Head Gasket Differences

Benesesso · 04-05-2006, 11:36 PM

I've done a bunch of searching and couldn't find any good answers. The 1990 Supra I recently bought only had 65k miles, and it ran fine for several months. The previous owner said he had retorqued the head bolts ~40k miles, and I believe him. At ~72k miles the HG started leaking slightly into cyl. 6 and a tiny bit into #2. Pulled the head off right away-no heat damage. The head bolts were right ~70 ft. lb.

So, I think I had a case of some previous HG damage from the orig. low torque, but retorquing did not prevent the BHG.

Since it appears that the Mark IV's don't usually have the problem, I just wondered what Toyota did differently. Looks like they kept the same 14 bolts but raised the torque--and maybe used a better HG.

04-05-2006, 11:36 PM	#3
Benesesso 3" Exhaust Join Date: Nov 2005 Location: Phoenix, AZ Posts: 145	I've done a bunch of searching and couldn't find any good answers. The 1990 Supra I recently bought only had 65k miles, and it ran fine for several months. The previous owner said he had retorqued the head bolts ~40k miles, and I believe him. At ~72k miles the HG started leaking slightly into cyl. 6 and a tiny bit into #2. Pulled the head off right away-no heat damage. The head bolts were right ~70 ft. lb. So, I think I had a case of some previous HG damage from the orig. low torque, but retorquing did not prevent the BHG. Since it appears that the Mark IV's don't usually have the problem, I just wondered what Toyota did differently. Looks like they kept the same 14 bolts but raised the torque--and maybe used a better HG. __________________ "You see, wire telegraph is like a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? Radio operates the same way: You send signals here, they receive them there. The only difference is there is no cat." A. Einstein 1988 and 1990 Turbo Supras