Important for Bill R, Winfred, etc: E46 330i Motor issues

[Jon K]

I know this is the wrong forum but I know that the right people hang out in here. Here are the details.

I have been working with a friend on his 330i. It's got an ASA supercharger/intercooler from Rennsport and such. Car has been running fine. We were to put a 3.15 differential in instead of the stock 2.93 differential and so that is what he worked on today. I wasn't able to get up to NY to help, but he managed to get the differential in all alone. I told him to torque things to spec, drive the car a bit, and come home and check torque specs again. So, he takes the car out. Reports to me that the 3.15 jumped his RPM only about 250rpm and that it's a nice improvement without being silly. We talk for 10 minutes about it and such and everything is running good.

I go out for the evening and come back to check up on the car and he tells me this horrible story. Essentially he was highway driving the car when the oil light came on red (on E46 this indicated oil pressure, but he didn't know). He had an oil pressure light come on before once when a line on the supercharger popped off. So naturally he went and checked those hoses and everything looked ok and he started the car again. The car started awkwardly and he drove it home not feeling right. He says the car had no power at all and he had to keep the gas on somewhat for it to not stall. This sounds like a big vacuum leak to me, but then again I am not sure. Once in the garage he tried turning it over. It cranks but doesn't turn over. Feeling really nervous about this he contacts some people who deal with the supercharger. They told him to check the crankcase ventilation line as they have had issues with this before. He checked the line and noted that it was pinched and when he tugged lightly on the hose he noted that it came off from down on the engine from the supercharger. The assumption here is that the pinch in the hose cause pressure that may have messed some things up here. However, when he said the oil light came on red and the car ran really weird and shakily I instantly think oil pump failure. Question is. To hook the ventilation hose back up, we need to pull the supercharger. If we do that, what is the likelihood that this hose is what is causing the car to not start and run extremely odd? I hate to say it but it sounds like the oil pump failed to me and he drove this car a couple miles in the state it was in, I fear he completely damaged the engine. What's the likelihood this motor isn't completely wrecked? Input please guys. Thanks in advance.

Jon

[632 Regal]

hopefully he shut it down as soon as he saw the light, if the oil pump got weak and was working at all with synthetic oil he may be just fine however if the pump completly failed with NO oil pressure he has problems. same goes if it wasnt synthetic, its a goner. You should be able to tell by the sound of the bearings are toast also by taking the oil filter apart would be a tell tale. If the light still comes on when he starts it thats another bad sign.

[George M]

hate to say it but your friend commited the cardinal sin...he drove the car after the oil light came on without finding the problem...just can't do that...he will never do it again, trust me. If the light comes on and you can't find the problem, you don't fire the motor back up until you do...its that simple. What he did the first time was OK...he found a hose had popped off the supercharger which is an aftermarket feature. You just can't drive a car home with the oil light on without addressing the problem and expect a favorable outcome...not gonna happen.
George

[Jon K]

hate to say it but your friend commited the cardinal sin...he drove the car after the oil light came on without finding the problem...just can't do that...he will never do it again, trust me. If the light comes on and you can't find the problem, you don't fire the motor back up until you do...its that simple. What he did the first time was OK...he found a hose had popped off the supercharger which is an aftermarket feature. You just can't drive a car home with the oil light on without addressing the problem and expect a favorable outcome...not gonna happen.
George

I know this, unfortunately he didn't. Worst case, the M54 comes out, the blower goes up for sale and an S52 w/ Turbo goes in. Hope it doesn't come to that though.

[George M]

The only other thing it could be best case scenario is if the pinched line radically changed internal crankcase pressure starving the oil pressure switch yet still maintaining adequate oil supply to the motor. This would be absolute best case and unlikely however. Other thing is the internals of the motor could end up being disparaged without completely trashing the motor...basically just took a lot of miles and life out of a previously fresh engine. Depends on the level of starvation and duration. Next step is to try and identify why the motor lost oil pressure. Since it has an aftermarket supercharger on it where oil supply runs external to the blower, I would start there with what went wrong. Can pull the valve cover to have a look at the cams to see extent of starvation up top. Top end oil starvation is normally a good telltale as oil passes up through the bottom end and is where the oil sending unit is.
George

[winfred]

i've never disected a m54 so i am not sure about how it's put together, generally the first things to suffer from oil starvation are the rod/main bearings, the valve train can take a lot of abuse and not really show it, i know on a m20 the #1 rod bearing is the first to go, easy to check with the pan off and if it did start to wear through the bearing materal as long as the crank is still smooth a new bearing will usually solve it. i am wondering why it lost oil pressure, oil pumps don't generally just die, unless the supercharger kit is poorly designed and sucking off too much volume and the oil pump just can't keep up

[Jon K]

i've never disected a m54 so i am not sure about how it's put together, generally the first things to suffer from oil starvation are the rod/main bearings, the valve train can take a lot of abuse and not really show it, i know on a m20 the #1 rod bearing is the first to go, easy to check with the pan off and if it did start to wear through the bearing materal as long as the crank is still smooth a new bearing will usually solve it. i am wondering why it lost oil pressure, oil pumps don't generally just die, unless the supercharger kit is poorly designed and sucking off too much volume and the oil pump just can't keep up

Well it took me a few hours to get him probing around... found a small single link chain dangling from under the car. He kept trying to describe what sounded like a chain from the valve cover area (vanos are on M50tu) but at first I could only think of the time chain, but this chain is like 10" circumference if linked. Turns out I think this may be the VANOS chain. I had him trace up the block to the crank case cover and needless to say... well.. there is a gaping hole. This would be the reason for oil pressure light no doubt. As to how this happened... that is another question...

[Jon K]

Well it took me a few hours to get him probing around... found a small single link chain dangling from under the car. He kept trying to describe what sounded like a chain from the valve cover area (vanos are on M50tu) but at first I could only think of the time chain, but this chain is like 10" circumference if linked. Turns out I think this may be the VANOS chain. I had him trace up the block to the crank case cover and needless to say... well.. there is a gaping hole. This would be the reason for oil pressure light no doubt. As to how this happened... that is another question...

Also, remember that the crank case ventilation tube was pinched... this is confusing. I don't think the ventilation tube would have anything to do with the car throwing the chain through the cover... but maybe it could. Help guys.

[winfred]

i have no idea what would throw a chain on that motor, like i've said i've not been inside of one yet. i've got a s52 with around 60k miles on it, it was in a m coupe that got hit hard enough to break the intake and pop a hole on the oil pan, i have parts to complete it but desided to wait to see what car gets it before buttoning it up, ie m50 intake/m52 intake or front sump/rear sump oil pan, i think the boss wants around $3200

[Jon K]

i have no idea what would throw a chain on that motor, like i've said i've not been inside of one yet. i've got a s52 with around 60k miles on it, it was in a m coupe that got hit hard enough to break the intake and pop a hole on the oil pan, i have parts to complete it but desided to wait to see what car gets it before buttoning it up, ie m50 intake/m52 intake or front sump/rear sump oil pan, i think the boss wants around $3200

Winfred, I will be contacting you about that motor shortly. Do you have the DME / harness and accessories?


Would a pinched crank case ventilation tube cause this damage??