Dumb Question Thread - No Flaming Allowed

[oceansize]

I’m currently eyeing an ‘04 E46 with 9X,XXX miles that looks be in great condition with respect to the interior and exterior. It’s currently for sale with a reputable dealer who providedthe Carfax which shows regular service throughout its life however no mention of any of the “Big 3” repairs. The sales guy would only say that he doesn’t know of any major issues before pulling out the dealer speak that “it’s one of the cleanest specs he’s seen.” As a novice to the E46 platform and used car purchases in general, my question is whether there’s a way to verify if the Big 3 have been done and if the dealer response is a potential red flag. Thanks in advance!

You can put it on a rack to check if subframe reinforcements are present, easy to spot. You might persuade a BMW dealer to get you the service history based on VIN which then might tell you if the rod bearings were ever done. However, that obviously isn't foolproof as an independent could have performed the service. Bottom line, no way to check rod bearings or vanos unless you get lucky with a dealer service report.

[Cronenberged]

I’m currently eyeing an ‘04 E46 with 9X,XXX miles that looks be in great condition with respect to the interior and exterior. It’s currently for sale with a reputable dealer who providedthe Carfax which shows regular service throughout its life however no mention of any of the “Big 3” repairs. The sales guy would only say that he doesn’t know of any major issues before pulling out the dealer speak that “it’s one of the cleanest specs he’s seen.” As a novice to the E46 platform and used car purchases in general, my question is whether there’s a way to verify if the Big 3 have been done and if the dealer response is a potential red flag. Thanks in advance!

I would offer him 5-7.5k less than asking if you feel the big three are that important. IMO, Vanos is the only must as rod bearings should be serviced via blackstone report of wear that indicates it, but you can always just go with @100k. Subframe reinforcement as long as it was street driven and not tracked shouldn’t be an issue.

everyone has various experiences, weigh the pros and cons and what risk you’re willing to accept. Each service with labor and parts is roughly 2.5K + or -

[adr_M3]

I’m currently eyeing an ‘04 E46 with 9X,XXX miles that looks be in great condition with respect to the interior and exterior. It’s currently for sale with a reputable dealer who providedthe Carfax which shows regular service throughout its life however no mention of any of the “Big 3” repairs. The sales guy would only say that he doesn’t know of any major issues before pulling out the dealer speak that “it’s one of the cleanest specs he’s seen.” As a novice to the E46 platform and used car purchases in general, my question is whether there’s a way to verify if the Big 3 have been done and if the dealer response is a potential red flag. Thanks in advance!

[CrisSilberGrau]

Maybe it depends on how deep as you don't want to diminish the lift and/or duration. What's been done before is weld on more material, then grind it down back to original shape.

At most there's maybe a mm missing from c6 lobe. Not sure how to accurately measure and portray this as the material eroded is over the circumference of the lobe where it applies contact to th rocker.

[Tbonem3]

Maybe it depends on how deep as you don't want to diminish the lift and/or duration. What's been done before is weld on more material, then grind it down back to original shape.

[CrisSilberGrau]

I have a set of Schrick 280/272 with damaged lobes on exhaust cyl 3 and 6, 6 being the worst. The eroded lobes in question have minimal material shaved. It does catch the nail on 6. I guess I'm asking if they can be salvaged, is there a service where this can be done if anyone knows? These cams were silly money in Canadian slave dollars to my door and just trying to get something back from them.

[bmwfnatic]

Any ideas on what to use to remove residue from cylinder walls?

"Carbon X Combustion Chamber Cleaner K1+K2" is a product that cleans carbon deposits insanely well.
It's a 2 part formula, one is the cleaner, which is like a thick shaving foam, and the other part is the neutralizer, which makes the foam turn liquid on contact.

The stuff is strong enough to clean without any abresives, I wouldn't put scotchbrite anywhere near my cylinder walls, it is effectively still sandpaper.

Just be cautious you can do more harm than good cleaning the combustion chamber and the top of the pistons if that means a bunch of gunk goes into the ringland area.
Painters tape is your friend...

[bmwfnatic]

If they have that green O-ring, that means they'd need to be replaced, yeah?

Officially yes, but if you put it on recently and not years ago I think they will survive reusing once for sure.

[sbay]

Yeah, it will be abrasive enough to remove heavy carbon buildup, but shouldn't remove any material from the iron block. You just don't want any of the fibers or loose carbon getting between the piston and rings. If you are going to leave the block and cylinders exposed for an extended period of time, it is good to spray them with WD-40 to keep moisture out; otherwise, they can start to form surface rust.

Really good video very informative

[Slideways]

Thank you…just to confirm, we’re talking about this scotchbrite?

Yeah, it will be abrasive enough to remove heavy carbon buildup, but shouldn't remove any material from the iron block. You just don't want any of the fibers or loose carbon getting between the piston and rings. If you are going to leave the block and cylinders exposed for an extended period of time, it is good to spray them with WD-40 to keep moisture out; otherwise, they can start to form surface rust.

[sbay]

WD-40 and scotchbright. Best to put rags in the cylinders to catch any the debris falling into the piston rings.

Thank you…just to confirm, we’re talking about this scotchbrite?

[Slideways]

Any ideas on what to use to remove residue from cylinder walls?

WD-40 and scotchbright. Best to put rags in the cylinders to catch any the debris falling into the piston rings.

[Slideways]

If they have that green O-ring, that means they'd need to be replaced, yeah?

Yes, TIS states to replace the entire plug. I have taken out the o-ring to measure it and it shouldn't be too difficult to find a bag of replacement o-rings.

The older style plugs, which I kept in case I want to revert back, did use a crush washer, but realOEM no longer lists a part number for the crush washer for the E46. You have to go to an older model, like the E31, where they still have it on the diagram funny enough.

[sbay]

Any ideas on what to use to remove residue from cylinder walls?

[IamFODI]

The ones on older cars had a crush washer, the ones you buy now have a green o-ring.

If they have that green O-ring, that means they'd need to be replaced, yeah?