Engine Knock at Start-Up - Toyota Nation Forum : Toyota Car and Truck Forums

mcdawgg · 12-02-2007, 01:01 AM

07 I4 engine - does anyone notice an engine knock when the engine is first started? It lasts less than a second when the engine is just started, and I never hear it any other time. I only use OEM Toyota oil filters.

***CharmCityES*** · 12-02-2007, 01:36 AM

get a vid of the noise.....we cant really give any help based purely based upon a description of the noise

marc780 · 12-02-2007, 12:23 PM

Well i think i'd be a little alarmed too, because a knock is metal on metal and the last thing you want in an engine especially a new one - does this knock happen every start or only the first start of the day?

I think if you take it to the dealer they will give you a run around because unless there has been a TSB about it or something, they wont know how to fix it either! Give you a new engine for a knock at start up or something.
Here is what i would try, try another filter besides toyota for starters. Anything but Fram - i'd experiment with other brands because maybe the OEM toyota filter is letting the oil drain back when the engine is off.

Also it cant really hurt to try dumping in an additive at next change, that might leave some lubricant behind when the engine is cold overnight. i would try in this order, STP, if not, then i'd try Lucas, then maybe even Slick 50 or Duralube. Then maybe your startup knock will go away.

The knock may just be part of the break-in process, we've all heard unexplainable engine noises that werent in any diagnostic book - but unless it is continuous its probably not abnormal. My 2002 V6 sometimes makes a quiet chup chup noise at idle that sounds like a hydraulic pump working (P/s maybe?) and the noise comes and goes. Its a little alarming but since its minor, and intermittent, and doesnt affect operation, what else is there to do but leave it the heck alone? Overhaul the engine or something for this. Im not going to worry about it unless and until it gets louder and that could be 100,000 miles away, if ever!

njerald · 12-02-2007, 01:06 PM

lasts less than a second? HA!

wonger · 12-02-2007, 02:16 PM

usually happens when its lacking oil . and once oil gets to where it needs to.. it stops

are you using 0w-20 or 5w-20 oil?

mcdawgg · 12-03-2007, 08:45 PM

I use 5w20 Castrol GTX dino. Will try to get a vid when I get a chance. It sounds great except for that 1 second at cold start-up.

wonger · 12-03-2007, 09:18 PM

Quote:

Originally Posted by mcdawgg

I use 5w20 Castrol GTX dino. Will try to get a vid when I get a chance. It sounds great except for that 1 second at cold start-up.

i know that chevy trucks do it and its normal according to chevy. im sure yours is normal. its just lack of oil at start up

JAKSTER · 12-04-2007, 04:11 PM

I would not want that knock if you do not have allot of other people saying ya i have it to,then its a bummer. I would make the dealership give me a new car or something like that.You could change the oil to AMSOIL Synthetic which eleminates cold starts.Then if it still does it its the connecting rod or a crank bearing and the motor will fail at half life or sooner. But go for a new engine or new car (replacement)The don't worry is bull shit. I had a new Ford F-150 small block Triton motor they said dont worry that knock is not a problem. At 41.000 the engine took a crap and it is sitting out back to this day. TRUST ME. The dealership may try and pull the synthetic oil trick to hide the problem. Ya see synthetic oils the good ones that is stick to ht metal and IE no cold start. Oil from dinosaurs runs off when you stop the engine so everytime you start the engine no oil for a second which is real bad on all parts. Someone here is a Dealer for AMSOIL I am to but we honor each others turf so go see him if you can't get with him let me know I will help you get hooked up. AMSOIL is the best Synthetic oil in the world no question and I can prove it. So any one that says Mobil 1 or Motule or Purple I will be glad to show the tests which have proven AMSOIL to be #1 for a long time. I will change my oil to LUBRICATION the first oil change. You can use by law in the USA any filter and any oil or lubrication you want as long as it meets the manufacturers specs and has the API American Petrolem Institute seal on it. AMSOIL has this seal on some of its lubrication which is BS because they had to pay the oil people $500.000 for each cert and its not petroleum its SAYNTHETIC LUBRICATION. Oil has carbon in it which is like sand paper. Pure Synthetic Lubrication has no carbon unless its cheep like Castorol and a couple of other oils which are blends. The Good old Boys in DC allow them to make a blend but they call it synthetic. AMSOIL makes a blend but they call it a blend so no BS just the truth.

TRD VVTi · 12-04-2007, 04:59 PM

I agree with most of the others that have posted. It's probably not a problem at all. Drop you car off overnight at the dealer and let them cold start it.

Amsoil does not eliminate cold starts as stated above. Also, the API seal doesn't mean squat either. Toyota approved oil has to meet the GF-4 specification, which will be listed on the container. That's all that you need.

ram · 12-04-2007, 06:10 PM

I think i have this 'knock' at start up as well. With me, it's when i first pull off, it sounds like a pop in the back under the car.... it is starting to worry me. I use full synthetic every 5000k miles

MargesLimo · 12-04-2007, 06:18 PM

Post the video.

I've heard of people confusing a "knock" on a cold start with timing chain slap. The tensioner spring gets weak, and until the oil pressure builds up enough (usually less than 2 seconds) the timing chain slapping around in there makes an awful noise.

This shouldn't be the issue with and 07 though...