My motor just started having a very noticable "thump" under hard acceleration and is blowing coolant out of the overflow. Truck still runs perfect, no thump or coolant loss if kept under 3/4 throttle and idles fine. Any suggestions? Valve or headgasket problems maybe?

 

Man... I hate to say it but I see a 12v head gasket and orings and Opies Bypass in your future!

Mine was doing the popping but had no coolant issues. I'm assuming you have no coolant in the oil?

 

I would definitely stop driving it. It sounds like either a burnt cylinder and/or head gasket!

 

no coolant in the oil, just blowing it out the overflow. No problems at all unless its under full throttle. Just had the studs put in a few weeks back

 

yep head gasket, boost climbs and the water squirts, it will get worse, and worse.... 2 pennies

 

If it's the headgasket, what's going to be my best option to go back with? Stocker from cummins, marine, 12v?

 

Mine popped at 68 then progressively got worse. While thinking it was a timing issue in a couple weeks time....I couldn't get over 55 pounds and it would flutter!

The cheapest route would be to have the head decked and go back with the stock HG. For me I know that the s400 will grow in a couple months so I went with the orings 12v.

 

O ringed with the 12v gasket going to be the most reliable? I figure the r700 kit will grow to the r850 kit in the months to come

 

I'm hoping so! I've only had mine back together for about a week....still need to do the final torque and its only seen about 20 pounds of boost. I'm following Tim Barbers break in rules to a T.

 

You have the part # on the 12v gasket?

 

I used the 3283337.

 

Quick question. . .

Isn't the only real reason for using a 12v gasket is because the cylinder holes are circular instead of the CR gaskets being a little off shaped making it easier to do Fire rings?

 

My understanding is it's the only way for orings...and yes for the circular crush ring. Not real sure on the Fire Rings.

Crash....are you still on the Stock HG?

 

How many of you guys went back with the stock MLS gasket? Some say it holds good and some say it dont. Way to many options here

 

I just had to pull up some invoices and see what is in my engine this go round. It is a 24V gasket Fire Ringed.