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A plan to resurrect my bent valved V6?

5K views 59 replies 13 participants last post by  muttony 
#1 ·
I started a thread about my misadventures with a broken cam chain tensioner on the passenger side. The result of the replacement of the CCT was that the car is misfiring on all passenger bank cylinders only. Drivers side is fine even though I changed the pads on that side (meaning I took the intake cam out and replaced it. It seems that the ultimate result of that was that I have some number of bent valves on the intake side of the passenger side bank. I have been dithering over the past week about whether I should try to fix it or just junk the car/donate it. I have a plan to fix it and I wanted to get people's opinion on what I might be missing from from the plan.

To start, A rebuilt head is out of the question. They cost anywhere from 500 – 1200 dollars as far as I can tell and that is without various gaskets and other parts that might be needed. If this car is to be fixed I'll need to do it myself. And it will need to be done relatively cheaply.

So the plan. I am assuming that the head is not warped or cracked. There is no reason to think it is as I did not suffer any overheating or broken chain or that type of catastrophic failure that would likely lead to that kind of damage. I tried to find used heads but they would only guarantee that the head was not warped and not cracked. There's no point buying a used head for $400 only to have to do the valves anyway.

The plan.
1) Take the front off car (in other words put it in the service position) but having removed the front bumper radiator etc.
2) Put car in TDC.
3) Remove Valve cover and verify timing is correct.
4) Rotate crank 30 degrees off tdc.
5) Mark passenger side bank's Timing chain's 16 rollers. They will not be exactly over the cam journal markings at this point, but I'll need to mark everything's place exactly.
6) Fasten the timing belt to the various pulleys not involved in the head to be removed and mark them. I was thinking of using the little fuel line clamps I have to physically attach the belt to the pulleys in the right places so that they don't move. I do not have a timing belt bar and don't know where I can get one.
7) Assuming I can adequately make the timing belt secure to the right places on the pulleys and on the other bank's cam, I could then unbolt the pulley from the passenger side exhaust cam. I understand that the pulley is not keyed and it should just come off once unbolted. It too, will need to be carefully marked for reassembly.
8) Remove everything connecting the head to the rest of the engine marking and photographing everything carefully for reassembly.
9) Remove the head bolts
10) remove the bolts from the exhaust manifold
11) remove the head
12) Mark each cam journal and lifter for reassembly
13) Photograph marked assembly for reassembly
14) One by one remove the each intake valve with a spring compressor
15) Replace Valve guides and valve stem seals
16) Manually lap the new valves using lapping compound and suction cup tool
17) Clean all lapping compound carefully to make sure it is removed.
18) Replace valve springs and keepers
19) move on to the next one.
20) When done do exhaust valves the same way
21) remove and smooth any sharp edges (from valves hitting)on the piston tops but leave in place otherwise.
22) Replace cams same way as they came out
23) Reassemble engine.

Parts needed:
(9) intake valves at $5.36 ea Rock Auto
(6) exhaust valves at 5.36 ea Rock Auto
Head Bolts set 50.95 Rock Auto
Gasket Kit includes Head, 2 exhaust, VCG and CCT gaskets 96.89 Rock Auto
Valve Stem Seals .95 ea/ 15.00 Rock Auto
Valve Guides 3.31 ea./49.65 Rock Auto
Valve Lapping Tool, Lapping Compound and Engine Assy Lube 20.35 Amazon.
Head Bolt Removal tool 9.56 Amazon
Total for job $325.80 plus shipping.


Tools Needed:
Spring Compressor
Valve Guide Remover
Head Bolt removal tool
Lapping Tool


Advice Needed:
a) Does this plan sound right?
b) What am I missing?
c) What chances of success?
d) Do I need to get the VW timing belt tool and camshaft pin (adds 50.00 plus shipping)
e) Where can I get a spring compressor and valve guide remover that will work with this head? What do I ask for at the Autozone rental counter?
 
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#5 ·
His scotts. The only place on the internet I could find readily available used heads was the national junkyards search site and they wouldn't guarantee anything except no warpage and no cracks. I'd love to find a RH head for $175.00 all done and dusted, but I haven't seen anything close to that and I've been looking for about two weeks.
 
#7 ·
Thanks wormybeech. That site is better than the other version I found that does the same thing, but it doesn't solve the problem because I don't know what I am getting for my $200.00 I don't know that the used part doesn't have bent valves, worn guides or anything else.
 
#8 ·
Is cruising the local pick-a-part an option? You can simply not buy anything that doesn't meet your standards. Even if you don't use the head itself, you can scavenge it for valves, which are going to be more trustworthy than $5 valves likely sourced from China. With luck the whole head will be good; you can tell a lot just by verifying the car went to the yard with the t-belt intact and tight and things look clean under the valve cover.
 
#9 ·
Even if you don't use the head itself, you can scavenge it for valves, which are going to be more trustworthy than $5 valves likely sourced from China.
Valves, especially exhaust valves, are perhaps the most material-critical parts in your whole car. That $5 valve had to be made and shipped for around $2, and who knows what kind of reclaimed metal it came from. Maybe they melt railcar loads of old valves, but I'd feel better using authentic German parts here.
 
#12 ·
I checked my Bently this morning and I see nothing specifying sodium filled valves. I've read on forums that they are, but I don't see it in Bentley. Perhaps I do not know where to look. The cylinder head is located in section D15-2. No mention of sodium.

These valves are 37.50 each on 1stvwparts.com. For that, the car is going to the junkyard.
 
#15 ·
These valves are 37.50 each on 1stvwparts.com. For that, the car is going to the junkyard.
The local pick a parts are few and far between. The closest to me is 1/2 hour away. There's 2-3 at that range but they're all in different directions (i.e. 1 is N, 1 is W and 1 is S) after those three it goes out to 1 hour away and the same problem.

Cruising the local junkyards isn't really an option.
Forgive me for saying so, but it really sounds like you're trying to justify not repairing the car. Compare driving 1/2 - 1 hour to the time you'd spend trying to rebuild the head yourself. Also, consider how foolish you'd feel if you put all that labor into the job using cheap parts, and it failed.

Be honest with yourself.
 
#13 ·
Hi sirwired.

The local pick a parts are few and far between. The closest to me is 1/2 hour away. There's 2-3 at that range but they're all in different directions (i.e. 1 is N, 1 is W and 1 is S) after those three it goes out to 1 hour away and the same problem.

Cruising the local junkyards isn't really an option.

I suspect the price difference is related to solid vs. sodium filled valves.
 
#16 ·
Thanks scotts. You are actually right and I didn't mind your saying so. I am totally torn about whether to try to fix the car or get rid of it. And I veer from one side to the other day by day. I really like the car and I want to keep it, but I have such a hard time investing lots of money in it. It's third car and I don't really need it (it's for my teenager).

Truth is the first thought I had was simply to swap the head with a junked one, but I got talked out of it by 1) the cost, 2) the lack of any guarantee that a used one would work and 3) the cost of timing belt etc all the other stuff that's going to come due.

If I could keep it for less than $500.00 then I would, but if I have to spend more than that then I am going to end up eventually having to pay as much as the car is worth just to keep it going.

Will you answer me this question. If I were to go to the junk yards to look for a used head, what criteria would YOU have in picking one. I called a guy in NH yesterday who had one and he told me that if I bought one that I should have it magnafluxed and checked anyway.

I am not a mechanic by trade. I am just a fairly mechanically inclined person. I have confidence that I can swap the head without doing further damage to the car, but I don't have confidence in my ability to pick a good used head from a bad used head. That's why I feel more comfortable trying it rebuild it myself as opposed to just swapping one out. In other words I have seen videos and read up on how to do the head rebuild and I think I can do it, but the simple swap worries me that it will be a waste of time and money because I could end up in the same position I am in now with another head in the garage.
 
#19 ·
Will you answer me this question. If I were to go to the junk yards to look for a used head, what criteria would YOU have in picking one. I called a guy in NH yesterday who had one and he told me that if I bought one that I should have it magnafluxed and checked anyway.
I'd bring a magnifying glass, a stainless steel ruler, and a pint of gasoline. You may be able to detect gross warping by holding the edge of the ruler against the mating surface. You'll be looking for fine cracks around the valves with the glass. The gasoline is for an old trick I learned: With the head upside down and level (and valves closed), pour some gas into the cylinder crowns. If it leaks out fast enough to notice, the valves aren't seating.
 
#17 ·
If you are leery about putting a few hundred into the car to keep it on the road, it's time to let it go. B5's of this age are going to need not-cheap repairs or maint. every single year or so. (Suspension bits, tires, brakes, t-belt, flex pipe, CV boots, ABS module, whatever)

At this point in the life of most B5's, any book value they have is little more than the base value for having a running, inspected, and registered car that does not look like a hooptie-wagon; no repair will actually increase it's value past that point. That means its actual "worth" (to you, anyway) is: "How much will it cost me to replace my B5 with something I will like and trust more?" Speaking for myself, under the "devil that you know" principle, it would cost at least 4-5x the (pathetic) book value of my '04 1.8T M/T wagon (now with 153k) to buy a car I'd trust as much as the B5 I'm intimately familiar with.
 
#18 ·
Thanks sirwired

Again, you are right, but you also point out the same thing I am struggling with. I actually have already done new shocks, brakes, flex pipe cv boots all within the last 4 years. What I forsee is t-belt, clutch, abs maybe, some suspension bearings/bushings (the car was starting to squeak when it went over bumps). I can take these things in dribs and drabs. But it is the devil I know.

Anyway, there's a cylinder head at a used parts place on the shelf for 100.00 I can get my money back for 30 days so maybe I'll take a punt.
 
#20 ·
You can also bring a 16mm ratchet and physically turn the cam while the head is on it's side. Verify all the valves close properly after opening.

As for the replacement, it would be easier to borrow or rent a cam tool. You can mark the timing belt and count the teeth in the belt, but it is time consuming and easy to make a mistake. You can use zip-ties to hold the belt in place, they are easier to use and less likely to damage the belt.

You will need to remove the intake, but do not disconnect the fuel lines. Just flip the intake upside down into the area above the cabin filter. The fuel feed line has a tendency to leak
(in very cold conditions) if re-used.

You should replace all of the O-rings in the coolant pipes since they you will have them apart. They are cheap and you will have the system apart anyway. It will save you 6 hours of labor. Once the intake is out of the way, it's much easier to remove the exhaust bolts. Leave the exhaust manifold attached to the head, remove it after the head is removed from the engine.
here is the writeup on the coolant pipes: http://www.passatworld.com/forums/b...724-diy-v6-coolant-pipe-seal-replacement.html


Good luck, and if you get stuck on anything, send a PM.
 
#21 ·
Well, I'm back from a day of parts cruisin. The parts guy only had a AHA cylinder head and my engine is ATQ. I've read here on PW that they are interchangeable. But every thread I found talked about changing from AHA to ATQ not ATQ to AHA.

There are ATQ heads out at 32-51 miles from where I live but the AHA yard will let me return the head if I take it home and go over it carefully and find something wrong and the ATQ guys won't.
 
#24 · (Edited)
muttony
You can go from ATQ to AHA. I've done it myself. I swapped out an 2001 ATQ into my 1998 AHA. It's my daily driver and runs perfect.
The only difference between AHA & ATQ heads is the how the oil gets delivered to the cam cap bearings.
The AHA head has a set of tubes running across to each of the cam caps, effectively connecting all of the cam caps together with this tube.
The ATQ heads did away with the oil tubes to the cam caps.

The main difference between AHA and ATQ is as follows, AHA is drive by cable (physical cable from gas pedal to throttle body), ATQ is drive by wire (no physical cable from gas pedal to throttle body - its all done electronically)
As long as I'm on this subject, the other notable differences are, AHA has (2) catalytic converters, ATQ has 4 of them.
Coolant sensors are different. And some other minor emissions components that are different, but this doesn't effect the swapping of heads.

But concerning the heads it's a straight forward swap.
 
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#25 ·
Hi All

Well, I bought the only head already off a car within 75 miles. It was an AHA head but according to AndreasPassat that will work. I brought the oily thing home and did some preliminary clean up just so I could touch it without getting constantly filthy. I turned the cam with a wrench and the valves all opened and closed so that was good. Unfortunately alot of bad too.

The bad. I tested the intake valves by filling the intake with water while the head was on its side with the intake openings up. Out of the 9 intake valves at least 1/2 of them if not more leaked. Drained out the water of course and blew the intakes dry.
Didn't bother with the exhaust valve testing because with leaking it means relapping in any event. The mating surface of the head also has a fair number of scratches on it. I could not see them at the yard because of all the grime on it. Probably from being taken on and off the shelf. The scratches are not hugely bad but definitely visible. I think this means that this cylinder head is no good. Please let me know if this is not the case.

There are no other acceptable Right Sided cylinder heads anywhere near me. The ones that are available are all still on the cars and I have checked with the yards and none of them came from a wreck, but all from engine problem cars so I cannot trust that these other heads are any better than the one I just bought (except probably not scratched up).

I guess that I could use the valves from this one and lap them into my current head, but now I'm back to rebuilding my own cylinder head.

Advice please.
 
#27 ·
The bad. I tested the intake valves by filling the intake with water while the head was on its side with the intake openings up. Out of the 9 intake valves at least 1/2 of them if not more leaked. Drained out the water of course and blew the intakes dry.
Because you didn't specifically say it, I have to ask: you did remove the intake cam before doing this test, right?
 
#26 ·
It seems that you have 4 choices:
1. Get another head (in good condition)
2. Lap the valves and reface the AHA head
3. Lap the valves from the AHA head into the ATQ head
4. Replace the valves in the ATQ head with new valves. (Expensive with OE valves, reliability very suspect with aftermarket valves)

As you know the ATQ head is good except for bent valves, I think I would go with option 3.
 
#28 ·
So I've started the work now. I confirm Dan_N, that I'd taken both cams out of the old head and it leaked. Even if it hadn't though the surface of the cylinder head was so scratched up that I couldn't trust it.

I began by following the timing belt writeup to "hinge" the lock carrier out of position. That is done. While I don't have the timing belt tool yet (it's coming in the mail), my plan now is to proceed as per PZ's coolant flange writeup to remove the intake manifold, then remove the cylinder head. I took the valves out of the used head and they all look good. I cleaned them up by soaking them in fully concentrated simple green overnight then using a ultra fine scotch brite in combination with finger nails to scrape off the carbon buildup. On intakes this was easy and the valves look new. They roll around on the counter in perfect beautiful circles. The exhaust valves were quite a bit more carbon covered but I protected the stems by wrapping them in duct tape, put them in the chuck of a drill press and then touching the ultra fine scotch brite (grey) to the bottom lubricated in simple green and all the carbon came off. These too roll around perfectly.

Once I get the intake manifold off, I'll proceed to replace the coolant o-rings.

Then, I'll prep the car as if I am proceeding with a timing belt change until after the point where the old timing belt is removed. Once the old timing belt is removed (I've ordered the various tools for holding the camshafts and the crankshaft) tensioners pinned and so forth, I'll take the cylinder head off, put duct tape over the mating surface so as not to scratch it, inspect the valves to see which ones are bent. Lap and replace the bent valves. To do this the cams will need to be out and the car is at top dead center. Once the valves are lapped in, I'll put make sure that no lapping compound is left then replace the springs, seats and keepers. Remove any high spots from piston heads. At the end of this the valves should all be in a completely closed position so that I can put the head back on while the car is still at TDC (Bently says not to do this, but I do not see how rotate the crankshaft 30 degree off as suggested without removing the camshaft locking pin, maybe I should? Comments?).

After, the cylinder head is back on I can put the camshafts and CCT ( properly lined up!) back in and this should put the valves where they are supposed to be while the car is at TDC (obviously I do not want to turn the engine or the cams without them being perfectly lined up where they are supposed to be (in other words as if the car had a timing belt on it) and certainly not without the timing belt on.

Once that is done, proceed with the timing belt change, then reassemble is the reverse right? Then cross fingers and pray!

Comments on the plan?
 
#29 ·
You will need to assemble the cams and CCT in the head and set the valve clearance before installing the head.

Check the 16 roller count as shown at the bottom of this link:
17748/P1340/004928 - Ross-Tech Wiki



Instructions for V6 Timing Belt replacement.
I suggest you carefully, and precisely in the order listed:
Disconnect negative battery cable.
1) Turn the crank to TDC. (Cylinder #3 TDC)
2) Compress the TB tensioner using an Allen wrench (clockwise) in the tensioner roller, and fit the pin in the tensioner.
3) Remove the Timing Belt.
4) Turn the crank counter-clockwise to about 45-60 degrees before TDC. (valves can't hit pistons in this position)
5) Remove the cam pulleys, and refit leaving them just loose enough to turn freely.
6) Then use the cam lock bar to turn the exhaust cams so the large holes in the pulley plates are facing inwards (toward each other), and fit the cam locking bar.
6a) Re-check cam chain timing, correct if required. (Not necessary if chains haven't been touched)
7) Turn crank clockwise to the timing mark on crank pulley, and fit the crank lock pin.
8) Fit the water pump, thermostat, TB tensioner, idler roller, and tensioner roller.
9) Fit the TB on the crank pulley first, then working in a counter-clockwise direction, fit it around all the other pulleys.
Make sure the belt is tight everywhere except the section that goes over the tensioner roller.
10) Release the load on the pin in the tensioner with an Allen wrench in the pulley (clockwise), remove the pin.
11) Allow a couple of minutes for the tensioner to extend, then pretension the TB, using a torque wrench in the tensioner roller turn counter-clockwise to a torque of 132in-lbs (15Nm).
12) Tighten the cam pulley bolts to 41ft-lbs (55Nm). (With cam bar still installed)
13) Remove the cam locking bar and crank lock pin.
14) Carefully turn crank 2 full turns clockwise back to TDC and recheck timing.
15) Put the rest of the car back together and go for a drive.

If you have any concerns about this, please ask before proceeding.
 
#30 ·
Thanks Tom. Few questions.

You will need to assemble the cams and CCT in the head and set the valve clearance before installing the head.

I had thought long and hard about this before concluding to put the cams in after the cylinder head was on because of the pistons being at the top. But I see you turn the crank in step 4 of your procedure so that should solve that issue and make puttinig the head together easier.

Other questions on your procedure (in bold in your steps).

Instructions for V6 Timing Belt replacement.
I suggest you carefully, and precisely in the order listed:
Disconnect negative battery cable.
1) Turn the crank to TDC. (Cylinder #3 TDC)
2) Compress the TB tensioner using an Allen wrench (clockwise) in the tensioner roller, and fit the pin in the tensioner. {Tensioner pin=5mm allen wrench, yes?}
3) Remove the Timing Belt.
4) Turn the crank counter-clockwise to about 45-60 degrees before TDC. (valves can't hit pistons in this position)
{Is this where the removal and replacement of the head fits in?, clearly I need to do that before I worry about the timing of the cam}
5) Remove the cam pulleys, and refit leaving them just loose enough to turn freely. {pulleys not sprockets, right?}
6) Then use the cam lock bar to turn the exhaust cams so the large holes in the pulley plates are facing inwards (toward each other), and fit the cam locking bar.
6a) Re-check cam chain timing, correct if required. (Not necessary if chains haven't been touched)
7) Turn crank clockwise to the timing mark on crank pulley, and fit the crank lock pin.
8) Fit the water pump, thermostat, TB tensioner, idler roller, and tensioner roller.
9) Fit the TB on the crank pulley first, then working in a counter-clockwise direction, fit it around all the other pulleys.
Make sure the belt is tight everywhere except the section that goes over the tensioner roller.
10) Release the load on the pin in the tensioner with an Allen wrench in the pulley (clockwise), remove the pin.
11) Allow a couple of minutes for the tensioner to extend, then pretension the TB, using a torque wrench in the tensioner roller turn counter-clockwise to a torque of 132in-lbs (15Nm).
12) Tighten the cam pulley bolts to 41ft-lbs (55Nm). (With cam bar still installed)
13) Remove the cam locking bar and crank lock pin.
14) Carefully turn crank 2 full turns clockwise back to TDC and recheck timing.
15) Put the rest of the car back together and go for a drive.
 
#31 ·
A brief update while I'm waiting for Tom's response.

I took off the intake manifold per PZ's instruction and I found oil all over the mating surface of the intake to head junction. In other words it looks like oil was pushed back up past the valves towards the intake. Is this the result of the misfires or something else? Also, on the seat sides of valves (the back of the valve's head) there looks to be some substance like sand on the back of the valves. What significance is that?

I suppose there is no real difference in plans since I'm replacing the head gasket in any case.
 
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