tapping noise when starting a 1997 2.7 liter

Hello,

I was seeing if anybody else has experienced this:

When I start my 97 Tacoma 2.7 liter 4x4 after sitting awhile, the motor makes a tapping noise, almost like its a old small diesel pickup. Once i get a mile or so down the road (motor has warmed up) its stops, and no more tapping, knocking.

Truck has 180k, I'm the third owner. Just bought it recently, and the noise started maybe 2 weeks ago.

If anybody has went through this, what did you do? what fixed it? etc

Thanks guys!!

 

Sounds like valves.

 

How frequently has the oil been changed, and with what?

You may not know the history, but what have you done since owning?

 

check your hoses for leaks or cracks. idol control valve hose comes to mind, or crankcase ventilation hose/adapter may be faulty

 

the first owner was a farmer, when the second owner bought it, it had been sitting awhile. From what i gathered from the second owner, he took really good care of it. He spent an hour going over the whole truck, he also communted everyday in it. He bought a new 2019 tacoma because of his long communte.

I changed the oil in it becuase the owner said it had been several months. the oil wasnt black at all, in fact, it surprisingly clean (if im taking his word for it) Ididnt tap when i first got it, or after i changed the oil (5w-30). Just started recently. Its gotten a tad but louder but as soon as i get a mile or so up the road its doesnt tap until its cold again, or sat an hour or so.

 

Yeah thats what it def seems like, anything i can do?

 

I've never had the issue, so I can't really give you specific advice on the 2.7, but a quick little search came up with:

https://www.tacomaworld.com/threads/adjusting-valves-on-2-7.143790/

https://www.yotatech.com/forums/f128/5vz-fe-3rz-fe-2rz-fe-valve-adjustment-tech-226997/

 

Mine did that when I used to live in Pennsylvania 80000 miles ago. I never did anything to fix it.

The exhaust valves are known to get a bit tight on these over time. About the only common deficiency these engines have.

 

Yes, check valve clearances. One could be too much and once the engine warms up things expand and the gap closes slightly and the tapping stops. At 180k it's around the mileage where the clearances can maybe start to be out of spec.

 

I got 188K and checking valve clearances have been on the to-do list for months. No abnormal ticking or tapping for me though.

 

Tapping is loose. Things too tight don't tap. Tight valves are more likely to burn than loose ones.

My bet is on a dirty engine internally, and it takes the time for the offending lifter(s) to move freely, then things are fine.

Before diving into adjustments, I'd try a couple of short cycle oil changes. Like 1-2k in length, just to see if it clears up. If not, time to pop the valve cover and measure/adjust as needed.

 

It's probably piston slap. Surprised no one has mentioned it yet. It's pretty common on the 2.7.

 

Yeah, after listening to it more, the noise never really goes away, its just gets quieter. Turning on the ac will make it a little more noisy. If its warmed up and im at a stop in nuetral and give it some gas, you can slighty still hear it. Just not as loud during a cold start.

Some one recommened things like Marvel mystery oil etc.

Thanks for everybody's replies.

 

Could be an exhaust leak also. I currently have one that isn't as audible once things are warmed up at the manifold. Spray some soapy water around there.

 

I get this every once and a while when I start up my truck. Like maybe once every few months. It's noticeable for sure. But I cant seem to hear it any other time. Noise goes away after the truck warms up. I'm gonna check my oil level too cause my oil light seems to be lingering for about a second after startup.

 

Collapsed Lifter??

 

Hydraulic tappets in the 2.7 my old one clattered when cold for 300K but just for a couple of seconds.

 

Soapy water to spot the leak?

 

Yes. It'll make bubbles. Works for finding leaks in all sorts of things.

 

If its on the exhaust manifold, it will evaporate before you see any "bubbling". Good technique for everywhere else though.

Smoke machine will be your best bet.