Replacing head, do I need to redo the timing?

IVAN AZCUE

MEMBER
1999 VOLKSWAGEN JETTA
2.0L
4 CYL
2WD
MANUAL
220,000 MILES

I just pulled the head off of my car listed above 2.0 AEG. I pulled the head because the spark plugged blew through it, decided to swap with a refurbished one.

My question, I do have the crank at TDC? How do I time the cam? Do I need to? 1st time getting this deep into a motor.

Also, I couldn't do a leak down test because the hole would not hold the attachment and so I could not get any compressed air. Any way of telling if that's cylinder and the rings are any good? Asking since I'm there.

Sunday, September 19th, 2021 AT 11:32 AM

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

On this engine when you put it back together you need to make sure that the timing marks are all lined up properly.
Failure to do so lead to an engine that does not start or run properly.

https://www.2carpros.com/articles/how-a-timing-belt-works
https://www.2carpros.com/articles/how-a-cylinder-head-works

As for the leak down test, have you already take apart the cylinder head?
If its not apart you can do the oil method, by pouring in about a table spoon amount of oil thru the spark plug hole and check the compression. If the compression increases then the piston rings are bad.

I have attached the procedures of lining up timing marks as well as timing belt replacement for your reference.

Please let me know of any questions.
Thank you.

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