Hello All,
Need some help or ideas on my newest enigma. First off, I have a 99 D1 SD, Automatic, gasoline, NA model, 177K miles. I think that covers it.

I had been experiencing a bunch of overheating issues so I put in new: intake manifold gasket, valve cover gaskets, all relevant sensors, ALL new hoses, new radiator, new water pump, thermostat, new gaskets, heater hoses, heater pipes, yes even the obscure ones, coolant bottle, cap, power steering pump and both hoses, oil pan gasket, new pickup, geez I think that's it. I'm kinda the guy that hates doing crap twice, so hey while I was in the area...

I was still freaking having over heating issues but I've apparently solved that. Seemed to be some air trapped in the system that I was able to purge after some time. A long time. Needle still fluctuates between normal and maybe 70% hot if you consider normal at 50%, but I don't even trust the dash gauge. Bottom line is it isn't seriously overheating.
I'll live with that for now.

But here's the enigma. At about 40-42 MPH I start hearing this sound I could best describe as if whoosing air and slight metal grinding had a baby.
It's not an OMG serious grinding sound but concerning, obviously. It seems to peak at about 45 MPH but continues as speed increases but less in loudness.

I've checked tranny fluid, it's old but not all burnt up and at proper volume. And never had a tyranny issue before this. Shifts at proper points, no lag, no slips. I get same sound in Drive or 3rd gear. I'm not leaking ANY fluids. Oil looks like oil, coolant looks like coolant. Doesn't seem to be engine internal.

I did replace the exhaust with a magnaflow cat back system at the same time of other repairs but that's seemingly fine, only given me that mild hum I expected. Not getting any engine codes but an occasional o2 sensor but that's a sometimes issue with the magnaflow. All the o2 sensors are newish.

Sorry for the long read but I'm trying to be thorough on the background. I've contemplated everything from sticking Parking brake cable, to internal tranny issue, to differential issues. I can move the differential through all its highs and lows, neutral, on and off....I'm just perplexed as to WTF this noise is, what's going on? Any ideas???

 

Check your idler pulley and the tensioner pulley. Remove the belt and see if they wobble. The other possibility on noise is the fan clutch, with engine warm and off you shouldn't be able to rotate the fan more than a half turn. If it spins freely it's time to give birth to a new one.

 

also, pick up an Ultra Gauge or other aftermarket gauge reader so you can get an accurate reading on engine coolant temps. there are plenty of OBD2 apps that are free and you will only need to purchase a dongle to plug into the OBD2 plug. you can use these to read engine coolant temps as well.

 

All good ideas. I originally bypassed them as my tensioner and most pulleys are also new. I checked them anyways and they're all firm. I also tested the clutch even though it was brand new and it turned with minimal effort. Not freely but easily. Sooooooooo I put the old one back in. It to will spin but with alot of force. Should it literally go half a turn and not move at all?

I swear I will NEVER try to skimp out again. Buying anything off Amazon is foolish and eBay is just scam city now. All the parts seemingly ended up having issues I've gotten from there. Never a problem with atlantic british. Never.

I decided to check to make sure the diff wasn't engaged and front tires spin freely, minus what appears to be a bit of disc drag. That's another issue.

I did discover one thing. On a test drive today my parking BRAKE light was on and stayed on. When I pulled the handle back to then push down and make sure it was off there was zero tension. So that cables taken a ****. Now it worked yesterday fine and had no light on. Is it possible that it's stuck on wherever it locks? Gotta check RAVE but I know on alot of American cars the cable goes to the back brakes. Especially with rear drums. For some weird reason I was concerned about the parking brake from the beginning but considered it unlikely. Maybe not. Not one too believe in coincidences.

 

​​​​​​​On my to get list now. Thanks!

 

Leave the original clutch on, see if your temp evens out instead of up and down. Should never go over half ever. Parking brake is mounted to the output on TC, drum brake, uh can't miss it.

 

if the switch is always on it can be that your low on brake fluid but if the light fluctuates with your parking brake then it is most likely the switch mounted behind the parking brake handle assembly. There is a little switch mounted to the bracket of the parking brake that may be out of alinement. I had to apply pressure downward to my parking brake lever so the light would turn off. If this is the issue you are having you can remove the wooden trim panel that houses your power window switches in the center console next to the parking brake then remove the four screws that are visible only by removing that trim panel, and once that is done you should be able to see the parking brake switch behind the parking brake lever. I had to adjust my parking brake lever switch just by applying pressure in the correct direction and then test the parking brake.

 

2 bits to add - in case. My daily D1 has a temp gauge that goes to the top - all the way on nice nights hot or cold. All I have to do is turn the lights off or the fan down or off and the temp gauge drops immediately. Seems the be triggered at a certain temp around 210-212 and it goes right to the top

I rely on the ultra gauge to see where the real temp is. Fun to have a rider see it and watch their reaction. -- "uh, is this a problem?"

One day I plan to trace the ground deficiency causing this.

 

Rick, if you are seeing 210-212 on a regular basis you are playing with fire.

 

Thanks Walt, I thought over 212 we started worrying about modern v8's. not so with these?