[sbhatcher]

Sorry if this has already been asked, but I could not find an answer by searching.
I have a 2001 Rodeo S V6 4x4 with the five speed. It has about 34K on it.
The issue is a noise that showed up around 31k. At 3000 rpm the engine makes a rattling noise and there seems to be minor power loss at that point.
I've had it into the dealer twice, and they claim that this is just "typical" Rodeo engine pinging, and that it would go away if I used higher octain gas. Well, I tryed running premium in it for the last few weeks, and it has not helped. If anything, its gotten slightly worde during this time.
Is this typical? Has anyone else had this problem, and if so, what fixed it? I would like it if I could tell the stealership what to look for, since it is under warrenty still.

TIA,
Shannon

 

[jdeal]

Are you sure it's not a lifter making noise? Isuzu are notorious for lifter noise. Does it get worse near oil change time or when cold?
I've also seen loose belts slap.

 

[JTK]

Yep. The lifters can be a PITA on the pre 1998 isuzu 3.2's. 1998+ do not have hydraulic valve lash adjusters. These engines use mechanical / solid shim & bucket adjusters. Sbhatcher, are you sure it's not a heat sheild vibrating somewhere? Also, I've seen & driven 5spd manuals (mostly GM truck variants) that rattle a bit in 4th & 5th. Was told that its a idler shaft in the tranny. Have you checked / changed the tranny lube recently?
G/luck
Joel

 

[2eyefishclaw]

the noise you are describing is most likely what is called spark knock caused by predetonation (timing issue) do not use higher octane fule for this will probarbly only agrivate the situation. There is a PCM calibration update avaiilable for your Rodeo (DEALER) which may help. NO it will not be cosidered as a warranty issue because it is treated as an adjustment which is covered for only 12 months or 12000 miles good luck I hope this info helps.

 

[wrenchmonster]

Howdy folks. Is the noise high or low in the motor? If it's high up your probably have a top end problem, which can cause, but generally is not related to pre-detonation. I think what 2eyefishclaw is referring to is the fact that the knock sensor will send a signal to the ECM telling it to retard the timing, hence your overall loss of power feel. However, with only 34K miles on the motor, I highly doubt you have a pre-detonation problem. Also, octane refers to a gasolines ability to burn evenly. Higher octane gasoline actually burns slower and more evenly. The kind of burn you want is like a grass fire, not an explosion. This is why your dealer tech probably recommended a higher octane gas. I don't think a higher octane gas would hurt your vehicle, but I also don't think it would help your vehicle either. Basically, you don't have to put any higher octane gasoline in your vehicle than what it was designed for. I would definately take advantage of any factory approved ECM reprogamming. Although I would think your dealer would do this for free or next to free, especially if there is a TSB on the subject. Don't let them rake you for $500 bucks to make a few programming changes.

-Kevin

 

[2eyefishclaw]

there is no service bulliten for the spark knock and if you have a decent dealer they wont charge more than $30/$40 Isuzu used to pay up to one hr. for this but if the dealer is equipped properly, which they should be it will not take more than ten minutes for an update programming

 

[Amigo-2k]

Just found this on another site:

My '99 Passport has been pinging every now and then. I started reseaching until I read a detailed article written by a chemist who used to work at Mobil, formulating fuel additives for mobil gas.

This is what I learned, any brand of gas will have their own kind of residue that tend to build up unless you switch to another brand which cleans up the residue but the second tends to form it's own residue. It was recommended to switch to another brand every few months to prevent residue build up, I switch every fill-up. Bottomline, switch from one brand to another. I also switch from 87 to 91 octane depending on the presence of the ping and then back.

I used to pour chevron techron fuel system cleaner with consistent elimination of ping but it then came back after about 2-3K miles. Now with gas brand and octane joggling, pinging has been well under control.