Hood shake at high speed

[dre256]

My 2013 5.0 has sit for last 5 weeks, I finally had a few days off where I could drive it and started today my hood shaking at 90 MPH. At 85 it starts to making a tapping noise on the driver side. Then at 90 starts to move up and down. Above 90 its a bad shake going up and down. Appears coming from the back by the windshield. I removed the hood insulation thinking maybe a few plastic pins where lose letting air pressure build up between the hood and insulation. Didn't do anything. Took off my 5 year old hood struts thinking maybe they are wearing out and letting hood shake. Didn't do anything either. I tried to turn bolts on the hood to the hinge, only got a quarter turn on them. I can not get to the hinge bolts that go to the body, looks like fender needs to come off to get to them?

I have tried to shake the hood in park and cant get it to really move let alone make that tapping noise it starts to do at 85 MPH. This is really strange! I have had this car up to 130 MPH on the tracks several times and hood is solid and and not jumpy. Any advice will be appreciated!

 

[702GT]

I can't comment to the '13 specifically, but my '08 had hood flutter at the track and occasionally highway speed. You can adjust your bump stops up so there is more pressure against the hood and latch, this will dampen the effect. I didn't care for this solution myself, as it required more force to close the hood as well. In the end, I ended up doing the Shelby hood pins. They were extremely effective, killed the flutter, secured the hood without doubt, and looked very sharp. Added bonus, the smog techs weren't allowed to open my hood anymore (not that it mattered).

There are plenty of hood pin options, from stealth kits to bling. Pinning the hood down is about safety, curing annoyances and cosmetics is just a side effect. If you don't wish to pin the hood, you'll have to play with hood adjustment and find out where air is giving the hood lift to cause instability. Bump stops are a start, but you'll likely need to adjust the hood at the hinges, possibly add spacers to one side or another, and experiment. Or pin the hood and be done. Just my $.02

 

[dre256]

Thank you for the advice! I will try the bump stops then go to playing with the hinges. Hood locks I can put on the table but try the other 2 first! At least I have some where's to start with bump stops as I was out of ideas!

 

[JJ427R]

Do you have any hood vents in your hood? I was having a similar issue at times in my 2010. At Road America when coming over the top of the hill on main straight my hood would lift a little bit in the front corners. Due to cooling issues I have recently added MMD hood vents in the center/rear of hood, have not run on the track yet, but I went out on lonely country road near me and did a high speed run and saw no lifting. My understanding the hood vents should help this from happening. I should install hood pins as well as I bury my needle at 140 at BIR. My next day there is Sept 10th. that will be the true test of the hood vents.

 

[nawagner]

Agree with the other suggestions. I went with Sparco hood pins on my '06.

 

[dre256]

Yes the car has the factory hood vents and I didn't just add the hood. I haven't came across this before. But I was thinking similar to you. I thought maybe the hood insulation was lose or something not properly removing the pressure build up from the factory vents. Unfortunately, removing the insulation didn't help.

 

[OX1]

My 2013 5.0 has sit for last 5 weeks, I finally had a few days off where I could drive it and started today my hood shaking at 90 MPH. At 85 it starts to making a tapping noise on the driver side. Then at 90 starts to move up and down. Above 90 its a bad shake going up and down. Appears coming from the back by the windshield. I removed the hood insulation thinking maybe a few plastic pins where lose letting air pressure build up between the hood and insulation. Didn't do anything. Took off my 5 year old hood struts thinking maybe they are wearing out and letting hood shake. Didn't do anything either. I tried to turn bolts on the hood to the hinge, only got a quarter turn on them. I can not get to the hinge bolts that go to the body, looks like fender needs to come off to get to them?

I have tried to shake the hood in park and cant get it to really move let alone make that tapping noise it starts to do at 85 MPH. This is really strange! I have had this car up to 130 MPH on the tracks several times and hood is solid and and not jumpy. Any advice will be appreciated!

Mine started doing this horribly @ the same speed after I swapped to Brembos and had to use an 8mm spacer. I had bought a set of AM 18 X 10's with 305 NT01's and put them on temporarily (no spacer required for them). Smooth as glass. When I put my street tires back, I made sure chamfer on spacer was facing in and no more vibes. I'm going to mark exactly where spacer and tire are on rotor, just in case I lucked out and that is the only way they can be installed and won't be out of balance.

My guess is you have flat spotted tires from sitting that long. I've had this in the past, since I have 9 cars and trucks, so many sit for very long periods. It seems worse on newer low profile, summer tires especially (IE, my 79 bronco on 35 AT's sits for 6 months or more and never flat spots). I have my own balancer, so I've confirmed it here and there, as many have said it could never happen. I have a Fusion Sport DD with Mich PS4S's and sometimes those have a bit of a vibe for a couple miles, even after sitting only a long weekend.

I'd crank the pressure up to max and take them back out for nice long ride, get them hot and see if it helps.