M42 running VERY loud (video), low oil pressure light is on

[kwill22]

I love florida... Lol

[bmwman91]

Chances are that you just need a new cat. I replace mine every other time I SMOG the car (well, about an hour before the test lol).

[Vivek]

Okay guys I filled another half a gallon of coolant into it. It took that plus a bit of water. I drove the car 200 miles today. I'm trying to clean out the exhaust since I failed smog.

[bmwman91]

Hey Vivek, glad you have it in good working order. Now you can relax and enjoy the car (and probably start thinking about the 100 other projects you had to put on hold!).

[wazzu70]

Like mentioned one of the reasons for running coolant is to prevent corrosion.

I run straight distilled water in mine without issue, but I also change it pretty frequently. Only reason for running straight water is I only drive in summer and drain over winter. The water does not have to go to the transfer station :)

[e304me]

just running water will corrode everything

[kwill22]

I had to bleed mine pretty often but I would recommend getting the coolant and just calling it a day. Unless you like messing around with your cooking system every few days.

And since tire running an electric fan it just depends on the temp for the sensor that'll control your temps.

[Vivek]

I'm not running a fan clutch ;). I should post a pic of my engine bay. I need to heat up the engine enough to cure the wrinkle paint on the intake and VC, and after this long idk if it even will. So with water should I just bleed it every so often?

[kwill22]

Running distilled is probably ok but id think you'd have to flush it much more often than regular coolant. Water cools better but if it boils it can introduce air into the system over time that I've seen. It isn't anything extreme but I've noticed a difference.

I don't remember where my needle held when I ran water for a bit as a sort of experiment. But the highest mine ever gets on a hot day with coolant is halfway and your fan clutch should actually kick in before that point.

[Vivek]

That's pretty much the plan except I'm not totally sure if my thermostat is opening. Is there any easy way to verify that? I'm about to go work on it some more because I just bought a new battery for it. I'd like to just start it up in the garage and let it run bleeding out the air just as you said. I'll report back.

Edit: looks like everything worked. With the bleeder screw off it took about another half a gallon. Is there anything bad about running only a couple cups of actual coolant in my system? The rest is just water. It never gets cold here. The fan works fine (held a lighter under the temp sensor) but hasn't kicked on yet. It runs cool, quite a bit below half, which it didn't before.

[kwill22]

Top hose hot and the hose to the thermostat from the radiator being "cool" to the touch is normal. You probably just need to continue bleeding. I've never had to park on a hill to bleed it but Of course I'm in Florida and there really are no hills.

Fill the resevoir and it'll go down and just keep filling it until it stops going down by itself. Then start the car, put the heater on and watch it until the thermostat opens up. With the bleeder screw open and top off of the resevoir just keep watching and filling until all the air is out and the resevoir is full to the line. Never taken more than 10 maybe 15 minutes. Test drive to verify and after a test drive I usually open the bleeder screw a little to insure all the air is out.

You'll get it. The hard part is done

[Vivek]

How much coolant did you put in? It takes well over a gallon if you start with it 100% dry. There should not be any need to prime anything since the coolant level will be at or above the pump when you fill it.

I typically pour coolant in until it fills to the very top of the expansion tank and then let it drop a little. Now, there is one thing that I have always made sure of, and that is that the little bypass groove in the thermostat housing is clear so that air can get out without turning the engine on / warming up. In MANY cases, that groove is clogged with corrosion and RTV sealant, which is not that big of a deal really. It just means that you have to run it and get things warm enough that the thermostat opens in order to let air out.

I probably have a few cups of coolant and the better part of a gallon of distilled water in there right now (I need to buy more BMW coolant). I think I just filled the reservoir and it drained into the engine, then I filled more. Then after driving for a bit, after I made my last post, it went down to the bottom of the reservoir so I then poured more water in.

I usually fill up through the top hose to fill the engine, then fill through the resevoir. They both work just a different way of doing it.

Is your top hose getting hot? Coolant flowing into the resevoir? If your fans not coming on check your connections and fuses.

Love the car color

Thanks man! The top hose on the driver's side going from the reservoir to the tstat housing gets hot. The other two going to the radiator do not.

park on the steepest hill you can find or jack up the front of the car. Fill res and open bleeder screw. Turn heater on full blast. Let it run. Go back and forth between inside gauge and bleeder screw watching for air. It will eventually clear out.

Are you talking about the screw on the top by the fill cap or the one down on the bottom? I've not had trouble bleeding this engine or radiator before and I've never touched the bottom screw. I'm just not sure if I've filled a completely dry engine before. I've changed my radiator and flushed/bled my coolant many many times for various reasons.

[jntar]

park on the steepest hill you can find or jack up the front of the car. Fill res and open bleeder screw. Turn heater on full blast. Let it run. Go back and forth between inside gauge and bleeder screw watching for air. It will eventually clear out.

[kwill22]

I usually fill up through the top hose to fill the engine, then fill through the resevoir. They both work just a different way of doing it.

Is your top hose getting hot? Coolant flowing into the resevoir? If your fans not coming on check your connections and fuses.

Love the car color

[bmwman91]

How much coolant did you put in? It takes well over a gallon if you start with it 100% dry. There should not be any need to prime anything since the coolant level will be at or above the pump when you fill it.

I typically pour coolant in until it fills to the very top of the expansion tank and then let it drop a little. Now, there is one thing that I have always made sure of, and that is that the little bypass groove in the thermostat housing is clear so that air can get out without turning the engine on / warming up. In MANY cases, that groove is clogged with corrosion and RTV sealant, which is not that big of a deal really. It just means that you have to run it and get things warm enough that the thermostat opens in order to let air out.