 engine.

http://forum.e46fanatics.com/showthread.php?t=899347.

As all above say a seized engine with a holed sump is going to be hard work overhauling and they take up quite a bit of space when stripped to keep all the good parts clean and tidy.
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Wow! Great resource thank you. It's a no lose situation stripping the engine. I should learn quite a bit. I might get some useful components off it. If nothing else it will be more transportable to get down the tip. And there's a remote chance I might discover it's salvageable.
 
the Nefyn cat said:
Done many an engine change on RWD cars/vans in the past and I'd definitely agree on taking the engine and gearbox out in one lump if at all possible, you'll be needing some sort of hoist anyway so the extra weight of the gearbox won't be an issue. It saves the hassle of trying to get the input shaft to line-up with the clutch splines (major PITA sometimes, been there done that), much easier out of the car. And just to be a PITA myself, if/when you get round to it would you consider standing the gearbox on a big bit of paper/card and drawing round it, marking the bolt holes as well? Reason being I feel the need to fit a 6-speed box but I'm not too sure which of the many boxes BMW use would actually fit.
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Very happy to do that - if I remember!
 
the Nefyn cat said:
It saves the hassle of trying to get the input shaft to line-up with the clutch splines (major PITA sometimes, been there done that), much easier out of the car.
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I did my first gearbox out at 18 years old. Trying to line the input shaft up took me hours and literally almost had me in tears!
 
the Nefyn cat said:
Done many an engine change on RWD cars/vans in the past and I'd definitely agree on taking the engine and gearbox out in one lump if at all possible, you'll be needing some sort of hoist anyway so the extra weight of the gearbox won't be an issue. It saves the hassle of trying to get the input shaft to line-up with the clutch splines (major PITA sometimes, been there done that), much easier out of the car. And just to be a PITA myself, if/when you get round to it would you consider standing the gearbox on a big bit of paper/card and drawing round it, marking the bolt holes as well? Reason being I feel the need to fit a 6-speed box but I'm not too sure which of the many boxes BMW use would actually fit.
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I have a 5 speed BMW box bell housing sat hear next to me right now. Its from a e36 i think??? It was cut off to mate a lexus auto bellhousing for a project i am working on. If we can find out any numbers or information on what is in your car? I can check against this and then draw around it for you today if you like?
 
I'm no engine expert but that's simply not the case. It might of course be scrap but the oil could be a red herring.

There is a hole in the sump inside out. The size and location of the hole suggests a con rod threw a bolt. At which point the engine could have seized. The oil then inconsequently leaked out. Now of course the bolt being thrown may have scrapped the block. But we don't know for sure. And neither do I know whether the engine limped on after throwing the bolt and it was indeed the oil.

But even then I know enough that not everything seizes at the same time. I failed to prime a rebuilt engine properly once and cause a crankshaft bearing to pinch - but that was all.

And it might be that the bottom end is scrap but the head is okay.

But to suggest categorically it can only be scrap is not true. Quite possibly true but at the end of the day if all I do is strip it, learn something and then take it down the tip I'm happy.
 
by all means open it up, it's only my opinion after all.

just that by my experience engines that appear to be ok and a runner can need a ton of money thrown into them, never mind one that has signs of a major failure. If the failure turns out to be caused by oil shortage, the heat build up would have been horrendous, and many parts that can appear to be ok can be heat damaged.

basically you have nothing to loose by having a look
 
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