How do you replace the timing chain on 93 Saturn?

Answer 1

It is a difficult job. Only a person possessed with fixing his own car should proceed. It took me 3 days to do the job. Sorry the write up is not in a proper sequence.

Use secure jack stands, as you will be under the car for much of this.

You must remove the entire right front inside the "fender well" plastic covers set, to access all the engine mount bolts and the timing cover bolts. (you knew that!)

Your goal is to remove the timing cover and the sequence you elect to follow is a matter of preference, remove the parts as you encounter the obstacles. You'll need to remove the intake air box and remove the valve cover assembly, plug wires etc. and any connections to the valve cover.

Use small labeled boxes to hold the fasteners from each component.

Expose all the bolts that hold the timing chain cover on. THERE IS ONE (1) BOLT YOU CANNOT SEE, IT IS RECESSED JUST BELOW THE TOP OF THE COVER UNDER A LIP AND JUST OFF CENTER. (If you proceed to "wedge & TAP" the cover with this bolt in it WILL fracture the timing cover casting!) Yeah, it happened to me... Thank goodness for the TIG welder.

Oil pan may be dropped to aid in removing the cover. You must remove the engine to transmission brace and drop the exhaust pipe (all hangars) and remove the ring gear cover to get at the pan bolts. Pan will be fully removed and cleaned upon the re assembly and you will temporarily remove the lower engine torque arm mount to do it.

You remove the serpentine belt and the tensioner assembly. Drain the oil and remove and drain the coolant fill bottle & Window washer bottle.

You'll also need to remove the upper motor mount entirely, that is the replaceable mount and the fixed black cradle that is bolted to the car (frame).

Replace both cam chain tensioner guides, see the book for timing issues, it is too much to write about here but must be "COG ON" accurate. Replace the fixed guide first, after the new chain is on, then the moveable guide and tensioner on the left side. a pin (drill bit) holds the tensioner back as you install it, then you pull the pin to release it.

Re assembly requires much cleaning and a knowledge of the proper sealants. It is a messy job. Some use RTV silicone and some prefer urethane sealants, a real mess to work with but unlikely to leak if applied to a clean surface.

Sadly you'll need what I call a Bridge to hold the motor up, I made one with steel tube and a mig welder. I used a turnbuckle and a "J" hook to temporarily hold the engine up (basically to get the oil pan off for a clean out. You may know differently, my timing cover just would not come off without dropping the oil pan, and besides, the pan was full of old cam chain guide chunks. And it must off to be cleaned and sealed properly.

You must shift the Power Steering pump towards the fire wall to allow the removal of the top left bolt, a difficult task.

Both serpentine idler and tensioner must come off to get the cover out. The cover also houses the oil pump so be ready for it when you get the cover off.

You MUST Fill the oil pump cavity up with Vaseline prior to reassembly to prime the pump, I used a syringe. Get new "O" rings for the cam chain cover to engine block interface at the oil pump inlet & outlet.

Replace the crank front oil seal. and squirt some oil behind it to see if the drain hole is clear...

Check the book for torque specifications and use them.

Good Luck!

Answer 2

Normally the timing chain will last the life of the engine and is not an item you replace. But on your Saturn it is critical that the oil/filter be changed exactly as listed in the owner's manual. The timing chain may also come into contact with the timing cover, causing noise in the engine. The only way to know for sure if the chain needs replacing is to look at it. If you do that, you might as well just replace it.