Engine Question

[Blake]

I've got a '97 Subaru outback that makes a rattle sound at certain RPM. I was told it was a loose heat shield. Google tells me that this is a very common problem for subarus, and that I should either just take off, modify, or pin back my heat shield so it wont rattle.

 

The question is: where is the heat shield? I don't know what I'm looking for. The rattle sounds like it's coming from the passenger side of the engine only. I suppose I could just have someone listen/look around while the engine runs, but I'm sure someone on here knows enough to give me a little help.

 

Thanks!

[Dr_Flush_Amazing]

I've got a '95 Suby with the same problem, but haven't bothered to mess with mine yet - keep meaning to get under there and tighten it up or remove it.

 

The heat shield is a thin sheet of metal underneath the engine, towards the back. It's function is to keep tall grass and stuff from contacting the hot exhaust pipe coming out of the back of the engine. Fire prevention. Not really necessary supposedly.

 

Click&Clack

[sexual_chocolate]

when the engine is cool, just start poking around from the bottom and the top. grab everything and give it a shake, and see if it rattles. i think the heat shield is by the exhaust manifold, and it's just sheet metal basically, so start there. the attachment bolts might simply be loose.

[G-spotter]

mine rusted out and fell off on my old '90.

[tvashtarkatena]

I've got a '97 Subaru outback that makes a rattle sound at certain RPM. I was told it was a loose heat shield. Google tells me that this is a very common problem for subarus, and that I should either just take off, modify, or pin back my heat shield so it wont rattle.

 

The question is: where is the heat shield? I don't know what I'm looking for. The rattle sounds like it's coming from the passenger side of the engine only. I suppose I could just have someone listen/look around while the engine runs, but I'm sure someone on here knows enough to give me a little help.

 

Thanks!

 

Same issue on my '99. Let us know how you resolve it.

[Choada_Boy]

"Where are heat shields?"

 

HS can be in a couple places, but all are near exhaust components. You may have an HS on the outside of an exhaust "header", on the car body above exhaust components, and on or above your cat converter. Since it rattles w/ RPMs, it's probably not on the body, it would rattle all the time.

 

Your car is a horizontally opposed 4 cyl. I'd start on each side, find the exhaust headers, find the HS, which will be thin "plates" of galvanized metal attached directly to the headers, and see if they are lose. When you have the hood up, grab the throttle body and give it a turn if you want to rev the engine. It's pretty obvious, as it's just about the only thing with a bare cable feeding into it. That's the throttle cable

 

Work your way back to the muffler (Have fun near the firewall!!). To repair, either rip them off, or tie them down with a bent metal coat hanger.

 

ps If your engine "clicks" at any RPMs, it's your "valve lash adjusters", which is an easy fix, despite what your subby mech might tell you.

[Blake]

Thanks for all the advise, sounds like a common annoyance. I will report back with a full-on TR.

[drater]

[quote=Choada_Boy

ps If your engine "clicks" at any RPMs, it's your "valve lash adjusters", which is an easy fix, despite what your subby mech might tell you.

 

And this fix would be?

 

Maybe I should PM AE.

[Choada_Boy]

The valve lash adjusters are small hydraulic cylinders that function as part of the rocker arm assemblies. As the cam pushes the rocker arm up to close a valve, say, the valve lash adjuster gets compressed. The problems is that oil needs to circulate through the things, and if it doesn't, they can seize, and won't compress, so the rocker arm will just hit into them, causing the ever-present "click"

 

You need to pull off the valve covers and remove the rocker arm assembly. (If you're careful, you can reuse the valve cover gasket if it looks OK.) The valve lash adjusters slide out, then you pop in new ones. It takes about 1.5h per side, and the only "special" tool required is a torque wrench for putting the rocker arm assembly back on. The torque specs and pattern can be found in a good manual (Chilton's) The timing is electronic, so when you start back up it may run rough for a bit until the computer figures everything out.

[archenemy]

And remember that if you do need a new gasket, you can make your own. Kits are cheap and good to have around anyway.

[Billygoat]

you got a car?! cool. When are you gonna pick me up and take us to that little problem we talked about

[Blake]

you got a car?! cool. When are you gonna pick me up and take us to that little problem we talked about

 

When the Highway opens and the snow melts!

[Blake]

So to everyone else who has this problem, or gave me some advice... I fixed it. Basically, the exhaust pipe/manifold that was just behind the engine had a couple thin pieces of loose sheet-metal surrounding it. I couldn't quite tell which ones were loose, but after banging around on various bits and pieces with an ice tool, I had a pretty good idea.

 

It helped to have a friend rev the engine to the usually-noisy RPM level, and i firmly held the suspect piece to see if that was the right one. I couldn't get the noise to completely stop by just holding it tight with my hand, but it quieted the sound enough to confirm my suspicion of what to take off.

 

It was a section that had a top and bottome piece that kinda wrapped around the pipe, and were bolted together at a couple points along the sides. I removed the bolts on one side (10mm nuts) then just manually bent/opened-up the whole thing and pushed it off the other side of the exhasut pipe. It would ne very difficult to remove the rusty bolts from the second side, once you've removed the bolts on the first side. (the piece wobbles around too much)

 

 

[joblo7]

your shields are down , captain!!!!!