Gremlin Chasing - loud whistle

[Evil-Jeep]

2003 TJ, 4.0L

So water pump went last week, no problem I replaced the pump last Monday(1week 2days ago)

all seemed fined, thought maybe the engine was a bit warmer than usual, but thermostat sat were it should, so I figured I was just being overly paranoid.

2 days ago started to get a loud whistle, didn't have time to look at but figured it was probably just a vacuum line or that the throttle body needed cleaning.

...... Today..... Can hardly get the jeep to go 100Km/hr in 4th gear, burned 1/2 tank of gas to work and back (80kms round trip highway) and she is screaming like a teapot, and everything is hot.

I figure I must be burning exceptionally lean, and this is likely causing it to run hot, new pump and fan are still keeping thermo stat readings in check.

So, did I possibly miss something during the new water pump instal, is this just a new problem. I am leaning towards a vacuum leak as I can not detect any exhaust leak, and can not hear any ticks while listening under the hood near the exhaust manifold.

I have sprayed carb cleaner along the base of the throttle body, vacuum lines, injector seals and ran throttle body cleaner down each vacuum line.


The whistle is not present at start up, but occurs when idling down or letting off the gas, the slightest pressure on the gas peddle removes the whistle.
both sensors on the throttle body have been replaced belt has been replaced. and I cant hear exactly wear it is coming from as it is too loud to pin point.



Thoughts, or suggestions to trouble shoot?

[TL-Iguana]

The whistles go wooop wooooop!

did you install the thermostat the correct way? They will fit in upside down as well.. Not sure if this would cause a whistle but could definately cause you to overheat..

[binare]

Get a funnel and a length of hose. Attach hose to funnel, hold funnel to ear and move hose around engine bay till you pinpoint the whistle. Works like a charm.

[Evil-Jeep]

Hoping I may have air or steam in the system, it would make sense other than the whistling dropping off when I am on the throttle, but who knows. Has any one delt with steam issues due to air or improperly mixed coolant.

[BUKI]

I would worry more about the running lean. Have you checked your plugs?? If you are lean, your plugs would be white. BUT if you are going through that much fuel my guess is rich, black and maybe wet. Could be a plugged cat too.  A whistle that goes away with throttle could be your throttle body loose intake manifold leaking... Or major exhaust leak letting fresh air into the manifold messing with your o2.


Sent from my iProne

[Evil-Jeep]

Sorry, I meant running rich not lean.

Checked Codes Last night...... nothing there.

Checked throttle body bolts.... 1/8 - 1/4 inch turn on each, no difference.

I think I may pull the water pump back off and redo that instal as well as try another new thermostat, and flush the system, as this all started shortly after putting in a new water pump.

[Evil-Jeep]

Not fluid level in the rad,

I also discovered that driving 50km/hr down hill for about 2km, will temporarily solve the whistle sound.

[TL-Iguana]

if your rad cap is not the highest point in the system then it would still look full even though there may still be air in a hose somewhere.. Driving downhill would put the high point further back causing the air bubble to move as well. Still not sure why its whistling...

[Evil-Jeep]

Well long story short...... take everything apart and put it all back together and the whistle is gone... for now.

[Evil-Jeep]

squeal fixed.....

Now I am so bogged down I cant get it to do 60 or 3000rpm out of gear

Error Code p0174 - Fuel System 2/1 Lean


At least I have something to work with now

[morerpmfred]

That whistle sounds like a vacuum leak. Vaccum hose cracked somewhere? Leak on intake manifold gasket? Throttle body leak ? All would cause it to run lean and overheat and computer would try to make it run rich.

[Evil-Jeep]

From what I have been able to make sense of is that Code p0171 is the front most bank and p0174 is the rearmost, I only have the one code - p0174.

This should rule out a leak at the throttle body, or any of the hoses..... it could be the gasket on the intake at the rear bank

I actually got rid of the whistle, but I am have also opened up the leak enough to prevent it from sounding.....

Guess now is as good as time as any to replace the intake gasket.

[JENSSEN]

Have you tried checking the torque on the bolts? I have had a few jeeps cured by tightening intake bolts,.. If you think the gasket is leaking use a unlit propane torch and run it across the manifold to head gasket. If the rpm increases you have a intake or vacume leak

[Evil-Jeep]

Longer sigh.....

Pulled the spark plugs out, front bank looked good. rear bank heavily carbon fouled. Cleaned and put back in.

Good suggestion on the torch...... ran on top and under no change. Reset computer and revved up, all seemed better.

And then I backed out of the driveway....

within 10 feet she bogged down, RPM won't even go up to 2000rpm. Clutch in no RPM's over 2000 rpm.

I would almost say bad fuel or clogged filter if I had both codes or any evidence in both banks.

Guess I will start replacing sensors, any other suggestions?

[Evil-Jeep]

I did re-tighted the bolts to the intake manifold, about 1/8 - 1/4 turn each