Jump to content
rubystargoats

2005 F350 high piched buzz/squeal when cold

Recommended Posts

The neighbor has a 2005 6.0 that makes a high piched buzzing noise when cold, comes from the drivers side toward or at the fire wall . When it warms up it seems to go away. It is pretty loud when first fired in the AM and seems to change with engine speed. Sounds like it is from the hydro boost on the brakes but can't tell for sure, as it could be that it is from the turbo resonating thru the intake. Is there something in the brake hydro boost unite that can vibrate at a high speed or ?? He says it also runs rough in colder weather until almost fully up to temp. a little over 200,000 miles on the truck but I don't think it is related to the buzzing noise. the turbo was replaced at 120,000 or so. and 2 injectors have been replaced. Y pipe was replaced but did not change it and it does not seem to be an exhaust leak. Boost seems ok, maybe a little slow to build but...

Share this post


Link to post
Share on other sites

running rough when cold is typical of poorly maintained 6.0's.

its due to stiction, the spool valve inside the injector sticks or is sluggish when cold due to varnish build up and poor lubrication.as temps rise, the oil thins out and the spool valve operates more normally.

as far as the buzzing, ive seen hydroboost make all sorts of strange noises, once again , typicly on poorly maintaied trucks. have him pres the brakes HARD and crank the wheel back and forth. does it change? can he even steer when standing on the brakes? whats the fluid look like?

the other thing to check, is manifold gaskets, look for tatle tale soot marks. ive seen trucks where the metal gasket winds up working like the reed in a saxophone. makeing all sorts of noise, but quieting down for the most part once things warm up and expand. this could explain sloow building boost. the vgt turbo winds up having to run partialy closed to make total boost # look normal.

Share this post


Link to post
Share on other sites

THe Power steering fluid has not been changed in 200,000 miles so maybe. even if not the problem it needs to be changed. Any advise on draining/purging/flushing all the old out? And getting all the air out when adding the new? Brakes and steering worked fine even when used together at idle.

Can't really see the exhaust manifold junction at the heads and no exhaust smell but... that would be in the right area of sound.... I will ask about if the manifolds were pulled when they did head studs.

Share this post


Link to post
Share on other sites

if i recall, the hose going from the res to the pump is 3/4". suck as much out of the res as you can, pull the hose off the res,let it drain into a pan, i recommend putting a hose on it to direct it to your pan/bucket. take a long tranny funnel and stick it in the hose that go's to the pump, fill the funnel with fresh fluid, be prepaird to keep adding fluid, have some onestart the truck, add fluid as needed to keep from starving it. have him pump the brakes while its running, and turn the wheel back and forth. let it pump clear fluid out for a little bit. then shut it off. re atach lines, fill res, take it for a drive. should see an imediate improvement. if fluid gets dark again fairly quickly then repete.

Share this post


Link to post
Share on other sites

id hope manifolds were pulled/surfaced when studs were done... ! hard to resurface a head with the manifold hanging off it... unless they didnt...

 

the exhaust ports are fairly visible thru the wheel wells

Edited by Gus 03

Share this post


Link to post
Share on other sites

So in conclusion, It was the exhaust manifold gasket, the bolts were loose. He tightened them up and wow, no more noise and better boost response. He is also going to change out the power steering fluid as it does not look too good and has over 200,000 miles on it.

 

Thanks for another happy ending.

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×