The timing chain can develop a rattling noise caused by failing timing chain guides. This is often due to extended mileage intervals between oil changes that allows the oil to become dirty and abrasive which wears away the timing chain guides until they fail. The timing chain and guides should be inspected at each valve adjustment, otherwise serious engine damage may result.Google+
Car Problem Reports
Toyota Pickup Failed Timing Chain Guides May Cause Rattling Noise
Toyota Pickup Problem
Engine Affected: 2.4L 4 Cylinder
Average Mileage: 130,000 mi (118,000 mi - 150,000 mi)
Visitor, 1994 Toyota Pickup, 2.4L 4 Cylinder, 150,000 mi
Timing chain was rubbing on timing chain cover, if long enough will eat into the block and mix coolant with gas. So I decided to replace it. Just for fun and pure curiosity, I queried my family mechanic, and he said 1,100 all and done. Being young and all, I didn't have that kinda money for it. So ran to advanced auto, picked up a FULL kit (chain, cam sprocket, crank sprocket, and chain tensioner) add all the gaskets it came to less than 100. Do some research, and be careful of timing, pay attention to the marks, and remember there are 2 top dead centers in a 4 stroke engine!
Visitor, 1994 Toyota Pickup, 2.4L 4 Cylinder, 130,000 mi
wore hole in chain cover
Visitor, 1992 Toyota Pickup, 2.4L 4 Cylinder, 122,000 mi
I love my Toyota Trucks but between the flawed timing chain issues that SHOULD BE COVERD BY TOYOTA BECAUSE THIS IS A HUGE PROBLEM and Toyota must have done something wrong with this set up and this is my 3rd. Toyota pick up truck (all 4x4s) and ALL 3 have had ROTTED OUT FRAMES!! I know there is a "secret" recall for Tacoma trucks from 1995 to 2000 but they keep it hush,hush since they do NOT want everybody to know that Toyota made a MISTAKE with the design of the frame or used garbage metal but they are BUYING them trucks back only to DESTROY them and sell NO parts off them. My 92 was called UNSAFE when at the dealer last year and he said it SHOULD BE TOWED HOME and is NOT safe to drive due to the "BAD FRAME" but they will do NOTHING to help ME because it is "TOO OLD"......but as mentioned...they said to me NOT to drive it....what do you do...they will NOT help and it is all I have? I must say...after seeing all these problems with Toyota trucks, I thing I will NOT buy another Toyota again!
Visitor, 1994 Toyota Pickup, 2.4L 4 Cylinder, 118,000 mi
i kept hearing a rattling noise i thought something was loose under the hood we finally pulled the valve cover off and found out the guides were the problem and i have always changed my oil every 3000 miles we put in new chain new guides and new gears