Page 2 of 2
Re: 528i in France
Posted: Dec 06, 2022 8:37 AM
by 1st 5er
Got a full tank of gas?
I doubt fuel cleaner would make that kind of impact in the fuel tank.
~ 1/3 tank of gas or less sure would with a failed in-tank pump.
Re: 528i in France
Posted: Dec 28, 2022 10:13 AM
by Engineer666
Sad update…
I’ve had the car at a local vintage/sport car shop for the last couple of weeks. I barely made it there on 4 cylinders.
After replacing spark plug lines, distributor cap, fuel filter, a few vacuum lines and most importantly a busted fuel regulator, the mechanic got it back and running. It now idles much better and revs normally.
Here’s the kicker: the cylinder compressions are really bad. That engine has lived a too long and too hard of a life and is in need of a full rebuilt.
From cylinder n°1 to 6, in bars (psi):
7.5 (108)
6.2 (90)
5 (72)
7 (101)
5 (72)
6.5 (94)
From what I gathered, pressures of a new engine should be around 9.3 to 10b (130 to 140 psi). So we are far from it. The engine chugs and mostly dies when the oil dipstick is removed…
So now, I have a decision to make: get rid of this car and try to cut my losses, have the engine rebuild (at around 6000€) but then I’ll have to restore the whole car… or find a new engine.
So yeah, this sucks but any advice is welcome.
Re: 528i in France
Posted: Dec 28, 2022 10:43 AM
by Aldo525
Engineer666 wrote: Dec 28, 2022 10:13 AM
Sad update…
I’ve had the car at a local vintage/sport car shop for the last couple of weeks. I barely made it there on 4 cylinders.
After replacing spark plug lines, distributor cap, fuel filter, a few vacuum lines and most importantly a busted fuel regulator, the mechanic got it back and running. It now idles much better and revs normally.
Here’s the kicker: the cylinder compressions are really bad. That engine has lived a too long and too hard of a life and is in need of a full rebuilt.
From cylinder n°1 to 6, in bars (psi):
7.5 (108)
6.2 (90)
5 (72)
7 (101)
5 (72)
6.5 (94)
From what I gathered, pressures of a new engine should be around 9.3 to 10b (130 to 140 psi). So we are far from it. The engine chugs and mostly dies when the oil dipstick is removed…
So now, I have a decision to make: get rid of this car and try to cut my losses, have the engine rebuild (at around 6000€) but then I’ll have to restore the whole car… or find a new engine.
So yeah, this sucks but any advice is welcome.
Hi Lionel,
Not good news but I believe you need to run that engine a little bit more time. When the engines are sttoped for a long time the rings sticks to the piston so may be you have to use some "oil flush" like Liqui Moly, run a hundred kilometers and see what happen.
See this video, that guy (M539 restoration) had a similar problem....see minute 0,52 and 24,50.
https://www.youtube.com/watch?v=u0tyVQ1 ... storations
Re: 528i in France
Posted: Dec 28, 2022 10:58 AM
by Galahad
Engineer666 wrote: Dec 28, 2022 10:13 AM
...The engine chugs and mostly dies when the oil dipstick is removed…
So now, I have a decision to make: get rid of this car and try to cut my losses, have the engine rebuild (at around 6000€) but then I’ll have to restore the whole car… or find a new engine.
Dying when you remove the dipstick is a good thing, it means you don't have major vacuum leaks. I agree you should wait a bit and see if the compression improves, my first m20 burned a lot of oil before I drove a thousand miles and then did an oil change.
If the engine does not improve I'd suggest finding another one in good condition, changing them isn't hard. I don't know how common they are in France though.
Re: 528i in France
Posted: Dec 28, 2022 11:33 AM
by Engineer666
Aldo525 wrote: Dec 28, 2022 10:43 AM
Not good news but I believe you need to run that engine a little bit more time. When the engines are sttoped for a long time the rings sticks to the piston so may be you have to use some "oil flush" like Liqui Moly, run a hundred kilometers and see what happen.
See this video, that guy (M539 restoration) had a similar problem....see minute 0,52 and 24,50.
https://www.youtube.com/watch?v=u0tyVQ1 ... storations
Hello, thanks for the input.
I’ve already driven around 600 miles since I got it. Even if a few of the 18 cylinders rings were stuck, they would have budge by now. I doubt it would show such a low pressure evenly on all cylinders. It is a 185000 miles stock engine.
Re: 528i in France
Posted: Dec 28, 2022 2:15 PM
by Aldo525
Engineer666 wrote: Dec 28, 2022 11:33 AM
Aldo525 wrote: Dec 28, 2022 10:43 AM
Not good news but I believe you need to run that engine a little bit more time. When the engines are sttoped for a long time the rings sticks to the piston so may be you have to use some "oil flush" like Liqui Moly, run a hundred kilometers and see what happen.
See this video, that guy (M539 restoration) had a similar problem....see minute 0,52 and 24,50.
https://www.youtube.com/watch?v=u0tyVQ1 ... storations
Hello, thanks for the input.
I’ve already driven around 600 miles since I got it. Even if a few of the 18 cylinders rings were stuck, they would have budge by now. I doubt it would show such a low pressure evenly on all cylinders. It is a 185000 miles stock engine.
And do you perform or your mechanic a valves adjustment???....maybe they are not opening and close properly. 300.000 km is not a lot for those engines. Also check or renew valve stems (if you see some blue smoke on exhaust this could be a reason for low compression) and finally (mechanics knows very well this but....) full throttle when cranking for every cylinder, this way a good amount of air is incoming the chamber to measure properly the compression.
My 525i has maybe more kilometers (odometer fail many years before my purchase) but compression is quite well (and the life of my engine maybe was the worse, no oil changes, no maintenance, no nothing, but the engine remains)