solog1977 Posted August 23, 2018 Share Posted August 23, 2018 Truck#1 1996 Mack RD/690s E7 300 Electronic Engine. Bending Pushrods, After converting from mechanical injection to electronic injection on a replacement motor, my former supervisor forgot an oil drain plug in the bottom of the econovance housing. So the extreme buildup of oil caused the pump timing to advance wildly to the point where the truck would not start. In the attemps to start, starting fluid was sprayed and pushrods were bent. We replaced those pushrods and found the plug, removed it and when setting the valves pushrods bent again. Found binding springs in the heads and had heads remanufactured, replaced pushrods and yet again when setting valves the pushrods started to bind. Camshaft appears okay, rockershafts look like they are moving correctly with piston stroke and cam lobes. Whats my next move, taking the front cover off and checking timing gears? Whats the chances of it jumping timing. Truck#2 1994 Mack RD/690S E7 300 electronic On this truck, coolant is pressurizing and blowing out of lower overflow (2 tank upper/lower). I first replaced air compressor, then water pump & housing, new steel upper reservoir, radiator, then cyl heads, new sleeves & pistons installed because a couple had chipped where the fire rings seal, the coolant stopped pushing out for the first cpl days afterwards. Because of a radiator hose blowing out it lost coolant, after repairing once again same ol problem more coolant pushing out, replaced air compressor with a higher end one hoping it was defective. It still pushes coolant out, theres no exhaust gas in coolant been checked 3 different times & if you run the truck with the radiator cap off you can see large bubbles constantly coming up and making coolant come out as the air purges which pressurizes the system. Im stumped my coworkers are stumped, I removed the pistons & sleeves, Mack came and installed the new sleeves/pistons. I know he checked the sleeve height, cant help but wonder if the blocks deck isn't right or if the water jacket pitting was too much. Anyhoo, any input on either of these trucks issues would be appreciated. Thanks! Solomon Quote Link to comment Share on other sites More sharing options...
fjh Posted August 24, 2018 Share Posted August 24, 2018 On truck one you say the rockers are fine rule that out I have only 3 thoughts The Valves were set wrong to start with if thats possible ! Or the cam gear has slipped on the cam its self never seen that happen.............. The valve guides were to tight of tolerance when assembled if they are reman that is possible and have seen it happen! observation! \As for truck two Judging by the work done my guess will been incorrect liner height ! low spec is 22 which is borderline usable! in my opinion! your allowed 00.2 thou between liners under one head This is some times hard to acheive when shimming liners you need to sometimes drifit them several times to get it right I believe the guy who installed the liners didn't spend the time to check his work the finished product before the heads went on ! Have also seen this happen There are things the Book don"t tell you and this is double check your work BEFORE the heads go on A good liner height for these Is 24-28 anything in between or slightly above is OK! and the spec between liners should be strictly adhered to! Zero Variation is best In my opinion but not always attainable This is where your issue lies in my opinion! Could be right out to lunch on this but judging from your comments its my guess! Just my 2 cents! 2 Quote Link to comment Share on other sites More sharing options...
Dirtymilkman Posted August 24, 2018 Share Posted August 24, 2018 On truck one was the flywheel put on in the right position? Not sure if it can be put on the crank a half or quarter turn off? But then when you set valves you'd be all wrong following the flywheel markings. Quote Link to comment Share on other sites More sharing options...
Freightrain Posted August 24, 2018 Share Posted August 24, 2018 From my limited experience, there is a ball in the flywheel that indexes it to the crank flange detent. If that ball was not used, it can be bolted on incorrectly and timing mark will be wrong. I only know this from when I put the 237 in my truck. I saw the bolt pattern was symmetrical and wondered how you would know how to put it on. That is when I saw the ball/detent and realized that is how. But can see how it could be left out and just bolted on any way you wanted. Thus causing problems when you timed it. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment Share on other sites More sharing options...
theakerstwo Posted August 24, 2018 Share Posted August 24, 2018 On the E7 the crank don't us a ball for location but uses a v shaped dowell and I have seen it taken out for some reason.On truck one I purchased a truck a couple years back from the dealer here that was not running.The engine was a rebuilt and the machin shop plugd the lower oil return from the advance and it did same thing.It would start but would go nuts on timing.It also had bent push rods and had set for four years after that.When I pulled the valve covers you still could smell starting fluid.The cam to the crank was out of time and the timing gear on the cam was loose. changed the cam and gears and half of the push tubes and it was a good engine after that.I could not press the cam gear off of the cam so I think it had sliped but why unless the rpm went too high trying to start it of either.On your truck one it has a dynatard cam and some people don't know how to set the over head. Quote glenn akers Link to comment Share on other sites More sharing options...
davehummell Posted August 25, 2018 Share Posted August 25, 2018 On that second truck problem I had a mack engine that ran along alright till it needed to be rebuilt it started to use oil so we pulled it and did the engine up with new parts. Started to run it in the fleet and it would overheat and push water out??? After screwing around for days I figured out it had a pinhole threw the block so I had to put all that stuff off the one engine onto another spare block then it was ok odd the way it went I would of swore the deck was screwed up. Quote Link to comment Share on other sites More sharing options...
Glensts Posted August 26, 2018 Share Posted August 26, 2018 On truck 2 we had the issue and it was cracked head port which would allow intake air from turbo to pressurize coolant system. coolant never leaked back tho when it was stopped. Heads got checked for cracks was how they found it after we did so much other stuff Quote Link to comment Share on other sites More sharing options...
solog1977 Posted August 27, 2018 Author Share Posted August 27, 2018 I appreciate the input guy's, the truck with the pressure issue is on its 2nd set of heads. Originally I had reached the conclusion that a head was getting pressure from the turbo into a coolant passage, so we replaced both heads and went from there. The liner height is definitely a possibility I didnt stand over the mechanic from Transource that came down to help us out. Pai supplied the heads & we've gotten bad heads before so thats a possibility as well. (Id like to add its not overheating) Far as the motor with pushrod issues, I pulled the front cover off and put eyes on the timing gears & it looks like the cam gear has slipped atleast for now it does, the pump gear has visibly slipped ive yet to pull the cam or cam gear off to check the key. Regarding the flywheel it is doweled but, (E7 manual lacks this) when the timing arrows at front are lined up the flywheel pointer is 20-30 degrees just past Valve setting marks 1&6. Shouldnt TC or some mark on the flywheel correlate with the engine timing marks? I tried to upload a picture of the cam & gears theres a paint stick mark on the cam & gear that has moved. Quote Link to comment Share on other sites More sharing options...
solog1977 Posted August 27, 2018 Author Share Posted August 27, 2018 On 8/24/2018 at 9:19 AM, fjh said: On truck one you say the rockers are fine rule that out I have only 3 thoughts The Valves were set wrong to start with if thats possible ! Or the cam gear has slipped on the cam its self never seen that happen.............. The valve guides were to tight of tolerance when assembled if they are reman that is possible and have seen it happen! observation! \As for truck two Judging by the work done my guess will been incorrect liner height ! low spec is 22 which is borderline usable! in my opinion! your allowed 00.2 thou between liners under one head This is some times hard to acheive when shimming liners you need to sometimes drifit them several times to get it right I believe the guy who installed the liners didn't spend the time to check his work the finished product before the heads went on ! Have also seen this happen There are things the Book don"t tell you and this is double check your work BEFORE the heads go on A good liner height for these Is 24-28 anything in between or slightly above is OK! and the spec between liners should be strictly adhered to! Zero Variation is best In my opinion but not always attainable This is where your issue lies in my opinion! Could be right out to lunch on this but judging from your comments its my guess! Just my 2 cents! 2 Zero Variation would be my preference as well. I dont want anything coming back thru these doors once it leaves. We have 31 trucks in our fleet and all but 7 are RDs these steeringwheel holders are very hard on them. Quote Link to comment Share on other sites More sharing options...
fjh Posted August 27, 2018 Share Posted August 27, 2018 2 hours ago, solog1977 said: I appreciate the input guy's, the truck with the pressure issue is on its 2nd set of heads. Originally I had reached the conclusion that a head was getting pressure from the turbo into a coolant passage, so we replaced both heads and went from there. The liner height is definitely a possibility I didnt stand over the mechanic from Transource that came down to help us out. Pai supplied the heads & we've gotten bad heads before so thats a possibility as well. (Id like to add its not overheating) Far as the motor with pushrod issues, I pulled the front cover off and put eyes on the timing gears & it looks like the cam gear has slipped atleast for now it does, the pump gear has visibly slipped ive yet to pull the cam or cam gear off to check the key. Regarding the flywheel it is doweled but, (E7 manual lacks this) when the timing arrows at front are lined up the flywheel pointer is 20-30 degrees just past Valve setting marks 1&6. Shouldnt TC or some mark on the flywheel correlate with the engine timing marks? I tried to upload a picture of the cam & gears theres a paint stick mark on the cam & gear that has moved. TDC Is TDC TIMING IS TIMING The cam / crank marks will line up on tdc #1 the valves on number six should be on the rock! Quote Link to comment Share on other sites More sharing options...
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