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My cousin just replaced the blown k20a2 that was in his eg this week. The motor he bought runs great pulls very hard everything as it should (no cmoke, no knocks, no ticks) but when it has been sitting for a while and you crank it up it rattles for a split second. It's not a rod knock in case your wondering it's defenetly a rattle. It only does if you haven't cranked it in a long time and it only does it for a split second. If you crank it up cold it will do it. Shut it off right away and crank it back up again and it's 100% quiet. It seems to have somthing to do with oil pressure building up I guess.

Do these motors have a timing chain tensioner that is activated by oil pressure?

And is this normal? His other motor never did that, that we know of.
 

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The k seires has a oil pressure activated chain tentioner, it should be fine as long as it just at start up after a long period of time.

My rsx does it to after a few days of not starting.
 

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fine on a stock motor but if you got aftermarket springs retainers you should upgrade the tensioner b/c it will fail over time i know from experience
 

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Since I installed a clutch switch bypass, (so that I do not have to depress the clutch to start the engine) I havnt heard any noises such as that. It was about 3.2 degrees F the other morning and turning the key on and cycling the fuel pump twice prior to cranking, and she started right up with no noise.
 

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I believe the k-series engines take 5w30, using the recommended oil is extremely critical. When a manufacturer builds an engine and recommends oil, they do it for oil pressure, and clearance purposes. If you don’t use 5w30 it’s going to take longer for the engine to build oil pressure, and most importantly the oil won’t properly sit between the bearings and crank surface. Remember the crank does not ride on the bearings; the crank actually rides on a film of oil called hydrodynamics. So damage to your engine can, and will occur.

5 is oil thickness at start up, w is winter, and 30 is oil at engine temperature. SO IF YOU WANT THAT CHATTER TO GO AWAY GO WITH 5W30 I guarantee you will notice a difference. Especially on cold start ups, the oil gets where it needs to go faster. Alot of Mercedes Benz’s use 0w20 or 0w30. Now if your engine is built with different clearances for racing, it’s a whole other story.
 

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My cousin just replaced the blown k20a2 that was in his eg this week. The motor he bought runs great pulls very hard everything as it should (no cmoke, no knocks, no ticks) but when it has been sitting for a while and you crank it up it rattles for a split second. . . . . . . . . . .

My '07 Si (K20Z3) with 30K on the clock chatters as well, but, only when it has sat without being started in a few days/weeks. My take is that gravity pulls the oil back down into the oil pan, the longer it sits the more oil that seeps down. I think the chatter is lifter tap and a "dry" timing chain/guides. When the motor builds oil pressure the noise goes away. I think it's normal. I'd start to worry if it gets worse or the chatter lasts longer than "normal".


I believe the k-series engines take 5w30, using the recommended oil is extremely critical. When a manufacturer builds an engine and recommends oil, they do it for oil pressure, and clearance purposes. If you don’t use 5w30 it’s going to take longer for the engine to build oil pressure, and most importantly the oil won’t properly sit between the bearings and crank surface. Remember the crank does not ride on the bearings; the crank actually rides on a film of oil called hydrodynamics. So damage to your engine can, and will occur.

5 is oil thickness at start up, w is winter, and 30 is oil at engine temperature. SO IF YOU WANT THAT CHATTER TO GO AWAY GO WITH 5W30 I guarantee you will notice a difference. Especially on cold start ups, the oil gets where it needs to go faster. Alot of Mercedes Benz’s use 0w20 or 0w30. Now if your engine is built with different clearances for racing, it’s a whole other story.

I agree with Mr. JrBreaker here with using the 5W30 manufacturer's recommendation here. However, just to point out, many older vehicles require 10W30. The reason being that newer vehicles have smaller "bearing gaps" than the older vehicles. Using a "thicker" oil in a newer vehicle may acctually prevent the proper lubrication of the engines internals

Yes, I also agree, 5W30 is better for the colder winter temperature initial startup. Better than say 10W30. In my daily driver elder cars, with 90K+ on the clock, I've noticed "engine noise" using the recommended 5W30 in the Summer. For that reason I switch to 10W30 in the Summer and back to 5W30 for the Winter.

The "enjoyable cruising" "Summer" season here in NY lasts from say mid-late April to mid-late October.

The "jonesing to cruise" "Winter" season begins for me mid-late October to mid-late April.

These "engine noises" are indeed reduced.

To go further, Synthetic blends reduce this "thickening" effect as these oils are designed not to change characteristics from cold to hot/hot to cold as well as last longer than their "regular" counterparts. Honda already uses these blends, I hear that Mobil 1 Synthetic Blend is the same as OEM Honda Engine Oil used @ Honda dealerships. So I hear anyway, :up:

To get back to the OP, this chatter/noise you are speaking of I believe is normal as long as it dont last for a prolonged period of time after start up, and stick to the recommended 5W30 :up:

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Definitely chain tensioner just pulled the engine out of my car. It used to rattle when I would start it cold; I thought it was my starter sticking on the flywheel. Nope, pulled the front cover out and the damn tensionaer was fully extended. Luckily I didn’t bent any valves but one piston had a crack probably do to detonation. So know I'm contemplating rebuilding the engine or doing a K20/k24 hybrid
 

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Mines started chattering a couple of months ago. I replaced the tensioner 20k miles ago. The only reason I changed it was because I had the engine out and wanted a fresh start.

It only does it in the morning or after the car has been sitting for more than 4 hours. Obviously the longer it's been since it was last started, the harsher the chattering is. It could last about 3 seconds at a time but once it shatters it and cranks, I can turn the car off and crank it up and it won't even remotely chatter. I guess it makes sense somewhat sense the oil goes back down to the pan and the tensioner looses pressure but I'm going to diagnose it and expect and prepare for the worst.

Time to check the cam angle command versus actual cam angle and then take a look at the teeth on the tensioner.
 

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My cousin just replaced the blown k20a2 that was in his eg this week. The motor he bought runs great pulls very hard everything as it should (no cmoke, no knocks, no ticks) but when it has been sitting for a while and you crank it up it rattles for a split second. It's not a rod knock in case your wondering it's defenetly a rattle. It only does if you haven't cranked it in a long time and it only does it for a split second. If you crank it up cold it will do it. Shut it off right away and crank it back up again and it's 100% quiet. It seems to have somthing to do with oil pressure building up I guess.

Do these motors have a timing chain tensioner that is activated by oil pressure?

And is this normal? His other motor never did that, that we know of.
Well Honda has a service bulletin 09-010 Engine rattles at cold start up for about two seconds. only applies to all 2008 accord and some 2009 accords. this only happens when the engine has not been started for at least 6 hours.

they say that the VTC Actuator must be installed in its unlocked position to avoid damaging its internal lockin pin.

the VTC Actuator can get locked during handling. Don't know if this is happening to your VTC actuators. just thought I would share this with you guys.

as GT35RK20 said it might be a good idea to check CAM cmd to actual CAM Angle to see if this locking pin causes any cam angles to be off. any of you guys disected the VTC actuator?
 

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my boys car does the same thing on the cold start.... great info guys.. thanks for the help...
 

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Yep. 06 FG with the z3. Right at 40k miles... definite crank bearing rattle after sitting for a day with no startup. Repeating the timeframe, i pulled the ECU fuse and did a few cranks. I replaced the fuse and started the car with no rattle. Its repeatable results. Welcome to loosely built, high revving Hondas.
 

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hmmm...interesting...i work for kona mazda here in hawaii and we have had some cx-7's with the same problem as stated above wit the accords but in our instance its due to faulty vtc actuators on the intake cam..........try swapping out your vtc with a known good unit and see what happens or if u got a long screwdriver put one end on the v/c near the vtc and have someone start the car and listen.....just my 2cents:D
 

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Update: I took the tensioner out and has signs of wear on the ratchet mechanism and on the teeth after only 1k miles and it still rattles. Covered under the standard 10k mile parts warranty from Honda. Put in the new tensioner 3 weeks ago and it still rattles. It even does it if I were to crank the car with the fuel cut off and then it stops after 3 or 4 seconds of doing this after a cold start. I'm ordering my hybrid racing tensioner when they have them in stock in about a week.
 
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