Calling all chevy gurus-need help!!

[polevault1977]

I have a 99 chevy 1/2 4wd new body style in the shop right now. I am having a popping noise in the front suspension. The mechanic and I can not find what it is. Checked upper and lower a arms, all ball joints, axles, torsion crossmember isolators. It's not the intermediate steering shaft. Been there. I feel the popping sometimes where the crossmember torsion bar ends. It feels and sounds like it is coming from the front right.

You'd be a hero, if you could solve this one!!!

Thanks in advance, Danny

[DirtyLarry]

One additional item for them to look at is the engine mounts as they are a somewhat known problem as the isolators in mounts get brittle and fall out as a result of heat damage from being so close to the exhaust manifolds on the Gen III engines. This can cause an audible popping noise and a horrible sensation through the steering wheel similar to a dry intermediate shaft depending which mount fails. In most cases, you will not notice an engine vibration although you should see the air intake pipe will be very close to the fan shroud, possibly to the point where the two start wearing into each other.

About the only way to get a good view of the mounts to verify if the mounts are wasted is to remove the front tires and inner fenders and peek at it from the side.

GM released a new engine mount with a heat shield to prevent this from reoccurring. The new design mount is 25828247.

Hopefully this will help you as I have seen many of these trucks with this condition. Good luck and let us know what they find.

Here is the new mount vs. a toasted original.

[polevault1977]

Thanks DirtyLarry, I just left my mechanic a note in his mailbox stating your reply. Hope this is it. We are really have a hard time finding this one. danny

[DirtyLarry]

Being they have been through everything else there is a good chance one of engine mounts (if not both) is toast.

If so, the driver’s side isn’t too bad to change but the passenger’s side requires the exhaust manifold to be removed. While the inner fenders are out of the way, it is a perfect time to throw in a fresh set of spark plugs while your mechanic is already there. Especially, if the truck is over 100,000 miles on the original plugs.

Keep us posted as to what the find.

[truckdude239]

just be sure to use platinum plugs in it

[polevault1977]

Engine mounts OK. This is going to sound crazy, but he replaced the front shocks, I think they were ok, but we did anyway. Relaxed front suspension and loosened everything, I mean everything. Lubed, aligned, torqued, set z height, etc. and upon reassembly, no more popping. The truck has never dirven so well. Got to get an alignment now. I really don't know what was binding and popping, but for now it's gone. Thanks for all the help.

As for the sparkplugs, I changed them about 20,000 ago. Parts house sold me iridium instead of platinium. Did I goof up? Seem to be running ok with 17.5 mpg.

[DirtyLarry]

Wow, that is odd it turned out to be something simple like shocks?? Glad it worked out though as that is much cheaper than the mounts.

I am not familiar with the plugs you mentioned as I only have used the OEM replacements…whatever they were.

[nekkidhillbilly]

steering shaft

[truckdude239]

almost all the new vechicles require a platinum plug, they has less resistant and last longer normally around 100k miles. older style plugs are called Resistor plugs. my roommate had a focus that called for the platinum plugs and she had someone install Resistor plugs and it burned up the plug wires ever 3 -4 weeks till i figured out they had the wrong plugs in it

[polevault1977]

Originally Posted by nekkidhillbilly

steering shaft

Already replaced.

Thanks for all the help, this forum rocks. Now back to working on the old 67.

dkf

[polevault1977]

I'm not going to start a spark plug debate, but I did a little looking and I think I'll be fine with my iridium plugs even though OEM's were platinum.

"Until recently Platinum was considered the best material to use on the top of an electrode of the sparkplug, because of its durability. How ever Iridium is 6 times harder, 8 times stronger and has a melting point of 1200 degrees higher than Platinum. Put that into a harsh environment such as an engine piston chamber and you have a spark plug that can resist wear much better than Platinum. Iridium is one of the most unique minerals known to man."

Here's a link to the above article. http://ezinearticles.com/?Iridium-Spark-Plug&id=101054

I realize this is just one man's opine, but since I have installed them, I'll just keep on truckin'!!

Thanks again,

dkf