Timing belt rattle

[CMF_Dave-G]

Hello everyone, I have just joined this evening. As with most newbies I guess - I searched about for answers then decided to ask questions from the well informed bods on here.

I'm active on a couple of Galaxy forums with the same username - but her indoors likes K11's as she hasn't been driving long and it's a car we don't have to worry too much about damaging.

Her superb 1.3 slx got written off a few days ago and I have struggled to find her a 5 door model in the area in a colour she likes. Anyway we settled on a 1 ltr to get her back on the road.

It had a rattle that I thought was an aux belt tensioner - I now know its a timing belt problem thanks to the forums I have searched and removing the belts.

It only rattles when cold - leading to me thinking it is only the top one from the posts I have read. The engine is otherwise very sweet running.

I'm tempted to only change the upper tensioner to see if that clears the rattle - could some tell me if that is feasible please and can it be done without removing the rocker cover?

TIA Dave

 

[CMF_nz_aj]

Yes you can. You need to remove the plate of the side held on by about a dozen M6 bolts. You'll need some sealant when putting it back on.

Removong the rocker cover is hardly a large problem. It has a rubber reuseable gasket. A couple of dabs of sealant are a good idea in the corners of the half circle rubber plugs

 

[CMF_Dave-G]

Thanks nz-aj. I took a looksee into the rocker cover via the oil filler and found a tad of gunge inside the cover and cap.

I use fully synthetic in my Galaxy (I've had four in the last 10 years) so kind of thought the sludge I saw was a thing of the past. I'm presuming the chain is splash lubricated from a spray bar to the rockers would that be right? or could some other oil delivery device to the chain be blocked with sludge.

With the advice you gave I feel inclined to remove the rocker cover and de-gunge it. Old Laquer needs coming off the outside too - to make it a look less abused. The car is low mileage and wifey will only ever use it local - hardly ever getting it up to full temperature, is synthetic a good idea?

I don't have the car here right now - but seem to recall the plugs are in deep recess in the rocker cover - would new seals be needed for these area's?

Thanks again guys.

 

[CMF_nz_aj]

If you see gunge on a low mileage motor its probably just been a long time between oil changes.
Regular oil (& filter) changes are far more important than using the most expensive best quality oil.
Use the right viscosity oil for the ambient temperature, e.g. for use above -10C use 20W-40 or 20W-50.

I can't quite recall the source of lubrication oil for the chains but there is an oil supply for the bush in the centre sprocket and the tensioners are hydraulic, so it's probably lubricated by the seepage from those.
On a sludged up CG13DE I had apart the oil supply to that centre bush was quite clogged.
If you've got noise from the chain you'd be best stripping it all & cleaning. I'd guess you'll find worn tensioners and/or guides at the same time that could do with replacement

 

[CMF_Dave-G]

Many thanks AJ.

New upper tensioner costing £53 somat.

 

[CMF_MicraNut]

Dave-G WROTE:

"Hello everyone, I have just joined this evening. As with most newbies I guess - I searched about for answers then decided to ask questions from the well informed bods on here.<BR><BR>I'm active on a couple of Galaxy forums with the same username - but her indoors likes K11's as she hasn't been driving long and it's a car we don't have to worry too much about damaging. <BR><BR>Her superb 1.3 slx got written off a few days ago and I have struggled to find her a 5 door model in the area in a colour she likes. Anyway we settled on a 1 ltr to get her back on the road.<BR><BR>It had a rattle that I thought was an aux belt tensioner - I now know its a timing belt problem thanks to the forums I have searched and removing the belts. <BR><BR>It only rattles when cold - leading to me thinking it is only the top one from the posts I have read. The engine is otherwise very sweet running. <BR><BR>I'm tempted to only change the upper tensioner to see if that clears the rattle - could some tell me if that is feasible please and can it be done without removing the rocker cover?<BR><BR>TIA Dave <BR><BR>

Hi Dave,

I've just had my timing chain replaced and the top and bottom tensioners had to be replaced along with timing chain and new gear idler. Just replacing the top tensioner could be false economy.

A mechanic told me that just replacing the top tensioner could work for a while but once it beds-in the timing chain rattle could return. He also said that it is best to get all the required parts whilst the timing chain is stripped out. It will save you having to put it back together then undoing it again to replace the worn parts!

 

[CMF_nz_aj]

The top tensioner was the only badly worn component on the slugded up motor I pulled apart that had a bad timing chain rattle (shake a paint tin with a few bolts inside & you'd get an idea of the noise at idle). The plastic block was totally worn through (a good 10mm of wear) & the chain was in the process of wearing through the pressed metal saddle that holds the plastic block against the chain. Both guides & the lower tensioner only had ~1mm deep grooves worn in the plastic. The the oil supply to that centre bush was quite clogged but luckly it hadn't worn.

The top tensioner can be changed relatively easily, i.e. take the side plate off & unbolt the tensioner.
It doesn't require taking off all belts, the sump, lower cast chain cover, chains, guides and anything else that got in the way.

A complete set of chains, guides & tensioners is fairly expensive. If you're dong the job yourself & don't value your time too highly, I'd definitely do some inspection first.

 

[CMF_Dave-G]

Point noted micranut - and thanks for the input. I usually take what mechanics who have their hand out for money with a pinch of salt though mate.

I'll go with the top tensioner inspection first though as it's relatively cheap and quick, no trouble to just put the plate back afterwards. The other bits can be bought later if needed. The bolts in a tin sounds about right too.

If the plastic has totally worn through and is now wearing through the metal base I'd say that could be a prime cause of chain failure if it starts snagging chunks of metal off it.

 

[CMF_deNs]

Hmm, my micra's had a timing chain type rattle but only on startup. Got told back then that it could possibly be the tensioners. Might get someone more knowledgeable to check it out for me. If it were belt driven, I'd probably have a look myself but doesn't seem quite as easy with this Especially compared to say, a timing belt on a RWD 4A-GE

What's the life expectancy of the chain/tensioners, or more importantly, how often should they be changed?

---dens

 

[CMF_mipcar]

Hard question to answer. My car with 300,000 k's has never been touched.
I reckon it depends on how the car has been used and maintained. Lots of short runs might promote sludegey oil that blocks the flow to the chain.

Mychael

 

[CMF_Dave-G]

I don't suppose anyone could be precise as to how the oil is delivered to said tensioner/chain could they please? It'd give a better idea of what pipes or channels channels to thoroughly degunge or push through etc.

 

[CMF_deNs]

My LX has only done 125,000 but I just want to be absolutely sure. It still might need some stuff replaced, but inspected by someone who knows their stuff first

---dens

 

[CMF_Dave-G]

Well 'er indoors just got in with the new tensioner assembly. It's spring tensioned rather than hydraulic - maybe that's the "update"?

The pack also has a red plastic thing in it which I at first assumed was some sort of setting device. Anyone know what it's for please?

I don't know if I can post multiple pics - if not please forgive me foe makeng several posts to let you see them

 

[CMF_Dave-G]

and this

 

[CMF_Dave-G]

another

 

[CMF_Dave-G]

and again

 

[CMF_Dave-G]

there more

 

[CMF_Dave-G]

there we go

 

[CMF_Dave-G]

Looks like there was at one time some sort of hydraulic action that has been capped off - at the top.

 

[CMF_MicraNut]

deNs WROTE:

"Hmm, my micra's had a timing chain type rattle but only on startup. Got told back then that it could possibly be the tensioners. Might get someone more knowledgeable to check it out for me. If it were belt driven, I'd probably have a look myself but doesn't seem quite as easy with this Especially compared to say, a timing belt on a RWD 4A-GE <BR><BR>What's the life expectancy of the chain/tensioners, or more importantly, how often <EM>should</EM> they be changed?<BR><BR>---dens

Nissan say that the timing chain and tensioners etc are to last the life of the engine.

 

[CMF_Dave-G]

I have had a bit more of a Google and found the item below which shows the tensioner piston much deeper into the cyliner of the tensioner body than my new one will go which is a bit worrying.

I aint no enginnering expert but the piston assembly seems to be much more complicated that is needed to be - unless the wierd ratchet looking thing in it is an adjustment device. There seems to be no way of keeping it to it's lower position while inserting it into the cylinder.

I also personnaly feel the reason the plastic (ptfe - I assume)gets worn down is because the spring rams the tensioner too hard against the chain.

http://www.carmechanicsmag.co.uk/cgi-bin/tftt.cgi?q=030603

In case the link does not work here is the picture

 

[CMF_nz_aj]

To keep tension the plastic has to be pushed against the chain. It's going to wear.

The only gunged up gallery & parts I recall cleaning was in the centre sprocket (the one shown in the photo in the post above).
To clean it means taking everything apart thou.

I would have sworn the top tensioner was hydraulic as well as having a spring. The back of the tensioner shown above has an oil passage in the back. Is what I have circled a drilling or something else?

I've still got a bag of bits somewhere, might try finding them tonight & getting some photos.

That red plastic thing looks like it's supposed to hold the tensioner retracted to make assembly easier. I would have held it retracted with my fingers or pliers.

On my Japanese made K11 motors the plastic the tensioners & guides are made of is black.

FYI, After reassembly, I cranked it several times with the spark plug leads disconnected to get oil pressure up before running it.

 

[CMF_Dave-G]

Aha - I see the pressurising hole now AJ, thanks.

There is another one that I have referred to as a breather - which probably lets the excess pressure escape whilst doubling up as a spray directly to the rear of the chain.

I too think the red plastic component holds the unit retracted - but the piston won't go fully into the cylinder no matter how hard I try to compress it against the spring tension. Those nibs in the small component that the spring sits in stop it from retracting. They could be a means of limiting how far it will retract when the oil pressure ceases when the engine is stopped.

I feel inclined to smooth them off a tad so the spring can be compressed - but I guess I ought to speak to nissan mechanic first - or at least see what the old one is like. I'd prefer to know how to compress it before I commence the work though.

 

[CMF_Dave-G]

I can't find my control panel to manage my attachments so here is an edited image of the earlier one that refers to the nibs which stop the tensioner from retracting. I can push and twist the nibbed component up inside the tube/piston freehand but it will not compress when inserted into it's cylinder because I can't twist it

 

[CMF_Dave-G]

Sorted now thanks guys. Someone on another forum put me right about the last cut out where the nibs are - I played about with it and it held in nicely.

The plastic retainer holds it in while you mount it - and releases the tension when you retract it. These online forums are absolutely brilliant - sooner or later you will always find some one who has or had the same problem.

 

[CMF_Dave-G]

This is the locking nib that holds the tensioner retracted till you release it. Twist and push the nibbed part against the spring pressure fully into the tensioner, then hold it in a clockwise position while slightly releasing pressure on it so that it springs out slightly and engages the retaining pin in the tensioner's tube. At this stage the nibbed part is virtually flush with the bottom of the tensioner with all nibs hidden by it.

The plastic part holds it slightly further down than this until it is removed.

 

[CMF_deNs]

I'll try and find out from nissan australia how much a new top tensioner is going to be, as I'm really starting to dislike the noise that it's making on cold idle now. If a new top tensioner doesn't fix it (hopefully should) then i'll just replace the entire chain.

---dens

 

[CMF_deNs]

Wow, got quoted less than I expected. My local nissan place just down the road from me doesn't have a parts department there anymore, but the parts place is now in Hallam.

Just called them up then. Was expecting like 150-200 for the tensioner. It'll cost $107. That's probably the next thing i'll do to the car, as it's high on the list of priorities. So yeah, shouldn't be any more than that for a genuine nissan upper tensioner

---dens

 

[CMF_nz_aj]

Fro $107 I'd be tempted to get some Nylatron or similar from a plastics supplier & cut it to shape.

 

[CMF_deNs]

Yeah would be nice to get something a bit more durable. If it'll last me another 100,000km I think i'll just use what I get and make sure that works first.

---dens

 

[CMF_deNs]

Paid AUD$91 for it (w/ discount ) and i'm hoping to try and get it in this weekend. If that's successful, i'll take some pics of how the other tensioner looks. Maybe a before/after video to show how it sounds now to how it should sound.

---dens

 

[smidge]

how'd ya score your discount??

my engines got 200ks on it and no signs of any signs or wear but i guess i should investigate it as i don't like the idea of it letting go

thanks for the pics guys very informative!

 

[CMF_deNs]

Uncle worked for nissan when they still had a factory pumping out cars down in melbourne.

I really hope it's a simple process of just relieving the tension off the chain, taking bolts out and putting new ones in then putting tension back on.

Can anyone who's done this shed some light on the process? I'll need to redo the seal on the cover once I come to putting it back on, i'll likely just use gasket goo.

---dens

 

[CMF_deNs]

Well I changed the tensioner over yesterday. Hasn't fixed it. Pretty annoyed about that actually. Sounds very slightly quieter on cold start, but I don't know if that's just me wanting me to hear it as quieter or not.

Some pics of the process and the wear on the original tensioner. I expected it to be a lot worse than it was. Odometer currently is 127,300KM.

The old tensioner before removal


The wear on the old tensioner


Another shot


Wear marks again


Pics of the new tensioner installed




There you have it.

---dens

 

[CMF_LWC]

The Izuzu 2L motor I had snapped a chain, bent some valves so I changed the timing chain & tensioner on (had the rachet action too).
I think as everything wears, it keeps the tension on the chain when it indexes onto the next rachet tooth without the chain being able to flap and push the tensioner piston back in.
(Ah, the days of aftermarket Holden prices for parts: 4 valves, VRS set, chain tensioner, chain, front cover gasket, rocker gasket = $219.00!!!)
Makes you green at Micra prices!!!

 

[CMF_deNs]

Well it seems the oil feed from behind it is supplying the pressure to keep it tensioned in addition to the spring that's inside it. It makes sense that it should keep it tensioned no matter how close it is to the metal.

What concerns me is that it could be the entire chain that's needing replacement, not just the tensioner. I don't want to even consider the cost of replacing that.

---dens

 

[CMF_Yom]

Its not your top chain which looks like its been stretched if the tensioner position is anything to go by.

Probably your lower tensioner causing the problems here.

 

[CMF_deNs]

Just found this on eBay UK after seeing it mentioned in a thread. One guy's bought one but i'm unsure of how well that went.

I'm scared to find out how much a lower chain or tensioner is going to be from nissan aus.

---dens