BMW X5 4.6 to 4.4 engine swap

[Mvt2009]

Hi guys unfortunately my engine has went in my 4.6 and I cannot really afford to have the car off of the road much longer, I have taken the engine out myself and it wasn't too bad, I was just wondering if I bought an x5 4.4 lump would it go straight in? It's the wife's car so performance not really that much of an issue, as long as it will work with the gearbox, wiring ecu etc then It's fine if it's a bit slower she nipping my head for her car back!!!

[AW8]

Insuring it cost effectively with disclosure of the different engine may restrict number of competitive quote providers. Some might rationalise that it should be cheaper but the reality may differ. There are also issues with notifying DVLA & consequentially VOSA...otherwise at MOT time it  will show on database as a 4.6 lump.

Cant comment on the swap techical issues although I believe (despite both using ZF5hp24), there may be subtlel gearbox differences. I cant expa as knowedge is scant without some digging.

[X5Sport]

You'll need the change the ECU, instrument cluster and most likely a number of other systems as the system will be set up for a 4.6 so you may well need to code the engine change into all the right places.  Worth changing like for like as it will (or should) just work.

[Mvt2009]

so I take it then if I put it in it won't run? Is that correct? Or will it run and be fine are the changes just required for emissions etc?

[X5Sport]

The ECU will need a 4.4 map in place.  It might run but be lumpy, or it might not start.  A BMW Dealer might be able to advise for certain.

[henrym3]

Having done an engine swap, in a car, I assume that the 4.4 would come with the engine wiring loom and it's own DME, and not just have been cut out of it's previous owner. There are differences in that the alternator is water cooled in the 4.6 and I believe the 4.4 isn.t. Hence things like that necessitate it's own loom. I don't think a dealer will offer any advice on such things. I would be reluctant to go down this route unless someone on here has done this conversion and is willing to give good solid advice. BTW what went wrong with the 4.6, interested to know as I have one.

[Greydog]

Morning Henry there is an inherent weakness in the BMW V8 not just the 4.6 the chain guides are plastic, add to that the timing chain tensioner design isn't the best as it relies on a spring to supply initial tension result a momentary chain slap. My experience (old engineer) tells me that after a many heat cycles two things combine (1) The spring softens so doesn't provide sufficient tension at cold start  (2) Due to the chain guides being plastic they become brittle after the same heat treatment that the spring has had, they start to break up under the chain slap at start up.
This results in chunks of plastic in the sump which can block the strainer on the oil pump.

When my 4.6 went at Christmas last year it had covered less than 100k and there was no audible chain slap at start up. When the engine was stripped it wasn't clear whether the oil pump failed causing chain guide failure or the other way around. The result of course is the same a massive bill if you want to rebuild it.
Fortunately having researched and following others advice I have a warranty so they paid 60% of the parts and all the labour (labour was about 40 hours) parts were around £2k the final bill £5.5k without the warranty I would have scrapped it.
While it was having it's heart surgery I researched a lot and discoverred that BMW aren't alone Jaguar, Audi and a few others have the plastic guide issue. The cause of failure seems to be consistent, a lack of oil pressure at cold start.
Not wanting it to re-occur I have fitted a pre-oiling system to ensure there is oil pressure when I turn the key.

[henrym3]

Hi Greydog, your answer implies that the engine was fixed at a cost off 5.5k with new tensioner and chain guides, has it broken again since it was fixed? Interested because I have one with 123k. Can't make up my mind whether to do this as preventive maintenance or wait till some symptoms start to show. 

[IanP]

[quote="henrym3"]
Hi Greydog, your answer implies that the engine was fixed at a cost off 5.5k with new tensioner and chain guides, has it broken again since it was fixed? Interested because I have one with 123k. Can't make up my mind whether to do this as preventive maintenance or wait till some symptoms start to show.
[/quote]

I would really do this as preventive maintenance. When they fail the cost can go up a lot. And it will probably fail at the worst possible time.  >:D >:D

[henrym3]

Hi IanP, I know your right, I know that is the sensible thing to do but it's so difficult to take something that is running perfect and pull it to pieces. I payed less than Greydog's repair bill for my 4.6 18 months ago. I did this repair about 6 months ago to my sons 4.4 which was in a horrendous  state, the noise unbelievable, but when stripped the chain was fine but all the guide rail plastic was gone down to the sump. The parts to repair were less than £400 which included gaskets. Of course it took me far longer to do without any specialist tools, which just shows how much crap is wrote about them. 5k mile on it's still running sweet as a nut. I may put it off till after Gaydon, hope I don't regret that. have put a pi in  of the 4.4 sump. 

[Greydog]

Morning Henry
My 4.6 I have owned almost 3 years it came with 75k and a complete Main Dealer history, since being in my ownership it is serviced annually at a respected BMW specialist. It is only just reaching the 100k, so the failure was totally unexpected.
My engine was rebuilt at a BMW specialist in January and is still running like new (well it should be). The decision to fit the pre-oiling system was mine based on what I saw and learned looking at the parts during the strip down. The tensioner was/is my concern so rather than risk a repeat I fitted the pre-oil system as a precaution.
If I keep the X5 I know it is sound in that department, if I sell it, I will be able sleep knowing I haven't sold on a potential financial time bomb.
I do like the X5 and the way it drives, what is a disappointment for me is how mechanically fragile it seems to be in so many areas. I have heard all the arguments it weighs two tons etc, well the designers knew that before they built it (I hope) I also understand it's an old car (12 years, yet I have a way to go to catch your mileage) one would hope that BMW have noted the often well documented failure points and
designed/engineered them out by now?

[henrym3]

Hi can you elaborate some on what you mean by "pre oil system" I haven't heard of this.

[Greydog]

Morning Henry
There are several systems the one I chose is from the States www.engineprelube.com it works by charging a holding tank with oil at the engines operating pressure, the oil is held there by a solenoid operated valve. At engine shut down the pressurized oil remains sitting in the holding tank until the key is turned as soon as the key is turned the solenoid releases the oil in the tank and the system is pressurized before it fires. As soon as the engine runs the system recharges it's self for a few hundred pounds and a days head scratching I think it was worth it.
Space is tight in the X5 engine bay but I found room under the oil filter.

[Mvt2009]

Don't suppose anyone knows about a 4.4 into a 4.6 engine swap then? Mine was oil starvation due to someone doing the chains in the past and not cleaning out the oil pickup properly

[lezmtaylor]

The 4.4 also has a watercooled alternator ( I have just changed mine)

Lez