Stef's 7A-FE Rebuild, up and running since 12/16/07 Options

[Daftboy]

Have you dyno'd this new engine?

[lagos]

he said "fuel cut" which is pretty much what limits the speed. and as far as I know thats the only limiter you can modify.

I think the bottom end can take more than you would think. Manny (presure2) ran his 5S up to about 8200 rpm or so (accidentally) once, still runs great.

If your still rocking the shims over buckets, then you cant rev it very high. Maybe 7k tops. If you go any higher then that, you risk the shims flying out and causing a huge mess.
You should be able to use the emanage to raise your stock rev limiter if you want to.

[hurley97]

Have you dyno'd this new engine?

no. I think that would end up being very disappointing. It feels much smoother and it's definitely faster. As it is now the car is 100% better than it was when I got it four years ago. I've put a lot into this car and I'm happy with it right now, I'm not too concerned with the numbers just yet.

[laff09]

Have you dyno'd this new engine?

no. I think that would end up being very disappointing. It feels much smoother and it's definitely faster. As it is now the car is 100% better than it was when I got it four years ago. I've put a lot into this car and I'm happy with it right now, I'm not too concerned with the numbers just yet.

Yeah but I am!

[hurley97]

so I have some problems...

First, I'm pretty sure there is another oil leak. It's not bad but its there. The rear mount bracket, crossmember, and bottom of the transmission bell housing are wet with oil. The passenger side axle cup is a little moist too. That would indicate a bad rear main seal. Popping the little cover off and looking up into the space between the engine and bell housing you cannot see the seal sticking out at all, meaning the rear main seal did not pop out of place like the crank seal did. So either the seal itself is defective or... what else could leak behind there?

Second, and slightly more importantly, I'm leaking coolant slowly into cylinder number 4.

I've heard a gurgling noise from the heater core ever since we installed the engine. I tried a few things thinking they would cure it and nothing has:
- Switched the coolant in and out hoses to the heater core thinking if they were backwards it would cause the noise, nothing.
- Flushed the coolant several times using different methods of getting out air pockets, nothing.
- Finally changed the radiator as a last resort thinking thats the only thing left that's different since putting in the new engine, now it doesn't do it all the time but I do still hear it a little. Maybe it needs more time?
- Pulled out all four spark plugs and the ceramic centers are all white except the one that came out of cylinder 4 which is a little pinkish. Not a good sign.
- Using a scope to look into the cylinders I could see two small drips of pinkish fluid come from right about where the cylinder head meets the block at the headgasket.
- When shining a flashlight down into the cylinders you can tell the top of piston 4 is a little more wet than the others.

The theories:
- The head is cracked or warped from the slight overheating. Theory being that if there was no coolant for the temp gauge to read so it was inaccurate and it actually overheated more than we thought.
- One or two of the headbolts that we reused were actually not reusable and did not stretch like they should have causing the headgasket seal to not be consistent.
- The sanding and leveling of the bottom surface of the head by the use of a straight edge and a mechanic's eye was not quite accurate enough and the mating surface is uneven.
- The headgasket itself is defective.

Proposed cure:
Send out the spare head from my old engine for inspection, cleaning, machining, shaving, valve angling, everything. Swap over my shims, buckets, and cams. Replace the headgasket, valve seals, headbolts, and any other associated gaskets that need to be removed. In theory that should take care of all the theoretical causes of the problems addressed in all my theories above. I need to know if I sound crazy or if that sounds like a good theoretical plan...

Current mood:

[97lestyousay]

Sorry to hear.

[lagos]

First, I'm pretty sure there is another oil leak. It's not bad but its there. The rear mount bracket, crossmember, and bottom of the transmission bell housing are wet with oil. The passenger side axle cup is a little moist too. That would indicate a bad rear main seal. Popping the little cover off and looking up into the space between the engine and bell housing you cannot see the seal sticking out at all, meaning the rear main seal did not pop out of place like the crank seal did. So either the seal itself is defective or... what else could leak behind there?

take a look at your distributor o-ring and inside the distributor cap. I had a similar leak and had to fully rebuild the distributor and install it with 2 orings before it would stop. Since the distributor is right above the crank/trans, it could be all just dripping down.

As for the motor itself, I wouldn't tear into it without doing a leak down test.

Where did you get a borascope from and how much was it? I want one!

This post has been edited by lagos: Apr 21, 2008 - 9:31 PM

[hurley97]

First, I'm pretty sure there is another oil leak. It's not bad but its there. The rear mount bracket, crossmember, and bottom of the transmission bell housing are wet with oil. The passenger side axle cup is a little moist too. That would indicate a bad rear main seal. Popping the little cover off and looking up into the space between the engine and bell housing you cannot see the seal sticking out at all, meaning the rear main seal did not pop out of place like the crank seal did. So either the seal itself is defective or... what else could leak behind there?

take a look at your distributor o-ring and inside the distributor cap. I had a similar leak and had to fully rebuild the distributor and install it with 2 orings before it would stop. Since the distributor is right above the crank/trans, it could be all just dripping down.

As for the motor itself, I wouldn't tear into it without doing a leak down test.

Where did you get a borascope from and how much was it? I want one!

If the leak was coming from the distributor it would be on top of the transmission, yes? The top is dry.

It's such a small coolant leak it probably wouldn't even show up in a leak down test. I already asked.

The borascope belongs to work, I just use it. I have absolutely no idea how much it costs.

[lagos]

If the leak was coming from the distributor it would be on top of the transmission, yes? The top is dry.

No. It just drips down the side of the block as it slowly leaks down. Feel around your distributor harness plug to see if its wet, or the area on the block right under it. If your on the original distributor, there is a good chance that the old rubber seal inside of it is shot.

It's such a small coolant leak it probably wouldn't even show up in a leak down test. I already asked.

Then honestly, I wouldnt tear anything apart to try to fix it. You may go through all time time/cost just to find out it was caused by something totally unrelated. As long as the car is not overheating, I wouldn't worry about it, and just see what happens.

[hurley97]

I'm pretty sure I looked all round the top of the motor and didn't see anything but it's worth another look with attention to that specific area. Thanks for the advice.

Thats the crazy part, the car runs perfectly. Never overheats, no smoke out the back at all, nothing but the little moisture ans pink color on the one plug and the slight noise which I haven't heard the last two times I started the car cold.

BUT, I know theres a problem and it bothers me. If I'm going to put the added stress on the motor I want it to be virtually flawless since any problem I do have right now is only going to get exponentially worse a few months from now.


Right now everything is washed down and levels are noted and I'm going to keep a close watch on what happens next to narrow things down a little more.

This post has been edited by hurley97: Apr 21, 2008 - 10:02 PM

[lagos]

BUT, I know theres a problem and it bothers me. If I'm going to put the added stress on the motor I want it to be virtually flawless since any problem I do have right now is only going to get exponentially worse a few months from now.

Think of it this way... If you really do have a small coolant leak from the head gasket, and it does get worse when you boost the motor, whats the worst thats going happen? Your situation wont be any worse.
On the other hand, you might do all this work, and still hear the noise from your heater core.

[Hanyo]

jeee i really don't want to post this; i'm probably gonna get flamed.

But when there is a small leak, the over-the-counter stop a leak stuff at autozone or kragen works.

to be honest, if you want perfect; send the engine out to a machine shop and have both the head and block decked. But what its worth, you will most likely have to pull the entire engine apart to fix it. So its worth a shot to give the $15 stop a leak a chance.

I suggest to fix the problem as fast as you can. I've had an engine rebuild failure where the problem got worse and worse to the point where water was getting into the oil givine me 10-30 capuchino.

*puts on flame suit*

good luck

This post has been edited by Hanyo: Apr 22, 2008 - 5:45 AM

[hurley97]

I'm looking for a permanent solution to the problem not a temporary band-aid.

I didn't think that the top surface of the block might have to be machined as well, that could be a problem. I was hoping it would be as quick and easy as just swapping the heads.

[97lestyousay]

I would start by re torquing the head bolts. Also if you start shaving head and or block
you should keep track of what is removed as this will up your CR, the difference can be made up
with a thicker head gasket.

This post has been edited by 97lestyousay: Apr 22, 2008 - 2:26 PM

[boostcrazy]

Think of it this way... If you really do have a small coolant leak from the head gasket, and it does get worse when you boost the motor, whats the worst thats going happen? Your situation wont be any worse.
On the other hand, you might do all this work, and still hear the noise from your heater core.

Stef you definitly need to fix the problem before boosting . Any foreign things in the combustion chamber i.e. coolant, oil, etc. can and will cause detonation. Boosting the 7afe is very delicate and almost has to have perfect chamber conditions in order to last. The added pressure to the head from boosting (if it is the head gasket) will almost be guaranteed to get worse or fail. Trust me I know.

But when there is a small leak, the over-the-counter stop a leak stuff at autozone or kragen works.

Im not burning you Hanyo and i agree this stuff does typically work, but it is a bandaid and it does eventually cause other cooling problems. Not a goos solution for a motor with so much investment.

I didn't think that the top surface of the block might have to be machined as well, that could be a problem. I was hoping it would be as quick and easy as just swapping the heads.

The block even if it has overheated more than likely will not have to be machined, these blocks are very resitive to warping and i have built several turbo 7afe from junk yard motors and they have never needed machining. The head on the other hand almost always does if it has over heated any bit. But be careful you will need to keep your c/r as low as possible for that turbo.

The theories:
- The head is cracked or warped from the slight overheating. Theory being that if there was no coolant for the temp gauge to read so it was inaccurate and it actually overheated more than we thought.
- One or two of the headbolts that we reused were actually not reusable and did not stretch like they should have causing the headgasket seal to not be consistent.

The celica thermostadt from my experience is VERY inaccurate. I have ran an extra thermo for a little over a year now and found a BIG diffenrence in the read out of factory and the aftermarket. I would suggest and oil press and aftermarket thermo before turboing just to have that extra security.

Its is not worth the chance of having to do another head job or engine failure to reuse old head bolts.

[hurley97]

I called the engine/machine shop we use at work (when they used to rebuild heads instead of order new ones) and they gave me a price of about $450. That includes inspection, cleaning, cutting the valves, valve seals, machining everything straight.

I'm really not sure if thats a good price, I don't know how much these things go for.

[alltracman78]

Real quick 'cause I don't have a lot of time;

The oil's not from your dist, you have an A series engine. It's a straight 4, not a slant 4, and IIRC the dist runs off the exhaust cam, putting the dist way up front, and straight above the trans, not hanging over like on the 5S.

Are you sure it's engine oil and not gear oil?
It's possible the input shaft seal is leaking, did you replace it when you put the trans in?

There's also another gasket for the rear main housing, as well as a worn crank [rubber seals wear the crank down over time].
What about the oil pan? They're a PITA to seal perfectly, especially on the ends where the main seal housings are.


How clean is #4 compared to the rest?
Have you tried a coolant tester? See if that forces any in.

$450 doesn't seem too bad if they're assembling the entire valve train for you in addition to all that work.
To save $ you can have them just machine the head surface and recut the valve seats. How did the valve guides look?
One word of warning, if you machine the valve seats you WILL need to reshim, and possibly cut the valve tips.

[hurley97]

Real quick 'cause I don't have a lot of time;

The oil's not from your dist, you have an A series engine. It's a straight 4, not a slant 4, and IIRC the dist runs off the exhaust cam, putting the dist way up front, and straight above the trans, not hanging over like on the 5S.

Are you sure it's engine oil and not gear oil?
It's possible the input shaft seal is leaking, did you replace it when you put the trans in?

There's also another gasket for the rear main housing, as well as a worn crank [rubber seals wear the crank down over time].
What about the oil pan? They're a PITA to seal perfectly, especially on the ends where the main seal housings are.


How clean is #4 compared to the rest?
Have you tried a coolant tester? See if that forces any in.

$450 doesn't seem too bad if they're assembling the entire valve train for you in addition to all that work.
To save $ you can have them just machine the head surface and recut the valve seats. How did the valve guides look?
One word of warning, if you machine the valve seats you WILL need to reshim, and possibly cut the valve tips.

Right, it's definitely not the distributor.

Yes, it is engine oil... or at least it doesn't smell like gear oil. The axle seals are new and neither of them are what's leaking, thats the first place I looked since that would be easier to change.

Yes, it could also be the housing gasket, that was the other theory. Either way the transmission has to come off so I guess I'll find out then. I'm pretty sure it's not the oil pan itself but again, it's worth another look with attention to that.

All the spark plugs looked very good actually, the only difference was the white ceramic in the middle. 1, 2, and 3 spark plugs were white and center of number 4 is pinkish

[alltracman78]

Input shaft seal, not axle seals.
They won't leak all over the bottom of the trans.
It's coming from some where in the center, and the airflow is blowing it across the bottom of the engine.
Whatever it is, like you said, you have to pull the trans off regardless, so you should be able to find it.

Have you checked your price for a brand new head?
It's probably recockulous, but it won't hurt to check.
No matter how good the machinist and tools, you can't beat a brand new head for trueness, or for good valve seats.

Coolant stop leak is crap. It can clog up your radiator, heater core, screw up the water pump, ect.
If you need it for an absolute emergency, it will do. Your case doesn't qualify [I know you weren't going to use it, just for general FYI].
But as soon as possible it needs to be flushed out.

Any foreign things in the combustion chamber i.e. coolant, oil, etc. can and will cause detonation.

I hate to be an ass, but coolant can not, and will not cause detonation.
It will actually prevent it, just like water injection.

[hurley97]

Input shaft seal, not axle seals.

Have you checked your price for a brand new head?
It's probably recockulous, but it won't hurt to check.
No matter how good the machinist and tools, you can't beat a brand new head for trueness, or for good valve seats.

that one took me a while

actually I just did after you suggested it, much less than I expected. Toyota World says $585. I think that's just the head only though, no valves.