weird engine noise between 1800-2200 rpm

Dragonmaster · Post by **Dragonmaster** » Thu Jul 17, 2003 8:18 am

Found this through GM's techline too:

Owners may comment about a noise coming from the engine between 1800 and 2200 rpm on some 1996-2003 Chevrolet and GMC trucks with the 4.3L V6 engine.

The rattle noise may be caused by torsional vibration of the balance shaft. A timing chain tensioner kit has been released to deal with this condition. The tensioner consists of a bracket which holds a nylon blade against the timing chain.

Components are shown in figure 5.

A Front cover

B Tensioner bracket

C Nylon blade

D Washer

E Dowel pin

F J-46165 Pin Driver

TIP: The noise may resemble detonation or spark knock, which must be ruled out before installing the tensioner kit.

Here are some of the highlights of the procedure. An upcoming bulletin and an IDL broadcast will provide additional information.

The engine front cover must be removed for access to the crankshaft and camshaft sprockets and chain. The camshaft chain must be removed. Depending on model year, either the cam gear or crankshaft sprocket must be removed to do this. Follow standard SI procedures.

The tensioner bracket fits over four existing holes (fig. 6). The upper two are the front cover center bolt holes. And the lower two are front cover alignment holes.

TIP: The nylon blade must be temporarilly removed from the bracket.

With the tensioner bracket in position, use J-46165 Pin Driver to drive dowel pins into the two bottom holes to retain the bracket.

Follow the bulletin procedure to complete the installation of the chain, nylon blade and sprockets.

TIP: The kit includes two washers. Place them under the two center cover bolts, which extend through the tensioner bracket. These are required to maintain proper crush on the engine front cover seal.

Post by **HenryJ** » Thu Jul 17, 2003 9:52 am

This is really good stuff!

Keep those techline updates coming

Anything that might affect a S-series is good information

Thanx.

Dragonmaster · Post by **Dragonmaster** » Thu Jul 17, 2003 10:02 am

I posted a few more over on the temp zrt2.com site as well to do with feet clunks, it said if you have an uadible clunk at your feet that you may need to put shims/washers between the torsion bar mounts and the frame but to make sure that the gaps were even on both sides of the crossmember to the frame. The other one was a water pooling in cab thing which is too long to write and probably won't affect most crews but it is there if anybody wants to read it.

ExMoparMan · Post by **ExMoparMan** » Thu Jul 17, 2003 10:07 am

I dont know about this fix. When I was turning wrenches we had a street sweeper that had teflon blocks as chain guides & Tensioners and they wore fairly fast with daily use. any burrs on the chain and peices of teflon will end up in the oil pan

What do you do if the blade wears off? Maybe I am just over reacting and this is a good thing

Post by **HenryJ** » Thu Jul 17, 2003 10:35 am

ExMoparMan wrote:I dont know about this fix... What do you do if the blade wears off? Maybe I am just over reacting and this is a good thing

I don't think it would be an issue. The 60* V-6 (2.8L, 3.1L. 3.4L) has a , what sounds to be similar chain tensioner.

I haven't heard or seen problems with those.

However, I still have reservations as you do. Unless it becomes a real problem for me , I'll live with a little rattle now and then

Jim · Post by **Jim** » Thu Jul 17, 2003 11:09 am

I'm not going to jump at this fix just yet. I really want my engine quite. I don't think the tensioner will wear down, back when I used to work on Mercedes the1972 2.8 inline 6 w/ double over head cams had tensioners & followers that never wore down. To point out how far ahead of its time the engine was it's design is almost identical to the GM 4.2 inline or should I say is it GM is finally getting a good design.

Socaldave · Post by **Socaldave** » Thu Jul 17, 2003 1:40 pm

Hey DragonMaster,

Can you provide us all with the link to the GM's Techline. I have that balance shaft rattle pretty bad. Would also like to read up on the "Foot Clunk" as well.

Thanks

duce · Post by **duce** » Tue Sep 23, 2003 9:54 am

ok i don't no if this is the same noise but when i get my rpm,s up between 2000 and 3000 i get a noise also. i cant really describe it but it only happens when the engine is hot .so i went to my dealer and had thir noise expert come along for a ride and he was puzzled buy the noise.so my truck is going into the shop on thursday so they can try and find the source.i will let you no what they find.....

Dragonmaster · Post by **Dragonmaster** » Tue Sep 23, 2003 12:04 pm

Socaldave wrote:Hey DragonMaster,

Can you provide us all with the link to the GM's Techline. I have that balance shaft rattle pretty bad. Would also like to read up on the "Foot Clunk" as well.

Thanks

go to service.gm.com and clcik on techline at the top of the page.

Hey Duce, let us know what the noise turns out to be as i have the same type of thing, but it is only between 2500-3000 rpm.

Warnoffroad · Post by **Warnoffroad** » Tue Sep 23, 2003 5:37 pm

do u have a T/B spacer?

Dragonmaster · Post by **Dragonmaster** » Tue Sep 23, 2003 7:48 pm

warnoffroad wrote:do u have a T/B spacer?

nope

duce · Post by **duce** » Wed Sep 24, 2003 2:21 am

they are keeping my truck for 24 hr so i will get it back on friday i will post the result than.its going to suck driving whatever loner they give me

Socaldave · Post by **Socaldave** » Wed Sep 24, 2003 5:25 am

DragonMaster,

That "service.gm.com" techline is a great site. I looked at it only briefly and saw several items that relate to my vehicle. The Balance shaft noise, the unreliable gas gauge, etc. Thanks for the info. I will look at it in more detail when time permits.........

Dragonmaster · Post by **Dragonmaster** » Wed Sep 24, 2003 8:37 am

Socaldave wrote:DragonMaster,

That "service.gm.com" techline is a great site. I looked at it only briefly and saw several items that relate to my vehicle. The Balance shaft noise, the unreliable gas gauge, etc. Thanks for the info. I will look at it in more detail when time permits.........

From the first part of the site there are a whole bunch of other resources that come in hady too, you just have to snoop around a little to find them.

duce · Post by **duce** » Thu Sep 25, 2003 3:12 pm

ok got my truck back today and here is what they said ,02 sensor connector contacting floor. rode test, did not hear noise still after engine warmed up with shopforman,still check under vehicle for any miss contacting. check exhaust system ok,found front 02 sensor conn mounted on top of trans left side contacting the floor of driver seat, inturn at certian condition it will crate noise.so i have no idea what all that means so maybe you guys can make sens of it.also had them look at another thing while they had it their...i have noticed on top of the roof pitting or blistering of the paint

also a little on the hood,they say it is from(now get this) dead bugs

aparintley if you don't remove dead bugs from your truck they will decompose and blister your paint as you can guss i did not buy this and called gm to complain they will be getting back to me on monday to see what can be done...

S-10CREWCAB.NET

weird engine noise between 1800-2200 rpm

weird engine noise between 1800-2200 rpm

update on noise and dead bugs.....