Hi,

owner of a chevy express 2500 2015

I was driving the van yesterday and it hadn't fully warmed up so the defroster wasn't on. It was raining pretty hard and flooding some areas. I couldn't see because of foggy windows and hit a patch of deep water probably 2 - 3 feet deep. I was going 40 mph and hitting the puddle caused a huge wave to come over the hood onto the windshield. I came to a complete stop from the friction of the water. I completely lost traction but managed to steer straight. I came to a complete stop in the deep water. I tried to climb onto the center divider but it was too high. Instead of pushing through the deep water I reversed out of it. I was able to get going again. however i noticed that the defroster or heater on full blast is very loud. sounds like the fan is really pushing hard. It is working and everything looks fine inside the engine compartment, but the heater on full blast is really loud. it wasn't like that before. It's vibrating too and not smooth.

Also when the vehicle is started now it SOUNDS horrible like it's water logged. The noise does quicly going away after starting up and it goes back to sounding smooth. But my starts use to be smooth as butter. Not rough like this. I checked the air intake dismantling all the way to look inside past that little plate that flips open to see deep in there. there is not water and the filter is completely dry. All the belts are in tacked. All it is now is that horrible noise. AFter driving for a while today it seemed like that heater fan noise was getting better and that the horrible sound from starting is going away. But I've never seen this before. Also seemed like it the tranmssion might be slipping.

any ideas on what happened here? similar experiences? what the heck could be the reason for the noise? THE heater desfrost noise sounds ROUGH AND LOUD. Also there is a vent under the windshield wiper, where does that lead?

 

That vent goes to your blower fan intake. The blower fan is in that box on the passenger side firewall. I guess it's possible that much water flooding into the intake vent overwhelmed the drainage holes and made it into the fan housing and ducting. Being cold and damp outside there won't be much evaporation right now so it might be sitting in there kicking around in the fan. If that's the case it'll slowly get better and if you have a warm dry day it'll get better quickly.

Not sure about the rough start. One guess is that the cooling fan didn't like the instant cold soak and the valves inside aren't too happy. If the fluid inside is pooling in a way that causes it to be imbalanced that might cause roughness until it all spins in place. As discussed in the other thread, if the fan is staying engaged longer it can sound like the tranny is slipping.

Is the roughness just after a cold start? If you shut it off after it smooths out and restart it right away is it rough?

 

If something sounds different you need to get it checked out.

 

The roughness is just after you start it. It goes away within a couple seconds though it does still sound very faint. IF you turn off the vehicle and turn it back on again it sounds horrible for a couple seconds and then it smooths out. probably just water somewhere it ain't suppose to be.

As far as getting it checked out, I did look around the belt area like crazy. What more is paying someone else going to do? I also don't have anyone I trust around here. moving soon and maybe I can find a quality mechanic.

 

Where is the sound coming from? Have someone start it while you listen with the hood up.

When you say "rough" do you mean it's running poorly like a miss or does it sound like something banging around or squealing?

 

Ok here is it what it is.

The fan is hitting the fan shroud on the bottom(lower shroud). I went underneath and looked and found one of the plastic tabs that secures the lower shroud had snapped. I am sure that you guys may well know that these vans all seems to have the two piece shroud which is a BEAR to get back on. I already dealt with this with the water pump. Hardest part was the shroud. I never messed with where the lower shroud mounts to the engine.

Here is what I think happened. I was driving so fast and hit the deep water it put a lot of pressure and weight on the already heavy radiator. As mentioned PO installed an after market radiator which is a 5 core vs the smaller one I usually see on these vans. All the weight was enough to snap the tab. Now the fan shroud is out of position, oddly it seems to be making contact only on the bottom which is why I didn't see it right away.

Not sure if the fan is still usable. It has been hitting the plastic shroud and I wonder if I need a new one AND OR a new fan clutch. IT's quite expensive. The fan looks a tiny bit frayed on the ends. I also have to wonder if when PO installed the after market radiator if he removed something from the fan shroud to make it fit. I also if PO even bothered to remove the fan shroud to replace the radiator as it is not necessary, you can snake it out just loosening the fan shroud. AS it stands the radiator is only held in place by 4 little rubber peices and it's mostly held up by the upper fan shroud. But I watched a video when replacing the water pump and the mechanic said this is the way it is suppose to be. The radiator seems like it wants to tip over without the fan shroud holding it up (the upper bolts near the air intake are the ones that hold it.)So it seems like PO did it right. The only issue I may see is that this radiator is WIDER than the OEM one and therefore doesn't fit AS SNUGLY into the four rubber inserts, if that makes any sense. But it is just a LITTLE Too wide, but perhaps in the world of mechanical things that is just enough to allow the radiator to shake too much, snapping the lower shroud where it bolts onto the frame.

As a bandaid I read somewhere I could maybe try and use spacers in between the two halves of the shroud to give the fan room. let me know if you guys have any solutions for me and do let me know if you think I need to get a new fan clutch or new fan. How can i get some clearance temporarily to allow me to drive around? like i mentioned the lower half of the shroud, the second piece as you know, has two tabs on it that connect to the chassis. One of those is snapped. what to do, what to do.

 

Good deal on figuring it out. It seemed like something fan related but i didn't think about the shroud being tweaked. That makes perfect sense.

I'm sure the fan clutch is fine. The fan is probably okay as long as it's not bent or frayed too unevenly.

The upper shroud is kind of a pain to get out at first but it will come out if you do it just right. I struggled the first few times but now it's not too bad. I considered cutting it in half and attaching the pieces with a piece of "H" channel so I could take it out in two pieces.

As far as forcing it to work it's just something you're going to have to look at. You can drill two holes in it and loop a zip tie through them. Hook to that to pull it out of the path of the fan.

You might also be able to hit it with a heat gun and shape it out of the way of the fan by pushing on it while it cools. You'd probably have to do it from the top with upper shroud removed.

 

Ok that is the plan. Use the zip ties to fix it. I'll probably get on it tommorow.

Do you loosen up all the dipsticks to get the upper shroud out? what is your trick?

I watched the videos of guys doing it but they go too fast and there are jump cuts. it's seems like these guys struggled with it too.

 

If you find a trick to the dipsticks let me know. Replaced my radiator and that was by far the biggest pain.

 

I just went ahead and undid all the bolts for the shroud. I didn't actually take the shroud out. I guess the lower part of the fan shroud is damaged on one side(the plastic is cracked), and on the other the the bolt that second the lower piece of the shroud to the vehicle was in ... plastic? the plastic has broken and the long square nut has popped out. Not sure if the PO did this or not when he changed the radiator. or the amount of force hitting all that water did it.

AFter un doing all the bolts I Was able to get the shroud correctly alligned. Now it's not hitting anymore Although I still don't have much clearance on the bottom, but at the top there is a ton of clearance. Is it the same on your guys rigs? how much room do you have in between the bottom of the fan blade and the shroud? I went ahead and used a zip tie to reinforce it where i Could. Looks like replacing all that plastic is next. props to anyone who knows where to get the little piece of plastic that the lower shroud tabs connect to... who's genius idea was it to mount to plastic ?

I'll have to get the van to a better spot to have a look to see how damaged the fan itself is. looks like it got skinned on the blades, not too bad. any way to know if it is out of balanced by looking at it? and yeah even with those dipsticks unscrewed and out, it's still a PITA to get that upper shroud out, I am not looking foward to that.