1. When you guys run the a/c, do you notice the fan also revving up with the engine when you take off sometimes, and it slowly goes away? My tahoe did this and it was annoying as heck. The engine appears very loud at first when you take off, but it's really the a/c or blower fan revving up with the engine. Is this normal, why does it do that??

2. What air pressure are you guys running in your 2500's?

 

1. Mine roars like an 18 wheeler when the A/C is on during takeoff. I'm pretty sure this is normal.

2. As for tires, I keep 60psi up front and between 60-70psi in the back depending on what loads i'm carrying. I have the BF Goodrich Rugged Trail tires.

 

Thanks Ramdan. I am wondering if this is normal with the a/c. Sure sounds better when it goes away after a few revs.

Thats a lotta pressure! It already rides like crap and my tires have 50psi all around from the dealer. Arghh. I have the same BFG's as you do.

 

Yeah, the ride is kind of harsh. That's why I want to change the shocks to Bilsteins once they are available. What's interesting is if you put a few hundred pounds in the back, the ride is instantly smoother and less jarring. As for the air pressure, my door sticker says to put 60PSI up front and 70 in the back. But there is also a tire pressure guide that has some recommendations based on how much you are carrying. When I had 50 PSI up front the tires looked a little low, but 60 seems perfect. I guess it's just a matter of personal preference. I have about 9000 miles on my rig and the tires are wearing very even so far.

 

I think that air pressure guide inside the door is for max load, but I could be wrong. I somehow thought it spec'ed more psi in the front than the back, opposite to what you said ramdan, but again, i'll have to go look.

I agree about the ride being better with weight in the back. I had my ATV (about 700lbs) in the bed a few days ago and wow what a difference!

Just finished this minute with my baby's first oil change. The mexican gorilla was back on duty, as my oil filter was on tighter than a (enter cliche). As I suspected, it's not possible to get every bit of oil out. This would go along well with my theory that the smell is due to overfilling the oil. I think most people just dump a full 3 gals in, which is capacity, not realizing that every drop of the original 3 gals doesn't come out....just a theory. Either way, when filling the last gallon in, I left a bit in the jug, started it and ran around the block, let it settle, then added till the level was right in the center of the 'safe' area on the dipstick. I read in the manual that you should NOT fill at all past the safe area. I guess when I go for a ride a bit later I'll see if the smell is still there. Gotta love these first few dino oil changes, they are so cheap...bracing myself for the 15k switch to delvac 1!

 

[quote author=Lightman link=board=17;threadid=21471;start=0#msg201336 date=1067112611]
I think that air pressure guide inside the door is for max load, but I could be wrong. I somehow thought it spec'ed more psi in the front than the back, opposite to what you said ramdan, but again, i'll have to go look.

I agree about the ride being better with weight in the back. I had my ATV (about 700lbs) in the bed a few days ago and wow what a difference!

Just finished this minute with my baby's first oil change. The mexican gorilla was back on duty, as my oil filter was on tighter than a (enter cliche). As I suspected, it's not possible to get every bit of oil out. This would go along well with my theory that the smell is due to overfilling the oil. I think most people just dump a full 3 gals in, which is capacity, not realizing that every drop of the original 3 gals doesn't come out....just a theory. Either way, when filling the last gallon in, I left a bit in the jug, started it and ran around the block, let it settle, then added till the level was right in the center of the 'safe' area on the dipstick. I read in the manual that you should NOT fill at all past the safe area. I guess when I go for a ride a bit later I'll see if the smell is still there. Gotta love these first few dino oil changes, they are so cheap...bracing myself for the 15k switch to delvac 1!
[/quote]

Yeah, the pressures quoted are for max load. I guess it doesn't help that the BFG tires have an E load rating, which makes them even stiffer.

At 10K I'm going to change my oil, so we'll see if the gorilla was on duty when assembling mine. I keep periodically checking the oil and even at about 9K it looks just as clean as day one. But I do a lot of highway driving and not too much extreme duty type stuff.

I noticed in your sig it was mentioning Biodiesel. Are you running this in your Truck or just the Benz? What are the prices like around you. I haven't found any close supplier of Biodiesel up here.

 

The roar your hearing is the thermostaic engine cooloing fan. For some reason the clutch mechanisim on the engine fan is real touchy for the first few thousand miles. It will be much less noticable with time.

Tire pressure: THe sticker on the inside of the driver door outlines the pressure needs. Just adjust your pressure based on your GVW.

I always put 11 qts of oil in when changing oil. THen drive it, let it sit a while and add as needed.

 

[quote author=mymaur link=board=17;threadid=21471;start=0#msg201348 date=1067115640]
The roar your hearing is the thermostatic engine cooling fan. For some reason the clutch mechanism on the engine fan is real touchy for the first few thousand miles. It will be much less noticeable with time.

Tire pressure: THe sticker on the inside of the driver door outlines the pressure needs. Just adjust your pressure based on your GVW.

I always put 11 qts of oil in when changing oil. THen drive it, let it sit a while and add as needed.
[/quote]

Yep the engine fan will quiet itself down after about 12 or 15k (mine did)
As far as smell I always add oil to the full, not just dumping in the rec'd amount. Last oil change was not as bad for stink. Worse when the e brake is on.
Ride is harsh. STILL waiting for Kelderman air ride for a shortbox.................................... >

 

The noise is the clutched fan doing its job..drawing more air at low speed and then as highway speed cools the engine..it slows down...I'm on my third Cummins and as far as tire pressure goes..I have run 40 psi in the front and 45 in the back with all 3 trucks..all rode great and no abnormal tire wear anyhigher pressures and they really do ride like a truck..the tires sometimes appear a bit low..especially if one is parked on a rock or something..but I check my pressures on a regular basis and can tell you that those pressures are fine for the life of the tires and sure make your ride alot more liveable