3.0 Eng issues/questions

joseph.rupp · #1 02-20-2014, 11:02 AM

Need some help in diagnosing a 3.0 V6 in my brothers '94 5 speed manual Mazda B3000. There seems to be a lot of pressure building up inside the block, enough to pop off the oil filler neck from the valve cover. The problem I was working with was replacing the water pump, then the themo and the radiator. Funny thing, it seemed like no coolant was ever making back to the surge/overflow tank. I figured it was because we only filled the radiator after replacing the fluid. I tested the new thermo and did the radiator flush, reattached the oil filler neck with a high temp RTV, everything tested ok and seemed to be running fine at the time. He drove it about 150 miles and right before it broke down, he said the heater started blowing cold air. The engine stalled out on him, coolant was everywhere and the oil filler neck had popped off again.
I'm frustraited and my little bro can only afford so much, so I want to get some more ideas about the possible problem before he has to throw down for a rebuilt engine or perform brain surgery on the engine he has.
Any suggestions would definetly help. Thanks.

djfllmn · #2 02-20-2014, 11:24 AM

Head gasket seems probable

joseph.rupp · #3 02-24-2014, 11:35 AM

Would a blown head gasket cause a whole lotta white smoke when he overheated and broke down? I asked another friend about your comment and he said that if the overheating cause damage to the heads (warped or broken metal), then replacing the head gasket is pointless, that's a new engine. What do you think?

rangerlocal · #4 02-24-2014, 01:13 PM

Yes it would. At that point, you would need a head gasket replacement as it's probably blown, and the heads if they got hot enough could be warped, so they would need to be decked to even them out. Don't replace just the gasket; get the heads shaved and check the block for squareness. More than likely the block is fine, but check it anyway, get the heads evened out and checked for cracks, then put a new gasket in and all should be well with the world. Don't go cheap on this job or you'll be pulling the heads again. The only way you'd need to replace the engine is if the block is cracked or warped.