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Please help me troubleshoot rattling in engine bay

52K views 49 replies 19 participants last post by  huntersdl 
#1 ·
Hey guys,

Thank you in advanced. I need some advise and help. I am stumped on this and I have tried my best to troubleshoot.

The link below is the rattling I am experiencing during cold engine startup. Once the engine is warm, it does not come back until I park it over night or if it is a very cold day. I live in southern California.



I tightened all the bolts to the intermediate heat shield and still the same. I put a screwdriver to the heat shield no rattling...I don't think this is a heat shield issue.

The noise is loudest on the passenger side around the pullies. You can hear in the video the rattling get louder around the pullies.

Can this be needing a valve adjustment? Maybe a valve making the noise?

Oil is fresh and full. Lots of tranny fluid. I do not experience any other problems while driving..it runs great. Just the rattling on startup. Im worried.

2007 EXL with 70K miles. I just bought the van. I will stab my heart with a spoon if this is an internal engine problem that will be involved to fix. I'm and experienced diy'r but I need your help or ideas.

Many thanks.
 
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#2 ·
TSB 08-045 Chirp From the Timing Belt Area
SYMPTOM
There is a chirp coming from the lower timing belt area.
The noise is most often noticed at idle, usually after the
engine has warmed up.
PROBABLE CAUSE
The idler pulley mounting surface is tilted, causing the
edge of the timing belt to rub against the side of the
pulser flange on the drive pulley (gear).
CORRECTIVE ACTION
Install a taper shim kit, and grind a deeper relief on the
engine mount bracket if needed.

TSB 07-005 Power Steering Pump Whines, Buzzes, or Hums
SYMPTOM
The power steering pump whines, buzzes, or hums
after driving for 30 minutes in temperatures of 35 to
40 degrees F (2 to 5 degrees C).
PROBABLE CAUSE
The power steering pump reservoir is defective.
CORRECTIVE ACTION
Flush the power steering system with clean power
steering fluid, then replace the power steering
reservoir.
 
#3 ·
Have you tried turning the steering wheel side to side while its exhibiting this condition to rule in or out the power steering system from contributing to the condition?

Could it be an exhaust leak? As the motor comes up to operating temp the leak seals itself, then as it cools down over night the leak reappears, only to go thorough the same cycle again the next day?
 
#4 ·
I have the exact same problem on my wife's 2006 EXL with 80,000 miles. Dealer thought it might be "piston slap" but could offer nothing more. I'm in South Florida, fresh oil change, correct level, turning steering wheel does not change sound. Goes away after warmed up. AC on or off, no difference.
 
#6 ·
It sounds like the noise mine's making. So far it's been diagnosed as the alternator via the diagnostic tool at AutoZone. I'm scheduled to get it diagnosed by my local Honda dealer on Saturday morning and replaced on the same day. That is, if it is in fact the alternator. Regardless, the dealer is going to check it out and contact me before they start the repairs. It's going to run me $487.00 parts & labor, which is a helluva deal around here. I'll report back Sunday morning if/when I get the van back.
 
#8 ·
Okay, I loosened the three bolts to the heat shield and left it loose on top of the intermediate shaft. I started the van with engine cold. It is still happening. This eliminates the heat shield which I thought wasn't the cause, but I had to do the process of elimination.

While the rattling was occurring, I got on top of the engine and put my ear on top of the upper cover of the intake manifold. Here I hear the rattling very loudly. So I took my mechanics stethoscope from Harbor Freight and tried to listen to the cylinder head cover, I could barely hear the rattling. I really doubt it is a belt or alternator, Im not hearing anything from these units.

Noise is definitely not coming from front of van, but on top of the engine. My next step is order valve cover gaskets, intake manifold gaskets, etc and do a valve clearance adjustment. I haven't done this procedure in at least five years. I hope to have this done in 4 weeks..guys, Im a busy person. I will keep you posted.
 
#9 ·
There are previous post in this thread below. There are two threads to this issue. Sorry for the confusion.

http://www.odyclub.com/forums/52-2005-2010-odyssey/88345-loud-tick-cold-start-2.html#post673643

Bottom line, it has been determined, thanks to MJODY contributor, this is a timing belt slapping issue caused by a weak timing belt tensioner. It can be easily determined by removing the serpentine belt, and remove the rear cam shaft timing belt cover. You may be able to wiggle the tbelt loosely and it will tighten up and the rattle noise will go away once the engine is warm. It is easy to see the rattling on cold startup. No need to put to the engine to Top Dead Center. It is not necessary to remove the front or right side cam cover because you will have to remove the adjusting pulley. Everything can be seen via left tbelt once you remove the cover.



Good day Mjody,

I have a decent video of the tbelt vibrating. I will edit and add to my youtube. This is beyond a doubt 100% the hydralic tensioner is the cause of the rattle.

I'm started to compile honda parts to fix the problem, then I went down the path of doing everything I could think of since I will be in the area of the tbelt. I want to replace tbelt, tensioner, adjuster, cam and crankseals, water pump, thermostat, crankbolt etc. However, there is something I haven't mentioned. My left wrist and thumb are bound by a brace. I hurt it a month ago and I'm in still in much pain. As such, with the Odyssey at 74K miles, I'm debating putting everything back and deal with the cold start rattling for now - at least until my wrist completely heals rather than adding more damage to it and possilbly nerve injury as well.

Since I am considering to put the engine back together, which would take me about hour and a half, I am revisiting the safety factor of leaving the problem as is. I have completely inspected the tbelt and it is in great shape at this mileage. As you said, it is loose in the cold morning and I have verified that extra play. When the engine is cold, I could easily wiggle the tbelt and it feels loose. It really tightens up after the engine is warm. I can't wiggle it once the engine runs for 3 min. I am thinking of leaving it this way at least until 90K or even 100K miles at which point I will change everything out . This makes more sense to me than changing the tbelt to water pump with those components having so much life left. Heck, I can try to deal with the morning rattle, which doesn't occur every morning. I figured the tensioner will give me warning before it give up like a constant rattle at start up and while in normal operating temp, but nothing like leaving me stranded or lose power while driving. I don't see this as a safety issue. Nonetheless, I am very relieved I did not purchase a preowned van with a major internal engine issue and it is something I can fix myself.

What really puzzles me is why the tensioner is so loose cold and why it resolves itself when warm? After all, it is an hydraulic component.

I welcome and want your thoughts.
 
#10 ·
Glad to help but even a broken clock is correct twice a day. :DD

No need to go "Bill Gates" on the parts replacement unless you are stupid rich and have money to burn. Do the tensioner and timing belt. The rest are very durable pieces.

FWIW, on the V6 motors, the seals rarely leak. If not puking, leave them alone. Forget the idler pulley and crank bolt. Just throw a new timing belt and tensioner on it.
 
#11 ·
Welll....I put the van back together again...but, the engine light came on and the TPMS light is still lit.

I used my OBD2 unit to erase the check engine light. It was P0570. As for the TPMS, not sure how to reset it and the service manual does not explain. I never disconnected the battery either.

From my understanding, I will have to visit the dealer to clear the light. I will drive around and check tire pressure tomorrow and see if it goes away.

thanks.
 
#12 ·
I used my OBD2 unit to erase the check engine light. It was P0570. As for the TPMS, not sure how to reset it and the service manual does not explain. I never disconnected the battery either.

thanks.
update - However, there is a page that states if there is a low battery detected, the TPMS will come on...go figure. The battery did get low during my troubleshooting proceedure. It goes on and explains to drive the car for a minute at least at 28min per hour or more and it should clear itself pg 18-106 of the thicker service manual.

Thanks Mjody, I will do just that. I will ping and update this thread when my hand gets better. Oh, it took me 1 1/2 hours to put the van back together. Getting the cam covers off and on can be a bit challenging.

thanks all
 
#13 ·
From the sound of the video, it seems to be rocker arms/valves as a possible source. Though the ticking is lower pitched than usual but NOT low enough for "piston" slap or rod bearing looseness.

Adjusting the valves is the logical step. You've isolated "out" the alternator, pulley etc.

Not too difficult. Use the "no go" gauges for a easier, quicker job....

Take note of any sludge as it would indicate passage problems leading to hydraulic valve lifter blockage...

Good luck,
 
#14 ·
Not too difficult. Use the "no go" gauges for a easier, quicker job....

Take note of any sludge as it would indicate passage problems leading to hydraulic valve lifter blockage...
Good luck,
Thank you Chiody,

I'm still learning, so I appreciate your comments.

I have a feeler gauge now. It is a 3" blade. I was going to use .008 and .012 for the valve adjustment.

What is the difference between this and a "no go" guage? Why do they call it a "go-no-go" gauge? I did a key word search, but no luck.

I've done valve adjustments once before on Honda 4 cylinders, but not on a V6 where the engine side valves are harder to get to. Will what I have be okay to use?

There are so many variations out there. I am more than willing to purchase another unit. I see there are long 6-9" gauges, but I'm leaning towards the 4" with a slight bend to it.

Any suggestions would be most appreciated. Thoughts anyone?
 
#15 ·
Go-NoGo gauges just get slighly thicker, as they go in, so it's easier to tell when you have the right one. If it slides it OK, and then stops if you go further, that's the right one.

Did you ever find the solution to this rattle?
 
#16 ·
PROBLEM SOLVED - Changed timing belt tensioner

Hello

THE SOLUTION - Changed the timing belt tensioner.

I purchased the tensioner from Hondaautomotiveparts.com

It has been at least six months now since I changed the timing belt tensioner. Shortly after changing the item, I drove the van from Los Angeles to Wyoming on vacation. I have not heard the rattle since.

I could have changed the timing belt as well, but I wanted to know which item was causing the rattle. Besides, at 100K miles, I plan to do major work on the van. I will change the timing and all belts, water pump, radiator, plugs, distributor and rotor, wires, all seals, all water hoses, all O2 sensors. For the most part, the van just sits, but I use it time to time and it has been quite. No more rattling on start up.

If you live in Los Angeles, give me a holar and I may be able to help you change it. It is not difficult at all.

Many thanks to everyone.
 
#18 ·
I left my wife's Ody overnight at the dealer and went this morning to start it up with their mechanic for the same issue. Of course it didn't make the sound that it has made on nearly every morning for the past year.

The mechanic was pretty sharp and after explaining this thread said that he has rarely seen a tensioner go bad, but replaces 7 of 10 of them for weeping when he changes the timing belt. He has yet to see any that are totally soft.

He said that he replaces a ton of o-rings on power steering pumps (one intake, one pressure side) as they let air in and cause the pump to cavitate and makes a similar noise. Before we head down the path of doing the tensioner / tb, he suggested the o-rings. Showed me how to access them and I bought the two for about $3. No charge for the diagnostic, test drive, and half hour of his time.

I have already replaced the reservoir and serpentine belt, and the rear motor mount recently. I'm going to replace the o-rings this afternoon and will report back in the next couple days.
 
#19 ·
06EXL, let us know how that goes. I had mine into the dealer last week with this issue, and they replaced the steering pump under extended warranty. The heavy steering is now fixed, but I heard the noise again once. It does not always happen though, so I'm not sure what to make of this. Other than the noise on startup sometimes, the van is running great.

Do most people replace the serpentine belt at the same time as the timing belt? Seems reasonable, but I did not see it listed in the manual, only the timing belt. I'm still 25K miles from the timing belt replacement interval, so I'm assuming the serpentine belt is OK until then.
 
#20 ·
I wish that I would have replaced the o-rings when I did the reservior a couple weeks ago because I had to turkey-baster all the fluid out again and disconnect the hoses.

Pretty simple - two 10mm bolts on the top pressure hose and the o-ring needed to be streched out of the groove with a small screwdriver. The old one was rectangular in cross section and the new one was round. I understand that if this one was bad, you would see fluid on the top of the pump, but mine was dry. If you replace the pump, you should replace this one as well.

To get the bottom one out, you need to remove a 10mm bolt below where the fitting attaches to the pump. It is a tight fit for a small box wrench but turning it 45 degrees at a time I was able to get it out. The old one was black and rectangular and needed to pick it out of the pump housing. The new one was red and round cross section and simply slipped over the male end of the return line. This fitting is part of a new pump assembly so no reason to change if you have a new pump. Mine was the original and if bad it would allow air to get sucked into the pump.

Now the waiting game - the noise only ocurred when the van sat overnight.
 
#21 ·
The cold start up noise is still there - changing the o-rings didn't do anything (except peace of mind on that system down the road). I'm just under 95K miles so I think that I'm going to bite the bullet and have the timing belt tensioner replaced along with the timing belt, water pump, etc. Will probably do this early next week and report back.
 
#22 ·
hi gang. i have an 06 touring with 71k miles on it. this exact same rattling is taking place in my engine bay so thanks to ariel for putting this thread up. wanted to know what sort of costs am i looking at for just the TBtensioner and installation. Also, do you feel at the mileage i have put on thus far, should i replace the TB and waterpump as well? Any help would be greatly appreciated.
 
#23 ·
Just returned from the dealer. The noise didn't happen immediately, but within 3 minutes the rattling started. The mechanic agreed that it was somewhere in the area of the timing belt and said it sounded like a bent valve, but if it was, it wouldn't go away. With 95K miles, I was commited to changng the timing belt anyway, so they dove in. The hydraulic tensioner was covered in oil and was not providing the resistance needed to load up the timing belt. Replaced the timing belt, hydraulic tensioner, water pump, and coolant. I recently replaced the serpentine belt, so they simply reused it. Total out the door, parts and labor $925. The tensioner part only was $146. I'll report back in a week or so an let you know if the noise is truly gone.
 
#25 ·
Hello everyone and mjody,

Its been a very long time now since I changed the t-belt tensioner. I have NOT heard the tick or slapping sound since. I purposely changed just the tensioner to help everyone out and understand only one item is causing the issue - timing belt tensioner.

My odometer currently reads 79,941 miles. I have driven and started my van many many times now in all types of weather. The slapping or ticking noise on the video is defiantely and 100% gone.

If you own mechanics tools, it is medium skill set to change out the tensioner. Nothing special than 10mm - 16 mm sockets if I recall correctly. You will need a nice Harbor Freight or Sears style 1/2 long ratchet to get the serpentine belt off. This part is challenging if you have no experience at this. I also recommend a small 3/8 ratchet for the tight areas. Otherwise, just evaluate the job before starting. At the time, my left hand was in a brace. I couldnt use it. I did the entire job only with my right. As such, it is just knowing what to do to get the job done.

If I recall correctly, 110K miles is the recommended timing belt job. This is a good time to get major work done. If you van is only 70K miles or so, I would either replace the tbelt tensioner or leave it. The noise is more embarrassing than a potential damage to the engine. However, if you are handy, go change it for $87. Get your parts from hondaautomotiveparts.com. I recall this is the cost.

If you are going to replace the timing belt, then I would change waterpump, spark plugs, etc.

My biggest fear was the timing belt jumping a tooth on the cam if the tensioner was loose. If this occurs, I understand it is a major catastrophe. Im not sure the probability of this occuring. Because I wanted to help others, I had the tools and the know how, I decided to diagnose and repair the issue. I take no credit in finding the problem. That I got help from mjody and others on this forum.

Just keep in mind, if you are close to 110K, just get all the major work done. It is a very hard decision to make especially if you have to pay $$$$. For me, I just pay parts and my time. I hate dealerships. Their purpose in life is to make money...albeit most of them rob people blind. Having four sisters growing up forced me to learn mechanic work. Last, it is Odyclub and it's members that really help out. Without Odyclub, none of us would know what to do.

Make sure you are reading the other thread too
http://www.odyclub.com/forums/52-2005-2010-odyssey/88345-loud-tick-cold-start-3.html

and the video at the begining of the thread should be very helpful.

Cheers.
 
#27 ·
Came across this thread while researching a similiar problem on our Odyssey. A loud knocking sound (that last for about 1-2 minutes on a cold start.

My mechanic checked our 07 Odyssey, 68,000 mi, twice. He seems to think the problem was the rod bearings. (I haven't been able to find much information on those other than its if it is that its going to be way expensive) I asked him about the timing belt tensioner and he thought the sound was coming from a spot lower in the enginer and that the timing belt tensioner noise was more of a rattle or chirping. He suggested taking the car to the local Honda dealer.

My question is how is the timing belt tensioner noise more of a knocking sound (like the engine timing is off) or a higher pitched sound. What makes the timing belt tensioner noise disappear after a minute or two? I am so hoping that the problem is not the rod bearings.
 
#28 ·
Hello Dave,

Did you listen and watch the video on post #26? It is a great summary of the situation. I took the extra time to video and edit it for you and others.

Ask you mechanic, if it were the rod bearing, would the noise go away after the van is warmed up? I would think the noise would continue if it were rod bearings causing the problem.

There is another thread to this post that I used and commented on during my troubleshooting. Have you read that yet?

Last, if you are mechanically inclined, as stated in the video, remove the rear camshaft cover (if I recall it is the rear cover) and see if the Tbelt is vibrating. This was evidence for me it was the tensioner causing the issue. You will immediately see if the noise goes away in conjunction when the belt eventually stops vibrating. The slapping or rattling noise is the belt not being tight during cold start. Once the engine warms up, the tensioner thightens up. I cannot explain why but maybe as the engine warms up it heats up the tensioner. I just know the problem stopped for me when I changed the tensioner. This is why I did not change the timing belt at the same time so I can learn exactly what was causing the problem. In my 07 Ody case it was the tensioner. I don't know when the problem started. I purchased it used at I think 72K miles. I wouldn't doubt it started much much earlier. I think this is why I got the van so cheap. The last owner dumped it for a song thinking it was a rod bearing. Instead, I fixed it for less than $100 and a few hours of my time.

Oh, tbelt tensioner is in the lower part of the engine, but it does not necessarily need to be a rattle or chirping. I was seeing and hearing was the Tbelt vibrating or slapping. Literally, the noise would stop when the tbelt stopped vibrating. Only way you can see this for yourself is with the cam cover removed.

If you have tools, fix it yourself. I would not change the tbelt though at such low miles.

North Carolina is not too far. Drive to LA and bring some bbq. You and I can fix it :)
 
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