Noise: "Squeak Squeak" on cold start

[sevenhelmet]

It's something in the fuel system.

I started up and crawled underneath this morning to have a listen. The noise is definitely coming from the front of the fuel tank- if I had to place it, I'd say its coming from the fuel filter. I suspect something to do with either the filter bypass or the fuel pump itself (hope not- that's going to be a pain.)

Any suggestions on a remedy? With nothing else to go on, I will probably try swapping the fuel filter and check for any vacuum leaks in the area. Might be a week or two before I get around to it though.

 

[jp22l]

Mine has doen exactly the same thing for close to 2 years now. Only when it is below maybe 50 degrees. I have always wondered what it was but is goes away so I have never bothered to look at it.

 

[trent.brown]

Chrysler has a leak detection pump that sits right on the front of the fuel tank. It puts pressure in the fuel tank for the first couple of minutes to test the operation of the evap system. It looks round and flat with an electrical connector and some hoses running to the engine and evap canister about a foot away on the drivers side. Put your stethescope or screwdriver up to it and see if that's not it. If it is, then it'll cost about 50 bucks at napa. Or live with it know its nothing serious. Good luck, if not LDP, then I would check the other parts of the EVAP.

 

[sevenhelmet]

Chrysler has a leak detection pump...

I think you might have something there. The noise is definitely coming from something round on the front of the fuel tank, up near the evap, and it always stops after the same interval, about 2 minutes.

Funny that it only does it first thing in the morning, though.

 

[sevenhelmet]

Started up this morning with a full tank of gas and... NO NOISE!

I wonder if it only does this below a certain fuel level. Let the experiments continue!

 

[trent.brown]

Any luck?

 

[sevenhelmet]

Not yet, it hasn't done it since I filled up with gas. I'm back down to 3/4 of a tank, and still haven't heard it. I did run seafoam through my last tank, I wonder if that changed something.

 

[Paul M]

Again, fuel pump...especially if a full tank eliminated the noise. Further thought suggests it may not be the pump itself but it could be loose which makes a noise every revolution of the pump.

 

[sevenhelmet]

Update:

Squeaks below 3/4 of a tank, but still only for 2 minutes after start and only the first start of the day, regardless of outside air temperature. I've started from 50F to 100F, and it only squeaks after sitting overnight. After 2 minutes, it just goes away. If I leave it parked at work for 10-12 hours during the day, it doesn't squeak on the way home.

My money is still on the leak detection pump. I plan to replace it, but not for a while- things have gotten crazy at work and at home so I don't have time for something so minor.

 

[trent.brown]

Before you go spending money on it, just unplug it one night, then in the morning if it dosent squeak then that's what it is. It will throw a code but when you plug it back in, it will go away. I'm not sure if it would squeak, but its
1. Electrical (doesn't correlate with rpm or speed)
2. Only runs for the first few minutes of operation.
3. Attached directly to the front of the fuel tank.
If it still squeaks with it unplugged then its probably going to be the fuel pump or maybe even one of the straps that holds the tank.

 

[sevenhelmet]

Newest update to the Evap debacle, yesterday I started up to go to Home Depot, and heard the squeaking. My tank was nearly full. Within 2 minutes of start, I had a check-engine light with P0455 code (large leak detected.) Yes, I checked the gas cap.

I crawled underneath and checked all the hoses again. I couldn't find anything wrong. My guess is the leak detection pump is failing. Unplugged the battery to reset the code, so we'll see if it does it again.

I'm honestly wishing I could get rid of the evap system completely. It's been the source of multiple check engine lights, it makes funny noises, and the hoses dry-rot at an alarming rate.

 

[sevenhelmet]

Does anybody know where I can find a 2003 KJ leak detection pump? I can find 2004-2006, but I think that gas tank is different than mine (18.5 gal.) There is no Chrysler dealership near me, and most online stores don't seem to carry one...

 

[trent.brown]

I had to get one from the dealer. Did you disconnect it and see if the noise stopped?

 

[sevenhelmet]

Nope, that's my next troubleshooting step. If it wasn't for the check-engine light it's now throwing at me once a day, I'd just be content to leave it alone. I hate the evap system.

 

[sevenhelmet]

Took me a while to get around to it, but:

Solved! It was the LDP (Leak Detection Pump.) It is very easy to change, but awfuly expensive for such a non-essential (IMHO) part. I got a discount and still spent $100.

The odd thing is the CEL went out on its own after a few days, although I still had the P0445 and P0442 codes. However, the codes cleared on their own after installing the new Leak Detection Pump and running the engine, and NO SQUEAKING!

 

[tjkj2002]

The odd thing is the CEL went out on its own after a few days, although I still had the P0445 and P0442 codes. However, the codes cleared on their own after installing the new Leak Detection Pump and running the engine, and NO SQUEAKING!

That will happen when the PCM goes through so many starts without a failure from that system.

Testing the LDP in a KJ is so simple,just need a vacuum pump and DVM.

 

[sevenhelmet]

I'll be sure and put those on my Christmas list.

 

[trent.brown]

Im pretty sure I didnt pay that much for my ldp, maybe 60 or 70. But thats in Georgia

 

[sevenhelmet]

Prices online seemed to range from $150-200, so I thought I was getting a good deal at $89+shipping. Either way, it's on the Jeep now and everything is working fine, so I'm not going to f#$% with it.

Until next time, evap system.