Piston slap

Have a 15 2.7 5speed 4x4 with 116,000 miles, bought with 99,000 last summer. I have owned several Tacoma’s with the 2.7 and more than 1 had piston slap. This truck started with piston slap last fall when it turned cool and continued all winter. Wasn’t concerned about it since I’ve experienced it before. Problem is since it has warmed up, I’m still getting some. Making me think I’ve got other problems. Thought I would ask y’all if anyone has had the same problems

 

How's the oil level? That may be playing a part.

 

Oil level is fine, and quits when gets up to temp. Been using 0W20, thinking of adding Lucas heavy duty oil stabilizer next oil change and see if that helps

 

I thought I was having this "piston slap" turned out it was just an exhaust manifold gasket. They leak on Tacomas and when the truck warms up the gasket seals better when it expands. I see a lot of Tacoma owners thinking they have "piston slap" and its not. Most every case I've seen in person was just the exhaust manifold leak when it was cold making a knocking sound.

 

Worth a look, thanks

 

Interested to see if the exhaust manifold gasket is really the issue.

 

I am also interested to hear if that's the cause. I fought an exhaust leak between the header and the midpipe for the longest time until i cut it out and replaced it with a flex pipe and v-band

 

Won’t be till next weekend because of work. Hopefully this is the cause instead of something more serious. Thanks guys

 

Please don't use Lucas oil stabilizer. You would be MUCH better off simply using a higher viscosity oil such as 5w30, which is OK to use in your truck even at low temps.

 

Little update, just replaced the manifold gasket even though the old one was fine. Still having a little knocking occasionally. And not using Lucas oil stabilizer after some research I’ve done. Kinda scratching my head trying to figure this one out.

 

I live in New England and anytime it gets lower than about 45 degrees F, I have that noise. I have had the truck for 7 years and it has done it for 6 of them. It doesn’t seem to affect anything. I let the truck warm up for a few minutes before I drive it and it’s fine. If you do figure it out, please let us know.

 

piston slap by itself is not an issue

a cold compression check

a cold leak down test will tell U everyhing U want to no

piston slap at normal driving & load can go a long ways

 

2.7 is infamous for piston slap - I live in NJ - you can install a block heater or a pan heater which will cut piston slap in cold weather to zero minutes of close to it.

 

I haven't made a post on this forum in ages. Just come here to read the new ones every so often. However, I had some very minor piston slap when I first got my Tacoma with the 2.7 about 8 years ago. I switched to 10-30 Amsoil Signature and it went away and has stayed away for 81,000 miles. This morning I wnet out to start it up and it had a knock so bad I thought it would throw a rod. Not a "deep sounding knock" like a crank. More like a rod knock. In any case it went away after about 15 seconds. I went ahead and drove it 400 miles today for Thanksgiving dinner and back. No noise at all after it sat for 8 hours and no problems running it at 75-80 mph the whole way out and back. I'm waiting to see what happens tommorrow morning once it gets really nice and cold again tonight.
In any case, I thought this was extraordinarily weird. Any opinions or advice would be welcome. My thought is that it's possible the ODV on the oil filter stuck open and that caused it. I am doing extended drains per oil analysis over a period of years and thousands of miles. I don't know for sure off the top of my head but I think I'm at about 7500 miles on the last change which I've done many times before with no problems at all per oil analysis. Maybe a faulty ODV on filter????

 

every noise emanating from an engine is very different

rod knock is louder & not the same as piston slap

oil change intervals shoudnt effect either at the indicated mileage

amsoil makes very good oil ..............as good as most

started after a long no run period

started on an incline

started 1 quart or more low

could yield a knock........................maybe