My Toyota pick up with 22R engine has done 225000km and still has its original timing chain.
I have always had timing chain noise on start up(cold starts only) for a few seconds, once oil pressure is up it goes away.
I was reading this on Wikipedia and it got me worried:
Toyota swapped the dual row timing chain used in older engines for a single row chain with plastic guides in 1983. This system reduced drag on the engine, but was inherently problematic. Every 80,000 to 140,000 miles, the chain could stretch to the point that the hydraulic-operated chain tensioner can not take up any more slack. When this happens, the timing chain impacts driver's side chain guide, breaking the plastic within a few hundred miles of driving. If the engine continues to be operated after the guide breaks, the chain will stretch rapidly (an unfortunate characteristic of single row chains.) The loose chain causes inaccurate ignition timing which usually results in noticeable rough running. In continued operation, the chain can jump a tooth on the drive sprocket or break entirely, with either case resulting in engine damage from valve-piston collisions. Also, the stretched chain will slap against the side of the timing cover due to the broken guide, and can wear through the cover and into the coolant passage behind the water pump. This will cause coolant to drain in to the crankcase / oil pan, possibly causing damage to internal engine components such as the bearings, crankshaft, camshaft as well as damage caused by overheating due to the lack of coolant (since it has drained into the engine oil).
Should I be concerned as my mileage is +/- 140000miles, but it has made the noise since I got it from 27000 miles?
If it was seriously worn would I not have noise on warm starts as well and a permanent noise?
I did find some info on another site that recomended heavier oils 20W50/15W40
I have been using Castrol 10W40 for years but have changed to Delo 400 15W40 a few OC ago.
I have always had timing chain noise on start up(cold starts only) for a few seconds, once oil pressure is up it goes away.
I was reading this on Wikipedia and it got me worried:
Toyota swapped the dual row timing chain used in older engines for a single row chain with plastic guides in 1983. This system reduced drag on the engine, but was inherently problematic. Every 80,000 to 140,000 miles, the chain could stretch to the point that the hydraulic-operated chain tensioner can not take up any more slack. When this happens, the timing chain impacts driver's side chain guide, breaking the plastic within a few hundred miles of driving. If the engine continues to be operated after the guide breaks, the chain will stretch rapidly (an unfortunate characteristic of single row chains.) The loose chain causes inaccurate ignition timing which usually results in noticeable rough running. In continued operation, the chain can jump a tooth on the drive sprocket or break entirely, with either case resulting in engine damage from valve-piston collisions. Also, the stretched chain will slap against the side of the timing cover due to the broken guide, and can wear through the cover and into the coolant passage behind the water pump. This will cause coolant to drain in to the crankcase / oil pan, possibly causing damage to internal engine components such as the bearings, crankshaft, camshaft as well as damage caused by overheating due to the lack of coolant (since it has drained into the engine oil).
Should I be concerned as my mileage is +/- 140000miles, but it has made the noise since I got it from 27000 miles?
If it was seriously worn would I not have noise on warm starts as well and a permanent noise?
I did find some info on another site that recomended heavier oils 20W50/15W40
I have been using Castrol 10W40 for years but have changed to Delo 400 15W40 a few OC ago.
