RussianVolk

Hi all, just finished my first head gasket replacement. Overall went pretty smooth but I do have a few issues:
1. Truck threw codes during driving, 42 and 47. It does not appear that it's charging. Worked fine before I took head off. I thought bad ground so I made sure that all paint on head is gone and surfaces are clean. Did not help. I'm pretty sure everything
is connected properly.Im going to jump ground to battery tomorrow and see if it helps. I don't know anything about the ASD or where it is even located. Any advice on this? I worked great before i took everything off. Cruise and AC works btw.
2. Coolant temp is all over the place. Engine would get hot, more than I'm used to (about half on gage) and then rapidly drop to first notch or just below quarter. Then it repeats. After driving 20 miles the top hose and heater core lines are hot but the bottom hose is barely warm. I did put new thermostat in, thought might as well while it's apart. I made sure to alight ball to 12 O' clock. Is it full of air? What's the best way to blead? Should the bottom hose be so cold? It's 78 here today. What temp do you see? I wish they had actual values...
3. Seems like I lost a bit power. All I could get was 15 psi Max boost.where before I could get 20s.I don't think I have air leak but going to check.
Was not beating on truck, just felt a bit sluggish.

Could not do the swap without the sticky, ver helpful. Thank you guys for all the info!

j_martin

Aftermarket T-stats tend to hunt a bit, plus you might have forgotten to burp the bubble out by cracking the plug on top near the thermostat.

RussianVolk

Cracking the plug would make a lot of sense... Did not do that. Thanks for suggestion, I'm going to try burp her out after work.

j_martin

I think you'll still see the water temp vary quite a bit. It's the way the thermostat works. For some reason the Cummins OEM t-stat goes to temp and stays there rock solid. The NAPA t-stat goes to the second line, then opens and drops down to below the first line, then hunts between there and just above the first line. I'm going to put in a stock t-stat before winter.

Alec

I don't know if you can see it in this picture too well, but there is a little notch in the Cummins T-stat that lets it "leak" as it starts to open, so the flow is modulated at the cracking temperature quite differently from the usual t-stat. I also read somewhere that the head pressure on the t-stat in the B engine is much higher than usual designs, so an inappropriate t-stat can't overcome the pressure to open, until it is quite over temp.

Nughuffer

FWIW I was having similar problems with temps. I put an aftermarket coolant temp gauge in mine & during warm up the factory gauge will begin to read well past the middle of its range while my aftermarket reads between 160-180. As soon as the aftermarket hits 180 the stat opens and the OE gauge quickly drops back to the first line. The factory gauges aren't linear from my experience and that makes them just slightly better than idiot lights.

As far a bleeding I just left the cap off and idled at 1000rpm for a while. Opening and moving the HVAC temp lever from time to time.

j_martin

When I replaced my radiator, it took about 8 warmup cycles, with topping off each time to bleed the bubble out of the radiator. Round 2 (dealing with a **** leaking OEM thermostat seal) I burped it at the thermostat and it took 2 cycles to clear the bubble.

I was under the impression that Cummins thermostats were expensive. I just ordered 2 from them, about $41 with new seals.

thrashingcows

Your temp issue is surely, as suggested, air trapped in the block. I always remove the plug from the head, just behind the T-stat, and lifting ring. Sound be either a 3/8 square, or 3/8 allen. And I always turn the heater on full heat and defrost after the initial fill up. Then top off my overflow tank. It usually draws a fair amount out of that over flow for the next couple days.

And I too went through the after market T-stats. Couldn't stand watching the gauge swing back and forth like that. I eventually put the OEM unit back in.

RussianVolk

If I try to bleed air now after truck ran by cracking the plug, wouldn't the air bubble be in heater core hoses by now? I.e. would it help at this point? Just trying to avoid making coolant mess.
I guess it would help if there is large air pocket...

thrashingcows

Air lock could be anywhere. No reason to believe it would be at the heater core. Probably wouldn't hurt to drain the coolant again, then refill with the plug in the head out. Then you know for sure that there are no air locks in the rad, or motor.

RussianVolk

Thanks for suggestions on air lock in cooling system. I spent the evening messing with charging system... no luck. First thing I tried is ran ground from alternator directly to battery. That did nothing. Then I pulled alternator off and took it to advance auto. They tested it, and it failed 3 times (can't remember what failed - going to take into autozone tomorrow). Got a new one, tested it there and it passed. So I put that one in - still nothing. Next thing I'm going to do is swap out ASD relay, but not sure which one it is. Is there a way to test the relay? I know I was getting code 42 - ASD relay (charging circuit supply) shorted or open, or no ASD voltage at PCM. That has me worried that PCM is not supplying. Is there a way to test this?

thrashingcows

Check the sticky...under the electrical threads. Looks for one named...What are these wires for on my intercooled motor...or some such thing. It shows, and lists, all the relays and wiring components.

RussianVolk

Alright, looked it up and going to try it tomorrow. Just to double check, if I have A/C and Over Drive, that does mean that my crank position sensor is ok, correct?