Non-BMW Stuff on a BMW Forum
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Anyone know what this plug is for behind the glove box by the ECU? Putting the interior back together and I don't see where this one should plug in.
Getting really close to starting this. Transmission is filled with fresh MTL, clutch is bled, engine has oil. The setback came when I filled it up with coolant and the thermostat cover was seeping. The part that sucked was the radiator was so full of crud on the bottom the drain valve didn't even work so I had to drain it by just removing the thermostat cover. Then I pulled the radiator and flushed it. Tons of gross stuff in there. That's back in. Tonight or tomorrow I'll fill it back up and then try starting it. The battery is charging now.
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I believe that is an extra maybe for autos? The car will run without it
Works for me! Thank you
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Okay, so it started up. Took some troubleshooting because I reversed the feed and return fuel lines. It sounded kinda gross at first but once it built oil pressure it sounded really good.
Two things I am noticing right now.
1. When I blip the throttle it kind of stumbles when the RPMs come back down.
2. The temp gauge was creeping past the middle mark on the gauge after about 10 mins of idling on jack stands. It does not have an electric fan, but hasn't had one in who knows how long and it was fine. My thought is maybe the coolant system needs to be bled since it was COMPLETELY drained.
Edit: Going to try adjusting the throttle body some to address the stumble.
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Okay, so it started up. Took some troubleshooting because I reversed the feed and return fuel lines. It sounded kinda gross at first but once it built oil pressure it sounded really good.
Two things I am noticing right now.
1. When I blip the throttle it kind of stumbles when the RPMs come back down.
2. The temp gauge was creeping past the middle mark on the gauge after about 10 mins of idling on jack stands. It does not have an electric fan, but hasn't had one in who knows how long and it was fine. My thought is maybe the coolant system needs to be bled since it was COMPLETELY drained.
Edit: Going to try adjusting the throttle body some to address the stumble.
I’ve had issues with the same stumbling, although it was accompanied by a somewhat poor idle. Check for vacuum leaks and make sure the throttle position sensor is adjusted correctly and work from there. What do you mean by adjusting the throttle body? I wouldn’t touch the adjustment screw, just make sure the cable isn’t sitting too tight so that it holds the throttle open slightly. That’ll screw with the TPS reading.
For cooling, I would definitely bleed it and then see what happens. If it was totally empty, there’s probably a good bit of air in there still.
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Got the coolant system bled tonight. Some hot heat in the car. Also replaced the ebrake handle and new floor mats.
One question I do have: each cold start up the engine was relatively loud, after a couple minutes it quieted down and sounded great. So I guess I'm wondering what you guys run for oil when its cooler out like this? I have Castrol 20w50 in it now per some other forums. But I did read that when it gets to these temps a 10 or 15w40 is recommended. I think I'm going to change the oil to a slightly thinner one and see if that helps.
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Way too thick, the incorrect general internet advice is to run mega thick oil. However the thicker the oil it may show high oil pressures on a gauge which people think is good but the oil pressure is not what keeps metal contact from happening. Think about it this way, there is roughly one square inch of bearing area that a connecting rod journal forces down on. If 60PSI is your maximum oil pressure, that is roughly what the pressure relief valve vents at, then it would only resist 60 pounds of force when combustion happens. If you only have 60 pounds of force you aren't going anywhere. Just from compression pressure say 150PSI x the area of the piston (3.5/2)2 x 3.14 = 9.6 square inches. You end up with a force down of 9.6*150= 1440 pounds, and that is before combustion starts.
The bearings in an engine work on the principle of hydrodynamic lubrication. Which requires oil FLOW not PRESSURE. https://en.wikipedia.org/wiki/Fluid_bearing
TLDR: The ideal oil weight is thick enough to maintain oil pressure above minimum spec when the engine is idling and fully hot. Usually a quality 5w30 is not a problem unless the engine is very worn. I use 5w30 in my M50 that has almost 300k miles and I don't ever have a flicker on the oil pressure gauge. Thick fluid is hard to pump and will not circulate as well causing a lack of lubrication, even worse when the weather is getting cool.
My recommendation is 5w30, use a 10w40 if you are paranoid and don't trust modern synthetic oil. But never 20w50 no matter how much the internets say to, the noise you hear is a lack of lubrication.
And FYI oil pressure spec at idle is only around 7 PSI.
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TLDR: The ideal oil weight is thick enough to maintain oil pressure above minimum spec when the engine is idling and fully hot. Usually a quality 5w30 is not a problem unless the engine is very worn. I use 5w30 in my M50 that has almost 300k miles and I don't ever have a flicker on the oil pressure gauge. Thick fluid is hard to pump and will not circulate as well causing a lack of lubrication, even worse when the weather is getting cool.
My recommendation is 5w30, use a 10w40 if you are paranoid and don't trust modern synthetic oil. But never 20w50 no matter how much the internets say to, the noise you hear is a lack of lubrication.
And FYI oil pressure spec at idle is only around 7 PSI.
Thanks for the input. Then I am going to pick up some 10w40 Castrol GTX to put in there.
I also read a lot about people using additives as well. Any need to use something if I'm running 10w40 GTX?
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Think about it this way, there is roughly one square inch of bearing area that a connecting rod journal forces down on. If 60PSI is your maximum oil pressure, that is roughly what the pressure relief valve vents at, then it would only resist 60 pounds of force when combustion happens. If you only have 60 pounds of force you aren't going anywhere. Just from compression pressure say 150PSI x the area of the piston (3.5/2)2 x 3.14 = 9.6 square inches. You end up with a force down of 9.6*150= 1440 pounds, and that is before combustion starts.
Not here to argue anything, but to simply point out that this logic isn't exactly sound.
This would be the case if you were to have the whole surface of the bearing being an oil passage, but it is instead adding oil into the bearing area to provide a fluid film.It's not uncommon to see 6-8psi oil pressure at idle, and if you were to be worried about the direct force acting on it you would never see oil going into the bearing.
But I agree, 20w50 is far too thick for that motor, only M30's seem to need that kind of honey in the summer.
You could add some zinc additive to the oil if desired, I know @snap should have some suggestions in that department.
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All oils are categorized by API standards, and that's the easiest way to determine what oil is "best" or equivalent to OE standards.
At this point in time I would be willing to bet that all oils that you can buy off the shelf are better or equivalent to what was available at the time when these motors were designed. -
All oils are categorized by API standards, and that's the easiest way to determine what oil is "best" or equivalent to OE standards.
At this point in time I would be willing to bet that all oils that you can buy off the shelf are better or equivalent to what was available at the time when these motors were designed.You're probably right. Which is why part of me says I'm entirely overthinking this and go to Walmart and just get some gtx 10w40 and you'll be fine.
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People that post on www.bobistheoilguy.com are insane and will fight to the death about how Castrol doesnt have enough ZDDP for their 1998 Duratec V6, meanwhile an Amsoil dealer lies in wait to go in for a sale.
Stick to the owners manual unless extreme circumstances dictate otherwise (racing/heavy modifications).
This was the only photo I could find from the E30 owners manual and its hard to read, but 20w-50 is good for all but our coldest months and 15w-40 is good for all but maybe an extremely hot summer day sitting in stop and go traffic. Pick a good 40/50 weight oil. Just dont get down into the 30 weight oils
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People that post on www.bobistheoilguy.com are insane and will fight to the death about how Castrol doesnt have enough ZDDP for their 1998 Duratec V6, meanwhile an Amsoil dealer lies in wait to go in for a sale.
Stick to the owners manual unless extreme circumstances dictate otherwise (racing/heavy modifications).
This was the only photo I could find from the E30 owners manual and its hard to read, but 20w-50 is good for all but our coldest months and 15w-40 is good for all but maybe an extremely hot summer day sitting in stop and go traffic. Pick a good 40/50 weight oil. Just dont get down into the 30 weight oils
And if it wasn't for it being pretty noisy at startup, it seems the 20w50 would be fine; but the engine was pretty rattly as it warmed up for a few minutes then it was great. I'll pick up some 10w40 and see how that works.
Thanks for your help!
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Snap is right about the bob site, massive amount of detail and oil loyalties as religion battles. Fun reading if you have the time. If you go to R3v you'll also see e30 oil debates, and Ranger on the spece30 site has spent more time than is healthy on oil issues, zinc contents, and more on his way down the rabbit hole.
You can do a Blackstone oil analysis to get a baseline on your engine, and follow up to see the wear effects of your oil choices.
When I was street driving the 325i it was dino 20w-50 summer, and fall to spring 10w-40. Racing it now with 190k on the m20 engine using 20w-50, changed every few events. All good per Blackstone.
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Back on the ground! Hopefully for a while this time. One of the tie rod securing nuts was frozen, so it got new tie rods. Oil is drained out and new stuff goes in tomorrow. Fixed the hood ground strap. Getting the lights finished. Pretty excited.
Now my standard question. How would I go about aligning this bumper?
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So I started it up tonight after putting in the new oil; Liqui Moly 10w40 with the friction additive. Anyway, noise was still there when I started it up. See the video:
After a few minutes it was gone and sounds like this:
I did a valve adjustment when I put it back together. Thoughts??? Opinions?
Going to start it in the morning to see if it sounds any better.
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Not here to argue anything, but to simply point out that this logic isn't exactly sound.
This would be the case if you were to have the whole surface of the bearing being an oil passage, but it is instead adding oil into the bearing area to provide a fluid film.It's not uncommon to see 6-8psi oil pressure at idle, and if you were to be worried about the direct force acting on it you would never see oil going into the bearing.
But I agree, 20w50 is far too thick for that motor, only M30's seem to need that kind of honey in the summer.
You could add some zinc additive to the oil if desired, I know @snap should have some suggestions in that department.
I was illustrating that the logic of oil pressure being what prevents metal contact is ridiculous. Maybe that wasn't clear.
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