denny805

Hi all -

I purchased a 1999 Suburban K1500 over winter and put about 1500 miles on it; ran great and got 17+ MPG. Changed the oil (and filter) a few weeks back with no issues. I also passed inspection without a problem less than a week ago.

So, to celebrate my new truck (I upgraded from an old Jeep XJ), I washed and waxed the 'burb Saturday (kiss of death I know). After, when I started it up, I could hear a click with a roughly 1/2 second frequency . Hoping it was something to do with a wet belt, I shrugged it off and finished cleaning up (didnt drive it anywhere but to the other end of the drive).

However - Sunday, I was ready to go fishing (finally) and when I started up the 'burb, the click was very loud. It's coming from the engine, on the drivers side, but I'm not sure of much else. I drove it around the block and I didn't notice a huge lack of power, but I kept the RPMs low (as to not put a rod through the block, etc.).

Now, I have been reading, and there seems to be at least a couple different possible problems, but I have a few questions:

1. Could I have damaged anything with water/powerwasher cleaning the grille area? I doubt it, but that was my frist reaction since I did not have a problem before the car wash.

2. If I unplug a spark plug and start the engine, what happens? ie - I'm thinking of removing the plug from the suspected bad cyclinder and see if there is still noise. I'm not sure what that would determine, but it's just an idea.

3. If it is a serious problem with a push rod, can I safely drive it to the shop or do I need to get it towed?

4. Without knowing other details, could doing an oil change help? What about additives?

5. I haven't let the engine "warm-up" with the noise (and I tdon't think it's piston slap) - but does piston slap always go away when the engine warms up?

6. Can piston slap be really loud? (this is much lounder than your typical deisel engine and more of a metal on metal sound than a slap).

7. Can simply removing the oil pan reveal serious issues?

8. If something usually goes wrong with the guts of an engine, isn't usually while the truck is running? I just don't understand how this could have happenend while sitting still...

9. If the problem existied when I purchsed it, could the PO have used fancy trickery to hide the noise? I've read about mystery oil, heavier weight oils, fuel additives, etc. She literally ran great wednesday, then this noise appeared on Saturday.

Thanks in advance, needless to say I've gone from stocked to bummed and my entire season of boating and fishing is in jeapordy. (And I starting to regret selling the old Jeep!)

Thanks,
Denny

73shark

Welcome to the forum.

If it has a metallic sound then it's probably not piston slap or sticky lifter noise. Maybe timing chain getting ready to let go. I'd get it looked at unless someone here has some more ideas.

denny805

cool thanks.

bill78

Drop the oil pan. If you find metal parts in the oil, you know the engine is starting to let go. You will know a lot before you seriously screw something up.

in2pro

if you can identify where in the engine the noise is coming form that will help narrow it down.

if its from the top of the engine its most likely lifter
if its lower it could be a rod bearing or cap coming loose.

I like your thinking on the diagnostics. thou discounting a plug wire in this case is not likely to help.

use a broom stick or an auto stethoscope to narrow down where the sound is coming from....and be careful with the engine running

zeke8226

does the noise speed up when you rev the motor up? one place to check is that it just might be a bad plug wire and the spark is arching