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        General >> Give/Need advice to/from others >> Chain rattle fixing
        
(Message started by: Octavian_P on Nov 25th, 2005, 12:18pm)
Title: Chain rattle fixing
Post by Octavian_P on Nov 25th, 2005, 12:18pm
Hello to all

I do not have a 2.9 cossie powerd scorp but reading the confidential list have found a memeber posting some ways of "pre-tensioning" the chain guides. Doing a lot o www-ing found this

"An alternative to engine additives: pre-pressurisation"

http://www.autoenginelube.com/pages/903473/index.htm

or

http://www.pre-luber.com/

These products store oil under pressure or have a electric pump. When activated it creates oil pressure in the system and also prevents cold starts and dry starts. These kits also reduce engine wear, make turn easier etc.

I think this could help a lot of cossies out there, and a lot of other scorps, i myself think of buying one for my 2.3, just to avoid rough starts, cold starts etc.
Title: Re: Chain rattle fixing
Post by Baz on Nov 25th, 2005, 8:09pm
I always always always turn the key with my foot hard down on the accelerator until the oil pressure light goes out. Never had any rattle in either Cossie I had because doing this does pre presurise the system and flows oil around the system without trurning the chains.

Plus having an oil change every 5-6000 miles and using magnatec works wonders too!!

Baz
Title: Re: Chain rattle fixing
Post by Octavian_P on Nov 25th, 2005, 10:56pm
[] Changing oil is good but did you know that when the engine sat for a few days ( all the oil went back) when you start it it's like doing 400 miles with it.
Title: Re: Chain rattle fixing
Post by ricky on Nov 26th, 2005, 7:06pm
baz , sorry but how dos pressing the throttle down stop the chains from turning and how dos it pressurize the system , rick
Title: Re: Chain rattle fixing
Post by Snoopy on Nov 27th, 2005, 11:47am
Because the engine does not start with the throttle fully open.. and therefore presurises the system.. When you release the accelerator pedal and start normally the oil ways have already been filled and hence no chain rattle>
Title: Re: Chain rattle fixing
Post by Baz on Nov 27th, 2005, 11:35pm
Thanks for that Dave, you beat me to it!!
Title: Re: Chain rattle fixing
Post by brewer on Dec 9th, 2005, 6:17pm
But the engine turns all the same!It simply doesn't fire up.
Title: Re: Chain rattle fixing
Post by david_molloy on Dec 13th, 2005, 7:31pm
Yes - but I think the theory is that it is turning a lot slower than tickover so chains don't flap about as much. Once tensioners pumped up no slack no rattle.
Similar to precharging oil filter.
Call me a boring old fart but whenever I,ve changed my Sierra oil filter I always disconnect coil HT and crank until oil warning light goes out then reconnect & start. Never had electric problem doing so.
Just don't like idea of plain bearings operating with no oil pressure.
As I'm a new Scorpio owner don't have any experience with 24V but flooring pedal appears to do same job as above & I will do it every filter change.
Well that's my take on the matter
david
Title: Re: Chain rattle fixing
Post by howiedintheplace on Dec 13th, 2005, 8:07pm
If your chain rattles on start-up then damage is occuring, that's what the noise is, so if you can stop the noise/damage by building the oil pressure up before it starts then I would think it is a good idea.
Best fix is the pre-lube system but the foot to the floor is also good as it will do the same job with very little if any damage to the guides/chains which is the parts that are being damaged when it rattles.
Some cars go for years with a start up rattle others die soon after. It is the way it goes. >:(
Title: Re: Chain rattle fixing
Post by SaveTheNight on Dec 13th, 2005, 10:25pm
familiarity breeds contempt though guys .. If it looks like a duck ..and walks like a duck ..and quacks like a duck .. then it definitely is a duck ! ....
... if there's a rattle it really is worn and should be sorted ... much as we all would like to think it will be ok ... just my view though ... STN
Title: Re: Chain rattle fixing
Post by david_molloy on Dec 13th, 2005, 10:56pm
Hello
Has anyone fit one of the pre-lubers refered to by Octavian.
The pressure vessel type looks tempting.
david
Title: Re: Chain rattle fixing
Post by SaveTheNight on Dec 13th, 2005, 11:05pm
We use them on race engines and they are very effective .. Vlad Soare on the site here has one fitted but we haven't seen him for a while ? .. but they WILL disguise the problem and it does add another possible problem.. at the take off from the oil pressure switch ..if a bad fitting was made there then the resultant quick oil loss would probably be terminal ... STN
Title: Re: Chain rattle fixing
Post by howiedintheplace on Dec 14th, 2005, 12:59am
Hmmm well if you have the rattle it is a problem, it is not normal for the engine, not a " oh they all do that sir dealer quote :-X"
I have took engines apart that have rattled on start-up for say 3 seconds that don't appear to be too badley damaged. It all depends on how long yours has been rattling (days/years?) & how well you have looked after the engine I reckon.

3 causes of the rattle:
Guides breaking up or badley worn so tensioner can not tension = strip & fit new.
Tensioner worn or partially cloged = fit new tensioner, pre-lube, change oil & use a flush, foot down method?
Chain stretch/worn = Renew

Problem is you won't know which one it is unless you strip the area, a pre-lube system for example is only going to help in one area & then it's not a fix but simply helps but will help to mask all the problems in their early stages, this will give you more miles.

Of course Scorpio's are getting to the stage in there life that you have to weigh up the cost of repairs so it is up to you what to do. A Scorpio could last years with a start-up rattle, or days if it is say the guides breaking up.

So for this reason I think pre-lube & the foot down method is both good ideas to get a few extra miles out of your 24V. Indeed it's possible they could help to prevent the problem but only where the tensioner itself is concerned.

& as STN pointed out the pre lube has to be fitted to a high standard as a major oil loss at say 4000 rpm on the motorway would destroy your engine before you could stop on the hard shoulder. Seen it before ;)

Well that's my view on it all.

To sum up.
Pre-lubes are good for new engines as most wear takes place upon start-up before the oil pressure has built up, an old engine will already have the wear but I guess it will help. If you already have a rattle then it's to late really.

I think this thread is prevention more than cure for the rattle, so I hope I have not waffled on too much ;D
Title: Re: Chain rattle fixing
Post by Highlander on Dec 14th, 2005, 12:50pm
Someone on the mailing list suggested  the oil pump sprocket teeth can wear quickly as the chain has a low contact area with the sprocket and could jump over the teeth especially when starting from cold with the added resistance of cold/thick oil.
Would this also sound like a chain rattle until the pump got moving?
Title: Re: Chain rattle fixing
Post by Pegasus on Dec 14th, 2005, 8:53pm
Hi,

excellent advice on this issue but can you clarify 1 thing for me:

When you've got the throttle on the floor do you turn the ignition to position II or position III?  :-/

What is the exact sequence for starting up when using this procedure?

TIA,

Paul
Title: Re: Chain rattle fixing
Post by Paul B on Dec 14th, 2005, 9:06pm
I think its position III Paul.

I did this once before, and the fricking thing actually started!  :o   Not good

Never attempted it again  :-[
Title: Re: Chain rattle fixing
Post by Pegasus on Dec 14th, 2005, 9:15pm
Hi Paul,
that's what I'm afraid off - can't be good for the engine when this happens
:'(
Title: Re: Chain rattle fixing
Post by Highlander on Dec 14th, 2005, 9:23pm
Shouldnt start on Wide Open Throttle, must be something wrong somewhere.

I press throttle to the floor and hold it there while I turn the engine over.
Title: Re: Chain rattle fixing
Post by SaveTheNight on Dec 14th, 2005, 10:23pm
Hi Paul .. as Highlander quite rightly says it's possible that the WOT relay is playing up but that's very unlikely ..more likely is that there is a natural inbuilt reluctance to floor the pedal whilst cranking over .. and we DO mean floor it !! ..even the carpet ruffled can prevent that extra bit required . .. I have actually told peope to do this before in fuel flooding conditions < which is what it's designed for > ..and for them to report that the car started .. after checking myself in front of them they reply " oh THAT far "  ... so ... ie: FULL TO THE FLOOR HARD ..  regards ....STN
Title: Re: Chain rattle fixing
Post by Highlander on Dec 14th, 2005, 10:34pm

on 12/14/05 at 22:23:45, SaveTheNight wrote:
ie: FULL TO THE FLOOR HARD


I also use this technique just as im about to be passed by a Golf GTI  ;D
Title: Re: Chain rattle fixing
Post by Dave on Dec 15th, 2005, 9:58am
I did it once too, but again don't think I pushed it down hard enough, just managed to get off it as it fired up and got about 2500 rpm. Phew  ;D
Title: Re: Chain rattle fixing
Post by howiedintheplace on Dec 15th, 2005, 8:27pm

on 12/14/05 at 12:50:26, Highlander wrote:
Someone on the mailing list suggested  the oil pump sprocket teeth can wear quickly as the chain has a low contact area with the sprocket and could jump over the teeth especially when starting from cold with the added resistance of cold/thick oil.
Would this also sound like a chain rattle until the pump got moving?


Hmm don't think that it is a problem at all, that sprocket has a very easy job with little resistance & from what I have seen is the least worn sprocket.

http://i20.photobucket.com/albums/b228/DavidHoward/Scorpio/th_BOB041.jpg (http://i20.photobucket.com/albums/b228/DavidHoward/Scorpio/BOB041.jpg)

My current ideas on this problem is that the anti return valve on the tensioners gets blocked slightly with crap/caked on oil. This lets the tensioner drain of oil as the valve don't seal correctly.
When you come to start the car the tensioners do not apply any force on the guides so the chain flaps around which causes the noise. As soon as the oil pressure builds up the tensioner does it's job & the noise stops.
The colder it is the longer the engine takes to build up the pressure hence the rattle gets worse in the cold.

While it rattles damage is being caused to the chain, cogs & the guides, eventually this will kill your engine.

Regular oil changes will help stop this.

I have found that a complete strip of the tensioner, a good soak in degreaser & the rattle has gone.

Also some people use instant gastet on the areas where oil flows which also bunges up the tensioners.
Also it's important to use the propa gasket for the tensioners.
Possible the tensioner gets worn as well & oil simply forces it's way past but I have yet to come across it.

You can see the valves below.

http://i20.photobucket.com/albums/b228/DavidHoward/Scorpio/th_BOB040.jpg (http://i20.photobucket.com/albums/b228/DavidHoward/Scorpio/BOB040.jpg)http://i20.photobucket.com/albums/b228/DavidHoward/Scorpio/th_BOB039.jpg (http://i20.photobucket.com/albums/b228/DavidHoward/Scorpio/BOB039.jpg)

These are only my views but it works for me ;)
Title: Re: Chain rattle fixing
Post by Pegasus on Dec 15th, 2005, 9:52pm
Hi there,
following all advice - just tried it - pressing so hard on throttle its lifting me out of seat.

It cranked for a second then BAM - its hit 4000 rpm  :o  :o  :o before I can get the foot off the pedal. Engine screamed and lots of bad smelling smoke out back. Happened so fast can't tell if oil light went out before firing up.  :-/

Don't think  I could have pressed any harder. Not sure if I want to try it again as dont want to risk damage to a beautifully running engine  :'(

Have I missed something? How long does it normally take before the oil light goes out?

Paul
Title: Re: Chain rattle fixing
Post by SaveTheNight on Dec 16th, 2005, 12:13am
er .... NO  ..don't try again ! .. it's not working ... STN
Title: Re: Chain rattle fixing
Post by Paul B on Dec 16th, 2005, 6:54am

Paul, that's exactly what happened the time I tried it.  :o
Title: Re: Chain rattle fixing
Post by Dave on Dec 16th, 2005, 11:15am
Ouch  :o
Title: Re: Chain rattle fixing
Post by Wafoo on Dec 16th, 2005, 8:07pm
Works fine on mine,foot on accelerator,crank engine,doesn't fire,release pedal,start as normal no rattle.
Title: Re: Chain rattle fixing
Post by Highlander on Dec 16th, 2005, 9:49pm
Theres a very small margin in the pedal position between starting and not starting, I had a little try earlier to see the difference
Title: Re: Chain rattle fixing
Post by Paul B on Dec 19th, 2005, 1:10pm
Going back to chains, sprockets and damage.... can one of those who know tell me how badly worn this looks?  

Or is it too difficult to tell from a photo?   :-/




http://img.photobucket.com/albums/v465/PCBoulton/Sprockets.jpg
Title: Re: Chain rattle fixing
Post by martin_rowe on Dec 19th, 2005, 1:17pm
no major signs of wear there, look for wear on the plastic guides where the chain rubs.
Title: Re: Chain rattle fixing
Post by Paul B on Dec 22nd, 2005, 10:19pm
OK, I'm going to be going deeper soon (into the engine I mean) and I think I need a part. Well, its a tool really.
The thing I'm after is a crankshaft locking tool. Those of you who've done this job will know what I mean I'm sure. Can I borrow/buy one from someone?  :-/
Title: Re: Chain rattle fixing
Post by howiedintheplace on Dec 24th, 2005, 12:43am
Paul you can do it with out it.

What you doing then changing the timming gear?

If so you need a puller for the crank pulley.

You can't really tell much from pictures why do you think there is a problem.
Title: Re: Chain rattle fixing
Post by Paul B on Dec 24th, 2005, 1:35pm
I've been getting a rattle on start-up for some time and its been getting progressivlely worse. Last couple of times I started her up, it was really rather bad  :-[

The engine has only done 74,000 miles (I think) but, having taken a few things apart, I can see that someone has already been there in the past  >:(

All new chains, sprockets, guides and tensioners have been bought, but I don't have these odd couple of tools.

Mind you, I think I may have overlooked something... I've got the 4 new camshaft sprockets and the crankshaft sprocket too, but I don't have that one from the middle. Is that the oil pump one which everyone keeps mentioning?  ???
Title: Re: Chain rattle fixing
Post by howiedintheplace on Dec 24th, 2005, 6:40pm
Yeah the oil pump is the middle one.
It should be fine but if yours has been rattling a while then it could be worn as it only really seams to wear when the chains are not tensioned correctly.

You can use one of these for the pulley

http://img.photobucket.com/albums/v487/seanyh/c524992f.jpg

From Halfords.
Title: Re: Chain rattle fixing
Post by Paul B on Dec 24th, 2005, 9:52pm
Ah, lovely. Cheers for that.

What else could I use to lock up the crank?
Title: Re: Chain rattle fixing
Post by VladSoare on Dec 29th, 2005, 9:53am

Quote:
Hello
Has anyone fit one of the pre-lubers refered to by Octavian.


Quote:
Vlad Soare on the site here has one fitted but we haven't seen him for a while ? ..

Here I am.  ;D
I have the first one, the one from AutoEngineLube.com. It works as advertised and does a very good job at reducing the rattle. The problem is that the tensioner needs a lot of oil to get pressurized, and I believe the oil tank is not big enough for this task. After all, the system has been designed just to fill the engine with oil, not to pump up a badly designed tensioner. :) I believe the rattle would disappear completely if only the system were able to maintain the pressure a few seconds longer.
That's why next spring I'm going to try the other system, with an electrical pump. Unfortunately, my engine must be already damaged to a certain degree, so I'll have to replace chains, guides and everything else. Installing an electrical pump at this moment would only hide the problem, not solve it. But if I replace everything and then install an electrical pump, I'm pretty sure that the rattle will never come back and there will be no more damage.
Title: Re: Chain rattle fixing
Post by Pegasus on Dec 29th, 2005, 8:58pm

on 12/15/05 at 21:52:51, Pegasus wrote:
It cranked for a second then BAM - its hit 4000 rpm  :o  :o  :o before I can get the foot off the pedal. Engine screamed and lots of bad smelling smoke out back. Happened so fast can't tell if oil light went out before firing up.  :-/


Ever since this happened the 1 second rattle has disappeared  :-/  :-/  :-/ when I just start up as normal - not sure why.

Definately not recommending this (blasting at 4000 revs) as a method of reducing rattle - just reporting experience since trying.

Paul
Title: Re: Chain rattle fixing
Post by howiedintheplace on Dec 29th, 2005, 9:14pm
Well I am doing 3 things to my new BOB engine build to help this.

Firstly all new gear is fitted.

1
Modded oil pump to give 60 psi of oil pressure within 2 secs of starter motor engaging.
2
Replaced tensioner springs with harder ones & increased tension of left tensioner when engine is not running for even tension up on start-up
3
Fitted a oil spray to spray oil onto the chains.

Another idea was to have more hard wearing guides made but don't think I need it now.

If this fails, I am going to fit the BOA timming gear >:(
As it seems more reliable.


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