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Low boost and poss blown h/g

robzombie4551

robzombie4551

robzombie4551
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land of the lost. TAKE YOUR COUNTRY BACK
I went camping last week,and before I left I adjusted the TM to lower the boost for towing. It would get 16/18 towing 14/16 unloaded. Well now I can't get it over 4/6 lbs. I think the actuator arm is worn out and not letting the wastegate seat properly. It has play both in/out and side/side.Is this a common issue with 220.000 miles. Also on my trip, an hour in the radiator upper neck split and I went to 230*. I got lucky in this one horse town that had one in stock and I put it in and made it to the campground. The truck went about 100-150 miles and the LCL came on. I put about a 3/4 gallon water in and kept going. About 75 miles later had to do it again. I don't see anything hitting the ground except AC water. Went out this morning same thing, about 3/4 gallon of water. The truck runs fine and starts fine and holds pressure and doesn't overheat. No water in the oil either. Is there a way I can verify bad H/G. Pull a inj.? Or?? Is it possible that it's blowing out the overflow while driving due to a faulty pressure cap.
 
You are probably burning it. Any smoke ? 16/18 psi is wayyy too much boost. You should have no more than 12-14 towing. Use ARP studs when you do your HG's. You could throw some GM coolant tabs in. Might buy you some time.
 
Still, it's going somewhere. If not in the oil or on the ground, then it's going out the exhaust..Hmmm...though you said you had the cooling system open and lost coolant. it's possibly the system is burping. I have had that happen where I had to add coolant for up to a week after a major coolant refill. Could try to keep driving it. As long as it's not in the oil you won't hurt it unless of course it's pouring into the cyls. Then you could hydraulic the motor.
 
One sure way to spot leaking head gaskets; look for bubbles coming up in coolant/ overflow bottle; after refilling and running it for a couple of miles to work air out. bubbles won't be huge, but consistant and will continue while engine is idling. This indication has been the same since the first GM auto diesel came out in 1977.
 
chessie 6.5 said:
One sure way to spot leaking head gaskets; look for bubbles coming up in coolant/ overflow bottle; after refilling and running it for a couple of miles to work air out. bubbles won't be huge, but consistant and will continue while engine is idling. This indication has been the same since the first GM auto diesel came out in 1977.
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That would indicate compression leaking into the collant. If he is burning coolant it may not bubble in the overflow tank. It depends on how the HG failed.
 
Acesneights1 said:
Still, it's going somewhere. If not in the oil or on the ground, then it's going out the exhaust..Hmmm...though you said you had the cooling system open and lost coolant. it's possibly the system is burping. I have had that happen where I had to add coolant for up to a week after a major coolant refill. Could try to keep driving it. As long as it's not in the oil you won't hurt it unless of course it's pouring into the cyls. Then you could hydraulic the motor.
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I'm hoping this is thecase for you. Sometimes it takes a while to burp the air out. You could do a compression test on each cylinder to but that is alot of messin around.
 
I also had to refill the water quite a bit after I took the radiator out and put back in. Although it was only once about half gallon.

Edit: that was a day after reinstalling the radiator, I obviously filled it up when I put it back in, but must have had an air pocket and low coolant light came on next day.
 
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another way to test for a blown head gasket is to start it up run 5 min shut down come back in half hour and open radiator cap. if there is pressure you've got a blown head gasket. just had to change mine out
 
if coolant at 15psi can get into engine cylinder, then I would think that 400 pounds of compression can get into the cooling system. With a dry intake manifold, no coolant is going to get in there.
 
Small leaks go unnoticed. I have a 3208T that needs headgaskets. I have to keep adding coolant but not alot. My Old GMC Jimmy 6.2 was same deal was using but no bubbles and not in oil. I had to put like a 1/2 gal in every few weeks. No external leaks. I threw GM tabs in it and it never lost any again until the day I sold it.
 
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