I picked up a 1988 325i coupe recently to the tune of $400. Decent shape and worth getting back on the road. I agreed to buy it sight unseen from the seller who described the reason it was parked was that the timing belt failed. Well, that wasn't a fully truthful description as it turns out they had removed the head and let the car sit under a tarp...since 2006! Fortunately, the head is in decent shape and looks like it would have no problem being reused with a new set of valves, but unfortunately the last few cylinders in the engine took on some moisture and rusted. Obviously the easiest choice would just be to swap in another M20B25, but I'm having trouble sourcing another engine locally and am worried about the cost of shipping one up from a salvage yard in the lower 48. I really don't mind rebuilding the engine that is in the car now, but the price of new pistons is insane. I have not come across any lower cost aftermarket options either. What is my best option for fixing the car at this point?
Candles are just our way of keeping fire as a pet.
How about honing the cylinders and slapping in new rings?
The reality is, the head needs to be rebuilt, and so does the bottom end, otherwise you are simply gambling with the parts/gaskets/fluids/etc that you would have to buy just to try the bare minimum to get it running. The only options I see that don’t involve gambling is either have the motor professionally rebuilt, if someone can do it locally, or buy a good used motor and bear the cost of freight. I do like his idea of honing the cylinders, you would have to strip the motor down, and hone every last pit out of it before even considering that. Not sure what level your tool/skill set is on , but it could be an option, as long as you realize thay you are essentially rebuilding the motor yourself at that point.
Last edited by msservices; 12-31-2018 at 08:05 PM.
Honing the cylinders and throwing in new rings isn’t an option anymore - the cylinder is rusted bad enough that the pistons are seized to the cylinder walls. Being realistic, it likely now needs an overbore and oversized pistons, but the only ones I can find run about $1500+ for a set, and I’m not looking for custom forged pistons, just some off the shelf ones for a daily driver is all I’m searching for. I can do the work myself, but I’m not happy about forking out $250+ per piston. At that price it would likely be cheaper to eat the freight cost and ship up another engine, but I can’t believe a low cost option to rebuild what I have doesn’t exist.
Candles are just our way of keeping fire as a pet.
https://www.autohausaz.com/pn/11251714810
I just searched e30 piston and came up with some that are $100 ea and it looks like they might come with the rings and
Wrist pin ?
Interesting...that would certainly open up the budget more.
Candles are just our way of keeping fire as a pet.
if your looking for a perfect world i would do a full rebuild....
that being said you have a couple frozen pistons. if this is a second car and you have the time you can break them loose and, if the pitting isn't bad, clean and run it. couple quick oil changes, and a compression test. if your lucky it will work, if not your in the same boat.
this is not mechanical advice. this is just what i have done more than once wile playing with beaters. the sound of a ring popping loose will make yourself shat a bit. life is messy.
can you find any eta motors? just use that lower end, if they are available? or even just drop the whole engine in and put your fuel injection and injectors in it. if that's an option, the 2.7 runs great on 325i electronics and you could even swap your I cam in, if its still good
No e30s again.
I'm in Kenai and I have an '88 325iX I might be willing to sell.
Have you considered an ETA engine? It is one of the easiest ways to get the 2.7L, ETA block (crank, piston, rods etc) and use the 2.5L head.
Not sure about prices in the US, but in Germany those ETA engines go for anything between €500 and €1K, depending on who is selling and what is coming with it (some sell the whole engine including intake, hardness, etc).
Personally, even if you find a used 2.5L engine, i would still tear it down, measure, balance, refresh everything (bearings, seals, rings etc) to get the max lifespan and reliability from that engine.
Remember, if you go with a 2.7L you need a chip to match!
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