PaulY
PaulY New Reader
3/12/09 2:21 p.m.

My brother's '90 corolla sr5 coupe and him and my dad are finding oil and water getting cozy in the coolant tank. How hard is it to do the head gasket on one of these? I've replaced one on a '99 gsxr600 with a friend before but that's the only one i've done. Also how much should they expect to pay if they take it to a shop?

Raze
Raze Reader
3/12/09 3:13 p.m.

With an iron block I'd say DIY, don't have to worry about PITA and costly thread repair unless there's damage or the engine was overheated/warped in which case the block surface will be highly suspect as well. Most likely the block is ok (you'll need to measure after head removal) to make sure it's within tolerance for flatness there are tons of sites on the web describing how to do this with a straightedge and a cheap $5 set of feeler gauges from AutoZone. Make sure to clean out the head bolt thread holes with a thread cleaner/chaser not a tap as you could cut the threads. Inspect the cylinders, if there was water sitting in there for long you're going to need to clean that out with something soft, don't hone your cyl walls. The head may be a different story being of aluminum, but again, flatness check to make sure tolerances are good. A local machine shop quoted me $25 for a cyl head shave just last week.

I'd get new headbolts even if the oems are reuseable, and go with a decent gasket, looking on RockAuto you can get away with as cheap as under $70 or as much as $150 for a new gasket and bolt set. Make sure you check with whomever the the bolt manufacturer is if they don't have directions with to see if they're torque to yeild, torque to angle or just torque to spec.

Most important part of the whole deal besides flatness of head and block is surface prep, can't stress that one enough, gotta be flat, gotta be clean, follow the HG manufacturer's install directions to the letter...

Dr. Hess
Dr. Hess SuperDork
3/12/09 3:16 p.m.

I haven't done a 4AF(E?), but it should be pretty straight forward. Get at least a Chiltons or Haynes, even if you have to borrow one at the library and go through it. Unbolt head, check for flat, put back together. The question is why is the HG B? Overheat? Is the head warped?

I don't think you can get a shop to do anything for less than five bills today. Probably more. It may be cheaper and easier to just get a used 4AF and drop it in there. My last 20v was under five bills. A 4AF can't be much more. I hesitate to recommend a 20v because of the electrical monster of a job it is, but if you want that AE92 to go fast like mine....

PaulY
PaulY New Reader
3/12/09 4:46 p.m.

Thanks for the advice! If I can get home for a weekend maybe that's what I'll do. How much do you figure an honest mechanic would charge?

As much as I'd like a quick car, my brother just needs reliable transportation. Is that 20v motor the one from the gts version of his car?

93celicaGT2
93celicaGT2 HalfDork
3/12/09 5:09 p.m.
PaulY wrote: Thanks for the advice! If I can get home for a weekend maybe that's what I'll do. How much do you figure an honest mechanic would charge? As much as I'd like a quick car, my brother just needs reliable transportation. Is that 20v motor the one from the gts version of his car?

Nah, it's from the overseas AE101 or the AE111. We didn't get it.

The GTS version of the car has a 4age 16v.

ae86andkp61
ae86andkp61 GRM+ Memberand Reader
3/12/09 5:22 p.m.

The 20-valve was offered overseas in the performance variant of 90's Corollas, so you would have to get one from an engine importer. As Hess said, wiring is the biggest hurdle, but it is good for a 50-75% jump in power, plus the fact that is it cool to have factory-equipped individual throttle-bodies, 5 valves per cylinder, and variable valve timing in an early 90's economy car!

The head bolts are reuseable, FWIW. I always recommend Toyota original parts because the quality is better than the bulk of the aftermarket stuff and while it is a bit more expensive, it isn't massively more expensive. Be careful to follow the recommended procedure for removing the head bolts in steps and torquing them in steps upon re-install. Also take care not to lose the washers under the head bolts, otherwise the bolt can bottom out before you are actually tight on the head. I mention it becuase sometimes the oil causes them to stick to the bolt and sometimes they stick in the head so it is easy to lose one or end up doubling up on them accidentally.

While you are at it, it would be a good idea to at least consider/prepare for replacing the timing belt, timing belt tensioner, and water pump as needed. It is fairly easy to check the bearings in the belt tensioner and the water pump by giving them a quick feel. I often just replace them anyway for peace of mind.

http://www.toyodiy.com is a good resource for Toyota home repair. It has exploded diagrams with part numbers and approximate prices for Toyota parts.

PaulY
PaulY New Reader
3/23/09 4:54 p.m.

So i got another update from my dad and the car is not well, it now overheats so they've parked it. Local shops want between 12-1500 and I'm not sure if that includes machining which they both have to sub-contract out. Since my brother only paid 1250 for the car that seems to be out of our options so I think i'll have to make a few weekend trips to the mainland to fix it. One weekend to take it all apart and buy parts, then send the head out for work and another to assemble it all together. I'm going to try and get an estimate of parts. Do I just need a head gasket and bolts?

Jerry From LA
Jerry From LA Reader
3/23/09 10:04 p.m.
PaulY wrote: Do I just need a head gasket and bolts?

If it was me, I'd get a "head set" which contains all the gaskets including the intake and exhaust manifold gaskets, the cam cover stuff and of course the head gasket. Also included is a set of valve seals. You can rent a valve spring compressor and change the seals. If you don't feel confident doing that, ask the machinist to do it for you.

Also, get your head pressure tested. If the valve job is OK, just replace the seals and go another 100K miles. A pressure check will also find a crack in your cylinder head. If your head passes on both counts, you'll know you didn't spend money replacing a head gasket on a bad head.

Jerry

Dr. Hess
Dr. Hess SuperDork
3/24/09 8:15 a.m.

I'd just throw a head gasket set on it and drive on. Check the head for flat while it's off. Or put a new used motor in.

PaulY
PaulY New Reader
3/24/09 9:31 a.m.

With this head gasket set, can I get it an an auto parts store or should I go to toyota? Also it seems like both of you are sugested to re-use the head bolts?

Thanks again for all the help!

Dr. Hess
Dr. Hess SuperDork
3/24/09 10:52 a.m.

On that car, I'd just get a Felpro set at the auto parts store. Yeah, reuse the head bolts. There fine.

Jerry From LA
Jerry From LA Reader
3/24/09 4:32 p.m.

The Fel-Pro set is a good one. Use the head bolts again. If they just give you a torque setting and no extra angle setting, you're good to go.

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