Timing and timing chain installation issue?

JOSHUA MAGIN

MEMBER
2018 HYUNDAI ELANTRA
2.0L
4 CYL
AUTOMATIC
150,000 MILES

I am working on a timing chain replacement job and forgot to set TDC on Cylinder 1 before removing chain and chain tensioner. The car has a timing chain. After some time, I set TDC by putting timing cover back on and did not touch the cam sprockets. I’m not sure if I’m on the compression stroke for sure. I used the balloon trick, and the balloon blew up with air both times I did each revolution so I’m not sure if I’m on the compression. Stroke. This is an interference engine.

1 Reply

STEVE W.

MECHANIC
13,556 POSTS

Okay, so you didn't set TDC, and you DID remove the chain and tensioner? Or you realized the problem, put the cover back on and then moved the engine? If the first just drop a dowel in a plug hole and bring it up to TDC, check the timing marks, they will either be correct or 180 out, turn it over again and they should line up. If it's the second situation, the easiest way would be to look at the cams and SLOWLY rotate the engine over until the intake cam has just closed the valves. Any tight areas or binding, stop. In that case you will need to pull the cams up to release any pressure on the valves. Then drop a dowel in the spark plug hole and rotate the engine until the piston is fully at the top. Now set the cam timing so it's all lined up correctly and you should be okay. In this case the cams set the actual timing so as long as piston one is fully up in the bore it's at TDC. Then you set the cams.