Hi All-
Please bear with me, this will be a little lengthy as I describe the issue that arose on Sunday. Some background first, I am a new Blazer owner for the the last month or so. I love it, and it runs great. Some minor issues I have fixed (replaced tranny fluid) or need to fix (shocks are bad), but it is in great shape and the main components are in fine condition. The only past issue from the previous owner was a replaced alternator, guage cluster (which may be acting up again), and an idler arm. It is a 1998, 4D, 4X4, with 104,000 miles. Now the issue...

So, I was coming back from up north this weekend. Ran fine, pretty much highway speed with no slowing down till I neared my house (~75 miles). As I get off the exit ramp and start to slow down, I hear this grinding noise from the front passenger side. As I pick up speed to go through the lights, I hear it again. So, before I park it, I continue to drive it around in a parking lot and listen. I pretty much heard it at any speed, louder the faster I go. I didn't really notice if the sound was dependent on which way I was turning, but it made the sound going straight. I couldn't really hear it in reverse, though I may not have been going fast enough. If I get going fast enough and hear the sound, then I drop it in neutral, I still hear the sound with no change. So I know it is not the transmission. Putting on the breaks only seemed to quiet the sound down, but I think it was because I was slowing down. So, after reading several posts from this forum, I deduced it was the front passenger side wheel bearing. Not the worst, I can get to it over Memorial Day as I will be replacing shocks as well.

So, I go out to listen to it again last night and don't hear it, at all. I jack up each wheel and spin it, they both sound the same, nothing unusual. I try rocking the wheel back and forth, both from the 12 & 6 position and 3 & 9 position. Only the 3 & 6 position seemed to have some play with the steering wheel, but it seems like that is common to some degree. Either way, I can't reproduce the sound. CV boots look fine.

I am baffled as to what it may be. Would driving it for 70 odd miles have gotten it nice and hot, thus causing it to make noise that I am not hearing after sitting all night? I imagine if it was the bearing, once it started making the sound, it would all of the time, right? What about something caught in the brakes? Not sure how it would have fallen out over night, but maybe. Any other ideas? I am kinda glad it has gone away, but not really. I like to take care of issues as soon as I notice them, but if I can't track this down, I can't fix it. Thanks everybody. Let me know if I need to supply more info.

 

Being a 4wd, I would have to wonder if your vacuum actuator isn't somehow applying partially, causing the noise. Try disconnecting and plugging the vacuum line to the actuator (under your battery tray), then working the cable back and forth to make sure it is free. The cable will need to be pressed all the way in (away from the actuator) to be disengaged.

 

Thanks for the suggestion. I can give this a try. What does the vacuum actuator do?? It sounds like you want me to just disconnect it, make sure the tube is free, and then reconnect, right??

Would this explain the sound seeming to come from one side?

 

The vacuum actuator engages the front axle when in 4wd. If, for some reason, it is getting vacuum supplied to it when not in 4wd, it could explain the noise you are experiencing. It is something else to check as you have checked most of the common drivetrain components already.

 

Hey swartlkk-

Thanks for the info and suggestion. I took a look at the actuator tonight, but this has completely gone weird. Sorry for the double post, I didn't realize I put it in the thread listed below.

So, after the last two days, this has morphed into a much greater problem, and much weirder. I have a longer description of what has happened in this post(Sorry, don't know how to post links to it):

Need help with front end clicking noise.

Seems I have the clicking again, and it's louder. And on top of this, an electrical problem. Everything is going bonkers. I see somebody else had almost an identical problem, but I could never track down what happened with it. Any ideas??

I pulled the battery out and checked the actuator, but I am not sure if I did it right. I am going to look at it again tomorrow and try the disconnect. Also, resetting the computer with the battery out didn't seem to fix the electrical problems or reset the codes going off. The dash information/lights and 4WD lights are all acting weird. Fuse blown or computer fried?? Thanks a bunch!!!

 

Quick update. Before work today, I went out and was going to have my wife drive it forward while I tried to listen and pinpoint where the "clicking" noise was coming from, if it was coming from near the vacuum actuator. Well, now it doesn't make the sound but all of the dash lights and guages that were screwed up last night, still are.

Has anybody heard of an electrical malfunction that would cause some warning lights to go on, some of the guages not to work and allow others to be fine, and also screw up the 4WD system such that the lights indicating what drive it is in are not lit up, pressing the buttons does nothing, and may be causing the vacuum actuator to pull vacuum for no reason every now and then.

I am pretty confident this is some weird electrical problem, but that only makes it harder to track down. So much of the vehicles now a days are electrical, so like finding a needle in a haystack. Thanks everybody for any suggestions.

 

Further update:

I talked with a mechanic friend of my family. He mentioned that some of these Blazers had issues with a faulty ground on the firewall. Said that may explain some of the weird electrical issues I am having. Since my shocks are bad, perhaps a hard bump finally took its toll. Any body have experience with something like this? He said I should try putting a new wire to reconnect the ground. Going to investigate it Friday night. Thanks.