Top end ticking

My 2000 tacoma 4cyl began a diesel like ticking in the top end when I started it in cold weather. Never when idling, it would only tick under stress when it was very cold. It now ticks under stress whenever I don't warm it up for 5 minutes or more, even in warm weather. I use 5-30 oil as recommended. Any thoughts?

Try checking the valve clearances.

i would lean twords piston slap, it wouldn't be valve clearance because the clearance gets bigger when the engine warms up, thus if it was valve clearance it would get worse as the engine warms up

...it wouldn't be valve clearance because the clearance gets bigger when the engine warms up, thus if it was valve clearance it would get worse as the engine warms up

I don't think that's true. Valve clearances tighten up when the engine gets hot. That's why the exhaust valves always have looser clearances when the engine is cold than intake valves - They heat up more than the intakes and tighten up the clearances more.

I had a sound coming from my last truck ('93 Mazda B2200) that I swore was lifter clack. It would only happen when the truck was cold, as soon as she warmed up, the sound went away. Upon closer investigation it turned out there was a slight air leak coming out of the exhaust manifold. A quick snugging of all exhaust manifold bolts remedied the problem. I guess when the manifold warmed up and expanded, it sealed and stopped the sound.

MrKrymson, I heard of nissan's doing ticking through the exaust manifold and know how that sounded but this really sounds similar to a quiet diesel rapping sound. I'll check it. Thanks for the reply

I finally took the truck to the local dealer. It was diagnosed as piston slap or piston rock as they called it. The mechanic went on to say that it's perfectly normal for that 4cyl motor when it's cold and doesn't require any fix. Surprising, coming from a dealer. Even more surprising is there was no charge. Thanks!