Engine Question

[JonnyBravo]

Hello there people hoping youÔš's can give me a few ideas on what to do

Driving down the road the other night and heard this weird noise coming from the engine, like a knocking sound was like oh sh!t donÔš't sound to good.

Left her in this morning to get looked at and the news is the head is sweet but the bottom end is not so sweet he thinks itÔš's the BIG end bearing or the small end

Would I be best rebuilding the bottom end? Doing a 2.7? or was thinking about getting a 2.5 E36 engine?

If the answer was 2.7 what would I need? And how mush

Rebuilding the bottom end what would I need? And how mush

ItÔš's a 1989 325i sport 2.5 M20 engine

Many thanks

Jonathan

[kam-325i]

If it was me, i would look into getting the bottom end of a 2.7 in there...

[JonnyBravo]

what bits would i need for the 2.7?

would the head from my M20 2.5 fit ok on the new bottom end?

cheers

Jonathan

[JonnyBravo]

got a quote for a M20 2.5 bottom end (still in good order) fitted for Ԛ£500

is that a good price?

still would love tha 2.7

[Adammcf]

Id say most of that price will be for labour and it is quite a big job as thats what Im doing with mine at the minute although Im replacing everything I can on the engine except the bottom end internals.

Bottom ends cost well under Ԛ£100. Its just the fitting thats a pain in the ass.
My problems and the reason mine has taken so long are due to old tight bolts etc that just wont loosen.

[JonnyBravo]

was looking Ԛ£250 for the bottom end

You rebuilding the 2.5 or doing the 2.7 man?

Be a nice job when you get her all finished tho, almost new engine

[Adammcf]

Ԛ£250 for a bottom end is about 5 times too much.
Fingers crossed mine should be sweet when finished but if it breaks anythign this time Im gonna burn the bastard.

[Fushion_Julz]

If it were mine, and I was just going to replace what is broken...like 4 like, then it would be better to have the crank ground and a new set of bearing shells...

Since you'll be taking the motor out in any case, it is better than putting in an unknown quantity like a dubious bottom end...

[keith52]

If it were mine, and I was just going to replace what is broken...like 4 like, then it would be better to have the crank ground and a new set of bearing shells...


trouble is where do you stop ? new oil pump ,thrust washers etc the list could be endless, because of the mileage would you trust the water pump not to be on it's last legs, Imo once you get to that situation i'd be either a complete rebuilt or swop with a known good engine

[chu346]

don't suppose you need a 325 crank?

[JonnyBravo]

Think 250 was for the complete bottom end tho, donÔš't know if that makes a difference but I was talking to M5pilot about a 2.7 bottom end so fingers crossed lol

If the 2.7 donÔš't work out I think the only option would be to rebuild my bottom end no point buying a 2nd hand one I donÔš't know much about and the same thing could happen that

[Brianmoooore]

Plenty of good M20B25 engines around with good bottom ends and cracked heads.
A reasonably well cared for bottom end is good for at least 250,000 miles or more, so I wouldn't be too worried about using a second hand one. M20 bottom end failure is rare.