Rd trouble!again!

[R.E.D]

Since I bought the rd I fixed minor details that are normal with an used truck but now I might be over my head..

Truck seems to consume lots of oil ...as much as 1 gallon a week....!!

It does not have any engine leaks ,it does not smoke much and it gets the same gas mileage as my 98 ch613.(which only has 300k & its very fuel efficient)

In the past cold mornings it has refused to start but with ether and I have begun to think that since it has 614,000 miles and 24000 engine hours it might be time for an overhaul.

Truck runs like a champ like the rest of the bull dogs in my small fleet yet this issue concerns me.

What is the best way to go about repairing the engine and since I assume its a bad compression issue due to worn rings or sleeves , what kits are available to fix this issue.

1996 rd688s , 350hp coupled to a 9 speed maxi.

PS:On mornings with normal temp the truck cranks and fires unenvenly for two secs and it goes on to normal idling.Also al filters changed 3 weeks ago..

Please help!!

RED

[hatcity]

Don't have the latest flier here, but full rebuild kits can be had for about $3000, or just one cylinder (muzzleloader)

[R.E.D]

I would rather rebuild all while the engine is apart.Also whats the best way to test compression and where could I obtain compression tolerance numbers?

[alex g]

this may sound crazy but I talked to a guy who had a diesel ford p/u truck and was using oil like crazy but not leaking or smoking.It turned out it was leaking oil to the return side of the fuel system and putting oil in the fuel tank.It may be worth a look if your truck is not showing normal signs of oil useage.

[R.E.D]

my tanks are the 75 gallon aluminum ..I can see the botton clearly even when full if it had oil the diesel could be darkened by the oil contamination ...could it be that I used a thin oil for the mileage 15w40?I was told by a old timer that that could be the issue...

[hatcity]

I doubt it is the oil you use. I have just under 700k on mine, use 15-40 ONLY and no issues.

I agree that if you have it opened up, do it all

[R.E.D]

i would like to check the compression on all the cylinders first since this is no easy task or bill...my local mack dealer quoted me 3800 for parts and 5500 in labor ..not including tax

[gearhead204]

if she is indeed wore out the draft tube should have considerable blow by. a monometer test will tell this, dealer should be able to do in 10 minutes or less (easer than compression test) have you checked the air side of the turbo for oil being pushed into the charge air cooler? the fuel system on the mack is different than the ford I've never seen a in line pump add oil to the fuel system but it can add fuel to the oil system

[j hancock]

Have you done an oil sample?

[jakebrake86]

I've got the same truck, same year, same engine, and almost the same mileage. When I bought it 3 years ago, if you ran it hard it would use a gallon a day. After about six months and ALOT of Rotella, it just stopped. It may use a gallon every two weeks or so now, but nothing like it used to. I guess it had a ring that came unseated and finally slipped back into place. Mine still cranks good all the time, though. If it weren't for the hard starting I'd say get all the life you can out of it. I'd love to freshen mine up, but I can't afford to do it if there's another 2 or 3 years worth of running left in her.

[R.E.D]

I will have this test done.charge air cooler was relatively dry..I had it welded the other day since it had a penny size hole where one of the mounting brackets had broke off...today I bought a battery since it was just running on 3...this should help with the no start issue since the 3 batteries seemed to weak to spin engine fast enough to build compression............

Jakebrake86 I definitely agree with u ..I would like to run it til she gives up but since I might be putting a driver on her I would like her to be in good shape. ! Since we all know that many drivers dont give a s### about equipment ...

[gearhead204]

how dirty is your environment? the hole in the cooler caused low boost or no boost but when shifting it will suck. until throttle is re applied this could dust the engine fairly quick if off road or dirt road. remove pipe between charge air cooler and intake manifold, wipe a finger on inside of pipe and manifold, is it gritty or just a little slimy? if gritty your day will be shitty

[R.E.D]

Enviorement is extrenely thick with dust and shifting did suck...it would take high rpms to shift in a split second. ..and yes there was a thin film of grit that had settled in the charge air cooler pipes...and it seems the hole was there for a good while too

...some genius had tried covering it with fiberglassand resin...I took it of and made short work of the

hole with my arc welder and aluminium electrodes. .

[gearhead204]

red hope you get lucky and more boost resets the rings but I doubt it. nothing like getting screwed by some ones half assed repair

[R.E.D]

yup it does suck...this is a very solid dog and its a shame that it ran so long with low or no boost...who knows how much debris settled in the engine....

[rsb502]

if it had a massive charge air leak that would cause it to burn up more oil, when you shift there is still positive pressure in the charge air system for a couple seconds with it sealed, with a big hole it will drop immediately and you will be pulling a vacuum as you apply throttle consuming more oil. Also the turbo was probably burning oil running hotter than it should due to an overspeed condition with that large a hole in the system. Have you run it with the repair made to see if it was still using a lot of oil?

[MACKS]

Since I bought the rd I fixed minor details that are normal with an used truck but now I might be over my head..

Truck seems to consume lots of oil ...as much as 1 gallon a week....!!

It does not have any engine leaks ,it does not smoke much and it gets the same gas mileage as my 98 ch613.(which only has 300k & its very fuel efficient)

In the past cold mornings it has refused to start but with ether and I have begun to think that since it has 614,000 miles and 24000 engine hours it might be time for an overhaul.

Truck runs like a champ like the rest of the bull dogs in my small fleet yet this issue concerns me.

What is the best way to go about repairing the engine and since I assume its a bad compression issue due to worn rings or sleeves , what kits are available to fix this issue.

1996 rd688s , 350hp coupled to a 9 speed maxi.

PS:On mornings with normal temp the truck cranks and fires unenvenly for two secs and it goes on to normal idling.Also al filters changed 3 weeks ago..

Please help!!

RED

One thing I learned over the years is when a diesel engine is hard to start on cold days it's most likely caused by low compression!!

[KECorbin22]

A lesson I learn a long time ago from a smart old mechanic/ machinist who I had the great pleasure of working with, would always break in a rebuilt motor with a straight 30w NON_Detergent motor oil. He claimed that a detergent motor oil would keep the rings from seating properly. He would allow the fresh engine to come to temp and then block off the front of radiator and let it go above the 200 degree range, he would run around this temp for 15 to 20 minutes then allow to cool back down to normal temps, He recommended changing the oil after 1500 to 2000 miles to what ever type of oil you want to use but always use the same oil afterwards. My 81 ford E150 300-6 has 750,000 miles on it and still runs, I did rebuilted the head back in 94. I have used this same method on used engines that had low compression with good results. It is worth a try before you spend XXXX dollars.

[genoredstar]

Nobody has mentioned operating temperature. I found that proper operating temperature helps maintain proper piston ring seating, reduces deposits around the rings and provides for proper combustion. I always check operatiog temp, whether its fully loaded or just idling. A truck that runs cold, especially in construction or vacational applications will surely benefit from some scrutiny as to why its running cold. You need a little heat to blow that carbon off the rings. Something as simple as a themostat could make a big difference. However it cant fix an engine that's been dusted

[thomastractorsvc]

A lesson I learn a long time ago from a smart old mechanic/ machinist who I had the great pleasure of working with, would always break in a rebuilt motor with a straight 30w NON_Detergent motor oil. He claimed that a detergent motor oil would keep the rings from seating properly. He would allow the fresh engine to come to temp and then block off the front of radiator and let it go above the 200 degree range, he would run around this temp for 15 to 20 minutes then allow to cool back down to normal temps, He recommended changing the oil after 1500 to 2000 miles to what ever type of oil you want to use but always use the same oil afterwards. My 81 ford E150 300-6 has 750,000 miles on it and still runs, I did rebuilted the head back in 94. I have used this same method on used engines that had low compression with good results. It is worth a try before you spend XXXX dollars.

This is poor advice you do not want to use a non detergent motor oil as a break in oil or for use in any engine except those without filters such as a mower, and even then with todays oil technology I don't recommend it or use it in mine or my customers engines. With todays oil technology using a non detergent oil is like going back to using animal fat to grease a wooden axle.

If you decide to rebuild make sure that the entire intake system is cleaned and dried of the oil and dirt, use a quality oil and a break in additive, use pre-lube where you can and try if you have the capability's to pressurize the oil system before fire up. Heat is required for efficiency and break in, but must be closely monitored, blocking the radiator making the engine run hot is poor advice also.

Low and steady rpm increases and varying speed is essential for proper engine brake in, keeping the engine between 180 to 200 is great, the initial run up should be under no load. Once it has ran at varying RPMs, with no oil pressure issues or heating problems, typically that can be up to an hour, than you can operate under a light load, after that I recommend an oil change and look at the filter and drain pan for problems, if everything looks good like it should, refill with favorite quality oil ( I like Rotella and Dello) and all should be good, after rebuilds I like to change the oil at a couple frequent intervals before with an oil sample.

Don't forget during break in to recheck your specs and torques.

[R.E.D]

Guys thanks for the awesome advice. .However I think I found the culprit to the oil consumption ..and it was right under my eyes...

everytime I would purger the air drier by the purge valve I get a 6inch splatter of grayish muck...after close examination I saw the it was oil..and lots of it...seems like air compressor is a goner and will need rebuilding or replacing....I also saw oil coming out of one the rear brake chambers. ..

I reckon I purge the truck 6 times a day on a regular bases...each time about an ounce of muck comes out multiply this weekly and u get more than a gallon...this explains why it takes so long to build up air...my 427 ch build in no time and they idle at the same rpm...please advise

[R.E.D]

Oh and I solved the no start issue with the battery and by not filling up both fuel tanks to the neck. ..leaving no space for proper breath2

[gearhead204]

IF YOU HAVE LARGE VOLUMES OF OIL IN THE AIR SYSTEM YOUR AIR DRYER BASICALY IS NOT WORKING (DESCANT AND OIL DONT MIX) MY ADVICE IS CHANGE COMP. WITH REMAN, FLUSH SYSTEM MULTIPLE TIMES WITH AIR LINE ANTI FREEZE, DRAIN ALL AIR TANKS AND LEAVE OPEN AS LONG AS POSSABLE . THEN REKIT THE AIR DRYER AND REBUILD THE UNLOADER VALVE IN THE AIR DRYER AS WELL THE OIL WILL CAUSE THE O-RINGS TO SWELL AND LATER WILL STICK THE UNLOADER VALVE.

[rsb502]

Each time you purge the dryer? A dryer has an automatic purge valve, are you talking about draining the tanks? What type of dryer does the truck have? It should purge every time the air pressure builds to system pressure automatically, if its not there's another issue. As above oil and the dessicant cartridges in air dryers don't mix, you'll definitely want to try to clean the system out and rebuild or replace the dryer also. If you have an AD9 they are relatively easy to rebuild or replace and are fairly inexpensive, one parts place locally has rebuilt AD9's for about $20 more than a purge valve kit and cartridge to do it yourself. Remember if it has an air dryer the Bendix recommended service is yearly or every 100,000mi whichever comes first.

[thomastractorsvc]

theakerstwo has just posted:

You got me confused now when you say check torque and specs.Is he going to tear it down again and retorque or iust retorque.If so he would not make it in a commerce shop.The way old timer did break a engine in is with non detergent oil for a few miles but that is not needed any more with the rings we have now. I remember those days.Any more a break in means tomost shops to run fast idle out side as hot as it will get maybe 3 or 4 hrs than turn it loose and advice the driver to work it but watch for leaks.Back out of it on long pulls to some degree and see you next time it needs the valve adjusted.

Not sure what happened to your post but to answer your question "You got me confused now when you say check torque and specs"

The simple answer is it was a general statement to go back and make sure no leaks, hoses/lines were tight and everything is good to go, also on some engines you are supposed to recheck the head bolts and other stuff depending on the manufacture specification. There would be no reason to tear down unless there was a problem with noise, overheating, oil pressure etc...

As far as making it in a commercial shop, so far I seem to be doing just fine in my own shop and teaching part time at a technical college