I have 94 integra gsr, 140k miles.

Every time i rev the engine to 3500 rpm there is quick grinding noise in the engine area. I cant particularly point where in the engine, either in block, head or exhaust.. It grinds whether running or not running, in all gears.

No grind below 3500 rpm, no grind passed 3500 rpm.

removed all heatshield, from headers to catalytic, removed belts for AC and PS, but noise is still there. im sure that i belt is in proper tension and i also tried removing the timing belt covers but still the same..

idle is pretty much perfect, no strange noise.. only at 3500 rpm..

if its LMA, should there be a noise at idle?

Thanks in advance!!!!!

 

Sounds like the problem I'm having. I think I need to replace my LMA's, whether they're causing the noise or not, but it's hard spending $180+ on 8 little springs with washers on them.

 

Do you have bad valvetrain noise at idle or during acceleration?

 

have some noise at idle, with perfect valve lash settings, and the noise I hear is most often heard as RPM drops.

 

I was asking the OP lol. We had bad valvetrain noise on a DC2 and after replacing the LMA's and performing a valve lash the noise issue was solved.

 

crap forgot to post the link to the thread I made in the Tech forum.

https://honda-tech.com/forums/tech-misc-15/what-heck-weird-rattle-sound-2500-rpm-2869487/

 

Had the same prob. Acura told me it was the (B pipe?) whatever that is but i guess the down pipe from the headers. do you have the factory headers? guess a weld came lose in it and its vibrating at that rpm. i threw on some cheap 50 bucks ebay headers for now and stoped problem.

 

not to threadjack but i have some lmas for sale somebody needs them.

http://hondamarketplace.com/showthread.php?t=2875625

 

thank you for all the reply guys.. this is driving me crazy, i have been figuring it out for months..

@the mask, i read your thread about the lmas.. and its a great stuff, i already bookmarked it. will definitely make the job easier. but those lmas are expensive, so i have second thought about it.. i should be 100% sure that its the lmas that makes the noise..

could it be lma's even if the idle is perfect, no strange noise at all, the moise only appears at 3500 rpm?.

i will try the down pipe, i read a lot of threads about this downpipe being the culprit of the rattling/grinding noise.. i will go to a muffler shop tommorow and ask them to put holes on it and then weld.. will update you what will happen..

about the lma's for sale if this doesnt work, i wil consider buying your lmas..

 

I would suggest buying the new spring-type LMA's that you can see in some of the links in my thread. The old type (in the for sale link above) were revised because of the problems so many people have had with them wearing out and causing excessive valvetrain noise.

But yeah if you still have the stock exhaust manifold I'd look there first. I had it on my original manifold, had it "fixed" by an exhaust shop blowing a hole through the outer and inner pipe walls, and welding them together. Then that one developed the rattle again, got another used manifold off a friend that had been "fixed" already, and then that one went on to develop the rattle yet again, right in the 3K-3500 rpm range. It's a nasty problem with that exhaust manifold design, to say the least.

 

will go to a shop today.. update later.. thanks..

 

problem solved, it was the inner pipe of the Y-pipe next the exhaust manifold..

i remove the exhaust manifold and went to a muffler shop, they made a holes in the Y-pipe then welded. noise is gone.

which means, if the noise is only at specific rpm, its not the LMA, its the Y pipe..