Advice for Engine rebuild

Here's some good repair guides for your Tercel :) Look here for help first!
Post Reply
greeneggs&ham
Newbie
Posts: 5
Joined: Wed Oct 26, 2011 10:19 pm
My tercel:: 1985 Toyota Tercel 4wd
Location: Bellingham, WA

Advice for Engine rebuild

Post by greeneggs&ham »

Hey folks,

I have a 1985 tercel 5spd, I've been doing tons of work on it over the last few months since I overheated the engine and blew the head gasket. So far, new head gasket, new timing belt and front seals, battery, radiator, PCV grommit. (I think that's all I have replaced so far..) And now I have discovered the engine has decided it wants to start leaking and burning oil pretty bad-ish. So I am trying to decide if I should just do a complete engine overhaul so that I can find all the leak points and start from "scratch" with this car (my skills are limited but I would like the learning opportunity) or buy a crate engine. I was curious what some of you might think, my mom's husband has a garage that has majority of the tools and whatnot if I wanted to do either. I just want to do my research and be prepared for either option.

Thanks for time and any input/advice ya'll may have.
1985 Toyota Tercel SR5 4wd - name is Otis
2010 Kona Dew - Roadbike named Blackie
2005 Honda Metropolitan- named Dreamsicle
User avatar
dlb
Highest Ranking Member
Posts: 7305
Joined: Mon Jul 06, 2009 9:03 pm
My tercel:: '87 sr5, '83 dlx parts car
Location: bc, canada

Re: Advice for Engine rebuild

Post by dlb »

i think going for a rebuild without doing a few tests would be jumping the gun. replacing the engine always seems like it might be easier but it's usually not--it's a fairly large job and you can't be sure the 'new' engine is going to be any better unless you've been able to drive it lots in a different car already.

i suggest doing a compression test and writing the #s down, and then dribbling oil down the spark plug holes and doing the compression test again. if the initial set of #s is at least above 130 PSI and all #s are within a 10% range of each other, your rings are probably good. if the #s are below that, your rings are worn out and a rebuild is in order. if only one cylinder is low and the compression doesn't come up after dribbling oil in and retesting, the problem is up in the valves and could be a burnt exhaust valve or the valves may need new seats. alternatively, you could try some engine oil additives before you go doing any serious work. forum member petros has had great results with the 'restore' product in similar cases but i have no first hand experience with it. others have reported that adding lucas oil also helps stop burning oil.

as for leaks, they're not a real issue it's really pouring out. spray the engine down with a cleaner, let it sit for a minute or do, and then hose it down. wrap the distributor and spark plug wires in a bag and seal it as best you can to prevent water getting in there. it's not a big deal if some does but the car will run rough until all the water evaporates out of the dizzy. once the engine is clean, you should be able to see over the next day or two where the leaks are originating from. most of the seals are not too difficult to get to and again, if it is leaking from some of the more difficult to access seals, you can try oil additives that help restore old, brittle seals.

let us know what compression results you get and where your leaks appear to be coming from. good luck!
Lil Beast
Top Notch Member
Posts: 308
Joined: Mon Oct 03, 2011 9:25 pm
My tercel:: 81 tercel sr5 GTS (4age RWD and 4WD application on build up for the moment) now im running a 3a with weber 32 dmsa 100,corolla gts front suspension, sway bar and steering, troush exhaust
Location: Oliver B.C. Canada

Re: Advice for Engine rebuild

Post by Lil Beast »

I think dlb gave you a good explanation on the compression test to know if it's the rings or the head! If you compare with my engine right now it's at 120psi all even only the number 3 needs a stroke or two more to reach it, when I dribble a bit of oil, it doesn't take the few extra stroke, so #3 rings is so so. My low comp iis cause by my valve seals, when I change them I get around 145psi, but I like the revs, the 3a doesn't so keep poping my valves seals, they are cheap. Another good way to know, me I know as soon as I get to a red light and blue smoke comes out the exhaust meaning 1 or more valve seal popped, if when you rev the engine then it start to smoke, good chance it's the oil rings. But a compression test tells a lot more things. An advanced user of the compression tester along with a vacuum gauge can pinpoint pretty much anything and knows exactly what to do. But that would require a full thread to explain in deep details! With the intruments, good instructions are usually provided! There is good tricks to change valve seal without having to take the head out and I believe the rings can be changed from the bottom(never tried yet but thought about it to save time on cheap rebuilds)
Dont let your eyes to fool you!!!

Labine R.
User avatar
Petros
Highest Ranking Member
Posts: 11930
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Advice for Engine rebuild

Post by Petros »

I want to add to DLB above, that the imported engines are cheaper than a rebuild (if you can find a good one, they are getting hard to find because of their age), presuming you decided to replace/rebuild the engine. OTOH doing a complete rebuild will allow you to tweak the engine and get a bit more power out of it, improve the durability, etc. You can also find a 4ac first and take your time to rebuild it, giving you a larger engine for more power, and than just doing an engine swap in one day when the new engine is ready.

BTW, did you use the head gasket procedure I posted over in the repair guilds section? If not you may have issues that should have been addressed unrelated to the gasket itself.

I like tweaking engines and did a rebuild on mine. I would go overbore, new pistons, rings and bearings, consider balancing it, lighten the flywheel, Delta Cams performance regrind, perhaps clean up the ports, regrind/replace valves and valve guilds, resurface the head, clean up the ports, new seals and gaskets. With the 4ac, and when you switch the weber carb you should be putting out about 90 hp. All this would cost you about $600-700 in parts and machine shop services, an imported engine would be about $400, but you would stuck with the stock 62 hp (of course you can install the cam and weber without the overhaul, but you will not have as nice an engine).

It does not take a lot of specialized tools to do the rebuild, most you do not have you can rent from the auto parts store. The machining and specialized work will be done by an auto machine shop.

And the list members are here to help you through the process.

Good luck.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
User avatar
Petros
Highest Ranking Member
Posts: 11930
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Advice for Engine rebuild

Post by Petros »

Lil Beast wrote:...and I believe the rings can be changed from the bottom(never tried yet but thought about it to save time on cheap rebuilds)
Not possible to replace the rings from the bottom, you have to remove the head and pull the pistons out the top. It would be possible to leave the short block in the car and replace rings and connecting rod bearings, but you need to pull the engine to replace the rear seal, clutch, main bearings, etc. But once the head is off and the short block is stripped of accessories, it is not difficult to pull it and do it right.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
User avatar
LittleRed4wd
Top Notch Member
Posts: 188
Joined: Sat Sep 18, 2010 11:36 am
Location: Boulder, CO

Re: Advice for Engine rebuild

Post by LittleRed4wd »

Another option if you can do without your ride for a bit is to pull your current engine, tear it down, and find the problem. If it's the pistons that are worn down and the block is within tolerances (you gotta be 100% sure) then the rebuild is easy-- $300 for a master rebuild kit with pistons from rock auto, but I along with most everyone here would reccomend upgrading to a Toyota or fel-pro head gasket with the mods Petros has talked about.

If the block needs to be drilled out (not within required tolerances) the build will cost much more and you're probably better off finding a parts car or Import engine. building the engine is super fun though, and you'll learn a lot, it was a great thing to do for me anyways!
86 Silver SR5 "Silver Bullet"- 3in lift, 205/75/14s, torque cam, big brakes- Sold
86 Red SR5 "Battle Wagon"- 2.5in lift, 205/75/14s, rebuilt 3ac, chalkboard hood- Totaled
86 White DX "The Gateway Drug"- All stock-Totaled
greeneggs&ham
Newbie
Posts: 5
Joined: Wed Oct 26, 2011 10:19 pm
My tercel:: 1985 Toyota Tercel 4wd
Location: Bellingham, WA

Re: Advice for Engine rebuild

Post by greeneggs&ham »

Wow thanks a ton folks for all the different tidbits of info here. I had a compression test done at an auto shop a while back and they said the results were good. I guess I'll get to learn how to do one myself since I am not sure they actually did a test anyways.

Petros, one thing that is important in a car for me is decent gas mileage, does the increase in horsepower affect the gas mileage you would get from 3-AC to 4-AC engine? I don't mind a put-put engine as long as it can make it up a hill and give me decent gas mileage heh. But I do like an engine that is clean and not omitting as much junk into the air. And in regards to the head gasket procedure you mentioned, I didn't have a choice in how it was gonna be fixed up. My mom's husband kinda just took over and did it all without me really being around for it.

Do any of you know of which car yard's in Washington are good prospective places to find car parts?
1985 Toyota Tercel SR5 4wd - name is Otis
2010 Kona Dew - Roadbike named Blackie
2005 Honda Metropolitan- named Dreamsicle
User avatar
dlb
Highest Ranking Member
Posts: 7305
Joined: Mon Jul 06, 2009 9:03 pm
My tercel:: '87 sr5, '83 dlx parts car
Location: bc, canada

Re: Advice for Engine rebuild

Post by dlb »

i upgraded from the stock carb to a weber and from a 3AC engine to a 4AC and my mileage didn't change with either mod. it was usually around 30 mpg. i've been having a problem lately though and am only getting 25-26 mpg and have yet to find the cause.

compression tests are easy, you just have to pick up a compression tester (around $15), pull the spark plug wires, pull the spark plugs, thread the tester in to a spark plug hole, and then crank the engine 8-10 times. write down the reading and then move on to the next cylinder. if there are any particularly low cylinders or if all of them are low, then do the oil trick to see if the low compression is due to worn rings.
User avatar
Petros
Highest Ranking Member
Posts: 11930
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Advice for Engine rebuild

Post by Petros »

If the compression is good it should not be burning oil, unless the valve stem seals are bad (they were not replaced when the head gasket was replaced?). Do you get a lot of bluish smoke when you rev it? It is much easier (and cheaper) to replace the valve stems seals than rebuild the engine. You can tell if it is the valve stem seals if you get oil fouling on one or more of the spark plugs.

Chances are you just have some leaks to fix, all are relatively easy. The most common places to leak are the front seal, the valve cover gasket, the distributor O-ring, and the fuel pump gasket. sometimes the rear seals can leak, but that is a big job and can wait until you need to replace the clutch.

Even if you do all of these repairs, including the clutch and rear seal change, it is still much easier than rebuilding a whole engine.

Doing the engine mods I listed will not harm the economy at all, these are relatively mild improvements and work to improve efficiency. it can even improve fuel economy a bit.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
Lil Beast
Top Notch Member
Posts: 308
Joined: Mon Oct 03, 2011 9:25 pm
My tercel:: 81 tercel sr5 GTS (4age RWD and 4WD application on build up for the moment) now im running a 3a with weber 32 dmsa 100,corolla gts front suspension, sway bar and steering, troush exhaust
Location: Oliver B.C. Canada

Re: Advice for Engine rebuild

Post by Lil Beast »

if there is a thing i'm good at it is the valve stem seals, they pop like pop corn! I use an old school trick with 1/4 inch nylon rope about 4 ft long. I start by making a template out of cardboard about the crank pulley size and draw a perfect cross in center that makes 0/360,90,180,270 degrees marks. when at tdc put the 0/360 mark align with the tdc mark on block back it to 90 considering you went clockwise with ur marking, you should be good for piston 1, pull the spark plug out fill the hole with the rope until slightly compress, DO NOT PUT ALL THE ROPE IN MAKE SURE YOU GOT SOMETHING TO PULL ON, then turn clockwise to 0/360 agin that should keep your valve from falling in the block! then you can attack the seals.Then for #2 its at 180 that it will be on top. When you do it often an hour and it's done(i do 2 piston at the time)!

good luck!
Dont let your eyes to fool you!!!

Labine R.
greeneggs&ham
Newbie
Posts: 5
Joined: Wed Oct 26, 2011 10:19 pm
My tercel:: 1985 Toyota Tercel 4wd
Location: Bellingham, WA

Re: Advice for Engine rebuild

Post by greeneggs&ham »

Hm, I've noticed the mention of coloration of smoke. I have not noticed blue smoke but I know my exhaust seems to let out a bit of smoke in general. Gonna be doing the compression check, address the leak coming from the oil pan, recheck the rocker arms, replace fuel filter all tomorrow. Hopefully we'll get some insight from the compression check.

Thanks again for all your inputs!
1985 Toyota Tercel SR5 4wd - name is Otis
2010 Kona Dew - Roadbike named Blackie
2005 Honda Metropolitan- named Dreamsicle
Post Reply