Loose timing chain!

[12T]

Finally got my engine out to have a look. I know this is a rare case but i happened to be one of the unlucky ones. What me and my brother found was my chain was very loose when cranked over also my toda tensioner was just crap lol i can push the piston in with so much ease :shock: I can also see that the teeth has worn on the piston not good at all from a big name comp.
Anyway i have compared the toda tensioner with a spare oem one i had lying around its basically the same thing but with toda logo on it, apparently the toda is suppose to have a stiffer spring. Also my chain has stretched but not much.
Only good news is that the timing did not jump but im still worried if i have damaged anything in the engine, I wont find out until i get a camera in my engine.

I have read up that this happens to people with aftermarket cams but i wasnt expecting this to happen so quick on my car with an aftermarket tensioner. My cams and tensioner was put in 2 yrs ago and only covered around 10k miles.

Just to give you guys a heads up if u have aftermarket cams and below is a list of symptoms before my chain was very loose.

Engine management light blinks once at 3k rpm then goes (dont know if its due to mapping)
Engine light blinks constantly at 150mph+ then goes away when slowing down.
Tapping noise in engine bay sounds like tappets
Tapping noise coming from the side of engine near the chain. Sound like dut dut dut dut dut...... and is slightly louder when the rev is dropping.

Last of all is the loose chain noise which u can tell by hearing it at the side of engine, cant miss it as its very loud. But this did not happen until recently which was too late for me.

 

[cpoh]

Interesting read! I posted something similar about chains stretching and tensioners needing replacing on here a while ago and the general consensus was that the k20 didnt need tensioner replacement at all when standard.

Will a new tensioner sort the stretched chain and make up the slack or are you putting a new chain on her?

 

[C&S Evo7]

a new tensioner will not fix a stretched chain, once stretched its stretched, so the distance between the teeth on the cam drive sprocket will be further apart and the cam timing will be out.

by having a chain that is too tight you will promote wear on the chain, sprockets and guides, it is very possible that an uprated tensioner will do this to your chain, you need to remember that alot of this stuff from toda and skunk2 for example is designed for racing, where they would cover nothing like the mileage you would in a road car and are rebuilt and this kind of part changed regularly, parts like cams etc (even suspension will be the same) are likely to wear out much much quicker than oem.

Honda invest millions making sure they have the correct design and material for the parts in their engines, skunk 2 do not. they will follow or copy someone elses design and add a stiffer spring etc.

K20 Timing chains and tensioners are designed to be lifetime parts and never require changing they are certainly not the K20 weak link like Skunk claim, i have never heard of a chain failing and only ever 1 or two changed due to total rebuilds etc.

 

[eXceed]

Blinking engine management light usually points towards the knock sensor going off. Especially if it goes on and off... Could probably hear it when you were doing 150mph if it was that frequent!

EDIT - just read your post fully, yeah that could be the engine knocking lool.

 

[cpoh]

a new tensioner will not fix a stretched chain, once stretched its stretched, so the distance between the teeth on the cam drive sprocket will be further apart and the cam timing will be out.

by having a chain that is too tight you will promote wear on the chain, sprockets and guides, it is very possible that an uprated tensioner will do this to your chain, you need to remember that alot of this stuff from toda and skunk2 for example is designed for racing, where they would cover nothing like the mileage you would in a road car and are rebuilt and this kind of part changed regularly, parts like cams etc (even suspension will be the same) are likely to wear out much much quicker than oem.

Honda invest millions making sure they have the correct design and material for the parts in their engines, skunk 2 do not. they will follow or copy someone elses design and add a stiffer spring etc.

K20 Timing chains and tensioners are designed to be lifetime parts and never require changing they are certainly not the K20 weak link like Skunk claim, i have never heard of a chain failing and only ever 1 or two changed due to total rebuilds etc.

Didnt honda originally specify the tensioner as a service item at 75k on ther ep3 for a good few years thoiugh?

 

[VT-Doo]

Honda invest millions making sure they have the correct design and material for the parts in their engines, skunk 2 do not. they will follow or copy someone elses design and add a stiffer spring etc.

K20 Timing chains and tensioners are designed to be lifetime parts and never require changing they are certainly not the K20 weak link like Skunk claim, i have never heard of a chain failing and only ever 1 or two changed due to total rebuilds etc.

xthumbsup

The only times I have heard of failure is after the engine has been fettled with. Too many people relate after-market parts as being an upgrade.



12T,

The EML blinking will be knock.


Did the engine make a noise when coming off the throttle?

 

[12T]

A little update here ppl after a week and a half working in the freezing cold. Finally got my car running I have put a camera to check the valves and bores, seems to be in good condition. Adjusted the tappets while engine was out new toda chain and hybrid racing tensioner put in, ported my rbc mani while that was done.
Engine is running good tappet noise was less noisy EML does not come on anymore at 3k rpm havent really tried it at top speed yet.
Engine still have alot of noises but thats due to the cams, v/s, Ti retainers and so on....

So the real problem was just the worn toda tensioner. I have replaced my toda CT with a hybrid racing CT instead of a skunk 2 CT because the design looked much better and more durable.

For owners who have a toda/stock tensioner and aftermarket cams replace it with a better tensioner.

 

[12T]

Honda invest millions making sure they have the correct design and material for the parts in their engines, skunk 2 do not. they will follow or copy someone elses design and add a stiffer spring etc.

K20 Timing chains and tensioners are designed to be lifetime parts and never require changing they are certainly not the K20 weak link like Skunk claim, i have never heard of a chain failing and only ever 1 or two changed due to total rebuilds etc.

xthumbsup

The only times I have heard of failure is after the engine has been fettled with. Too many people relate after-market parts as being an upgrade.



12T,

The EML blinking will be knock.


Did the engine make a noise when coming off the throttle?

I had the car running with EML like this for more that 6 months with no noise. I have heard a couple of k20a knock and it doesnt sound pleasant lol. If it was a bearing that went it can only get louder and louder through time.
Just got my car on the road now the light has disappeared and hopefully for good. I think it might be the loose chain making a noise which triggered the EML light at every 3k rpm and at top speeds.

VT Doo & c&s evo you are right but how many dc5 owners keep their cars standard? hence why other companies have found problems with some parts so they rectify it with stonger or better parts through testing, some successful some a failure. They wont spend millions because they are not designing an engine from scratch. And yes you are right with many companies they do copy and prob add a lil bit of this a lil bit of that! and even copy other comps that have spent thousands on r&d then put their logo on it but thats just how the world goes around.


Russ

 

[C&S Evo7]

The only difference between the tensioners as far as i can see is an uprated spring.

The spring is only in play during the startup sequence until theres enough oil pressure to maintain the pressure on the chain, which usually is a few seconds, if it was all the time the car was idling they would be very noisy.

If you have a kpro and are getting a flashing eml then i would datalog the rpm. spark and knock count. i would be pretty certain it will be knock you are experiencing.

 

[Kinli]

The only difference between the tensioners as far as i can see is an uprated spring.

What??

Come on. This is such an old subject and it's been covered here so many times that one could assume you know better than that. The spring isn't the problem.

I'm too busy to write about this again so I'll just quote you guys, "Use the search".

 

[C&S Evo7]

Well I just posted my observations ;-) , I had the Honda one in my hand and a toda one with the difference being the spring rate being higher on the toda tensioner . As the spring only really comes into play during startup then relies on oil pressure I've never worried about swapping them