4.3 liter engine ticking even after lifter replacement

[jefftech61]

I have a 97 sonoma with about 250,000 miles on it. It has been a great engine but I have recently developed a ticking in the motor. I replaced the fuel injection system and the lifters but it is still making the same noise. Is it the timing chain or something else. I have researched all over the internet and many people have the same engine noise (youtube videos) but no one has mentioned what the solution is. I have been repairing my own vehicles for 35 years but this own is tricky. Please Help!

 

[Molson02536]

I have a 97 sonoma with about 250,000 miles on it. It has been a great engine but I have recently developed a ticking in the motor. I replaced the fuel injection system and the lifters but it is still making the same noise. Is it the timing chain or something else. I have researched all over the internet and many people have the same engine noise (youtube videos) but no one has mentioned what the solution is. I have been repairing my own vehicles for 35 years but this own is tricky. Please Help!

Could be also your cam my be worn down. GM had issues with cams that was mad in china.

The 4.3 was built in to plants, one in Tanawada NY and the other in Romulus MI. The cam bearing sets are different, depending on whether the block was made in Romulus or Tonawanda. The Tonawanda blocks use two larger diameter cam bearings, one in front and one in back, instead of only one large one in the front. Both bearing sets are available in the aftermarket.

If it’s a Tonwanda engine, it will have a "T" stamped on the machined surface on the block just in front of the right cylinder head. The engine ID will be number stamped on the pad, and the chamfer on the cylinders will be quite shallow.

If it’s a Romulus engine, it will have an "R" stamped on the machined surface on the block. The ID number will be made up of a series of dots, and the cylinders will have a deep chamfer on them.

Hope this helps if you have to replace your Cam.

Keep us posted and let us know what is causing your Ticking.

Molson02536

 

[drwet]

FWIW many years ago I tore into an engine to solve a similar noise, only to eventually figure out that it was a leaking exhaust manifold. Make sure of where the noise is coming from.