suprageezer;1940037 said:
My own personal 12 years of 89 Supra NA experience, blown head gasket on original 7MGE repaired, never ran right after that, 500.00 ebay jdm 7mGE motor, decent miles, then blown head gasket, professionally rebuilt 7MGE, began to have problems buring oil in number five cylinder within a few thousand miles, eventually died showing zero compression, Kaizen Motorsports installed used 2JZGE on 7MGE electornics, including smog equipment, runs perfect, burns no oil, reliable and a little more power. Next upgrade is CA 94 Lexus computer and harness, then a trip to the smog referee.
So what was different from my 12 years of 7M-GE ownership...
Bought the car Feb 29, 1996. Joined the mailing list at supras.com by June. Re-torqued factory head bolts to 72 ft-lbs when I did the timing belt in May 1997. Zero issues (Excluding A/C where I had largish issues for a while) until 1999 when the differential failed. Oh wait. That's not the engine either, though it did start using some oil around then, too. (~300,000 km.) Another new timing belt and new spark plugs. By 2004 there was a pretty consistent blue smoke on a cold start, and I was going through oil more quickly. I'd put almost 300,000 kms on the car over 8 years at this point. I never did do the valve stem seals. After ANOTHER 100,000 kms, I blew the coolant hose under the distributor, and the engine overheated. At that point, I pulled it out, and swapped in a 7M-GTE. 483,000 kms on the odometer, but since I was about 10% out since about 300,000 (3.909:1 means that the speedo and odometer were reading -10% vs the factory 4.300:1 differential), the actual chassis mileage would have been over 500,000. 390,000 of those was with me driving it.
Oil changes every 5,000-6,000km, coolant flushes every spring, when I also cleaned out all the crap that accumulated between the radiator and the A/C condenser. Amazing how well these engines last if you take care of them.
It it "the greatest engine ever"? Nope. But it can be a good solid reliable engine if cared for. I don't think that just swapping a JZ in is the answer to reliability issues. If you're not going to take care of it, NO engine is going to make reliable power. See how long your JZ lasts you without maintaining the cooling system.
Oh, for the cracks about a 7M on a stand... Yeah, I've got one of those. There's also one in my '89 and one in my '90. The one in the '89 is knocking.
My own fault. I pulled one from a car that had been sitting with a quarterpanel smashed in for God knows how long, and put it in without having pulled the crank to even LOOK at the bearings. The one in the '90 runs fine, just needs a clutch. The one on the stand is being built to make considerably more than stock power, and it's been there a while because I'm only devoting spare time to it.