Welcome to the North American Subaru Impreza Owners Club Wednesday April 16, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 03-16-2005, 03:02 AM   #1
aGoGo
Scooby Newbie
 
Member#: 83124
Join Date: Mar 2005
Lightbulb newbie need advise, 93 1.8 AWD, engine noise at certain RPMs

Hi all,

I just pick up a 93 1.8L AWD last week. It is a very interesting car and totally different from what I was used to, 85 Rx7. The engine is a very different beast from rotary, lot of torque and 'not as smooth' but runs great. It had K&N filter Nology wire and 'Beru'(spell?) plugs, has been using Castro synthetic all around and I just changed oil last week along with some MMO in the oil and gas (87).

The problem I am having is that, when I have a very easy acceleration about 1500 rpm or coasting down from around 3000 in gear I hear a metal tapping or rattle noise from the engine bay, this noise can also be heard in neutural about 3000 rpm as well, oh during shift (around 3000) if I let off the acc padel a bit fast I can hear a chirp of this noise too. But if I rev a little ways past 3000, this noise is gone and the engine roars louder as it should. Most of the time, if I accelerate normally to 4000, this noise might not present. The noise sends like the valve. I am new too those cars and could some one give me some advise on what this might be? A fix? Thanks!

With regards
* Registered users of the site do not see these ads.
aGoGo is offline   Reply With Quote
Old 03-16-2005, 03:11 AM   #2
Storm
Scooby Guru
 
Member#: 5218
Join Date: Mar 2001
Chapter/Region: MWSOC
Location: SAUL'S Motorsports
Vehicle:
96L Most Over-
Developed Beater

Default

Sounding off at that RPM only makes me think it might just be a heat shield around the exhaust. Given the age, it's likely they need to be removed.

Jay Storm
Storm is offline   Reply With Quote
Old 03-16-2005, 03:14 AM   #3
aGoGo
Scooby Newbie
 
Member#: 83124
Join Date: Mar 2005
Default

Any reasoning here that can assure me it is not the valve? Thanks!
aGoGo is offline   Reply With Quote
Old 03-16-2005, 03:26 AM   #4
aGoGo
Scooby Newbie
 
Member#: 83124
Join Date: Mar 2005
Default

I did have a very brief check around the car, and I felt a bit on the heat shields under the car as well, they was pretty solid, this car was maintained well.
aGoGo is offline   Reply With Quote
Old 03-16-2005, 12:48 PM   #5
aGoGo
Scooby Newbie
 
Member#: 83124
Join Date: Mar 2005
Default

had a another run this morning, this metal rattle sound basically happens about 3000 rpm and when coasting down or during shift, during acceleration is ok. It is obvious from inside of the car, however when I tried to work the throttle under the hood, I can not dig this sound out since the engine is loud. I 'believe' I can feel this sound on the shifter too (or I am just too paranoid). I checked the heat shield too, they are solid and even no rust. I am not very knowladge on those engines, and just want to make sure the engine will be fine. Any input would be appriciated.
aGoGo is offline   Reply With Quote
Old 03-16-2005, 10:24 PM   #6
RS-Flyboy
Scooby Newbie
 
Member#: 70331
Join Date: Sep 2004
Chapter/Region: NESIC
Location: North Central Connecticut
Vehicle:
04 Silver Baja
1999 Impreza 2.5RS

Default

Alright:

I had a squeeling noise, from idle, to about what you're saying, between 2.5k to 3k RPMs. Turns out, that sound was my tensioner pulley for my timing belt about to give up on me. Needless to say, it crapped out, and cause the belt to snap. A few new valves later...


You get the idea. Get your pulley checked out.
RS-Flyboy is offline   Reply With Quote
Old 03-16-2005, 11:03 PM   #7
Storm
Scooby Guru
 
Member#: 5218
Join Date: Mar 2001
Chapter/Region: MWSOC
Location: SAUL'S Motorsports
Vehicle:
96L Most Over-
Developed Beater

Default

But all 1.8s are non-interference.
Quote:
Originally Posted by RS-Flyboy
Alright:

I had a squeeling noise, from idle, to about what you're saying, between 2.5k to 3k RPMs. Turns out, that sound was my tensioner pulley for my timing belt about to give up on me. Needless to say, it crapped out, and cause the belt to snap. A few new valves later...


You get the idea. Get your pulley checked out.
Good luck finding the source.


Jay Storm
Storm is offline   Reply With Quote
Old 03-17-2005, 02:23 AM   #8
aGoGo
Scooby Newbie
 
Member#: 83124
Join Date: Mar 2005
Default

Thanks guys, I will get a more detailed check this weekend
aGoGo is offline   Reply With Quote
Old 03-17-2005, 02:50 AM   #9
aGoGo
Scooby Newbie
 
Member#: 83124
Join Date: Mar 2005
Default

I just did a search about this "interference" and "non-interference" but still don't get the essence yet, can some one elaborate it abit? Thanks!
aGoGo is offline   Reply With Quote
Old 03-17-2005, 03:07 AM   #10
Storm
Scooby Guru
 
Member#: 5218
Join Date: Mar 2001
Chapter/Region: MWSOC
Location: SAUL'S Motorsports
Vehicle:
96L Most Over-
Developed Beater

Default

Interference means that if timing between the valves and piston is lost, they will collide and bend or break the valves. The pistons usually take a beating in that regard as well. Another type of interference is when the timing is lost between the cams on a DOHC head allowing the intake and exhaust valves to hit each other if they both open at the same time.

Non-interference means that there is clearance between all of these parts at all times.

Jay Storm
Storm is offline   Reply With Quote
Old 03-17-2005, 03:27 AM   #11
aGoGo
Scooby Newbie
 
Member#: 83124
Join Date: Mar 2005
Default

Thanks man! The explaination was very clear. That means an 1.8 won't bent a valve due to timing belt or the tensioner failure, right? or even this engine should have reliable valves?

Actually, the previous owner told me, the timming belt was replaced in 2002, I would assume it is still in good shape.
aGoGo is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Drop in power/torque at certain rpm?? whitewolf2 Open Source Reflashes 9 02-08-2009 01:08 AM
Help me figure out why my car is bucking/bogging at certain RPMS! vipernj Factory 2.0L Turbo Powertrain 11 01-30-2006 08:29 PM
rattle at certain rpms with cusco heatshield mpower22 Factory 2.5L Turbo Powertrain 3 11-12-2004 04:29 PM
rattle noise at 2800 rpm golfs2good Transmission (AT/MT) & Driveline 3 10-30-2002 01:26 PM
WRX Vibration noise at 2000 rpm and WOT? Cosworth Factory 2.0L Turbo Powertrain 4 06-21-2001 02:39 AM


All times are GMT -4. The time now is 01:31 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.