Symptoms of a blown head gasket?
04-06-2008, 01:40 PM
#47
Registered User
Thread Starter
Alright fella's.I tapped the bottom of the bajo bolt for the relief valve and plugged it.Still running like crap.Same symptoms.Engine gets to running rough once over 15kpsi of RP.Can turn the mp-8 up and change what rpm it gets rough at,rough running is definitely coincididng with a certain level of RP.I'm back to stumped.I thought I had it figured out.
04-06-2008, 03:30 PM
#48
DTR Advertiser
I have seen this symptom once before on another truck, but at 8000 PSI, not 15,000 PSI. It turned out to be a connector tube not sealing good enough.
We see the same thing on the test bench since it uses connector tubes like a truck would. If we get a bad seal between the two, the readings get goofy.
We see the same thing on the test bench since it uses connector tubes like a truck would. If we get a bad seal between the two, the readings get goofy.
04-06-2008, 03:37 PM
#49
Registered User
Thread Starter
I have seen this symptom once before on another truck, but at 8000 PSI, not 15,000 PSI. It turned out to be a connector tube not sealing good enough.
We see the same thing on the test bench since it uses connector tubes like a truck would. If we get a bad seal between the two, the readings get goofy.
We see the same thing on the test bench since it uses connector tubes like a truck would. If we get a bad seal between the two, the readings get goofy.
04-06-2008, 03:58 PM
#50
DTR Advertiser
The leaking volume would go into the return circuit. This just goes back to the tank. Unfortunantly you can visually see the return volume in the head, but it is measureable. This volume is what techs measure when they do a back leak test. It finds bad tube connections and leaking injectors.
When you install the inejctors do you lightly tighten the injectors and then tq the tubes down to say 40 ft lbs and then go back to final tighten the injectors?
When you install the inejctors do you lightly tighten the injectors and then tq the tubes down to say 40 ft lbs and then go back to final tighten the injectors?
04-06-2008, 04:16 PM
#51
Registered User
Thread Starter
The leaking volume would go into the return circuit. This just goes back to the tank. Unfortunantly you can visually see the return volume in the head, but it is measureable. This volume is what techs measure when they do a back leak test. It finds bad tube connections and leaking injectors.
When you install the inejctors do you lightly tighten the injectors and then tq the tubes down to say 40 ft lbs and then go back to final tighten the injectors?
When you install the inejctors do you lightly tighten the injectors and then tq the tubes down to say 40 ft lbs and then go back to final tighten the injectors?
04-06-2008, 05:53 PM
#52
Registered User
Thread Starter
went thru the injector and tube procedure again.Still have the same problem.When the RP gets to 15k and above(in neutral) truck runs extremely rough and lots of white smoke.Light stabs at the throttle cause no problems.Heavy stabs causes a stutter.Slowly ramping the the rpm's up, the RP climbs steady till 15k psi and then does a sudden spike to 17-18k and the rough running begins.I can get pressure in excess of 22k by applying more throttle during the rough running.Any input from Don or John would be welcome.
04-07-2008, 06:52 AM
#56
Registered User
Thread Starter
I really don't think its the cp-3 but at this point I am willing to try anything.I'm about to the point where the head is going to come off so I can eleminate the head gasket and valve seats.I take it you got your truck back on the road?Maybe I'll run into you at an upcoming pull here in the next month or so.
04-07-2008, 04:31 PM
#58
Registered User
Thread Starter
No injectors here yet Don.DHL has always got here before 3 pm est.Have the truck tore down ready and waiting.Is there a chance they were not scheduled for delivery today?