Burrrrr noise when going uphill

[XRing]

--edit--
This thread turned into a DIY RT4WD to FWD conversion. I had a lot of trouble with rusted parts,
one of the lessons learned was if you live in the snow belt, think about rust treatment on new cars.
When I purchased my V on Y2K, I never expected to keep it this long.
Had I known then, what I know now, I would have taken it in for anti-rust treatment the next day.
-------



Burrrrr noise when going uphill or even slightly 'lugging' by going up any size hill while in a gear that might be a little too high for low RPMs..

Say I'm on a flat section of road going 35-40 MPH in 4th gear.
The RPMs aren't real high, maybe 2400 or so..
Everything is is fine until we start going uphill and the engine starts to lug. Even just a little bit.
That's when the low freq Burrr noise starts. It's pretty loud too.

It goes away the second I down shift and get more RPMs or if I just step on the gas and speed up.
If I hit the same hill faster or in a lower gear, (higher RPM) no noise..

I have not inspected the muffler yet and I'm wondering if something is loose, like the time I had a loose cover on the catalytic converter that made such a racket.

I did some tight turns in the parking lot and heard nothing odd..
I know should not let the engine lug, but this noise just started a while back and it's a little irritating.


Any ideas?

[Carbuff2]

Originally Posted by XRing

I have not inspected the muffler yet and I'm wondering if something is loose, like the time I had a loose cover on the catalytic converter that made such a racket.

I think a muffler heat shield is a good place to start.

[Racoon]

Originally Posted by Carbuff2

I think a muffler heat shield is a good place to start.

x2


.

[sgtsandman]

There isn't a heat sheild on the muffler is there?

Or did you gentlemen mean on the cat?

[Racoon]

Cat, of course.

[Carbuff2]

Originally Posted by Racoon

Cat, of course.

Sure! The Cat. Mrrreow. Burrr.

[XRing]

Are there covers over any of the pipe of muffler hardware in the back??
That seems to be where the sound (or maybe vibration) is coming from.


I listened to that dang cat-cover for months before I looked it up on the forum.
Once I got under there, I found it was rusted loose in three places.
Only one connection left. I ripped it off and drove away in blissful silence..

The road chemicals around here eats away at your car from day one.
After 10 or 15 years, there is nothing left but the paint job and the
aluminum parts!

[sgtsandman]

If there is any kind of heat sheild in the back, it would be by the fuel tank. I'm pretty sure there isn't one around or near the muffler since it is too far back for anything to be needing shielding. Look for a loose hanger bracket or something. One could have rusted off. There are three back there if I remember correctly. Two for the muffler and on further towards the front.

[mdugan7000]

I sometimes get a mild resonating sound around 2500 rpm's when giving it slight throttle on mild inclines. I just assumed it is, well... a slight resonating...

Yes, I have done the CAT heat shield mod, twice, now. First time I was stupid and did not use a stainless steel clamp... I have learned.

[Racoon]

Remember, there are two (2) heat shields on the catalytic converter...upper and lower. The upper one tends to be the one that starts vibrating first. Maybe your lower heat shield is now ready to join the upper shield in the refuse pile.