Engine Knocking

40258 Views 76 Replies 29 Participants Last post by epi, May 1, 2017

gp4camping

Discussion Starter · Mar 17, 2009

I have a 07 LE and my engine knocks when it is cold. I noticed that when my engine is cold, I hear a faint engine knocking/pinging. It goes away when the engine is warm. Anybody know what this could be? I want to address it now since mine is under warrenty.

61 - 77 of 77 Posts

billjay

· #61 · Aug 20, 2010

I got tired of waiting for colder weather. I needed an oil change anyway, so I left it overnite and went for a cold start test drive with the tech.

Big surprise.... the tech heard the noise immediately and volunteered that some Siennas have Piston Slap. That's a first for my stealership. Until today they were either deaf or scoffed at piston slap. I think the word is finally getting out.

The tech was very helpful. He gave me a sample of my old oil and suggested I get an oil analysis before my next visit. He also told me to discuss my concerns with the Service Manager and schedule an appointment with the area factory rep this winter. The noise is definitely more pronounced and lasts longer in colder weather.

I'll keep you posted.

billjay

· #62 · Aug 21, 2010

Here's something odd to think about it..... Since my oil change the "piston slap" sounds louder till the engine warms up. Based on posts below, I expected the new, thick 5W30 dino oil would "cushion" the pistons more than my old, thinned-out 5W30 with 4K miles on it.

The last time I got the oil changed I'm sure the piston slap was a little quieter. Why not quieter this time?

billjay

· #63 · Nov 3, 2010

My van was in for tranny replacement (don't ask) at 22K miles last week and a funny thing happened. I mentioned my piston slap issue to the service manager and it appears that somebody (aka Toyota) told the dealerships to stop using the words "piston slap". We talked for at least 15 minutes and he carefully avoided putting a name on the "noise". I kept trying to explain that my once cold weather noise is now a year round problem. Yesterday I got a follow-up phone call from him stating that Toyota is aware of the cold startup "noise" and says its absolutely normal and is not causing any internal damage. Now I feel so much better. Yeah...Right.

Meanwhile I was doing some further research regarding my Aug oil sample analysis (attached). Everything looked good except for a very high moly reading (160 ppm). Everyone tells me that moly is an oil additive, but I found info online that the Lexus 2GR-FSE uses moly coated pistons to reduce friction. I'm still trying to determine if the Toyota 2GR-FE uses moly coated pistons also. I've also asked the dealer to identify the brand of oil he used at my last oil change before the sample was taken. I'm trying to determine if my high moly levels are really just an additive or actual wear material from the piston skirts.

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mikesienna

· #64 · Nov 3, 2010

My wifes 2008 has the engine knock also. It is annoying, especially since I drive a 2003 CRV and sometimes a 1992 toyota truck and you can barely hear the engine. When I drive her van I just turn up the radio. The knocking does seem to lessen as the van warms up.

Also, has anyone noticed the van's rpm's race upward at times especially on low speeds. It is not like the acceleration issue we hear about, just noticeable and bit annoying.

Otherwise the van's ride comfort is excellent and very smooth on the interstate.

wiswind

· #65 · Nov 4, 2010

Bill J
Molly IS a oil additive, some brands have a LOT, some don't.
What brand of oil was used?
Since Blackstone did not flag it as an issue, I am thinking that they viewed it as being a oil additive.
However, be aware that the Molly level will likely be different between different oil brands.

billjay

· #66 · Nov 4, 2010

Moly coatings are also used as a friction reducing coating on some pistons. That's why I've asked my dealer to identify the brand of oil he used for my oil change prior to my sample analysis. I'm trying to determine if it came from the engine or its just an oil additive.

wag

· #67 · Nov 4, 2010

Like I told you before Bill, if moly was coming off of the pistons and/or rings, all of the other oil analysis results would be WAY out of whack.
Besides, the moly coating/plating used on piston rings (and/or any other moving parts in an engine) is combined with chromium so you would also see high level of chromium and iron listed in the analysis results and Blackstone certainly would have given you a red flag on this.

GMul

· #68 · Nov 5, 2010

FWIW, my '02 Sienna developed a loudish, annoying top end rattle at about 75K miles. It would last about 45 seconds then go away as the engine warmed.

It was assessed as normal by the Toyota dealer.

At 83K miles the timing belt was changed and the problem went away. Now at 96K miles the engine is still as quiet as it was when new.

I speculate that my timing belt wore prematurely (despite oil and filter changes every 3000 mi).

Gary

wag

· #69 · Nov 5, 2010

GMul said:
FWIW, my '02 Sienna developed a loudish, annoying top end rattle at about 75K miles. It would last about 45 seconds then go away as the engine warmed.

It was assessed as normal by the Toyota dealer.

At 83K miles the timing belt was changed and the problem went away. Now at 96K miles the engine is still as quiet as it was when new.

I speculate that my timing belt wore prematurely (despite oil and filter changes every 3000 mi).

Gary

Correct me if I'm wrong, but, weren't the recommended timing belt replacement intervals 60k miles in 2002? Regardless, even at the 90k mile recommended change interval on the later models, I would hardly call 75k miles premature given the time frame involved. Belts age and wear out with time as much as they do with miles.

GMul

· #70 · Nov 5, 2010

wag said:
GMul said:

FWIW, my '02 Sienna developed a loudish, annoying top end rattle at about 75K miles. It would last about 45 seconds then go away as the engine warmed.

It was assessed as normal by the Toyota dealer.

At 83K miles the timing belt was changed and the problem went away. Now at 96K miles the engine is still as quiet as it was when new.

I speculate that my timing belt wore prematurely (despite oil and filter changes every 3000 mi).

Gary

Click to expand...

Correct me if I'm wrong, but, weren't the recommended timing belt replacement intervals 60k miles in 2002? Regardless, even at the 90k mile recommended change interval on the later models, I would hardly call 75k miles premature especially given the time frame involved. Belts age with time as well as miles.

My owner's manual states: "All V6 an V8 powered vehicles - Replace timing belt every 72months/144,000 km". This works out to 90,000 miles. The Toyota 2002 Maintenance Menu states the same time/mileage.

I fully agree with what you are saying. Indeed, my post was to suggest, based on the sounds described, the possibility some of the folks on this thread could be experiencing timing belt problems.

Gary

wag

· #71 · Nov 5, 2010

Although you had not reached the 90K mile interval, I have to assume that you were past the 72 month interval and your timing belt actually needed to be replaced.
The 3.5L GR series V/6 engine that Bill J and others are talking about does not have a timing belt, it has an internally lubricated timing chain which does not need replacement as part of it's normal maintenance.

GMul

· #72 · Nov 5, 2010

wag said:
Although you had not reached the 90K mile interval, I have to assume that you were past the 72 month interval and your timing belt actually needed to be replaced.
The 3.5L GR series V/6 engine that Bill J and others are talking about does not have a timing belt, it has an internally lubricated timing chain which does not need replacement as part of it's normal maintenance.

Thanks for the info.
Gary

billjay

· #73 · Nov 9, 2010

For what its worth.... my service manager just confirmed that their version of Toyota Genuine Motor Oil is something called PRIMEPLUS. God knows what that is, but the spec sheet says its GF 4 compliant.

billjay

· #74 · Nov 11, 2010

Good news.... My service manager contacted Toyota about the long list of problems I 've had and they offered a 8 year/125K mile platinum warranty at no cost. My confidence that Toyota will eventually do the right thing has been restored.

tbalon

· #75 · Nov 11, 2010

WOW! Bill... Toyota comes through again! Ohhhhh yeeeaaaaaa....

robo5

· #76 · Nov 11, 2010

Nice to hear this Bill J.

I know this has been a consern with you. Nice to hear that an extra measure was put in place.

epi

· #77 · May 1, 2017

Good afternoon, I have a 2009 sienna motor 3.5, I'm having problems with it...I have taken it to several mechanic's and it seems no body can find the problem, it turns on but after 15 seconds it turns off and the engine wont respond back no more...can somebody please help me to find the problem... thank you!!!

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