It's the side seals between the radiator and the housing. Somehow they are not staying put and get sucked into the housing and torn up by the fans. The fans themselves are just fine.
I decided to start a new thread so that this is easy to find for those who want to check their SRT8, or need to address this very issue. It certainly is a DIY possible task. Please consider this for the KNOWLEDGE BASE section. As far as I know it will apply equally well to the 5.7L fan housing as it does to the 6.1L engine cooling system.
While on vacation recently we noticed an alarming noise from the engine bay one morning. It sounded like a rock grinder. At the time I didn't know whether it was within the engine or something else, but it quickly became obvious it was something to do with the fans, not the engine.
I contacted FnkyChkn over at LXF to see if it was feasible for a non-gearhead like myself to investigate further, or should I just take it to the dealer. He provided the following schematic diagram and procedure...
(1) RADIATOR FAN ASSEMBLY - (2) ELECTRICAL CONNECTOR - (3) UPPER RADIATOR HOSE
1. Disconnect negative battery cable.
2. Partially drain cooling system (Refer to 7 - COOLING - STANDARD PROCEDURE).
3. Remove upper radiator hose (3).
4. Disconnect cooling fan electrical connector (2).
5. Remove cooling fan mounting bolts.
6. Remove radiator cooling fan assembly (1) from vehicle.
Of course you have to remove your air intake (stock air box or CAI) back to the throttle body. You also need to move the electrical snake that crosses over the radiator up and out of the way.
I see no reason (unless your paranoid about electrical issues) to remove the battery cable. I did not. The only electrical items are the IAT sensor and the fan control cable. Both those are foolproof connectors and pose no difficulty. He also indicates to remove the top radiator hose. I also found this unnecessary. You simply need to move it out of the way. The Tstat bolts are 1/2 in. and use a zip-lock or other plastic bag to catch the antifreeze that will run out. DO NOT open the coolant overflow reservior or you will need a much bigger bag. I took out the Tstat as well, but that really wasn't necessary.
I did this using a short bungie chord and the fuse box terminal as the anchor...
This is a good time to check inside the Tstat housing connector and down inside the radiator hose itself. When I did this I didn't particularly like the look of the Tstat housing... it looks as if it was painted internally, and of course the antifreeze does a number on paint. But what was left didn't wipe or scrape off, so I left it.
The fan control chord connector is on the fan housing, just above the low-speed fan and easy to access and disconnect once you've moved the radiator hose. Then there are only two bolts (either 10mm or 8 mm) which hold the fan housing assembly in place. The first is located just under the other end of the top radiator hose... it can be accessed without removing the hose entirely.
The other bolt is on the opposite side in a similar location...
I was concerned that there might be a third and fourth bolt down below, but was pleased to find that the connections on the bottom side are merely slide on positioning pins. It took a little bit of persuasion to lift the fan housing out of the engine bay. You have to work the bolt tabs and the lower positioning pin tabs past the radiator hose on the passenger side and the two small hoses on the driver's side.
When I got the housing out I examined it closely. I saw no impact marks, and no wear marks on the housing or fan blades. I heard no rubbing and observed no wobbling when rotating either fan blade. I was baffled. Then I looked down into the engine bay to examine the back side of the radiator.
Clearly there was "minor" damage to the fins, but in no discernible pattern that I could detect. Then I saw something laying down near the bottom, and in fact there were two pieces. I didn't take a picture until I had them laying on the table with the fan housing...
These two stips of plastic/rubber were totally chewed up! Here's a closer look.
But it was not obvious to me where they are supposed to be mounted. They are the right length to go along the side of the housing, but... There is no tell-tale sign of something that slipped off the housing (like a dirt line), and they didn't appear to be curved in the way that would follow the outer edge of the fan shrouds.
Then it occurred to me that perhaps they mounted on the edge of the radiator itself. There seems to be a place where the plastic part could mount and leave the rubbery fin reaching out to seal to the fan housing.
So I don't know if this is correct, but I tried a test fit to visualize my theory...
Wherever they go, they clearly were/are not reusable so I simply put the fan housing back it and reconnected everything. It is difficult to see anything AFTER you put things back, but I did have a little angle to view down beside the washer fluid and ABS brake distributor. There clearly is a gap now between the housing the the edge of the radiator... as indicated by the arrow.
If you have NOT experienced this fan issue, you might want to check a similar visual in your car to verify what the side seals are supposed to look like, or if they look near failure. I would think you will not be able to see the radiator edge as you can in the picture above.
All in all the whole investigation took me a couple hours (because this was a first for me and I took my time and took pictures). To do it again would take maybe half that much time.
I plan to take the two destructed pieces to my local dealer on Monday morning and get or order (under warranty) replacement parts. I think I probably can install them myself, but to maintain warranty considerations I probably will schedule a time when they can install them... with another dozen donuts of course!
Ok... I'm done. Comments?
Last edited by GoofyTimL; 08-20-2009 at 04:23 PM.
Still in love with my first wife, and first car ('68 Charger)... Still have the wife!
The dealer completed the reinstall in the MSRT8 today, and also rotated by tires (6.2k on the clock now after the trip to Cleveland and Pittsburgh this weekend). While it was "up" I asked them to complete a lube check as well... but that really doesn't pertain to this thread.
What does pertain is pictures of what the side seals should look like when everything is hunky dory. So let me remind you of the last picture with the side seals completely gone (removed by me and taken to the dealer as "evidence")...
Now here is what it is supposed to look like (less "zoom" than the previous picture by arrows used to point out approx. the same space in the "bare" picture.
It looks to me like the hard plastic portion of the seal are supposed to grip that bright aluminum "cogged" side strip, and then the soft rubber "fin" is supposed to lay over toward the car's center and flex to seal against the forward edge of the housing.
This is a little curious to me because the suction from operation of the fans (at low speed should cause this seal to "leak" and may be the driving force for pulling it into the fan housing and the blades. Under highway speeds I would think there is slight positive pressure within the housing which would tend to try to blow the seal outward and seal better.
So maybe the design problem is stop-n-go driving in which the block and coolant get so hot so as to cause both the low speed and high speed fans to engage creating lower pressure inward of the seal and such a breeze when it leaks that if it lets go the only way to "fall" is into the housing...
Well... that's my story whether it "sucks" or not! LOL
When is this thing going to get reviewed so that others can see it and comment?
Last edited by GoofyTimL; 08-20-2009 at 04:27 PM.
Thanks Tim and some additional info as posted at SRT8OC.
I took the entire piece out over a year ago and I have had no overheating and no ill effects... and I live in Phoenix.
(Waiting "patiently" for the 300C SRT8 8-speed) Coming.....soon?
I figure the benefit comes from low-speed operation in traffic. When these things get moving "we don't need no stinkin' side seals!" LOL
GREAT write up -- thanks for the complete procedure. beans to ya!
2006 Magnum SRT8 "HEMIWAGN"; HalfFast Performance built; OST Dyno tuned; Frank Racing Extreme Heads, Scudd Cam & Ported Intake; Paramount Performance Dominator 4400TC & Valvebody. Best 1/4: 10.898 @ 123.25 MPH, 1.577 60', 3500lbs with driver, DA -595
Glad that you found this old thread useful!
great write up,I've just fixed mine.Thanks
I've been hearing something like this when the car is first started in the morning - sounds like something hitting the fan - it doesnt always do it. Reminds me of "playing cards in the spokes" like I used to do when I was a kid.
I bet this is it. Think the dealer will fix this under warranty?
2007 Magnum SRT8 Steel Blue Metallic/Option groups 1,2,3/Roof Rack/Sirius/Everything but VES
My dealer took care of mine under warranty, and I had removed everything before I took it in. I had copies of these pictures.
Took mine in today and they got the noise stopped. I dont know if they actually replaced them or not, it was done pretty quickly (about an hour an a half).
Maybe it was something else, but the noise has stopped, so Im happy I guess.
Well I now have the dreaded noise and it scared the crap out of me today. i was sitting in traffic and the temp rose a bit so all the fans kicked into high cool mode(Predator settings) and i was WTF is that, pulled over to the emergency lane popped the hood and just listened in horror as the loud buzzing continued. i got home hopped on the forum and found this thread Thank You Very Much... It will be fixed tomorrow........
Mark2007 Magnum SRT8 aka"Beast"
Glad to hear that this thread continues to help folks!
Thanks Tim once again your thread has helped another LX'r. This noise just happened to me the other night at the track and honestly was a little freaked. At this point I don't know if this is my problem but I now know a course of action to take so as I said, Thank You...
Yes... it's a horrible, frightening sound when you first hear it. You want to just turn the engine off in hopes of it not falling apart (the motor, or a flywheel, or something). I hope what you heard was nothing serious and that the info here helped.