Author Topic: 1.6NA Headgasket Sporked, Rebuild Questions... (Read 6399 times)

RacerZX · « **on:** November 06, 2007, 08:11:42 am »

It started as a gradual unlocateable coolant leak for several thousand miles on my 400K mile old '85 Jetta, but it eventually got bad enough to visibly drip on the ground at idle. Wasn't hard at that point to find it was coming out of the head gasket next to the firewall under the exhaust manifold. Sigh...I bought it 10K miles ago and the seller said they'd "just redone the head", lame-ass wrench monkeys... So, a few rebuild questions:

Looks like I can pull the head without mucking with the injection pump, correct?

If I buy a rebuilt head, any reason not to get the hydraulic version? Can they just be swapped? Or are those 11mm vs. 12mm head bolts going to screw that up?

I'm tempted to do the rings at the same time with the motor still in the car. Various posts here seem very happy with the rings from http://www.totalseal.com, anybody ever have issues with them? Is it really reasonable to expect a new set of rings to seat well without honing the cylinder walls?

Lastly, since I'm already in for a fairly major surgery, it's tempting to bolt on some simple low-boost Eco style turbo for improved fuel economy and a little more power. Finding the needed parts out there though looks rather hard, are there any kits available anybody knows of?

Thanks all!

burn_your_money · « **Reply #1 on:** November 06, 2007, 08:58:09 am »

Head gaskets fail, it's not uncommon. The PO may have just gotten a bad one or perhaps they screwed up the torque sequence. I don't understand why you are planning on replacing the head. Are you using lots of oil?

Your mech head is 12mm just like the hydro ones however your block is missing an oil passage way on the front of it. People plug them and run them like that but I wouldn't bother.

You don't need to touch the pump

If you replace rings you need to hone the cylinders or the rings won't seat.

I'm not aware of any TD kits, although I have a lot of the pieces you will need and most of the others can be found in the classifieds

RacerZX · « **Reply #2 on:** November 06, 2007, 11:14:08 am »

I guess I'm thinking that since the PO's work is suspect, it would be good to have the head fully gone over when it's checked for warpage, and if one is going that far then buying a rebuilt one isn't much of a further step, and then if one is buying a rebuilt head then why not the Hydro for less recurring maintenance. You can see how twisted the path of my logic is :wink:

I do burn about a quart of oil every 2-3K miles, plus it's a bit hard to start, and I'm getting alllllmost enough blowby to blow off the oil cap (currently it just bobbles around on the edge of falling off like the relieve valve on a pressure cooker). But all that I was presuming is due to rings of unknown age, not a head issue.

How do you hone the cylinders with the motor in the car?

Vincent Waldon · « **Reply #3 on:** November 06, 2007, 11:50:46 am »

Quote from: "RacerZX"

How do you hone the cylinders with the motor in the car?

- pull the head
- pull the oil pan
- deridge the cylinders and pull the pistons
- cover as much of the crank as possible with saran wrap, tin foil etc
- hone the cylinders with a fine hone/Flexbrush and electric drill... a very light honing to break the glaze is all that's needed
- hose the cylinders and bottom end with several cans of spray solvent, brake drum cleaner, etc, and compressed air. Flush and dry, flush and dry, etc... gotta get all the grit out of the bottom end
- reassemble with lots of assembly lube
- run the car for a couple minutes then stop and do an entire oil change, including filter

A bit getto, and you risk grit getting into your bearings, but it can be done.

Vince

RacerZX · « **Reply #4 on:** November 06, 2007, 04:05:10 pm »

Hm, never thought to rev the motor to test blow-by, I'll give that a try as well as checking head bolt torque. Fingers crossed.

burn_your_money · « **Reply #5 on:** November 06, 2007, 04:52:02 pm »

Air coming out of the engine is normal. White smoke is not. Which do you have?

I'd go with Andrew's suggestion and retorque. I'm not positive but I think it's an additional 1/4 turn (follow the torque guide)

RacerZX · « **Reply #6 on:** November 06, 2007, 05:26:11 pm »

I get a puff of smoke on a cold start, but that's all, no dense smoke problem out the tail pipe or oil cap.

Vincent Waldon · « **Reply #7 on:** November 06, 2007, 08:42:12 pm »

Quote from: "libbybapa"

Only thing I'd add is that if it's a TD you need to remove the squirters.

Andrew

Good catch.

I also would never go that far and not replace rod bearings and main bearings... they are cheap, you're only ten bolts away from doing it all, and with it all apart there's much less chance of grit in the bearings.

The mains seem like a pain with the crank in place, but with a thin plastic putty knife cut to the right size those suckers slide out wonderfully... the entire job will take less than 10 minutes.

burn_your_money · « **Reply #8 on:** November 07, 2007, 05:19:26 am »

If you are going through all that work take the 45 minutes and drop the engine. Your back will love you

RacerZX · « **Reply #9 on:** November 12, 2007, 12:20:55 pm »

Okay, rev'ing the motor does make all traces of blow-by dissapear, sweet, I presume that means rings are all good?

I looked over the manual trying to figure out how to 'test' the torque on the head bolts but I don't see how it would be possible. Using a torque wrench isn't going to tell me if that extra 3/4th of a turn (first a half, and then another quarter after 1K miles) has been done, nor if dorks who did this job previously even used new head bolts. So I'm just going to replace all the head bolts this weekend with new and keep my fingers crossed it all seals up good again.

Black Smokin' Diesel · « **Reply #10 on:** November 12, 2007, 01:38:38 pm »

Quote from: "Vincent Waldon"

The mains seem like a pain with the crank in place, but with a thin plastic putty knife cut to the right size those suckers slide out wonderfully... the entire job will take less than 10 minutes.

Wait you can actually replace the main bearings without dropping the crank? Wow I didn't know that.

Quote from: "RacerZX"

I looked over the manual trying to figure out how to 'test' the torque on the head bolts but I don't see how it would be possible. Using a torque wrench isn't going to tell me if that extra 3/4th of a turn (first a half, and then another quarter after 1K miles) has been done, nor if dorks who did this job previously even used new head bolts. So I'm just going to replace all the head bolts this weekend with new and keep my fingers crossed it all seals up good again.

I wouldn't even bother replacing the bolts. I'd give 1/4 to 1/2 turn. If that doesn't work, off with the head.

burn_your_money · « **Reply #11 on:** November 12, 2007, 01:43:22 pm »

If you change the bolts you need to change the head gasket. Don't just take one bolt all the way out and then replace it. You will most likely warp the head. You need to follow the proper sequence for removing the bolts.

RacerZX · « **Reply #12 on:** November 12, 2007, 02:22:30 pm »

Yeah, I was going to back all 10 bolts off in steps down to finger tight using the manual's prescribed patern, then swap one at a time to new bolts, and then do the full torqing procedure. If it fails no big loss, $35'ish worth of bolts lost that's all.

Black Smokin' Diesel · « **Reply #13 on:** November 12, 2007, 04:39:39 pm »

Quote from: "burn_your_money"

If you change the bolts you need to change the head gasket. Don't just take one bolt all the way out and then replace it. You will most likely warp the head. You need to follow the proper sequence for removing the bolts.

Isn't it how APR says to do when replacing bolts for their hardware? One at a time.

burn_your_money · « **Reply #14 on:** November 12, 2007, 05:46:07 pm »

No idea.