Very odd blown headgasket
Very odd blown headgasket Has anyone ever seen this happen before? I started losing coolant from the back of the driver side head a few months ago. Assumed it was the banjo bolt. Been working on removing it (its partly rounded). Well the leak got worse, so now the car is parked. Whiling letting it idle i hear a hissing from the front of the motor. Now i got coolant coming from the front side of the head. It looked to be coming from the top water pump bolt but its running down the seem between the head and the block. So today i put it up on rams and laid under the car till it got up to temp and coolant started flowing. I got a straight view of the banjo bolt and its dry as a bone. I get a mirror and with some positioning i could clearly see coolant and bubbles coming from the back of the block at the head gasket. NOW here is the odd part about the whole thing. The oil is PERFECTLY FINE. No mixing at all and NO SMOKE out the tail pipe. That doesn't mean a tiny bit might not be getting into a cylinder and burning off but its not enough to smoke even a little. Is it even possible for the head gasket to blow like that and not leak coolant into oil or cylinders just out the front and back of the block?
At least stock head gaskets have been notorious for blowing out in the back of the block and yes, quite possible for a blowout to not breech oil especially since there are no oil passages on the mating surfaces. Once you remove the gasket it may also be difficult to spot where the gasket has blown out. In your case, though if it's gurgling like that with no pressure it may be obvious. It's quite possible a cylinder head could be warped. Once the heads are off you need to ensure they are true, and if not, have them milled. Nothing like just slapping the heads back on and this happening all over again. Did the engine overheat before you discovered this?
At least stock head gaskets have been notorious for blowing out in the back of the block and yes, quite possible for a blowout to not breech oil especially since there are no oil passages on the mating surfaces. Once you remove the gasket it may also be difficult to spot where the gasket has blown out. In your case, though if it's gurgling like that with no pressure it may be obvious. It's quite possible a cylinder head could be warped. Once the heads are off you need to ensure they are true, and if not, have them milled. Nothing like just slapping the heads back on and this happening all over again. Did the engine overheat before you discovered this?
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Depends on the shop,, you can gain a nice small bump out of a good valve job, and cutting the guides shorter ,,, couple of the shops I used charge like 75 bucks a head to do a "base" head cleanup.. No angle grinder work to speak of.. I think they also de-burred the oil drain passages and made sure the chambers didn't have any sharp edges..
Thanks not a bad price. I appreciate the input guys. Im more or less a home mechanic so iv never seen / heard of a head gasket goin and not mixing with something. Learn something new every day.
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Verdad Gallardo I have 3 questions I hope I can get some help with or at least some recommendations.
1. What head gaskets would best be used for a stock motor. Fel pro 9966 pt or the fel pro 1074, from what iv read its hit or miss on the 9966. But the 1074 I haven't seen a post on any failures. Mind you i do run the motor hard from time to time.
2. Head bolts. The only head bolts I could find seem to be for the iron heads with no washers so that leaves me with the arp 134-3601 (I believe). I'm not opposed to goin arp, just don't want to go over board on something not needed. If stock bolts are fine and I can get a part number for ones with washers cool. If not no biggie, I'll go arp.
3. Head bolts torque. If I go arp then it should be the 3 step up torque method correct? If it's stock GM bolts it's 22ish then the angle method?
1. What head gaskets would best be used for a stock motor. Fel pro 9966 pt or the fel pro 1074, from what iv read its hit or miss on the 9966. But the 1074 I haven't seen a post on any failures. Mind you i do run the motor hard from time to time.
2. Head bolts. The only head bolts I could find seem to be for the iron heads with no washers so that leaves me with the arp 134-3601 (I believe). I'm not opposed to goin arp, just don't want to go over board on something not needed. If stock bolts are fine and I can get a part number for ones with washers cool. If not no biggie, I'll go arp.
3. Head bolts torque. If I go arp then it should be the 3 step up torque method correct? If it's stock GM bolts it's 22ish then the angle method?
1074's will be fine
ARP's all the way especially since they can be reused.
If that part number is for SBC and does have the washers then get them. I believe there is a tapered side to the ID of the washer and that goes against the bolt head. Make sure to put a trace of oil between the bolt head and the washer before torquing.
I've always torqued in a 3-step fashion for head bolts. I don't know what the torque spec is on those head bolts. You may want to look up the part number or call ARP. I've always stuck between 65 and 70ft. lbs in three steps. Don't forget there's also a torque sequence you must follow or risk warping the head and being right back to square one.
ARP's all the way especially since they can be reused.
If that part number is for SBC and does have the washers then get them. I believe there is a tapered side to the ID of the washer and that goes against the bolt head. Make sure to put a trace of oil between the bolt head and the washer before torquing.
I've always torqued in a 3-step fashion for head bolts. I don't know what the torque spec is on those head bolts. You may want to look up the part number or call ARP. I've always stuck between 65 and 70ft. lbs in three steps. Don't forget there's also a torque sequence you must follow or risk warping the head and being right back to square one.
1074's will be fine
ARP's all the way especially since they can be reused.
If that part number is for SBC and does have the washers then get them. I believe there is a tapered side to the ID of the washer and that goes against the bolt head. Make sure to put a trace of oil between the bolt head and the washer before torquing.
I've always torqued in a 3-step fashion for head bolts. I don't know what the torque spec is on those head bolts. You may want to look up the part number or call ARP. I've always stuck between 65 and 70ft. lbs in three steps. Don't forget there's also a torque sequence you must follow or risk warping the head and being right back to square one.
ARP's all the way especially since they can be reused.
If that part number is for SBC and does have the washers then get them. I believe there is a tapered side to the ID of the washer and that goes against the bolt head. Make sure to put a trace of oil between the bolt head and the washer before torquing.
I've always torqued in a 3-step fashion for head bolts. I don't know what the torque spec is on those head bolts. You may want to look up the part number or call ARP. I've always stuck between 65 and 70ft. lbs in three steps. Don't forget there's also a torque sequence you must follow or risk warping the head and being right back to square one.
On my block there are two bolt holes on each side in the middle row/front and back that do not tap into water jackets. I only put a trace of oil on the threads of those. Not too much or it could hydrolock the bolt and will give a false torque reading. All the rest get permatex thread sealant. The intake bolts also get sealant or oil can creep up from the oil valley and leak outside the bolt heads onto the manifold. The ARP's are not TTY, and can be used more than once barring the threads are still in good condition.