Broken timing belt aftermath: Update
09-26-2008, 10:48 AM
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Broken timing belt aftermath: Update
You may remember a couple of weeks ago the timing belt in my 2.7T let go.
The bolts between the exh. manifold and the turbo were a bear, but hey, it gave me an excuse to get a really nice I-R impact gun.
I had to partially remove the coolant plumbing across the back of the heads to get a clear shot at the front-most bolt on the left head.
Two of these bolts got rather chewed in this process, so I'll want to replace the lot. Also, the Y-connectors on the boost and wastegate signal lines snapped.
Anything special about these parts? Sources?
So, the damage from the belt letting go is thus:
All 12 exhaust valves marked the piston and were basically flush with the mating surface of the head. The center intake valve on cylinder 2 is slightly bent (not seated correctly) and the center intake valve on cylinder 5 is flush with the head like the exhaust valves.
All valves are intact, no visible damage to the cylinder walls. The marking didn't leave any thin spots, it looks like a fly-cut valve relief.
So, I think I'm going to leave the bottom-end in, and replace the heads. RLG: You've got mail.
A few more questions:
Should I replace the head bolts?
Anything else while I'm in this far?
The bolts between the exh. manifold and the turbo were a bear, but hey, it gave me an excuse to get a really nice I-R impact gun.
I had to partially remove the coolant plumbing across the back of the heads to get a clear shot at the front-most bolt on the left head.Two of these bolts got rather chewed in this process, so I'll want to replace the lot. Also, the Y-connectors on the boost and wastegate signal lines snapped.
Anything special about these parts? Sources?
So, the damage from the belt letting go is thus:
All 12 exhaust valves marked the piston and were basically flush with the mating surface of the head. The center intake valve on cylinder 2 is slightly bent (not seated correctly) and the center intake valve on cylinder 5 is flush with the head like the exhaust valves.
All valves are intact, no visible damage to the cylinder walls. The marking didn't leave any thin spots, it looks like a fly-cut valve relief.
So, I think I'm going to leave the bottom-end in, and replace the heads. RLG: You've got mail.
A few more questions:
Should I replace the head bolts?
Anything else while I'm in this far?
09-26-2008, 11:39 AM
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'00 2.7T 6spd, 158k total miles. Est. 60k since PO changed belt
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09-26-2008, 12:40 PM
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You will need new head bolts
Well done for taking it off. Head bolts MUST be replaced - they are the stretch type. The gaskets between the turbo and manifold do not come with the headset and you may want new ones. I re-used mine and have no leaks. They appear to be dealer only parts and my dealer is not very local. Other than the obvious stuff at the front, new valves, guides if damaged/worn, valve stem seals, head gasket set, that should do it.
09-26-2008, 02:42 PM
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Last we talked about this, the valves didn't sound like an easy replacement...
..and if I'm going to pay someone to check and replace the valves, it's probably not cost effective next to a set of used heads.
09-26-2008, 02:45 PM
#7
You can check the valves yourself to get an idea of the number damaged.
Figure on replacing the lifter for each bent valve too. Even a dozen or so bent valves is cheaper than a head or two.
Not to mention that you can be sure of the condition of used heads.
Not to mention that you can be sure of the condition of used heads.
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09-26-2008, 02:56 PM
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So, Bay Area recommendations to get the valves replaced?
I'll call for a quote, but I'd be surprised...
Looking at ECS, unless I cheap out and go with the non-sodium valves, it's a grand in parts.
Looking at ECS, unless I cheap out and go with the non-sodium valves, it's a grand in parts.
09-26-2008, 03:51 PM
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Second that, might not be easy, but well within your capabilities
if you can remove heads and put them back on.
Replacing the valves may be a fiddle but it isn't nearly as hard as removing and installing the heads. Key is to get a nice valve spring compressor to take as much effort as possible out of the job.
I would expect the guides to be OK judging by your description and there is no reason to suspect that the heads are warped because it didn't overheat. So, you shouldn't need a machine shop to touch the heads.
I have bought valves from Autohaus Arizona for very good prices. You can check your lifters - I found out how:
1. Look for external damage, scratches. Replace if not smooth.
2. Press down on inside plunger with something soft - if it compresses easily the check valve has failed and it will rattle on start-up.
3. Using a drill press, press them up and down with enough force to make it stroke, best to do this with them in a pot of oil. Discard any lifters that are seized. If you don't use the pot of oil, they will rattle when you start after the rebuild.
You will need the chain tensioner tool to remove the camshafts, but other than that no other tools are needed above what you already have.
This is just my advice, others will probably be more cautious and spend more to mitigate the risk of having to take a head off again, but I don't mind pulling heads if I have to - just a days work.
For a head gasket set, check out emiata.com ($35?) for the 2.8L set and buy the intake gasket from anywhere that carries Victor Reinz gaskets.
Used heads are tempting too if the price is right and they are in good shape. You won't know if the tensioners are noisy until you turn the key and you might find some noisy lifters. Other than that other stuff can be visually checked for wear. There are different heads on the 2.7T though - mine does not have the EGR valves found on others.
Enough! Good luck!
Replacing the valves may be a fiddle but it isn't nearly as hard as removing and installing the heads. Key is to get a nice valve spring compressor to take as much effort as possible out of the job.
I would expect the guides to be OK judging by your description and there is no reason to suspect that the heads are warped because it didn't overheat. So, you shouldn't need a machine shop to touch the heads.
I have bought valves from Autohaus Arizona for very good prices. You can check your lifters - I found out how:
1. Look for external damage, scratches. Replace if not smooth.
2. Press down on inside plunger with something soft - if it compresses easily the check valve has failed and it will rattle on start-up.
3. Using a drill press, press them up and down with enough force to make it stroke, best to do this with them in a pot of oil. Discard any lifters that are seized. If you don't use the pot of oil, they will rattle when you start after the rebuild.
You will need the chain tensioner tool to remove the camshafts, but other than that no other tools are needed above what you already have.
This is just my advice, others will probably be more cautious and spend more to mitigate the risk of having to take a head off again, but I don't mind pulling heads if I have to - just a days work.
For a head gasket set, check out emiata.com ($35?) for the 2.8L set and buy the intake gasket from anywhere that carries Victor Reinz gaskets.
Used heads are tempting too if the price is right and they are in good shape. You won't know if the tensioners are noisy until you turn the key and you might find some noisy lifters. Other than that other stuff can be visually checked for wear. There are different heads on the 2.7T though - mine does not have the EGR valves found on others.
Enough! Good luck!