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cam chain tensioner?


dazzer-b

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Hi,

 

is there any way of diagnosing a faulty cam chain tensioner?

 

a chap i know who is a mechanic thinks the loud rattle that comes fro my car for the 1st 2 seconds when its cold is this, but looked into it at work and said the labour to replace it is roughly £1000, i trust him totally in terms of labour costs for that job as he is a family friend but i dont think he is the best mechanic in the world,

 

just wanted to know if there is a simple test that can get carried out to determine if thats the fault before parting with that much money.

 

Cheers

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Some 350s are known to rattle for a few seconds from cold start and there are numerous factors which might cause this.

 

However if you have explored all the possibilities and the rattle is from the one of the cam chains, then I doubt if it will be the hydraulic tensioner and is more than likely to be one of the cam chains.

 

This year alone I have replaced cam chains on two 350s due to similar issues.

 

From cold, If you check how far the tensioner is protruding from the tensioner housing then that will give you an idea what is going on.

 

Circa 10mm protrusion is acceptable and circa 20mm is not.

 

If the protrusion is circa 20mm then the reason usually for this is that the small cam chain will be stretched and the tensioner has to come out further to take up the slack and the rattle you get is due to the chain interfering with the casing.

 

If the above is your issue then a new cam chain and tensioner will fix your issue.

 

Also best to replace the chain guides and slippers when you are at it as Nissan have upgraded these with more efficient and durable parts.

 

Alex. :)

Edited by ZMANALEX
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There are many issues which can cause an engine rattle on start up, and with out hearing it I am afraid I can not give you an informed diagnoses.

If you are not confident in your technicians diagnoses then I would highly recommend that you let some one who is a VQ35DE engine expert to have a listen. This issue should be able to be diagnosed without serious stripping.

 

Alex. :)

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  • 1 month later...

Some 350s are known to rattle for a few seconds from cold start and there are numerous factors which might cause this.

 

However if you have explored all the possibilities and the rattle is from the one of the cam chains, then I doubt if it will be the hydraulic tensioner and is more than likely to be one of the cam chains.

 

This year alone I have replaced cam chains on two 350s due to similar issues.

 

From cold, If you check how far the tensioner is protruding from the tensioner housing then that will give you an idea what is going on.

 

Circa 10mm protrusion is acceptable and circa 20mm is not.

 

If the protrusion is circa 20mm then the reason usually for this is that the small cam chain will be stretched and the tensioner has to come out further to take up the slack and the rattle you get is due to the chain interfering with the casing.

 

If the above is your issue then a new cam chain and tensioner will fix your issue.

 

Also best to replace the chain guides and slippers when you are at it as Nissan have upgraded these with more efficient and durable parts.

 

Alex. :)

 

Hi Alex,

 

Is the cylindrical device with the pin at the back next to the dipstick then chain tensioner? If it is and judging by the measurements you have given, it looks to me that this might be on it's limit. Difficult to say for sure I appreciate but a guesstimate would be useful.

 

IMG_2559_zps9242cac9.jpg

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The chain tensioners that I refer are inside the engine beside the chains.

 

Alex. :)

 

So, just to make sure I understand this, you can only check the chain tensioners by partly dismantling the engine to see whether or not they are within the limits you mentioned.

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Gonna try and help - hope I don't get it wrong :lol:

 

You have 3 chains in there I am assuming as Alex said to change the guides and slippers we are referring to the big one :)

 

Front of engine

 

DSC_0001-14_zps26d218ab.jpg

 

Covers removed -

 

DSC_0002-12_zps4e2d659b.jpg

 

On the left you can see the chain tensioner when the cover plate is removed and this I believe is the one you need to check :thumbs:

 

Close up

 

DSC_0024-4_zpsca28807c.jpg

 

with the complete cover off you can see this

 

DSC_0021-6_zps3c8cabd0.jpg

The 2 smaller chains at the top also have tensioner

 

DSC_0004-10_zps85b04b81.jpg

 

but you would need to take the cover off to completely to get to them.

 

FYI - The part you showed in the pic is the VVT control the "Cam sensor" or CPS is at the back of the engine. (I only pointed that out to avoid confusion)

 

Hope that helps :thumbs:

 

More info on stripping and credit for photos I stole :ninja:

 

see these links

 

:)

 

http://www.350z-tech...over-chain.html

 

http://my350z.com/fo...ng-chain-2.html

 

Good luck :thumbs:

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Gonna try and help - hope I don't get it wrong :lol:

 

You have 3 chains in there I am assuming as Alex said to change the guides and slippers we are referring to the big one :)

 

Front of engine

 

DSC_0001-14_zps26d218ab.jpg

 

Covers removed -

 

DSC_0002-12_zps4e2d659b.jpg

 

On the left you can see the chain tensioner when the cover plate is removed and this I believe is the one you need to check :thumbs:

 

Close up

 

DSC_0024-4_zpsca28807c.jpg

 

with the complete cover off you can see this

 

DSC_0021-6_zps3c8cabd0.jpg

The 2 smaller chains at the top also have tensioner

 

DSC_0004-10_zps85b04b81.jpg

 

but you would need to take the cover off to completely to get to them.

 

FYI - The part you showed in the pic is the VVT control the "Cam sensor" or CPS is at the back of the engine. (I only pointed that out to avoid confusion)

 

Hope that helps :thumbs:

 

More info on stripping and credit for photos I stole :ninja:

 

see these links

 

:)

 

http://www.350z-tech...over-chain.html

 

http://my350z.com/fo...ng-chain-2.html

 

Good luck :thumbs:

 

Thought you had taken apart an engine in no time just to help the guy out! then I read the end part :dry: I am disappointed Keyser :p

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Thought you had taken apart an engine in no time just to help the guy out! then I read the end part :dry: I am disappointed Keyser :p

 

Is it pick on Keyser day???

 

I have taken an engine apart :p pics in one of my build threads somewhere. :D

 

But next time I will happily take apart YOUR car to get a picture of a widget or whatever the request is :lol:

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Thought you had taken apart an engine in no time just to help the guy out! then I read the end part :dry: I am disappointed Keyser :p

 

Is it pick on Keyser day???

 

I have taken an engine apart :p pics in one of my build threads somewhere. :D

 

But next time I will happily take apart YOUR car to get a picture of a widget or whatever the request is :lol:

 

I think he deserves it 100% for those comments, go Chris go!

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