M62TUB44 vs M62B46 - interchangeable?
 

Hello.

I did some google search and searched this forum as well as some others, did not get a definite answer to my question...

I presently have an 2002 E53 X5 4.6iS that needs engine work, and sourcing parts is a financial nightmare, and considering a replacement M62B46 is equally nightmarrish... However, I have seen plenty of M62B44 and M62TUB44 floating around at rather affordable rates...

Besides the obvious of demoting of the beast to the regular level, is it possible to drop an M62TUB44 in place of the M62B46 engine?

If it is possible, what is involved in making sure it is working properly? Will the ECU and the rest of the brains communicate as it is, or some reprogramming must be done? are there incompatible parts? It will not be a DIY project, a professional mechanic will do the work but I wanted to be on the knowlegable side of the issue.

I know that some people pull I-6 in favor of V8s in some racing applications, thus "upgrading" the car - I just want to get the thing back on the road...:(

This plea is out of desperation, as my wife wants a divorce from the 4.6is and I hope to save the car's dignity instead of abandoning it somewhere under a bridge on an interstate!!!!ouch:

The opposite conversion has been done in an E39. While functioning, the swap was not seamless at all. It involved a lot of harness changes, programming differences, etc. I did not ever hear if he ever got everything worked out.

While his upgrade was the opposite direction and on a different chassis, it can be reasonably assured that the challenges would be very similar.

What's up with your 4.6 motor?

I would think the block and most of the accessories would be nearly identical on both motors, the tune would be different though.

Depending on what kind of parts you need, maybe there is something aftermarket available? ie; pistons, rods, valvetrain

the chain guides went dead, the chain slapped around long enough to break one of the engine covers and bend some pistons or valves or who-knows-what - just long enough for me to pull over from the main lanes of traffic onto a side street... Damage was done...

the mechanic thinks that it would be better to get a replacement engine, but this particular engine is rare, and whatever i can find costs a lot... the car with fully functional engine tops at $12K maximum, with a generous buyer... dropping $6K-$8K into this car makes no sense... I was hoping to get a $1.5K-$2K M62TUB44 and get it up and running for the local errands, nothing long distance anymore...

I am no expert but I guess it might be doable if you can get the ECU that belongs to the motor.

do an S85 swap :D

I think your first step is opening it up to assess the damage. You might be able to rebuild the motor. If not, bolt the 4.4 in there and fire it up. I'll bet it runs on the 4.6 ECU.

Is there room for the V10 in this thing? :thumbup:

V10???

wow!!! years ago, I chose the nik Terminator, because this thing would terminate anybody's attempt to pass it on a highway... I had taken that particular car to 140 MPH and it was rock solid...

Over the years it had gathered some battle scars, some are just "tissue" deep and some were more heart-breaking... It is like an old war horse, I just don't have enough guts in me to part it out, but getting a full fledged 4.6 engine is hurting the wallet...

I was thinking about 4.4 V8....

But if I will get the V10 then maybe I will have to change my nik to

FrankensteinX5!!!! Unless it is already taken... lol...

V10 will cost a lot more. I bet it doesn't run with a 4.4 motor with a 4.6 ecu. You would probably need ecu, cluster, and harness. Then you would need to code all the electronics to new ecu.

So tell us about the moments leading up to the failure. Mine is approaching that mileage, need to know what to look and listen for.

It was business as usual - except I heard some whistle from the engine bay, as if it were some belt or something... I popped the hood, listened... it wasn't hissing, like from a vacuum, nor it was belt whistle when I was up close... it did sound like a sharpening stone, the kind that rotates and you sharpen a knife - the tone was rather of a higher pitch, as if the knife was of a smaller statute... As I realized in hindsight, that was the timing chain cutting through the last remnants of the plastic guide... About 45 miles the car sounded like a tractor but sitting inside I had no clue - it was rolling fine, accelerating fine, no messages on the board... The passer-bys kind of flagged me, so I rolled the window down and that's when I heard "tractor"... while my slow brain was trying to apprehend what was going on, the dash lit up with some scary messages, and I started to pull off the main drag into some parking lot - as soon as I stopped, I just shut the engine off... it was off since that time... The engine is apart now, and the mechanic says that it might be better to get a used one and slap it in... it might work with normal engine, but stupid me got myself a rare breed... lol... me and mechanic are still talking about it... sooner or later, something is going to give... either we will get it fixed, or i will sell it as it is....

the car will be a classic someday as they only made about 3,000 4.6is's, so if it were me I would go for an engine rebuild.

hahaha... by the time the car will be classic, i will turn into antique!!! but I am still debating, as wife wants a fresh ride, and she is eyeing up a 2010-2013 3-series... At this rate of financial downfall, I can only lease, and I am looking into ED leasing options and into taking over a lease with a lot of available miles (she drives a lot), looking into swapalease website...

nothing is carved in the stone yet...

This maybe a foolish question but did you ever get ahold of Alpine M3 who was parting out the 4.6is. He was last active in June.

I tried to get hold of someone who was parting a 4.6iS on this forum, but i have not heard back... :(

just tear the heads off, check for piston damage and just repair the valvetrain if the bottom end is good

A leak down test of the cylinders will be way easier than pulling the heads of for starters . You might be lucky and just need new chains and guides .

And the 4.4 engine might work out as the capacity is only 25 cc - ish per cylinder less , use all the 4.6 manifolds etc . On the other hand you might blow the 4.4 quickly due to overfuelling but a remap of the ecu might work if you find someone who knows the figures to detune your ecu .

The diagnosis is a bit loose, how did your mechanic come to the conclusion that the engine is toast? If it is only the chain and the cover then I'd go for a repair. I guess he is thinking the sump needs to come off to clean out the debris? (Then you'll need to reset timing. In all a fairly involved bit of wrenching.) Why does he think the pistons/valves are bent?

If it is indeed a goner then I think Slick's approach is the most cost effective one with an assured outcome. I.e. Swap the motor, brain, cluster and engine harness (from th same donor car obviously). Then recode the electronics in your to match.

oldschool v6 nissan valves touched pistons> no piston damage

You can, but why? Getting your heads rebuilt and doing new chains/guides would be cheaper. Call up VAC, CSS Motorsports, or any local machine shop that does foreign cars and see how much it would be to rebuild the heads. If the chain let go, chances are that the motor shut down well before any other damage was done. If you need new cams, I have a spare set.

Yea I agree. Before you pull the motor. Do a leakdown test after a compression test. See what the damage is like.

the leakdown test is no good, some valves are bent...

i did some cross reference between TUB44 and B46, it seems a few parts are the same... so, maybe, instead of considering downgrading, i just get a used TUB44 engine for donor parts?... I have couple pieces of engine walls busted broken in small chunks of metal...
i still will need fresh gaskets and maybe a few 4.6 specific parts...

stilll looking into it...

The heads are different, just pull them and get them rebuilt.

Rebuilt heads won't help with a broken block.
You may want to speak with VAC Motorsports. I know they can sleeve the blocks. Maybe sleeve a 4.4 block to the 4.6 bore and rebuild from there?
You may check with these guys
http://http://www.data.bmrparts.com/bmwparts/BMW_ENGINE_ASSEMBLY/BMW_11007515721_4.6L_used_long_block.html

While I don't have the 4.6, I do have the 4.4 and was wondering if you were getting the chain slap with cold start ups? If so, how often? In hindsight, should the guides be replaced when we start hearing the brief slap in the mornings?
I've changed the tensioner but it's still happening.

2002 4.4is 132k miles

Absolutely!!! If I knew what these symptoms were, I would have replaced the guides and be done with it...

The block itself is not broken (at least, it does not seem to be a problem at this moment), just couple covers, and they seem to be interchangeable...

Did you look here for an engine?

Used and Rebuilt BMW Engines For sale -- BMW Engine Ready to Ship

You sure its bent the valves?? Mine did the same thing at 70mph and I had to drive it about 2 miles with a hell breaking loose under the bonnet to get to a pull over. Cam chain bits were not happy, but no damage anywhere else (at that time anyway). I would pull it out and strip it first. Its got to come out no matter what you decide to do, and taking it apart is cheap. If you do it yourself putting it together should cost no more than 3000 of your American dollars. You might get away with a cam cover, chain and guides

Yo Terminator,

What's going on with your motor? Hope you are getting more good news than bad.

So im guessing you need a 4.6 motor? I have one for 2500 no ews3 tho. I was thinking about doing the swap into my e39 but, i cant find a good enough write up. Im in need of 2-3 M62B44 motors my self.

tell me more about your motor...
EDIT: removed my email address

:bmw::band:

Yayyyyyyy, maybe the 4.6is will live again! lol

then i can test them side by side, the 4.6 and the 4.8!!!! wheee-haaa!!!!

Ohhhhhhhhh I'll drive the 4.6is!!!!! I'll volunteer!!!! lol

:gun:hehehe, whatever you do, make sure that you do NOT press THAT RED BUTTON!!!!!:explode:

DAMNITTTT. I was looking forward to flipping open the button and havin all the guns and such come flipping out.

hehehe, reverse psychology at work - of course I know, if I say do NOT push, you WILL push!!!!

:gun::gun::sw::fencing:

the fellow hasn't emailed me yet, maybe he got rid of the engine already... lol..

I still have it!!! For some reason xpost doesn't send me notifications any more so, I check it only when I remember to.... Emailing now!!!

Old thread, just wanted to say if anybody reads this - something self experienced, I had this repaired in my own engine:

chainguides are a big problem regardless of M62, M62TU or S62. The old M60 doesn't have the problem though. It stems from the fact that BMW removed a gear when they did the M62 development (cost savings probably), and instead relied on chain guides to do the work of the gear that is in the M60.

These chain guides are coated in PLASTICS. No wonder that plastics breaks with age.

SO: regardless if you get another M62, TU or S62, you will get the same problem. Chain guides need to be replaced around 170 K miles.

That said, it's obvious that TerminatorX5 should rebuild his M62B46.

I would have rebuilt the engine, but we live in a "throw-away" society - once a TV, or a computer, or refrigerator breaks, we just toss it and get a new one... granted, a car is much more expensive than a refrigerator, but after so many years and miles the value is far less than someone (me!) is willing to invest into... I got rid of the 4.6iS in May of 2013, and have a 4.8iS now (in E53 bodystyle, just can't bring myself to E70, or god forbid - to F15!!!). It was the only financially feasible option, given the value, the cost of parts and labor and the offer to sell AS IS.

I loved that car, it was with me in a few countries, crossed some hanging bridges over mountain creeks, pulled through torrential rain in rain forrests, drove on beach dunes in some wild beaches, witnessed some crooked cops/paramilitary dudes with machine guns, endured some serious snow and cold in Russia... but, it was time to let it go...:(

If it was with you for that much I would've rebuilt the motor because of some serious sentimental values.

I spent about 2200 USD to have it rebuilt; you have to dismount everything in the front (radiator etc), so you can remove the front cap and get to the chain guides. I had all chain guides replaced, all three cam chains new, new chain tensioner, new gaskets everywhere and new new drive belts.

When it was together again we did a rinse, filled her up with regular standard oil, a little diesel and STP engine flush, started it and let it idle for 30 minutes. Then we flushed the oil together with a lot of goo that came out -- then new Castrol oil and filter. I also had the valve caps repainted silver (the old BMW color flakes)

It was 2200 dollars to have it done, with material. But now I have a fresh engine, everything worn replaced. The chain guides are a problem in all M62/S62 engines, unfortunately.

LSx swap and make it RWD only, FTW...that's going to be the first thing I do once the engine or trans drops in my X5. I wish I'd done it in my 7, but instead $14k later I've got a rebuilt engine in my car from www.bavengine.com