Engine/Transmission (1994 - 1998) Truckl making noise?

[TravisG]

My truck is making a noise. Not really at idle, but while I am driving down the road. I guess if I could describe the noise a little bit it would help. It kind of sounds like a light knock or a tick, and it seems to be coming from the bottom end or on the drivers side. I am a little concerned because when I checked my mileage today. I only got about 12mpg. Does anyone have any suggestions. I know this is kind of vague. But any help with somewhere to look would be apprecieated.



Travis



p. s. I thought that it could be a u-joint or something drive line related, but I checked all that and there does not seem to be any problems there.

 

[SMorneau]

It may be a pulsing noise transmitted thru the fuel lines. Use a mechanics stetascope and listen to those and the lift pump. Also check the lift pump.



Let me know what you find.

 

[rnolen]

I might have the same problem as you. I was driving in town and rolled down the passenger side window and there was the sound. I checked the driveline as well and could find nothing. I can only hear the sound with the passenger side windown down and I need to be up against something (guardrail or cliff) to clearly hear it. We are going to put it on the lift in the near future to find out what it is. but everything back there was greased and full of fluid. I will let you know, and please keep us updated on what you find. I don't think my mileage has dropped any because of this.

Russ

 

[mullady76]

The Lift pumps my guess. I had a similar ticking noise coming from drivers side of the engine. The sound got worse over time. I wound up replacing the L. P. because I found metal shavings in the fuel filter. After the replacement the ticking went away.

 

[TravisG]

Just replaced the lift pump about 15k ago. Do they go bad that fast? How do you check the lift pump? My F. P. is pretty good I think. About 25 to 30 in the morning, and about 20 the rest of the time. Maybe I should change the fuel filter.



Oh yeah, I figured out why my mileage took a dump. For a few dayz last week w/ the snow and ice, I had a bunch of sand in the bed. Sometimes I think I would lose my head if my wife didn't keep it in her purse.

 

[mullady76]

The reason I replaced my lift pump was because I found metal in the filter house. I later found out that the ticking noise was the plunger on the lift pump was bouncing off the cam lobe. BTW The pump was working fine when I changed it.

 

[SMorneau]

so if the pump is making a noise like tapping on the cam wouldn't the noise be obvious at the pump with a stethascope?

 

[JohnE]

I noticed ticking type noises in the recent cold weather. I thought it was lift pump or other related things, but determined it was the heavy amount of #1 fuel I was running. Filled up tonight on straight #2 which droped the #1 ratio from 70% to less than 30% and the truck got really quiet.

 

[Coalsmoke]

I thought we didn't have to worry about lit pumps on our years (94-98) of truck.

 

[rnolen]

This sound doesn't sound like a fuel sound. My reaction was the same as TravisG's. I checked the driveline and everything seemed ok. I can hear the sound in what seems to be the rearend of the truck. Fluids were fine back there. We are going to do some brake work here in the next few day and will be having to take a look at the rear brakes. It seems that the sound is moving along with the speed of the truck. If we are moving fast it is faster and when I slow down it slows down with me. I did notice that it stops when I turn a corner. After learning that I am baffled at what it could be. I will still try and determine if it is the lift pump or not. I don't drive the truck everyday. Usually on the weekends and maybe on day out of the week or so.



Thanks in advance

Russ

God Bless

 

[BNH4221]

Are you sure it is not the U-joint? I would think that if it increases steadily with speed then you could rule out the engine by increasing engine speed without the vehicle moving.



If you are stopped and raise the engine speed does the ticking increase? If not, I suspect driveline.



2 thoughts:



First, front u-joint. I had them go on my 95 gasser and it was a steady ticking while moving that increased with speed.



second, brake shield. sometimes they get bent a little and rub on the rotor. It's a long shot but worth a check.

Probably more of a squeak squeak squeak if it is a shield.



Best of luck



Steve

98 QC 12v

158000 happy miles.

 

[rnolen]

I will recheck the u-joints. When you said front u-joint went out on your gasser I am not real sure I checked them all the way up. I am going to be doing some brake work next week as well as the fuel lines, so I will double check on brakes. If I am stopped the noise is not there, whether I rev the engine or not. That is also why I thought it was not the LP.

Thanks

Russ

God Bless