Neglected 183k Mile BMW N51 (pic)

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Jul 23, 2005
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Bought this from a salvage company and the history indicates that it was donated to charity; I can only assume due to the variety of issues that I've mostly addressed. Any suggestions regarding cleaning this up? BG EPR? Auto-RX? Thanks in advance.
20220806_022711.jpg
 
I would try a couple of short runs (1000 miles) with Mobil 1 0W-40 or 5W-40. Then maybe use the HPL 30 engine cleaner over a longer oci of M1 0W-40, maybe 2000 miles. For all of these, keep an eye on the filter, or just replace frequently since easy to access.

I would stay away from the BG stuff.

How is it running now?
 
I would try a couple of short runs (1000 miles) with Mobil 1 0W-40 or 5W-40. Then maybe use the HPL 30 engine cleaner over a longer oci of M1 0W-40, maybe 2000 miles. For all of these, keep an eye on the filter, or just replace frequently since easy to access.

I would stay away from the BG stuff.

How is it running now?
I'll definitely keep an eye on the filter. I'm worried about making it worse since it's so crudded up in there. Rubs off easily on a shop towel, so it's likely to become a mess in any solvent pretty quickly. Sticker indicates that they'd been using Kendall oil, probably 15k intervals.

It runs well so far. A little roughness to the idle now and then, but no relevant codes. It still had the original, completely blown shocks and struts! Bobbed and weaved like a hoopty on the interstate. The water pump had failed and I assume that that was the last straw. Somehow it was still on the original one. Also needed a new fan, oil filter housing gasket, crank balancer, and to have a radiator leak fixed.
 
That's a great candidate to test engine cleaners on. It's easy to take before and after pictures, and in between shots for product testing.

If you decide to journal it with pictures take a few more shots from different angles, and post pictures in intervals from those same angles of lets say 1,000 miles. Subscribed.
 
Bought this from a salvage company and the history indicates that it was donated to charity; I can only assume due to the variety of issues that I've mostly addressed. Any suggestions regarding cleaning this up? BG EPR? Auto-RX? Thanks in advance.
It doesn't look that bad. Just some varnish.

I would run M1 0w40 on a 5k mile oci and take it from there.

Nothing is going to clean that up in one treatment. You're going to have to put some miles on the car.
 
I'll definitely keep an eye on the filter. I'm worried about making it worse since it's so crudded up in there. Rubs off easily on a shop towel, so it's likely to become a mess in any solvent pretty quickly. Sticker indicates that they'd been using Kendall oil, probably 15k intervals.

It runs well so far. A little roughness to the idle now and then, but no relevant codes. It still had the original, completely blown shocks and struts! Bobbed and weaved like a hoopty on the interstate. The water pump had failed and I assume that that was the last straw. Somehow it was still on the original one. Also needed a new fan, oil filter housing gasket, crank balancer, and to have a radiator leak fixed.
Pretty much the usual deferred maintenance stuff. Being able to fix these things yourself makes this vehicle practical again.

The BMW oil monitor on my '00 528i recommended oil changes at about 24,000 Km (15,000 miles) so the 15,000 oil change interval isn't a surprise. The shop foreman at my dealership said, "change the oil at half that interval without resetting the oil monitor" and that's exactly what I did. What you see here is probably what would have happened otherwise. Using that approach, the OEM filters lasted the full 24,000 km and came out clean and in good condition.
 
Flood car?
Could be, but the cost of the deferred maintenance builds up and at some point would cost more than the vehicle is worth. For example, that oil filter housing gasket itself is maybe $10 but would cost a few hundred dollars to replace. It seems these gaskets all fail eventually with the engine block in that area always oily. Not what you'd like to see but easy enough to defer.
 
I agree with those who suggested M1 0W-40 w/ @High Performance Lubricants engine cleaner.

That said, Dave has indicated that their oils have more cleaning power (more esters) than the engine cleaner, so, if it's in the budget, I might be inclined to try one of their Euro oils.
 
Bought this from a salvage company and the history indicates that it was donated to charity; I can only assume due to the variety of issues that I've mostly addressed. Any suggestions regarding cleaning this up? BG EPR? Auto-RX? Thanks in advance.View attachment 118553
HPL cleaner has worked for some posters and cleans alot of Junk . Run short filter change intervals to get the Junk filtered out.
 
How many miles does it have? At what million did the waterpump break?
I love some e90 content, I’d love to hear more either here or in a pm, assuming time permits 😀
 
It doesn't look that bad. Just some varnish.

I would run M1 0w40 on a 5k mile oci and take it from there.

Nothing is going to clean that up in one treatment. You're going to have to put some miles on the car.
This.

I'm willing to bet this car was short tripped using the BMW oil life monitor, so longer change intervals and never brought up to temp. I'd run a good Euro oil (Mobil 1 0w40, Castrol 0w40, Valvoline 5w40, etc) and shorten the oil change interval while also taking it for nice long drives. It should clean up nicely. I really wouldn't introduce any aggressive "cleaners" into the engine. A friend's 2006 325xi has close to 200k miles and looked similar when he bought it from another owner in our circle of friends who neglected the maintenance on it. After about 25k miles in his care it has cleaned up nicely with just good oil and 5k intervals. He also drives it 50 miles a day.

There are filter screens in the cylinder head for the Vanos solenoids that you can pop out and clean, I would do that as well, they might have some build up.
 
The Gentlemen who say it isn't that bad and to use the HPL with a good syn Euro oil are spot on.
I'm one of the ones who ran the HPL Cleaner in a BMW (N52 = sibling of the N51) that didn't have quite that much carbony stuff, but did have as much red varnish. The black buildup cleaned up in 2k , miles. The red stain only hurts an anal retent's eyes. Some in the BMW and MB worlds call it "Castrol Red".
If I were to do it again, I'd go straight to the HPL Euro oil for a full 5k miles and change the filter more often.
The major contributors to this gunk is long OCIs, bad/leaking PVC, and possibly incorrect oils.
Replace the PCV and hoses. Even if they aren't bad today, they will be.
Don't bother with just doing short OCI's (which won't clean up that goo). Go straight to HPL and get it done/over one OCI.
 
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