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Misfire on cylinder three?

Tiny
BHAMDOC1973
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Wow. I believe it. I had same scenario for a an 02 wagon I think it was a v8 mechanic ended up removing engine for a coolant hose, could be the same hose.
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Friday, October 27th, 2023 AT 3:58 AM
Tiny
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Ugh. Same results after valve fleaning. Possible exhaust side?
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Monday, October 30th, 2023 AT 5:19 PM
Tiny
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Hi,

Certainly, it could be. Have you checked to see if there is any change in compression?

Let me know.

Joe
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Monday, October 30th, 2023 AT 7:17 PM
Tiny
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Not yet.
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Tuesday, October 31st, 2023 AT 5:37 AM
Tiny
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Measured, still around 30.
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Tuesday, October 31st, 2023 AT 6:46 AM
Tiny
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I took a few pictures, does this look like a bent valve or is this normal? Not sure if the cylinders usually have groves on these engines.
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Tuesday, October 31st, 2023 AT 8:14 AM
Tiny
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Hi,

Are the pics you attached all from the same cylinder? I do see marks in picture number two, but pics 1 and 3 don't appear to have the same marks. Also, if there was interference between the valves and pistons, you would know. The pistons would have a clean mark where they touched.

The idea that you may have a bent valve really isn't shown in these pics. Remember, since you have 30 psi compression, which indicates there isn't a bent/stuck open valve. Based on that information, I would suspect something is preventing one of the valves from fully closing.

Let me know.

Joe
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Tuesday, October 31st, 2023 AT 6:28 PM
Tiny
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Yes, all from same piston 3, one was a side picture to show valve. Strange problem to tackle.
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Tuesday, October 31st, 2023 AT 6:34 PM
Tiny
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Is it pic 1 that shows the valves? If so, they don't look seated properly. I may be wrong because it's difficult to tell in a picture, but is what I see.

Let me know.

Joe
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Tuesday, October 31st, 2023 AT 7:16 PM
Tiny
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Yes, that's what I am seeing. Do exhaust valves usually suffer from carbon build up as well?
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Wednesday, November 1st, 2023 AT 6:40 AM
Tiny
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The only thing that scares me when removing the head is the chain. I don't want to deal with timing as I know I am not so good at it. So, I don't want to remove the chain completely but rather just hang it on each side. Also, I see some people remove the turbo aside some don't so I don't know which is easier in this case, whether to leave it on car or remove it with the cylinder head.
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Wednesday, November 1st, 2023 AT 6:52 AM
Tiny
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Hi, 43

Either valve can have a carbon issue. If you check other cylinders, do they look the same?

As far as the timing is concerned, I totally understand. This vehicle will require special tooling to hold the cams in place. I attached the directions for camshaft timing chain removal and installation so you can see what needs to be done.

Let me know if this helps.

Joe

See pics below.
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Wednesday, November 1st, 2023 AT 6:54 PM
Tiny
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Thanks. All valves had build up which I walnut blasted. Still same exact compression of 30 on that cylinder. No knocking, no timing codes. Ya the chain is scary, I have seen people remove the sprockets and hood the chain to each side tight till done, but not sure if it's doable. One mistake and it's done. I have all of these tools pretty much. Not sure if the issue could be on the exhaust side or if build up can happen there like it does on intake side.
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Wednesday, November 1st, 2023 AT 7:16 PM
Tiny
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It could be either side. If you decide to remove the head, let me know. I'll try my best to help from here. Also, as long as the colored links on the chain are aligned with the marks, it will be in time. Once reassembled, you can rotate it by hand to make sure there is no interference.

Let me know if I can help.

Joe
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Wednesday, November 1st, 2023 AT 7:32 PM
Tiny
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Yes, I do not like the timing chains on Audis, done it before on VW's and it was ridiculous. I will see what I decide to do with it cause it's a clean car with good miles and I don't want to spend $2,500 on a motor. Would you remove the turbo/exhaust manifold to the side at this point to look at valves if it was you?
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Wednesday, November 1st, 2023 AT 7:35 PM
Tiny
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Hi,

If you plan to remove the cylinder head, I wouldn't. If, however, you don't want to remove the head, then yes, I would likely remove it for inspection.

And yes, the timing is a nightmare. Hang in there.

Joe
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Wednesday, November 1st, 2023 AT 9:17 PM

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