Engine/Transmission (1998.5 - 2002) adjusted valves wow

[Mhannink]

well ive been having an problem with my truck when the ac is on it would chug like a train and sometimes kill the motor. well i thought it was fuel related since i backed down the fp on the regualtor and it got better but was still there. well the other day i did the valves and they where a little out of spec. adjust them and now i have yet to get the problem to come back. i say a little more power and a little less smoke so it seems to have helped a lot. also cleared up the slight intermitent miss at idle too. engine now runs smoother and better then it ever has. moral of the story for anyone having issues with rough running that cant be totaly explained check your valves if they are out of spec it might be your problem.

 

[DLGonzo]

How many miles on the truck? Per Cummins no need to adjust untill 250,000. I'm almost there, but Dealer check at 95,000 when they did injector change. anyway, glad to hear that things are running better. How long did it take you to adjust. My vavle experience only goes as far as a Yamaha. I have done a couple injector changes on my truck though. Valve adjust looks like it should be pretty straight forward.

 

[JApol]

It does seem a straight forward procedure but I have not done mine yet. i don't know about the 24v but some people have done their CR engines with as low as 25k and got results.

 

[Bob4x4]

How many miles on the truck? Per Cummins no need to adjust untill 250,000. I'm almost there, but Dealer check at 95,000 when they did injector change. anyway, glad to hear that things are running better. How long did it take you to adjust. My vavle experience only goes as far as a Yamaha. I have done a couple injector changes on my truck though. Valve adjust looks like it should be pretty straight forward.

Where did you see 250k for an ISB ?



Bob

 

[FourBarR]

I thought book called for 150,000k for valve adjustment.

 

[Bob4x4]

I thought book called for 150,000k for valve adjustment.

I have seen both 100k and 150k in print but since they are set up by a machine... ... ... ... ... . I have always recomended the first time be MUCH sooner



Bob

 

[Cummins724]

I adjust my valves every 20-25k just to be sure. I set them at . 10 intake, . 15 exhaust. My truck runs smooth & sounds great.

 

[Mhannink]

130k on the clock and i dont know when they where adjusted. they are straight forward. the biggest key to doing it is not what spec you put them at but that they are all consistent. i personaly go to the tighter side of the spec range . 009 intake . 015 exhaust and let the feel gauge move easliy. it hard to describe sense it a touch u feel as you learn but for me i turn the nut till just before i cant easily move it. there is some resistance but any tighter on the screw and it wouldnt move easily. thats where i like them some like them tighter some looser. my way as far as im concerned is closest to what cummins wants. as far as how often i run them typicaly 25 to 30k miles and regardless of what is said in print i useally find a valve a little out of spec. if not enough to make a difference.



on my truck they where all out of spec but as i said before consistancy they where all close to the same wich is why the engine ran smooth. however not so well loaded

 

[Wyomingcowboy]

Sounds like fun. Anybody got any pics or diagrams or something that could tell a novice like me how?

 

[DLGonzo]

Where did you see 250k for an ISB ?



Bob

I had some literature from Cummins when the ISB first came out bragging on the durability and "Maintainance Free-ness", obviously not a maintainance schedule. Maybe I ought to check mine sometime.



Question: will the valve cover slide back over the fuel lines, or will they thay have to come loose?

 

[jkalchik]

I did my 99 24v valve job last spring at around 180k. The truck did seem to run a bit smoother at road speed, but the BIG difference was down low with a warm engine. It used to lurch between 1,200 and 1,500 RPMs, now I can do a top gear roll on at 1,100 RPM and no bucking at all.

At least on my 99, I did not have to touch the fuel lines at all. It does take a little finagling, but the valve cover does come off without disassembling anything else. It would help a bunch if you've got a helper that can watch the cam gear for TDC and BDC while you're turning the engine over.

As far as directions... . there are links scattered around to do the task. I cheated, I've got the electronic FSM.

 

[obert]

I move the cover to my left, over the heater hoses. You might have to cuss it a little but it does come out. I think the back bolt stays in the cover, too, only makes things worse, nut there's not much room to get the bolt out under the cowl.

 

[John - K5AWO]

I'm a bit confused here guys.

I thought the ISB has hydraulic valve lifters?? And, if that is so, why is there a need to be adjusting the valve clearance? should it not be zero like in other engines with hydraulic lifters?

 

[Mhannink]

no they are mechanical lifters most if not all big diesels(not that ours are but the name is) use mechanical adjusted lifters.

 

[David_VT]

Sounds like my truck is due for a valve adjustment. Hopefully the process is in the service manual...

I don't suppose that this might address blowby? I freely admit not really understanding the source of blowby oil...

I was under my truck friday replacing a clutch slave cyl and saw an enormous amount of blowby oil under the engine...

 

[Mhannink]

it could contribute to blow by reason being the late valve opening and force compression past the rings mostly though blow by is just compression slipping past the rings late valves or not.

 

[Don Tanklage]

imo they would have to be really loose...



a easy way to adj valves (esp when you are doing it yourself) is when ex opens adj intake, when int closes adj the ex



don



ps - are you adj them hot or cold?

 

[Cummins724]

Word of advice to guys about to adjust your valve lash. Cut the insulation above the rocker cover before removal & ditch it. The dust will go all over the engine during cover removal.

 

[Mhannink]

i adjust cold as per cummins specs. yes i agree the valves would have to be really loose to contribute but who knows look at my truck its a perefect example of something that doesnt seem that bad really was.



an easy way for me is #1 cyl on tdc compression then go to number 5 and sing ol mcdonaldes. you know old mcdonaldes e i e i o only go e i e i both exh. int. exh. int. both. next turn the engine over and put numer 6 tdc compression start and cyl 2 and do the same thing over again.

 

[obert]

an easy way for me is #1 cyl on tdc compression then go to number 5 and sing ol mcdonaldes. you know old mcdonaldes e i e i o only go e i e i both exh. int. exh. int. both. next turn the engine over and put numer 6 tdc compression start and cyl 2 and do the same thing over again.

I think thats right, that is the method in the engine manual.



1I 1E 2I 3E 4I 5E DONE ON #1TDC. For #6 TDC I start at the back and do 6E 6I 5I 4E 3I 2E. Clear as mud?