Pulled the head on my 86 tercel 4wd

GTSSportCoupe · Post by **GTSSportCoupe** » Fri May 14, 2004 10:32 am

Well, I pulled the head on my 86 tercel 4wd (newly acquired parts car) to see how badly the engine was damaged as a result of the blown head gasket. I could not believe how easy the engine was to work on! It took almost no time at all to pull the head off. The engine was bad news inside. The head gasket was blown between two cylinders (3 and 4) and between the water jacket and one of the cylinders (4), as well as between one of the water jackets and an oil return. The engine had sat this way for a long time, with some coolant/water in cylinders 3 and 4 and coolant/water in the oil. This had allowed the rings and cylinder walls to rust somewhat. It's not so bad that the engine won't run ok with a new head gasket, but there would definitely be low compression in those cylinders as well as blow by past the rings. None of the other engine components are corroded though (valve train, bottom end).

So, I'm trying to figure out if I should hone out the cylinders as best I can, and throw it back together with a new head gasket, and put the engine in the car I will eventually sell (for cheap), or if I should scrap the engine, and put a 4ac in the car I will keep, and put my good 3ac in the car I will sell. I don't want to loose much money either way. But I think an engine burning oil with low compression will pretty seriously devalue the car I am going to sell. Not that I plan to get much for it. I'm going to call around for pricing on low km 4ac and 3ac's at wrecking yards. I could always just throw a 4ac bottom end in the car too - from what I understand, it will bolt right up to the 3ac head.

Just thinking out loud. Damn these cars are easy to work on...

GTSSportCoupe · Post by **GTSSportCoupe** » Fri May 14, 2004 10:58 am

Thinking some more... If I buy a 4AC and shave the head by 20 mils it will raise the compression from 9.0:1 probably to around 9.5:1. This, coupled with the displacement increase from the 3AC would probably be good for around 75hp and 90ft/lbs. This would be a decent increase over the tercel's stock 62hp and 75ft/lbs. Hmmm...I think I'm going to source myself a 4AC.

Thereminator · Post by **Thereminator** » Fri May 14, 2004 12:27 pm

If the 87s in good shape you could probably recover all your cost and then some if the buyer knows the car has a low~Mi(used~Jap.)engine.I would think about how much the unknowns are worth to a potential Buyer,a used 4-ac would cost me $350 after taxes but thats down-here.If you just want to get it off your property you could strip the good~stuff off,Tow~it to the yard and put your energy into your New~Rig!

tercel4wdrules · Post by **tercel4wdrules** » Fri May 14, 2004 10:16 pm

I say if you can keep the 87 then keep it. You have spent quite an amount of time and energy on it.

GTSSportCoupe · Post by **GTSSportCoupe** » Sat May 15, 2004 11:02 am

Found a 4AC for $75 CAD at a wrecker

. They say it burns oil though (thats why its so cheap). I'm hoping its just the valve oil seals not the rings. I'm going to the yard to look at it asap and will do a compression test. If the bottom end is good, I'll buy the engine and use the top end from the 3AC and the bottom end from the 4AC.

The 4AC will end up in the 86. I'll just leave my 87's engine in the 87. The 87 is the one I'm going to sell (after I trade all my new parts and the interior from it to the 86). I know I've put lots of work into it, but I want the sunroof and tilt etc in the 86. And having a 4AC with more power will be awesome.

Lots o' work ahead of me. Gotta go.

GTSSportCoupe · Post by **GTSSportCoupe** » Sun May 16, 2004 12:21 am

Well, it turns out the 4AC is garbage.

But I did find a super perfectly mint 3AC. It only has 144,000kms on it and was obviously very well maintained. It looks brand new on the outside. Under the oil cap I can see that the engine is very clean inside. It still has golden oil in it. I will probably be able to get another 200,000kms out of it. I've bought it and will be installing it this week into the 86.

tercel4wdrules · Post by **tercel4wdrules** » Sun May 16, 2004 12:47 pm

Hey, hopefully I will be able to find an engine like this for the 85. The compression on the 83 is : #1 115, #2 105, #3 115, #4 115. Supposedly it needs a valve cover gasket, that's why it's leaking like crazy. I on the other hand want to just replace the head with another used one and replace the gaskets on one of those. A mechanic friend of mine who has an independent shop and specializes in Toyota's told me that if the difference between the cylinders is 15 PSI or more then that cylinder will start failing.

GTSSportCoupe · Post by **GTSSportCoupe** » Mon May 17, 2004 3:39 pm

tercel4wdrules wrote: Hey, hopefully I will be able to find an engine like this for the 85. The compression on the 83 is : #1 115, #2 105, #3 115, #4 115. Supposedly it needs a valve cover gasket, that's why it's leaking like crazy. I on the other hand want to just replace the head with another used one and replace the gaskets on one of those. A mechanic friend of mine who has an independent shop and specializes in Toyota's told me that if the difference between the cylinders is 15 PSI or more then that cylinder will start failing.

Whoa! :huh: Those are pretty bad compression readings! Your compression readings are close enough that no damage will occur to the engine. I'd say your compression is probably low as a result of leaky valves. It happens on old worn out engines. New valve seats and a valve grind would fix your compression problems, but the rest of the engine is probably just as worn out. I'd say you are best off looking for a whole engine replacement from a wrecker. You can use an engine from a fwd tercel too; as long as it is a 3AC it'll work. The engine I've bought is from a 3-door hatch tercel.

Good luck!

tercel4wdrules · Post by **tercel4wdrules** » Mon May 17, 2004 8:44 pm

Hmm... you understand me, the guy who put that 3A-C into the 83 doesn't. He believes that it's still good for another 5 years! I say that anything below 125 PSI is garbage. Of course when we bought the 83 the cylinders had like 70-75 PSI all around and it only lasted 2 years before the thing gave up in the freeway at 1:00 A.M. in the morning. Smoke was coming out of it and it somewhat cranked quicker, but it would never start because no compression. The one it has now was from an 85 Tercel probably a hatchback auto because of the flywheel it had. At one point you would rev it at 2000 rpm and clouds of bluish white smoke would come out. Then we have just put Bardahl (hopefully I spelled that right) and it sort of stopped the major smoking. I just want to replace the engine on that thing. I want an engine that has 175 PSI or better all around. Its amazing how many things that engine has stood up to. It really got bad 2 years ago and now with a worn out clutch it an't keep up on the road, you have to constantly nail it. I know something else is wrong with it because it doesn't seem to move freely. I'll post the symptoms that it has on another thread so you guys can help me out. Thanks Nick for your help!