V8 Engine Problems

[TNTramair]

im sorry that Dealers "suck" but you have to understand that when we try to diagnos vehicles for "noises" they dont allways cooperate. especially when you have to do something specific or start it at some point in the day to make it happen etc. if you're only getting this noise under acceleration than i would be inclined to think that its either a belt tensioner going bad or some kind of exhaust related issue. since you are allready using 93 octane than you can pretty much rule out detonation. also a piston slap would be very noticeable sitting idle (especially cold) so if you dont get any noise at idle and its just under accel than i would rule out piston slap aswell..(since it gets worse when it gets warmer and with your a/c on). when you turn your a/c on it puts alot more strain on your pully/tensioners which is another reason im thinking its related to that.

my suggestion would be to leave the vehicle with your dealer over night and have them check it the next day and through out the day. as long as you're willing to leave the vehicle than they should figure it out with time. you have the vehicle all the time obviously and we only have it for an hour or so while you wait so it allways helps us trying to correct issues like this if we have alittle more time with it.

if you dont get anywhere with your dealer than try another. there's a reason why some dealers are awfull and others do the right thing.

i went as far as running through some tsb info for ya and come up with nothing related to this concern.

let me know if there;s anything else i can do.

Rick

 

[rd9528]

Engine knock on 2007 Toyota 4-Runner Limited with 4.7 V8

I have the same problem with my 07 Toyota, but it doesn't occur all the time. I took it into the dealership and, of course, the knock didn't appear the next morning with they started the engine. I'd like some answers also, since my 60,000 mile power train warranty is about to expire.

Hi,

I could really use some help/advice.

I have a 2007 Toyota 4runner Limited 4.7L V8 2UZ-FE

After sitting overnight, when I startup in the a.m. and put it into any gear while holding the brake i get a knocking.

The knocking is definately engine, sounds like lower engine, a lower frequency knock, not like tap or a rattle.

The severity changes depending on the teperature, worse during colder days.

I always let the the motor run for a few min, at least until the needle passes the "c" on the temp gauge before moving.

It lasts for a block or two, or about 2 stop signs, hearing it at each stop sign.

I use Mobil1 5-30, change every 3k no matter what.

I use premium gas (93) from moble or shell

What could this be?

Thanks for any responses,
TONEDOG

 

[CJ3Flyr]

As mentioned earlier a little piston-slap is "normal" for the 4.7L when cold.

As I just read this entire post I have to wonder if the OP was hearing 'cheap gas ping' and if the knock sensor had an issue.

 

[TONEDOG513]

CJ3Flyr - hey thanks for your interest. I can rule out the cheap gas ping because I have been filling up (from empty) at all kinds of different gas name brands on premium.

TNTramair - Thanks

byrden - Thats an interesting one "manifolds" How can you diagnose or check the manifolds?

ps.. Any that says running 93 makes no difference, i'd have to "beg to differ" I ran for almost 6 taks of regular and found that the startup knocking was the same but the pinging was more than ever and the difference in power easily noticeable.. border line "night and day"

T

 

[CJ3Flyr]

ps.. Any that says running 93 makes no difference, i'd have to "beg to differ" I ran for almost 6 taks of regular and found that the startup knocking was the same but the pinging was more than ever and the difference in power easily noticeable.. border line "night and day"

T

If it's truly "pinging" get the knock sensor(s) checked. If the knock sensor has failed even Premium won't keep it quiet.

The computer advances the timing as much as it can until some exhaust gas threshold is met or it pings. The knock sensor is an electronic "ear" that listens for actual noise. It should be sensitive enough to intervene before our human ever hears pinging.

The other thing I'd check is the vacuum. Confirm there's no intake manifold leaks.
:cheers:

 

[notrayray]

Engine rattles during hard acceleration. Sound like pistons or lifters maybe timing chain rattle (but I think I have belt not chain in the 2UZ-FE)

This has been since the motor was factory new.

I guess I'm confused as to why it has not been looked at by the dealership, if it has been a concern for a while.
Especially considering your are buddies with the tech guy.

 

[rook]

What about valve adjustment?

 

[Sporin]

You've got to get a good tech to diagnose it. Even the most educated forum member can't diagnose an engine sound 2nd hand.

My 06 V8, with 73k on it (I bought it with 45k on it) is easily the quietest big engine I've ever heard. Never a ping or piston slap, even on 20 below Vermont winter mornings.

 

[TONEDOG513]

notrayray -it has been.. "normal" is the answer for rattling between shifts, under hard acceleration and when the a/c is engaged.

rook - like that, maybe it does gotta get someone to look into it

Sporin - wanna trade?

t

 

[Sporin]

notrayray -it has been.. "normal" is the answer for rattling between shifts, under hard acceleration and when the a/c is engaged.

rook - like that, maybe it does gotta get someone to look into it

Sporin - wanna trade?

t

No way. :hiding:

 

[S p a r k y]

Since your at a Yota dealer, line 2 other 4runners up beside yours. Start them all, bring the tech guys out, and ask, "does this look and sound normal?"

 

[inscarguy]

you can get the manifolds replaced for free. just tell them you have the sulphur smell coming from the rear of the vehicle. the manifolds are part of the cats so when the cats get changed so will the manifolds. i just did it to mine a few months ago. i still get the injector click though, otherwise nice and quiet.