I have a 2001 Toyota Tacoma that has a knock or ticking in cold weather. The problem starts sometimes immediately after I start and other times it is only when I press on the gas in the cold mornings after a few min warm up. The noise goes away after 10 min.
The question I am wondering is this:
1: could it be worn piston rings and the pistons are slapping the cylinder wall
2: is it an oil pump problem or a oil restriction issue
3: is it a valve guide issue
4: with the history of the 2.7 having exhaust manifold issues (poor manufacturing) could a cracked manifold be the issue
5: any other possible issues I am unaware of?
I change the oil myself, the oil filters have been OEM toyota, the noise has been going on since 60,000 miles, the truck is at 230,000 miles.
Piston slap occurs when the skirts of the pistons slap the cylinder walls because the piston skirts shrink in colder weather. Then as the pistons heat up the skirts expand and the piston slap stops.
Piston slap isn’t damaging to an engine. It’s more of an embarrassment.
I have an '01 Sequoia with a “ticking” sound when cold. It is pretty loud, and goes away quickly as the car warms up. My sound has been attributed to an exhaust manifold leak which is why it goes away so quickly as the manifold heats up. I consider it a characteristic of the car now, and won’t fix it. My mechanic says there are shields and such that make the manifold hard to access adding cost to the job. We’ll just let it ride until there is another reason to do a repair in the same area, if ever.
If your Tacoma is a V8 is shares the same motor as my Sequoia.
Tacomas don’t have a V8. The choices are straight 4 or V6. Since you said 2.7, I’ll assume you have the straight 4.
When it’s ticking, CAREFULLY put your hand near the exhaust manifold to try to detect if that’s the source of the noise. Check where the manifold meets the head and at the flange.
Before you do that, does the exhaust manifold have a heat shield? If it does, it may be worth taking it off to see if the manifold is visibly cracked.
Another possibility is that your valves need adjustment. I believe the adjustment involves replacing shims. If it’s only noisey when cold, the valve lash is too great. As things warm up and metal expands, the valve lash changes. Valve lash is supposed to be measure and adjusted cold. So just because the noise goes away eventually doesn’t necessarily mean everything’s 100% okay.
Does the noise sound like it’s coming from the top end or the bottom end?
2001?
I’m going to guess hat you have a licky stifter…er, sticky lifter.
That motor has hydraulic lifter (okay fussy guys, tappets!)s, and they can get sticky over time.
I’d suggest getting a mechanic’s stethescope and see if you can isolate the area of origin.
Thank you for the information, As soon as I get back from Afghanistan I plan to take it to the dealership. I wanted to have some possibilities so that when I talk to the Rep I can be prepared.
@krazyKarl. If you take it to a dealership, be careful. They can scam you for service you may not need. Valve adjustment is helpful, but their cost is high. If you can find a quaffed mechanic with some experience in this service , you will be better off.
+1 to Dag’s comment.
If you take an 11 year old vehicle to a dealer for anything they’re guaranteed to find $3000 worth of work that NEEDS to be done…$2900 worth of which is BS.