another nikasil question

[adamsbomb]

I just came back from looking at a 94 540. The guy drove an hour to meet me halfway. When he got there, the car was idleing smoothly, temp guage in the middle no prob. (it was about 85 or so today). After 10 minutes of talking, I got in and it fired right up, took it on the highway, ran her up to 80 or so. No smoke at startup or on highway, tranny went right into gear, shifted smooth, no probs. We drove about 20 minutes with the air on, when I got back to my truck I noticed the car was running kind of rough at idle.
Question is, with the nikasil problem, will the rough idle come and go. This car did have the engine replaced (with another nik in 95 or 96). It had a pre inspection on it and it does say it needs motor mounts due to a power steering leak (fluid eats at rubber).
Other issues, clearcoat on bumpers not to good, slight vibration at around 70 (guibo, on list) Little bit of vibration when coming to a stop, shop says bushings and links (had lemforger and 750 bushings done a little over a year ago, along with springs and struts) It also needs the powersteering hoses replaced, powersteering felt good, no noise, just leaks. Car has about 160k on it now, interior is perfect, everything works, no dents or dings. I can get it for right around 4k-4.4k Sound alright or pass cause of miles and engine?
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[Tiger]

Wow... nice to know my car depreciated another $4000 this year... Dang BMW!

[DueyT]

Hmmmm....if the mounts are gone, that may be causing some engine rock, but in my experience, around 2k rpm is about where the M60 will vibrate most if the mounts are going/shot. Rough running is more than likely a vacuum leak issue, especially if the engine was smooth before and rough after...likely you'd have to replace the rear PVC plate and gasket and might as well do the intake manifold gaskets too. The 70mph...is it a shake or just a mild vibe...does it change with power application/coast or is there a change with braking effort? Changes under power ususally indicate a centre bearing...are you sure you have a guibo? I though 540iA's had a hard coupler flange on the front shaft, and 540iMs had the Guibo - my ETK shows a guibo for my car but the flange for auto 540's. If you have more vibration under braking load around the 50-70 mph range, it may still be the thrust arms. I think mine are going...I looked under the beastie and I can see twisted cracks in the rubber of the bushing...I think the BMW shop that replaced them for the prev owner (3 months before I bought the car) didn't torque the bushing while full weight was on the front suspension...that'll kill a thrust arm pretty quickly -- at locks the bushing with a pretty wicked preload as what sould be a neutral/equilibrium position. Overall, I think you have a good deal there, but expect to spend at least $1200-$1500 in parts for all the bushings, mounts, gaskets, etc... to bring the car up to snuff.

Cheers.
Duey

[Bill R.]

i posted all the pics of would start out dead cold rough and after about 5 minutes of running it would smooth out , then when completely warmed up it would start running rough again, and this is after changine the pcv plate, all the intake manifold gaskets, replacing the oring where the throttle body mounts to the manifold, checking the fuel pressure regulator and replacing the vacum hose to it, replacing the vacum caps on the pcv plate, and checking and replacing all the other vacum lines going to the intake manifold. There's only the vacum line on the regulator, the brake booster and one other on the throttle body, its not like theres a large number of vacum lines to leak... After doing all this, cleaning the throttle body, checking the plugs, he previously had replaced one coil and the dme based on another mechanics recommendation before they had the leakdown done on it. It still has a rough idle a good portion of the time when running, it smoothes out off idle just like you'd expect but he only expects it to get worse now.. You have to take into consideration that these are aluminum cylinder walls with a very very thin coating of nikasil, and as the bore is heating up and cooling down it may not be concetric so the damage may have an exxagerated effect under these conditions. If you're serious about it for a long term keeper, i'd add 3 grand to the imaginary number of 4.4 k for a new shortblock and since its got 160k on the rest of the car i'd figure in the cost of a rebuilt trans soon, and all the other wear items associated with 160k that may or may not have been done yet.. This way i would arrive at a realistic projection for what the car is probably going to cost over a couple of years.

I just came back from looking at a 94 540. The guy drove an hour to meet me halfway. When he got there, the car was idleing smoothly, temp guage in the middle no prob. (it was about 85 or so today). After 10 minutes of talking, I got in and it fired right up, took it on the highway, ran her up to 80 or so. No smoke at startup or on highway, tranny went right into gear, shifted smooth, no probs. We drove about 20 minutes with the air on, when I got back to my truck I noticed the car was running kind of rough at idle.
Question is, with the nikasil problem, will the rough idle come and go. This car did have the engine replaced (with another nik in 95 or 96). It had a pre inspection on it and it does say it needs motor mounts due to a power steering leak (fluid eats at rubber).
Other issues, clearcoat on bumpers not to good, slight vibration at around 70 (guibo, on list) Little bit of vibration when coming to a stop, shop says bushings and links (had lemforger and 750 bushings done a little over a year ago, along with springs and struts) It also needs the powersteering hoses replaced, powersteering felt good, no noise, just leaks. Car has about 160k on it now, interior is perfect, everything works, no dents or dings. I can get it for right around 4k-4.4k Sound alright or pass cause of miles and engine?
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[pbrown]

Heres what happened to me. in december 2003 My 1994 530it ran perfect. No indication of a problem rocking or smoking. One very cold day it would not start, thats when I found out about the nikisil issue. After much debate and troubleshooting we determined if we moved the car a few feet without fully warming up the engine then shut it off thats when the problem would occur. Theory is the the rings don't get a good seal and that the tolerances due to the wear on the nikisil cylinders is bad enough the compression is reduced. And it seems totally logical since every time we had to get it running again we would do it by spraying WD40 or a few drops of oil into each cylinder to regain compression. And it would start. I replaced that engine last april 2004. We haven't had a problem since. I you are considering buying a car with the nikisil engine Do a leak down test at a BMW dealer. But all in all expect the that engine will fail at some point So don't pay what their asking price My replacement engine was $3000k Unknown milage and I did the install myself. I took a about 4 days total
Dealer want 8000k to 10,000k to do it

[adamsbomb]

Yeah, the funny part was, he just drove it at least an hour in the heat to get there, when he arrived it was smooth as could be. Started right up, no smoke, ran great, lots of power, was just rough when I got back and let it idle. The temp guage always stayed right in the middle.

[632 Regal]

do a leak down test if your in question, now's the time not after you get it and dont want to know like me

[Beemrplt]

I have a 94 540 w/ 78k on the clock, nikasil and runs fine but sometimes a little warmer than I would like... BMW increased the engine temp. to increase fuel burn and combat the high sulpher fuel problem....yada, yada,yada.. AND buffered the temp. gauge to the mid point so it would not flucuate as the termo. opened and closed....totaly usless now. So don't rely on the temp. gauge as a true reading of temp. after running hard and coming to a stand still. Mine is a little rough after doing so, but settles down when the temp. does. BTW the cams on the 4.0 V8 are a little lumpy

[wengenstein]

Hmmmm....if the mounts are gone, that may be causing some engine rock, but in my experience, around 2k rpm is about where the M60 will vibrate most if the mounts are going/shot. Rough running is more than likely a vacuum leak issue, especially if the engine was smooth before and rough after...likely you'd have to replace the rear PVC plate and gasket and might as well do the intake manifold gaskets too.

werd.

If you're worried get the test.. I think $4k is a pretty good price though.

Also (not to hijack the thread or anything) how common do you guys think the "power steering leak leading to a damaged engine mount" problem is? I think my left engine mount is going/gone, but I just had them both replaced a year ago. Now that I think about it though, for the past year I've also had a small ps fluid leak.

Dennis

[avitt2]

werd.

... how common do you guys think the "power steering leak leading to a damaged engine mount" problem is?

Dennis

...I think it's really common. In fact I just had that problem repaired myself, which brings to mind another peice of advice: Make sure that it's just the power steering hoses that are leaking, and not the box as well. While I think it's fairly uncommon, my box had a pretty good leak, and had to be replaced along with the hoses (and engine mount).