Welcome to the THE H.A.M.B. forums.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community 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 fast, simple and absolutely free so please, join our community today!

Go Back   THE H.A.M.B. > General Discussion > The Hokey Ass Message Board

Reply
 
Thread Tools Display Modes
Old 12-02-2005, 04:57 PM   #1
Wild Turkey
Member
 
Join Date: Oct 2005
Location: Elizabethtown, KY
Posts: 904
Default Need help with Chevy 2.8

Got a carbed 2.8 V-6 in an '85 S-10 Blazer. (not original engine -- omit long sad story )

It's got a noise and I would like to narrow the possibilites down before I decide what to do. (17 year old son flipped his Neon -- didn't even need a band-aid but car is totaled. Yes, he believes in seat belts now )

Noise is a tapping/knocking, seems to be in top left rear of engine. One guy says wrist pin, another says lifter, etc.

It's worse under acceleration, but not always.

What can I check to help narrow down the problem? I've got a stethoscope to help. I've been told to pull plug wires to see if it stops the noise to isolate which cylinder, but is there anything else I can do?

Love to put a 3.4 in it, but can't find one, etc, etc, etc.
offline   Reply With Quote
Old 12-02-2005, 06:02 PM   #2
BOBCRMAN
Member
 
Join Date: Nov 2005
Location: Holly
Posts: 624
Default Re: Need help with Chevy 2.8

2.8-3.1 engines sometimes loose a rod bearing. Due to the GM aluminum oil pump wearing out. When this happens it is common for the piston to hit the head on each revolution and sound like the problem is on top. If the noise is approx 1/2 engine speed it may be a pin or broken/galled skirt
offline   Reply With Quote
Old 12-02-2005, 06:04 PM   #3
Grinder
Member
 
Join Date: Mar 2001
Location: east of eden just south of taintsville fla.
Posts: 735
Talking Re: Need help with Chevy 2.8

Quote:
Originally Posted by Fat Hack
Boy, you're really painting a bullseye on your ass asking about a 2.8 in here!!

(Especially if you're not slipping it into some old tin!!)

Anyway, try pulling the spark plug wire off the cylinder that you suspect a problem with hile the engine is running and see if the noise goes away.

(Sometimes taking the load off of a bad rod or wrist pin will silence it.)

The valve covers come off easy...I'm betting you'll find a loose or broken rocker arm, or maybe a bent pushrod if you go looking.

There's a bunch of things it COULD be, and it's really hard to diagnose from here...but mind the basics...does the oil pressure light come on or flicker at all...especially at idle? A spun bearing will cause a drop in oil pressure usually.

Is it a ticking noise, or a knock?

S-series 2.8 exhaust manifolds are VERY prone to cracking, warping and leaking...and will produce an exhaust noise that can be heard very plainly as a loud ticking sound...the 2.8 in my 49 Chevy leaked at the back of the passenger's side exhaust manifold...I just ignored it, because I knew what it was and didn't really care...the car was a fun summer beater!

2.8 Chevy motors can take more abuse than most will imagine...I've run 'em out of oil and coolant, overheated them, driven the crap out of them and just plain abused them. Never had one fail yet...something I CAN'T say about small block V8s!!

Put some top lube in it for vavles and lifters and run a tank of super high test in the tank. My 92 pu has v6 always ran high test in it started to use low grade an the knock started same as what you describe.Try that first.
offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 12-02-2005, 06:08 PM   #4
Grinder
Member
 
Join Date: Mar 2001
Location: east of eden just south of taintsville fla.
Posts: 735
Default Re: Need help with Chevy 2.8

Quote:
Originally Posted by Grinder
Put some top lube in it for vavles and lifters and run a tank of super high test in the tank. My 92 pu has v6 always ran high test in it started to use low grade an the knock started same as what you describe.Try that first.
P.S just like fat hack said.I had one blow a hole through a water passage.
offline   Reply With Quote
Old 12-04-2005, 03:52 PM   #5
Grinder
Member
 
Join Date: Mar 2001
Location: east of eden just south of taintsville fla.
Posts: 735
Default Re: Need help with Chevy 2.8

Quote:
Originally Posted by Grinder
P.S just like fat hack said.I had one blow a hole through a water passage.
well what did you find out
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 On

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 05:22 AM.