Hello, I have a 99 that has been makign a really strong chugging noise through all RPM's. I first really noticed it after changing the harmonic balancer last winter. (I also changed the water pump, and radiator cap, the engine overheated a few times)

Here's the video:


I have already:

Changed the spark plugs
Changed the wires
Changed the Distrbutor Cap
New TPS
New IAC
checked for Vacuum Leaks (though how competently I cannot say)
Cleaned the throttle body
Disconnected the upstream O2 sensor
Checked for the obvious signs of a head gasket failure (Oil looks good, checked the spark plugs, they looked fine)
I am going to change the PCV valve today.

I have a check engine light on, no I haven't pulled the codes yet. Yes I know I should do that.

I am just wondering if anyone out there can look at this video and say "Oh! I know what that is. It's _____"

My next step after the PCV valve will be a compression test, unless someone has a different suggestion.

 

Sounds like it might be an exhaust leak, but my suggestion for your next step is getting the codes read.. unless you just really like throwing money at it, hoping you solve the problem with blind luck.

 

Definitely don;t want to just throw money at it. Everything I've done so far was stuff that really needed doing anyway. Was just hoping that they were the cause as well. I'll check the codes

Is there any chance that it could be caused by a bad cps? I.e. that I did something that messed with it when I changed the harmonic balancer?

 

Unless you are complete mad man when it comes to throwing tools around, I can't imagine how you would do anything to the CPS while working on the balancer... they are not anywhere near each other... plus, the fact that it is running at all, tends to make me think there is nothing wrong with your CPS.

That noise sounds like with could be a small exhaust leak, or if it started directly after you did the balancer, perhaps your belt is not the correct tension. If you tightened it to much, you could be putting some real strain on some of the pulleys, with could be enough to cause a similar noise. You can always get yourself a mechanics stethoscope... I think I got mine for less then $5 at Harbor Freight, and pin point where the noise is coming from.

 

Solved this after trying all else....... my intake manifold was loose...... after messing with my TPS and checking forums it was as simple as tightening a few bolts that hold the intake manifold on........ it was letting too much air in, which threw the TPS off and would high idle... causing over heating...... tightened em down and now she purrs..... and never over heats..... I feel like this should be the first thing to check.... happens pretty often with these older jeeps.

 

 

The factory torque specs for the intake were too low. They frequently loosened up. we used to tighten them up at the 30,000 mile service at the dealer I worked for.
don't worry about using a torque wrench either. Nearly impossible and unnecessary.