Debating rebuild vs used engine

[Lazyokie]

First I'd like to thank you guys for all the great info and videos on this site.
My project (Yoda) an 85 tercel 4wd sr5 I purchased a little while back is giving me trouble with its revival.
I bought it becausei need a 4wd every once in a while and it seemed like a fun candidate. The car is in relatively good shape, rust free, has 250k miles and interior is missing some interior panels and carpet and dirty as hell. the previous owner stated "it just quit runnin"
So I got it home and a quick carb blast got it running. A carb cleaning/rebuild later it starts easily/quickly but doesn't have enough power to get out of its own way. Spark is good on all 4, and timing is good. Vac lines are mostly good, as far as I can tell.
I did a compression test today and got 30 on cyl 1&2 and 125ish on 3&4.
I'm assuming this means head gasket, but I'm debating whether a full rebuild would be a better more definitive solution compared to a used engine.
Or can I get away with just doing a head gasket?
What are approx cost of each?
Also I'm in ABQ if any of you happen to know where I could locally source a decent engine.
Thanks

[dlb]

125 psi on cylinders 3 and 4 is getting pretty low so even if the head gasket was the source of the lower psi on cylinders 1 and 2, getting them up to 125 still wouldn't be great. it would run but might lack power and burn oil. the head gasket may also not be the source of the low compression, which would mean a full rebuild. lots of work, not sure if you want to invest that in that particular car.

if you can find a known good engine, i would go that route. the difficulty with that though is that i have a hard time trusting an engine unless i can actually drive it for a while, or get it from someone i know i can trust. maybe you will get lucky and find someone here who has one kicking around.

[Lazyokie]

Yeah I have trust issues with used engines too.So far I've only found 1, the guy is a mech shop owner and claims it's an LKQ engine and trans he bought for a customer that fell through.

I also want to believe it'll do OK with a head gasket as it doesn't throw a lot of smoke, or burn oil.(some white smoke with first startup)
I don't know, I love the idea of this little car, but don't want it to end up investing way more than I should into it.

[marlinh]

You could also have a bad valve in both those cylinders. That could be determined with a cylinder leak down test.

[Lazyokie]

Can a leak down test kit be rented? I've never done that test

[Petros]

Do NOT bother testing it, the head has to come off to fix it anyway, might as well get it off and take a look at it, you can decide to replace it than if you want.

If you do a complete overhaul with cylinder boring, new piston, rings bearings,etc you will spend about $700-800 in parts and machine shop time, and lots of hours pulling it and reinstalling, plus tear down and build up. I have done a number of times, but only on cars I intend to keep. I actually like doing it, but most would discurage you from spending that much time and money on an old car. I intend to keep mine as long as I can still get parts to keep it on the road.

it would be far cheaper and easier to just swap out a good used engine rather than a rebuild, but typically it means a lot of work before you can find out if the used engine is any good. I have had bad luck with that, and will only take an engine to install if I had confidence that it was any good, particularly if I can drive it before it was pulled.

You can just replace the head gasket for about $40 worth of parts, and it will run better. Go read my procedure for head gasket replacement over in the Repair Guilds. Here is everything you need to know about replacing the head gasket: viewtopic.php?f=7&t=6059

If I had that car I would just pull the head and rebuild the head only: you can have the head off in 1 to 2 hours, strip it and take it to an auto machine shop. have the intake valves and seats reground, replace the exhaust valves with new ones (not worth using the old ones, they can fail badly and wreck your engine), and have them install new valve stem seals. Check the head for being flat, if it is flat than do not have it resurfaced (the machine shop will want to do it anyway, but pay for it only if it needs it, you can resurface it yourself better than the shop, go read how my repair guilds). Than just replace the head gasket using my procedure over in the Repair Guides part of this forum.

If you rebuild the head, it should raise your compression, reduce oil consumption, and greatly improve power and economy. If you find it still burns some oil than do a "Seafoam" treatment to the engine oil (will clean up gunk around the rings, often works wonders, you can find the procedure elsewhere on this forum), and add some Restore to the engine next time you take it on a trip (I have had good luck with the "Restore" brand of adaptive, I would not bother with anything else). Doing this may not bring the compression all the way back up, but it will run good and serve you well.

All of that should not cost you more than about a day or two worth of work and perhaps $200. And you will know what you have, and it should be good for another 100k miles or so. That would be cheaper than replacing the engine, and more reliable. Adding a quart of oil every 2000 miles if you have to is far cheaper than replacing your engine.

Good luck.

[Petros]

One other thing: make sure you find out why the head gasket was blown, typically it was because it was badly overheated. Make sure you replace the thermostat with a good quality one (not made in china t-stats, they are junk). DO NOT TRUST the one that is in it, it may be why the head gasket has blown, and they usually go bad if the car has sat for a long time (my experience with saving some 20+ old tercels). If the upper and lower rad hoses are bad replace those too, check the water pump and radiator over carefully before you reuse it. You can get a good deal on this stuff from Rockauto.com, as well as seals and exhasut valves, and head gaskets. You might also consider replacing your timing belt and front seal, extra work but they are not costly and you are half way there anyway with the head off.

Too often I have replace a head gasket on a "fixer" and found out after I got it running the radiator or t-stat was bad, that caused the orignal head gasket to blow. From now on I ALWAYs replace the the t-stat preemptively on any car right away. Had to redo head gaskets too many times to risk it any more. Get only a good quality t-stat, Napa and Autozone sell the "gold" or top of the line t-stats, (about $16 to $22), and cheap ones for about $8, do not bother with cheap ones. BTW, use gasket sealer to hold the new t-stat in place to keep it from getting misaligned as you tighten the cover down (it can happen).

good luck.

[dlb]

i like peter's idea of doing the head gasket and valves (if need be), then doing a seafoam oil treatment followed by some restore oil additive. i have used seafoam lots with good results, and restore twice, also with good results. seafoam cleans carbon buildup, and restore is a quick fix to build up the cylinder walls an increase compression/decrease oil consumption. it has done just those things quite significantly on two of my vehicles. those would definitely be the quickest, easiest, and cheapest ways to get the car back on the road and in decent running shape without investing too much in the project.

[irowiki]

My 87 had a bad head gasket right after a rebuild because whoever rebuilt it did not torque the heads properly.

I agree with everyone else, doing the head gasket is the quickest easiest and cheapest way to see how your engine is faring. You could also do a "cheap" rebuild, replace rings, bearings, maybe pistons if your bores look good.

[Petros]

I want to share an amazing experiance with the Restore. i pick up a fixer Tercel4wd in a trade from Silverton NM, it ran okay but burned about a quart every 300 miles, and so badly coked up the the #2 spark plug it would be running on 3 cylinders when I pulled over for a fill up. I was driving the car to Austin from NM to visit my daughter, I got some extra spark plugs to swap out at each fuel stop, and on a whim bought a can of restore to throw into the crank case. From El Paso, where I put in the restore, I drove to Austin, back to California, than home to Washington state over the next few weeks. I did not have to change the spark plugs out even once, and it only burned about one quart of oil total in over 4000 miles of driving after I put the restore in it. I was very pleasantly surprised it worked so well.

I would not have believed it, I usually do not trust the wild claims of these additive companies, but it worked perfectly, and far better than I would have expected. I have tried it on other high mile cars, but the result was not as good, so I suspect it would be beneficial to ad it when going on a road trip. the material in the Restore settles out of the oil carrier, the instructions say to shake it well. I noticed it will still be stuck on the bottom of the can unless you really really shake it up well before you open the can. Which I suspect means it will settle out while it sits in your oil pan. So on a long road trip it will stay in circulation much longer, and do more good than just dumping in your engine one night on a normal commute day of driving. So save it for a day you will be driving long distances.

[irowiki]

Also, if you buy a used engine, I would just plan on rebuilding the used engine first.

[Lazyokie]

Thanks for the replies, it's good to hear from experience before I jump too deep into it. Unless the guy with the engine produces better evidence as to the condition of his engine, I think Im going to replace the head gasket, thermostat, and timing belt. Also adding restore and seafoam along the way and cleaning the cooling system. The car seems good other than the two bad cylinders, hopefully this will give me a few thousand miles before I have to decide to rebuild it.
I should be able to get time for it in the next couple weeks, I'll let you guys know how the Yoda turns out

[Petros]

Make sure you also replace the front seal while you are replacing the timing belt, it will be exposed when you get the belt off and they do not cost much. They typically go bad at about 150 to 200 k miles, well worth doing preemptively while you have the timing belt off. They only cost about $12, even less from Rockauto.com.

One other consideration, once you do those things (rebuilt head, new exhaust valves and valve stem seals, timing belt, etc), should you decide later to rebuild the engine, all of the work you did on the head is still good to reuse later. IOW, if you are not happy with the way it runs after the head rebuild, you can take your time and look for a good short block assembly (lower engine: block, crank, pistons, connecting rods) from a wrecking yard, craig's list, or other forum members, and rebuilt it at your leisure. When you are ready you can pull the old engine, swap over the rebuilt head, timing belt, etc. and put it back in on a week end. You did not waste any money on the head since it will still be good to reuse later. the only "extra" cost is that the head gasket can not be reused (but it is only about $20, less from Rockauto.com).

BTW, you can also use a 4ac short block as well, the 3a head will fit on the 4ac block, they are almost identical. The 4ac is slightly larger (1.6 L vs. the 1.5 L of the 3ac), and came in the same year Corollas as the Tercel4wd, and more common. It will bolt up exactly the same in the car as the 3ac block. you will also get perhaps 6 to 8 more hp in the deal too.

Either way, you will not go wrong to rebuild the head first and replace the head gasket. Likely that is all the work you will have to do for quite a long time. With a good radiator and thermostat, it should last a long time.

BTW, water pumps are not too costly, so when you have it apart, check the water pump carefully for any play in the shaft, or water stains coming from the drain hole on the underside (you do not have to remove it to check it). If you have any detectable play or roughness when you turn the shaft, or there are water/coolant stains from leaks on the underside, replace the water pump with a new one. If you need one, do not waste any money on a rebuilt one, most of them are junk. New ones are not too costly and last 100k to 200k miles and well worth the small extra cost for a new one, not a rebuilt one. Rock auto would be your best bet there as well, but NAPA sells a lifetime guaranteed new pump, from the same supplier as Toyota uses, for only about $45. You would be lucky to get a year on a rebuilt water pump, a waste of time and money, and you risk an overheat and damaged head gasket.

The last rebuilt water pump I used, a number of years ago on our Mazda MPV 4x4, after 13 months (one month after the warranty expired), it shredded itself up, blew coolant everywhere, overheating the engine, and sent metal shavings all through the cooling system. It plugged up both the heater and radiator, I tried back flushing both but no such luck, it cost me $80 to have a radiator shop take it apart and clean out the tubes with small brushes (it was a new $200 radiator!), and I never did get the heater core cleaned out very well. It puts out heat, but not as much as it used to, even after soaking it in acid and flushing. I will next use my new handy powerflushing gun on it I just bought last month. Needless to say, the $25 I saved on the POS rebuilt water pump was NOT WORTH IT. On the mazda, it is a six hour job to replace the water pump! Last time I ever install one of those.

However, replacing the water pump is easy on the Tercel, so if it does not need one, do not worry about replacing it now. I have replace the water pump using just hand tools in about 30 min on my Tercel, from draining the radiator to get started, to having it back together and turning the key to run it to check for leaks (none found!). It may take you longer your first time, but it is not a big deal to do later (unlike the newer cars with a transvers engine installation, a real PIA!).

Good luck!

[ARCHINSTL]

Not much to add, save that i bought a new water pump from Advance last year for only $27. The part # is T-1088.
Think about installing new belts as long as you have the pump off.
If equipped with PS, sometimes those pump bolts can be "challenging.'
See viewtopic.php?f=3&t=10433&p=77360&hilit=belts#p77360
See viewtopic.php?f=7&t=10640&p=78755&hilit ... ump#p78755 xirdneh's XLNT video link!
See viewtopic.php?f=3&t=10492
Tom M.