Jump to content
LegacyGT.com

Loud screeching above 2700 RPM


Recommended Posts

Hi, I am new to the forum and I have a 2005 Subaru legacy I picked up recently. The problems it had were, miss fires, hesitation, rough idle, no start, oil consumption. To start it used oil pretty good and I pulled the turbo to find a lot of shaft play and oil being put through the intercooler. So I rebuilt the turbo. Next I was getting Bank 1 too lean, so I replaced the 02 censor. Next I was getting a Bank 2 camshaft position sensor code, so I replaced the camshaft position sensor. With the camshaft code I received a knock sensor bank 1 code. After replacing the sensors the car runs much smoother and has a ton less hesitation, still a small amount at high rpms. Now the real problem...... the car has a wicked loud screeching noise above 2700 rpm. Its not the turbo, or an exhaust leak. The noise will not happen if I rev the car slowly no matter what rpm I go to. The noise only happens when the revs are bounced 2500 or higher, or the car is accelerating down the road. So it seems the problem only happens under load. When is say its loud I mean its holy shit loud. It sounds like a belt squeal but I have removed the serpentine belts and the car is still screaming. I used the good old listen through a pipe technique and its coming from passenger side timing belt/frontal engine area. I am thinking exhaust valves? Maybe a cam is effd. Before I go crazy and pull this engine what are some more suggestions you guys have.
Link to comment
Share on other sites

Do you know the service history for the timing belt and components?

 

Timing belt is due at 105K miles or 105 months (~9 years), whichever comes first.

 

Often, when people replace the timing belt, they don't change out the idlers, tensioner or water pump (which is driven by the timing belt). Trying to save money, but that is false economy. If the bearings go in idlers, tensioner or water pump, it will destroy the belt and you will have serious engine damage since it is an interference engine. Tensioners can go bad over time, also, leading to the belt slipping and engine damage.

 

Suggest you pull off the front timing belt cover and inspect everything behind it. A good idler should turn silently, a bad one will make noise when spun. If in doubt, replace. Also, check your timing belt condition and check the timing belt guides that help keep the belt on the correct path.

 

It can be intimidating to mess with the timing belt components since it is an interference engine. It is not that bad if you have done it once before. There's lots of info and how-to posts on here and elsewhere if you are comfortable with the DIY'ing.

Link to comment
Share on other sites

I am in the middle of checking out the timing belt as we speak. I was told that the engine was rebuilt completely before I bought it. Of course 4 of the timing belt cover screws are completely stripped and wont come out....... I would assume that it has been done but I want to check timing and all its components before taking the next step. How can I tell if the belt has been changed? just visual inspection? If it looks new chances are it is new...?
Link to comment
Share on other sites

Since it is protected by that cover, the timing belt can stay new-looking for years. The timing belt idlers or tensioner are usually the first things to go. But, if your timing belt shows visible cracks, missing bits of rubber on the teeth, an overall dried-out appearance, it is time for a new one. They are not expensive, though, the labor to replace them is the main expense.
Link to comment
Share on other sites

The whistle from a boost leak can be pretty loud.

 

Take the hose off the air filter box to the intake and plug it with a pint size paint can, pull the small hose off the BOV, give that hose a quick blast of air from a compressor, put your thumb over the hose, listen for leaks.

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

Link to comment
Share on other sites

Ok, I will give that a try this weekend. I think I will order a new timing belt kit as well. Thanks for all the help!

 

Make sure its the Aisian kit, don't get a Gates kit.

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

Link to comment
Share on other sites

The whistle from a boost leak can be pretty loud.

 

Take the hose off the air filter box to the intake and plug it with a pint size paint can, pull the small hose off the BOV, give that hose a quick blast of air from a compressor, put your thumb over the hose, listen for leaks.

 

Along with this I would suggest checking the exhaust gaskets. I know you are saying it's not the turbo or exhaust leak. When I wrapped my UP (removed broken heat shield) I didn't have new gaskets for the manifold/headers. Above ~2700 RPMs I would get a loud metal screech. Thought my turbo was on it's last legs. Got a DP (and a tune) and new gaskets all the way around, no more screech.

Link to comment
Share on other sites

  • 2 weeks later...
Well I bought all new exhaust gaskets, 2 manifold, 2 cross pipe, 2 up pipe, down pipe. and I put a small bead of muffler putty around each gasket on both sides before install. The terrible metal to metal screeching noise is gone. Its amazing what strange noises some leaking air can make. Thanks for your help guys!
Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.



×
×
  • Create New...

Important Information

Terms of Use