Help! Anyone changed a head gasket?

[GringoEJS]

OK, I bought an 89 240SX with a blown HG. I have changed headgaskets before(On Supras and 300ZXs) without any problem, but in this case, hours after I replaced the HG, it blew again. I had the head resurfaced and I did everything right. Anyway, I suspect the HG may have been faulty since the coolant holes were only around the 4th cylinder, but looking online and at the HG, it seems that is the design. I am wanting to buy another HG and punch holes where all the coolant slots will be and just wanted to know if anyone else has done this. I did a search and came up with nothing. It did seem that coolant was not circulating through the engine correctly just before it failed so that is why I suspect the HG. Have others used the HGs with only 4th cyl. coolant holes without a problem?? Thanks in advance, Gene

[themadscientist]

I have never seen a head gasket with coolant holes just around #4, that's weird. If it's a fiber gasket with firerings around cylinders I would do what you are thinking about too.

[:: orion ::]

The KA headgasket is just like that...and they come that way from the factory.

Did you follow the TQ specs in the FSM when you put the head back on?

Did you use new headbolts?

My money is on a bad resurface job...I have successfully reused stock HGs when pulling the head to replace a piston (temp fix), and have also done a resurface job with a wood block and 400 grit...both held for a LONG time, and were under boost (KA-T).

What I'm saying is that the KA is pretty forgiving in this matter...so you had some major problem for it to go so again soon.

- Brian

[GringoEJS]

I had a machine shop resurface the head, I used new OEM headbolts, and torqued it down to 80 pounds. I have never had problems before and this was an easy job compared to others I have done. Would it at all hurt if I did punch holes into the coolant spots on the other 3 cylinders? I guess I need to have the head resurfaced again. Block still seems flat. Thanks for the replies

[180fan]

OEM bolts to 80 ft/lbs? My money is on improper torquing procedure.

[:: orion ::]

Your issue IS NOT coolant related...unless you had air pockets and the motor overheated badly after you reassembled it (thermostat never opened).

But not from the HG design.

It's desinged to keep coolant around the cylinders and soak up heat...you go and open up other holes, the coolant may flow too fast and not absorb heat...making your problem worse.

So leave the HG alone.

...

Torque sequence - Did you follow the FSM?...did you torque to a lower spec, then retorque to the final #...?

If so, I blame bad machine work...it takes VERY little imperfection of the head to cause bad sealing.

And why do you believe it's blown again? White smoke? Pushing coolant out into the resevoir? Poor compression?

What made you do the HG job in the first place?

??? - Brian

[GringoEJS]

OK...thanks for the info on the HG. I read somewhere to lube the bolt, torque to 22lbs, then 58lbs, loosen, retorque to 56lbs, then to 80lbs. I bought the car with a blown HG. It smoked and overheated quickly. Milkshake oil, oil in coolant. I believed it was blown again because when I re-changed the oil, it was completely milked down again. (I changed it prior to letting it run.) It was very watered down, which is what I filled the car with to flush it before putting coolant in it. I am beginning to suspect bad machine and already took the head to a different shop. I checked the cylinders for cracks and didn't see anything obvious so I am hoping it was a bad resurfacing job.

[:: orion ::]

Good luck with it second time around...

- Brian

[yellow_jacket]

It sounds like the car is overheating because you are losing all of the coolant into the oil. Pull the front cover. The SOHC motors like to eat front covers. There is a good chance there is a hole in one of the coolant passages. This will allow all of the coolant to flow into the oil. And of course then the car will overheat.

[GringoEJS]

Nice call, Yellow Jacket. I pulled the front cover and saw that the timing chain had chewed through the cover by the water pump. I will change this out ASAP. I am assuming this is because of the tensioner..? Well, that explains the coolant in the oil and the car overheating and blowing the HG. Thanks

[GringoEJS]

The right idler pulley had broken in half. $11 dollars at AutoZone...