Knocking when cold...

We had our first below freezing night here in Virginia the night before last. I go out and start my truck in the morning and let it sit about a minute before I take off, well when I rev up a little to go I hear a loud knocking and quickly let off. When its at idle its quiet but when I revved it up it knocked until it warmed up a little more. Is this normal and will it hurt any thing. Its a 2004 2.7 with 130k on it.

 

My SAAB 900 did that too when it was freezing out, but it only did it for a minute then went away. I went from 10W30 to 5W30 and it stopped. I also had 244K on that car. My tacoma did it I think once last winter, changed my oil the next day, and it never did it again. Are you using 5w30? I also have the 2.7.

 

Yea just changed the oil a week ago, 5w-30 for the winter....

 

Was it a tapping, like a lifter? or a knocking like a deeper sound?

 

It was a knock, defintely not just a valve train tap.

 

Have you had your oil pressure checked? How many miles?

 

Never checked the oil pressure it has 135k miles on it, never really heard of a tacoma oil pump gone bad, especially one thats only 5 years old.

 

Neither have I... But hell, you never know? Something isn't right. Mine was just a sticky lifter.

 

Yea Im hopin its something like thick oil or somethin...

 

They make this stuff you can put in your oil, "Marvel mystery Oil" that is what I put in my SAAB, and it never did it again.

 

I have the exact same issue with my 01 Taco 2.7 liter. It did it the last 2 winters, and it’s doing it again. Only at a certain temperature and only for that moment. Once its warmed up for the day it doesn't do it anymore. For me, oil changes have made no difference. One mechanic mentioned piston slap. I was told this could go on 100,000+ miles. I try to warm my truck before driving. It only has to run 1 or 2 minutes to prevent it.

 

I'll add to the club!! Mine does the same thing, scared the crap out of me the first time I heard it, I thought me poor baby was going to give up on me. I only have 90k on mine and its been doing this for 2 winters now. Only on real cold mornings. Start it up and it knocks, deff. not a light knock but not like beating with a sledge hammer either, lasts for about 15-20 seconds and goes away when warmed up. I have no idea what it is but I wish it would stop.

 

My was also doing the same thing. Weird noise coming from the engine. I sprayed some WD40 around the drive belts, seemed to quiet it down a bit now.

 

what kinda oil filters ya using? Wonder if the oil is draining back into the pan, and getting thick when its cold, preventing the oil from getting into the motor right away, thus the knock?

 

Yep WJF i was thinking the same thing i only use OEM Toyota with the check valve.

 

Well I dont think the oil filter needs a check valve on the 2.7 because it sits straight up. The oil filters with check valves are the ones that mount sideways or so on the motor and need a valve to keep the oil in the filter. The oil filter on the 2.7 wont drain out because it sits straight up and down and act like a cup for the oil to stay in. Im thinkin my problem may be piston slap. I plan on runnin her until she quits.

 

My 2002 2.7L Tacoma does the exact same thing when it's cold and there are only 73K miles on the engine. I have emailed Toyota and they claim to know nothing about this. Kind of funny that this forum is full of 2.7L engine noise when cold and they know absolutely nothing. Engines may run for quite sometime time with this condition, but should not be acceptable to any owner what so ever!!

 

Yea it is definetly a problem. I think everyone that has this problem should notify Toyota and who knows we may get a service bulletin...

 

Piston slap is a possibility but the way mine knocks doesn't sound like piston slap. I had a 2000 chevy z71 with the 5.3 and it had the common piston slap problem, the piston slap is a fast paced rattle like knock. The cold knock in my Tacoma is more of a slow, deep lower end knock.

 

My 2.4 did it too for like 2 days when it was kinda cold... like 40 or so. This morning it was perfectly fine at 20 (although my garage opener didn't work )