No I didn't trade my truck in for a Ford or Chevy

My truck has 8500 miles on it now and has had a loud knock at idle and lower RPM's since day one. My truck was a dealer trade and had 150 miles on it when I got it, so who knows what happened to it before that. From all the reading here, I didn't bother taking it to the dealer for the "Thats normal for a Diesel" speech. After hearing a truck that was 2 months older than mine, run much quieter, I decided to do something about it.

It took me a solid six hours to remove the valve cover,rocker arms and all six injectors then put it all back together. While I had everything apart I re-torqued the head bolts and adjusted the valves. I also put all the injectors back in the reverse order that they came out. #1 I put back into the #6 hole, #2 I put into the #5 hole ect. ect. just in case.

I was suprised at the amount of carbon built up around the nozzles of the injectors. For anyone that has not seen the tip of a diesel injector before,(like me) the holes that the fuel sprays from are almost invisible to the naked eye. There was alot of carbon right around the holes that would definitely affect the spray pattern, maybe even partially block the spray. Before I cleaned the carbon off I could not even tell were the fuel sprayed from. Being careful not to scratch the nozzle, I just used carb cleaner and a rag to clean it.

All the valves were within factory specs but they have a pretty wide tolerance so I adjusted them all to a little tighter than the midpoint. I don't think any of the noise was coming from the valvetrain. You have to remove the exhuast rockers to take out the injectors and you have to remove the intake rocker arms to torque some of the head bolts, so I adjusted all the valves after reassembly.

I had to remove the intake plenum and all the high pressure fuel lines to get the injectors out. Overall I didn't need any special tools and I re-used all the gaskets except the intake plenum gasket was torn and needed to be replaced. If my truck was'nt so new I would have replaced the valve cover gasket and the carrier assembly (goes under the valve cover, the VC bolts to it)gasket. Both gaskets are rubber o-ring style so I saved some money.

Now for the good news. It sounds like a different truck. I went to the drive-thru and didn't have to shut the truck off . The truck is quieter throughout the rpm range and felt really smooth. Hopefully with the Power Service I'm using now I can keep this from happening again. Feel free to ask questions.

 

Maybe those first 150 miles she was lugged & ideled alot. Now shes happy & will probably reward you for your TLC.

 

You must be a mechanic!! If not, I'm impressed, I thought I was doing good to change my own oil.

Jamie

 

Yes I'm impressed you jumped right in there. Glad you fixed it. I'm thinking the truck saw a lot of demo drives also . Never was worked hard. I'm wondering if a good workout, like towing 10,000 lb for a week with some fuel additive in there if it would have cleaned self.

 

I'm not a mechanic anymore but I do have my own shop. I only wrench for fun nowdays.

My last tank of fuel I put in a whole bottle of power service and I thought the truck might have been a little quieter but there was a suprising amount of carbon on the injectors that I don't think would have come off by itself.

Maybe 6 hours straight at 75 mph pulling our 7000lb trailer would've helped but I'll have to wait until spring for that.

I notice when I burn my fireplace really really hot it will burn all the soot off the inside bricks and make them look brand new again. Maybe I need to get the EGT up around 1300 more often.

 

gatf4-
Want to come to Tx and do mine ? ? ? ...... LOL
Weather sure is nice here this time of year ! ! !

 

Good job gatf4.

Everyone with problems similar would benefit from this. I think he hit the nail on the head.

 

Thats basicly what the dealer did to mine. The tech told me my truck with 14000 miles on it had more carbon builup than most he tears down at 200k. He said he used a tooth brush to clean the injectors and then reset the valves. The truck is a little quieter but not near what it was new. He said that if I dident change my driveing habits that the nois would come back. When the truck was new it was my daily driver. I would start it and let it idle for a couple minutes then drive 8 miles to work and shut it off. I never realy worked it hard. He said that it either needed to be worked hard on ocasion or not driven such short trips so frequently. Now it just sits in the garage all week and I resorected my old work car to drive durring the week. I asked if pulling hard would burn the carbon out and he said to hook onto 20k and pull it to Denver, 750 miles one way, that might help. This spring I intend to do just that, not because he told me to but because I already had a trip planed for Colorado with 6 of us taking ATVs out for vacation. The trailer wont be 20k but at least 10k. Hopefully that quiets it down a bit.

 

Thanks for the compliments. Texas sounds nice, but Colorado with ATV's sounds better . Seriously, if you were closer I'd love to help you out.

Our next trip will be to the Silver Lake sand dunes in Michigan as soon as they open in spring.

 

gatf4,

How hard was it to get the carbon off? What kind of rag did you use? I'd be afraid of accidentally contaminating a critical part (although I suppose most of the critical parts are located much farther up inside the injector).

I'm glad you posted this...it may serve me well down the road!!

Also, for curiosity, what did you use to turn the engine during the valve adjustment process?

 

I just used a regular shop rag soaked in carb cleaner. I kind of wrapped the tips in the rag to soften it up. I probably spent about 5 minutes with each injector. There is a small copper sealing washer up from the tip that i removed and cleaned also. There is a small groove under it that was filled with carbon. I used a really small pick to scrape that out.

My Alldata program said you needed a special puller to remove the injectors, but I just used some big Channel Locks and they came out easy. They may be harder to remove on a higher mileage vehicle. The program also said you need a puller for the injector supply tubes but I was able to pull those out with my fingers.

I just used a 24mm socket and 1/2 inch ratchet on the Alternator nut to turn over the motor. The belt slips if you turn one way but turns the motor over nicely when going the other way.

 

gatf4,

FWIW, according to my DC shop manual those copper washers are supposed to be discarded and new ones used when you reinstall injectors.

 

Thanks Ed, thats one of things I did want to mention. If I was going to do the job over I would have those ahead of time. I'm sure they cant be more than $20 a piece from DC . They look like brake hose washers where they attach to a caliper. I just cleaned them up and gave them an extra 5 inch lbs of torque when I tightened them down.

 

My engine had a knock at idle and just off idle, usually after pulling a load. I was going to take it in to the dealer to have it looked at, but got busy and didn't bother. The noise went away by itself about 8 months ago and I haven't heard it since.

 

- Concerning the copper washers -

If you don't want to replace them I'd suggest you anneal them. The annealing process re-orients the grain structure within the copper and allows you to get a bit more life out of them. Annealing the copper washers will make them a bit softer.

To anneal them all you need is a propane torch and a glass of cool water. Heat the entire copper washer up until it glowes a mild cherry red then dunk it in the cool water.

I'd only do this once, maybe twice then certianly buy new.