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Engine Specific Info and Questions => IDI Engine => Topic started by: busguy71 on April 29, 2007, 05:23:59 pm
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I have a 1.6na, I overheated it and blew the coolant reservoir. The motor still runs perfect. I replaced the reservoir, but it seems to be over-pressurizing the coolent system. The new reservoir is leaking out of the cap now. My friend thinks maybe the compression of the motor is leaking into the cooling system due to a failed headgasket/ warped head. Anyone else have this experience? Just want some feedback before I go tearing my engine appart.... dont want to do it if I dont need to! :lol: thanks
(temp fix is a 1/8 hole in the reservoir cap, car still runs like new)
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you have a bad head gasket, a warped head, or a cracked head. or you could just need a radiator cap. i'd try the radiator cap first. if that doesn't work then you gotta pull the head, take it to a machine shop have them check it for straightness, and do a pressure test on it.
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I check my heads for warpage with a carpenter's square and a feeler gauge. If you're not sure your square is straight, test it on a mirror or window.
Best case, your gasket is blown. Worst case, it's cracked. In between -- warped -- it's still fixable. There is a place in Seattle that will heat it in an oven and straighten it for a couple hundred bucks.
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ok I guess I have some work ahead of me. Whats the max you can have the head decked and maintain piston to valve clearance? and will the AAZ head gasket fit my '84 1.6 na? thanks :lol:
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I'm having a similar problem and am getting ready to replace the head on mine since it jumped it's time a while back (several thousand kms ago) and had slight valve piston/ valve contact. I'm assuming it's the gasket or head too because it really overheated when the heater core blew (All this in one weekend at 30 below and no garage). Mine only leaks out the cap as soon as I shut the car off, never while it's running. I always thought though that it would have to run hot if it was leaking compression into the cooling system. Mine never runs above half way on the guage.
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ok I guess I have some work ahead of me. Whats the max you can have the head decked and maintain piston to valve clearance? and will the AAZ head gasket fit my '84 1.6 na? thanks :lol:
There is some debate on milling diesel cylinder heads. Some people say no way you can't do that, some people say there's no problem. A better solution may be to send it to Autosport Seattle to have it straightened in a special oven, then you can avoid to whole issue.
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I think it isn't recommended because of the harder prechambers and that you need to have the camshaft bearings bored. If the machine shop knows how to do this than it shouldn't be a problem.
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How much does a good machine job usually cost?
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I'm looking to do this as cheaply as possible. Just the minimum amount taken off, not even a valve job, I just need to get this car running NOW. Do you NEED to have the cam bearing caps bored? Even for just a few thousanths of decking? and how much does autosport charge for the straightening?
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When I emailed Autosport in March of '06 it was $100. The website is http://www.autosportseattle.com if you want to get an update from them.
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I think it isn't recommended because of the harder prechambers and that you need to have the camshaft bearings bored. If the machine shop knows how to do this than it shouldn't be a problem.
this is the truth. if you bring this up and they look at you funny, keep looking for a shop :lol:
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I called one shop and they just wouldnt do the work. They said they use cutting bits and you need a grinding type machine to do that kind of work. I did find another shop that could do it for $75. I'll pop the head off and check it for straightness before doing anything though. Thanks for all the advice!
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Yup, because of the pre-combustion inserts the popular wisdom in some circles is that you have to use stones to surface the head rather than the usual milling tool. But, I've heard lots of people say they can be milled, you just have to go slow !
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I had mine done but the shop didn't know the right way. it took 6 tries and 3 heads before they figured it out. It can be done but the right shop is the problem. I would check out the Seattle guys if they have had good luck. My brother lives up there so I will definetly see them on my next visit.
Welding the cracks is very hardwithout filling the oil and water ports. If the shop does not know how to you are wasting time. Also the heads have to be heated very slowly before welding or the cracks come right back. A good machine shop can do this but it is a matter of knowing the machinist. Not a yellow page look up.
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as far as welding any crack (if I'm so unfortunate to have any... :roll: ) I know two very highly skilled welders. I'd have them do all the work if only they had a milling or grinding machine! but they dont :shock:
the one shop that said he wouldnt do it told me that it makes a hell of a racket when the cutter hits the hardened surface.
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I'm ready to get the head off, but dont have the right tool to take the bolts out. Can anyone tell me what tool that is? 12 point allen socket, what size? or is it VW specific? I just got the cam off and found a cracked lifter :roll: here we go.....
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12mm "triplesquare" is the search term I used to find my tool. I tried using a Torx, bad idea, stripped the tool and two head bolts that then had to be drilled out.
Snap-On sells it but it's darn expensive. I ended up getting mine from some no-name place online a lot cheaper. Sorry I don't remember where now, I probably just used Froogle and picked the cheapest place.
Autohausaz.com sells new solid lifters for about $20.
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canadian auto parts sells new lifters for $10/piece
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cool, now I know what to look for 8) thanks! When we talk about these engines having the 11mm or 12mm head bolts, is it the diameter of the bolt or just the size the bolt head?
Just finished changing out my rack-n-pinion, swaped a 3+E trans onto the motor, and now I'm cleaning and re-packing the cv joints. All this for a car that you could "drive anywhere, excellent running condition!" ...boy did I get hosed :x
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I think 11mm or 12mm refers to the thread size, but I bought a 12mm tool and it fit my head bolts, so apparently the thread size and tool size are the same for this application.
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got the head off...
and it has cracks between every valve. :x
So it would probably cost more to fix than to buy a new one
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got the head off...
and it has cracks between every valve. :x
So it would probably cost more to fix than to buy a new one
Not necessarily. How wide are the cracks? If they are small then they are fine. Many heads are running around with cracks between the valves with no problems. They are only a problem if they extend into the water jacket. Here is a cross-section:
(http://i19.tinypic.com/6gxqdeb.jpg)
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Heres a pic, they all pretty much look like this. I got an estimate from a machine shop for a valve job and its $250-300, plus more to deck it, plus welding..... and a new head is $395. Or maybe I'll spring for a whole new motor.....
(http://i15.photobucket.com/albums/a399/busguy71/DSCF0156.jpg)
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That's pretty small. I would check it for warpage and if it's less than the max allowable in the Bentley I would just slap a new gasket on there and call it good. My head was a little warped, just under the maximum allowable and the head gasket is holding so far. It's cracked between valves too.
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well that makes me feel a little better anyway :lol: thanks for the input
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minor warping may be dealt with in a number of ways...
my dads head was a little warped - evidenced by a leak at one point. He fixed it by adjusting the tightening sequence to put more pressure on the places where the head had "lifted". his car has been runnign around with no leaks or other problems for a good 12 months now.
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He fixed it by adjusting the tightening sequence to put more pressure on the places where the head had "lifted"
Interesting. If you could afford it though, I really think ARP head studs are the way to go. If they can withstand 30+PSI of boost, they should be able to keep a warped N/A head clamped.
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this is a total thread hijack, im sorry but...
i live in australia, what would be a good way for me to get hold of some arp head bolts and what would i be looking at price wise?