Engine Mechanical problem
1994 Toyota Pickup 4 cyl Two Wheel Drive Manual 246000 miles
I bought this truck new with ten miles on it and now 16 years and 246k later the motor is starting to make noise when you are at the higher end RPM's say just when you're about to shift gears. Could this be the timing chain has finally worn out? Also what would be a fair estimate for a timing chain replacement? I will have the water pump replaced at the same time since it's never been.
The noise could be caused by the timing chain but it could also be due to others malfunctions. When timing chains are worn, the engine would tend to rattle for a short period of time at initial start up from cold or whe engine has been stopped for a short period of time.
Book time for timing chain replacement is about 11 hours and it requires the cylinder head to be removed.
Parts should cost between $350 to $ 500 depending on what needs to be replaced.
September, 28, 2010 AT 1:07 PM
Thanks for the reply. The motor runs fine at low RPM's and the noise happens when the motor is warmed up when your winding up the rpms between shifts. It doesn't have a tach so I can't give the rpm range. I don't notice any power loss, but there's 247K on the motor so far. The valve cover has never been removed. It does use some oil but nothing that's out of the norm that I would say for a motor this old. It's a daliy driver for me, about 50 miles round trip to work M-F.
September, 28, 2010 AT 1:14 PM
Timing chain noise would sound more like a rattle whereas if it is from the valve trains, it would be more consistent with engine rpm.
If it is from the pistons or con-rod bearings, noise would be prominent during throttle opening.
If the noise is external of the engine, it could be exhaust related.
September, 29, 2010 AT 3:13 PM
The muffler was replaced 2 months ago. The motor runs normal from low rpm to say 2,500 to 3,000 rpm. The noise sounds like a fast rattle. Maybe something attached to the motor or belts is coming loose. What is an average life spand of a timing chain for this motor?
September, 30, 2010 AT 12:56 PM
Life span of timing chains are dependant on oil changes and usage so it is difficult to put a lifespan. Most can last up to 300k miles or more.
The syptoms do indicate a possible timing chain problem and the only way to check it is to remove the valve cover and check the extension of the tensioner, chain guides and slack.