BMW E46 Fanatics Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
23 Posts
Discussion Starter #1
guys, please spare me some of your time. i'm still searching everywhere for this. about two weeks ago, i blew my engine. my head got damaged: camshaft, intake and exhaust valves, valve guide. everything on top. i had the engine block checked and it still looks good. the machine shop confirmed to me that my block is good and that all i need to replace is the head.

thing is, it's going to take 4 weeks or more for a new head to arrive, however there is another e46 at the shop which was rear ended, totalled. we have different engines and different transmissions. mine is an n40 engine, manual. while the other is an n42 automatic. can i swap my engine and still use my manual transmission? or do i have to go auto? i really need my car as soon as possible, that's why im considering this engine swap.

please help me guys.

marc
 

·
Registered
Joined
·
278 Posts
guys, please spare me some of your time. i'm still searching everywhere for this. about two weeks ago, i blew my engine. my head got damaged: camshaft, intake and exhaust valves, valve guide. everything on top. i had the engine block checked and it still looks good. the machine shop confirmed to me that my block is good and that all i need to replace is the head.

thing is, it's going to take 4 weeks or more for a new head to arrive, however there is another e46 at the shop which was rear ended, totalled. we have different engines and different transmissions. mine is an n40 engine, manual. while the other is an n42 automatic. can i swap my engine and still use my manual transmission? or do i have to go auto? i really need my car as soon as possible, that's why im considering this engine swap.

please help me guys.

marc
Everything top end got damaged? Are you sure? Have you seen the damage? Did the timing chain jump teeth? I honestly would get a second opinion if I were you.

Please explain the circumstances and how this happened. I have done a few engine rebuilds and this sounds really fishy to me.
 

·
Registered
Joined
·
23 Posts
Discussion Starter #5
Everything top end got damaged? Are you sure? Have you seen the damage? Did the timing chain jump teeth? I honestly would get a second opinion if I were you.

Please explain the circumstances and how this happened. I have done a few engine rebuilds and this sounds really fishy to me.
sorry bout that. yeah i have seen it already. i broke my camsahft into two. and the clamp like thing holding it down. i think it was calld camcup or something. overhaul gasket is also on the list. i've got bent intake and exahust valves. with it are valve guides.

not sure why this happend though but i have two theories:

first: it started when i was driving arround to get some groceries. my engine died. i restarted thinking it was my foot: letting to early my clutch. it started good, but it died again. three times actually. i tried to start it again but no go. foolishly i tried what my friend told me. roll it down the hill, keep it in gear, then pop the clutch. it felt like it started for about 2 seconds then died again. yes i know. it was a bad move. really stupid. with that, i broke my camshaft, and so on. arriving on the shop later that night on top of a trailer, the thing causing the engine to die was my MAF sensor. it was going out and the engine was having trouble mixing air and gasoline.

second: i just over did my driving. we've got open roads here. not much stop signs. cops dont even bother if you drive a bmw or an expensive car. being really dumb, i drive my car fast all the time. shifting at about 5000 and so on.

the shop owner, really great guy, told me that starting the car downhill and popping the clutch could've been the reason but driving my car like hell was the better theory. i just, as he said it to me "over-revved" my car.

also i need new clutch. great, i just had a new one not too long ago. it's really my bad driving.

for the pinoys here, im at 300 thousand pesos already. the other e46, the totalled one is at 400 thousand. with it are new leathers seats, m sport body kit. m sport suspension. stuff like that. while mine, on the other hand is just a plain 316i.
 

·
Registered
Joined
·
550 Posts
Broken camshaft...sounds familiar. Anyway, you need to make sure you did not punch a hole in the top of the piston when it struck the valve. Yes, you can covert to manual or automatic from either, no problem. If the engine displacement is different (not familiar with the "N" engines) then you will have to have your DME (engine computer) software changed to match the engine.
 

·
Registered
Joined
·
15,231 Posts
I'm assuming the N40 is 316 and N42 is 318, correct? I think they're also both 4 cylinders, one is just a 1.6 and the other is 1.8. Therefore it will work, just swap transmissions and retain the engine's computers. The tranny will bolt up, driveshaft length won't be affected, and you already have that working manual transmission in your car anyway, so you're good to go.
 

·
Registered
Joined
·
14 Posts
OK, your mechanic's explanation of what happened is crap. Shifting your 1.6L at 5,000 on a regular basis isn't going to cause that kind of failure. An incorrect A/F ratio (caused by a bad MAF sensor) would cause burned valves or pistons or simliar symptoms, not top-end damage! It sounds like your timing chain may have slipped a tooth or several, possibly due to an overly-aggressive bump-start (rolling down the hill and dropping clutch). I sort-of doubt that, though.
It sounds like your timing chain was just old, might ought to have been replaced a long time ago, and simply skipped. That caused your valves to hit your pistons, causing top-end damage.
Do be VERY careful, and check out your pistons, as they are very likely to be damaged. I'd go ahead and swap those engines, dude. If I'm not mistaken, the only difference b/w the 1.6 and 1.8L is the stroke. Can anyone confirm this?
-Matt
 

·
Registered
Joined
·
550 Posts
... If I'm not mistaken, the only difference b/w the 1.6 and 1.8L is the stroke. Can anyone confirm this?
-Matt
I tend to agree, but not sure. Yes, the 1.6L DME will work with the 1.8L DME, but I would suspect you would not get full potential out of the 1.8L. I am about to find out as I am swapping a 2.5L for a 2.8L. The 2.8L will certainly gulp more air which the MAF sensor will detect and change the fuel delivery accordingly. What I do not know is whether or not the DME will think things are out of range and thus cause a problem. Either way, I plan on having the 2.5L DME reprogrammed with 2.8L software. This in itself will be a challenge as BMW coding/programming tools will think the car is still a 2.5L and thus not want to allow the 2.8L software to be installed. Will probably have to find the back door...still thinking about this part of the equation, so not for certain about any of this.

BTW, the camshaft on my 2.5L (previous Owner) snapped due to oil starvation. I surmise one of the main camshaft bearings seized and thus caused the cam to snap.
 

·
Registered
Joined
·
23 Posts
Discussion Starter #10
thanks to everyone. i'll certainly check my chain tomorrow. it was declared as a special holiday. no classes for me. i'll visit my car.

the n42 engine has the 316 badge at the back. but i have to check the papers for engine displacement. hope it's the same. it'll be cheaper overall with this swap cause i'll be buying the whole car with the sport suspension, sport body kit, and the other "upgrades" it has. i'm really leaning towards this swap. if my chain's broke, what else should i look for?

and so it was not my popping the clutch downhill that killed my camshafts? the scanner also saw vanos failure.

also, how often do you change your oil? i change every 11,000 - 13,000 kms. as instructed by my instrument cluster. the shop owner told me that i should change every 5,000 kms cause it's a big engine with very few oild. 4 litters i think? and the 6 cylinder ones are at 5.5 litters? or something.

ill try to post pics later.
 
1 - 11 of 11 Posts
Top