Engine/Transmission (1994 - 1998) Please Help with missing coolant

[lilthumper]

DMC, the owner told me that he and a buddy did the rebuild, so the warranty question is null. I am fairly mechanical, I have built my own 600 RWHP stock block 302, I am just not familiar with the cummins yet. Yes, the motor does take a while to get to temp, but I almost always drive far enough for it to reach 190. I am just scared that I am causing further damage as a result of my slow diagnosis.

 

[cartman]

hi thumper the more we find out about your truck the worse it sounds, this guy must have rebuilt the engine the same way he drove the truck. how long ago did you by this truck? i know you said it has or is what you were looking for but this is not good maybe you could talk to someone to get some legal advise because you were not told any of this when you purchased the truck and now it is costing you more than what you expected.

well it was just a though hate to see you haveing trouble like this

good luck and let us know what your going to do

 

[Brandon]

retorque on 1/4 turn fastners, I am still waiting...

 

[DMC]

Brandon: I Took what they said on the retorque.

As being an additional 90* after the motor was near operating temps. I wouldn't do this on a head that had been on for very long. I get what your saying, that method when used on bolts that have been set for a while could pose some problems.



Don

 

[lilthumper]

Ok, I used a Snap-On coolant presure tester yesterday. I pumped it to 17 lbs and waited for about 15 minutes. It lost maybe a 1/4 lb and then I stuck my ear close to the connection at the cap and the damn spap-on tool was leaking slightly, I could hear a very faint leak at the cap. Should a cracked head or gasket at a coolant source show a good leak on a pressure test????

 

[Andy Redmond]

Lil Thumper:



Ck the oil cooler first, you have two gaskets that have the oil cooler sandwiched between them.



You mentioned no coolant service. . I changed an oil cooler recently that had the inner gasket rusted thru allowing the coolant to mix with the oil. The cooler itself was suspect as well and did not hold the 70psi air pressure ck. specified by Cummins.



The head was removed as well for external and internal leaks. The head had cracks in the valve seats, it was more econimical to replace the head.



Maybe it will be the lesser. . The oil cooler gaskets are about 50 for both and about $300 for the cooler?



Good luck and let us know what you find.



Andy

 

[Brandon]

I dunno man, An additional 1/2 turn seems like alot, how do you know when the bolts are bottomed?

 

[lilthumper]

ANDY, everyone has told me that if the oil cooler was bad that the oil would go into the coolant. I have no oil in my coolant.

 

[Andy Redmond]

The oil cooler may not be your problem, I was just trying to share an experience/symptom that I was paid to repair. Yes, that's usually the case (oil in the coolant overflow=a bad oil cooler/gasket), but in my example the gaskets that rotted due to rust and corrosion and the perferated (sp) cooler allowed the two fluids to co-mingle. The head gasket was definitely bad too, as internal and external leaks were noted, but two problems existed (with no oil in the coolant overflow bottle).



If your head bolts were streched, this could be a clamping issue.



You have 6 long bolts (rocker towers) 14 medium bolts (center of head) and six short bolts along/above the exhaust manifold.



A plastic go / no go gauge is available thru Cummins distributors for gauging the length of the bolts to see if they are stretched beyond the service limit.



Good luck, Andy

 

[JohnE]

Originally posted by Brandon

how do you retorque torque to yield bolts, I might learn something here? because I am very confused about the whole torque to yield thing. I always thought the truly proper way to retorque is to loosen nut or bolt then torque, not just cranking down on it... very confusing

The local shop uses net and not the torque to base level plus xx° Cummins standard.



They folow my old school training on net torque to specs on the bolts and go run the engine until at operating temps that open the thermostat. Let it cool back to around 100&deg and then run the bolts in sequence at the same torque setting. That's the 90° on the forward bolt.



In my old mechanic days we always got a bit of rotation on reorque. Some rebuke this saying the bolts are warm and expanded. Well so does the head block, and gasket. Bolt stretch (and thread condition) contributes but so does the block hole quality. We always wire brushed the bolts and tap chased the block followed by solvent clean and dry.



Torque plus is a black art to me. How precise is a torque to 180 ft-lbs then add 90° +/- 45° bolt rotation (M-11 specs)? To me no more accurate than the quick mechanics that overtorqued by 10-20% to avoid the re-torque.



Finding coolant leaks is a pain. Sometimes they are as simple as a loose hose clamp and other times $$$