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        General >> Give/Need advice to/from others >> 24V Timing Chain Tensioning
        
(Message started by: John Dickinson on May 11^th, 2010, 12:39pm)

Title: 24V Timing Chain Tensioning
Post by John Dickinson on May 11^th, 2010, 12:39pm

Can anyone explain the apparent failure of my timing chain tensioning system. I was aware of a very slight rattle which I thought was a loose heatshield which I had experienced on a previous occasion. As it had worsened I decided to take a closer look and found the noise to be coming from top LH side of the engine. This was yesterday, and appears to have spread to the RH side today. I'm fearing the worst and preparing to de-commission the car as I am not prepared to spend the relatively vast sums I suspect will be needed for repair. Annoying really as in all other respects it runs well.

Title: Re: 24V Timing Chain Tensioning
Post by Highlander on May 11^th, 2010, 12:56pm

Hi John,

the RH tensioner was revised early in 1997 due to this problem.

The oilways get blocked and the tensioner fails, the chain guides then get worn or broken off completely which sounds like what has happened to yours?

http://www.fordscorpio.co.uk/timingchain29.htm

It can be repaired but as you said, the price of the parts is excessive compared to the likely value of the car.

Cheapest and easiest fix is fitting a second hand engine.

Title: Re: 24V Timing Chain Tensioning
Post by Matt on May 11^th, 2010, 1:04pm

if its just a rattle on start up then dont worry about it, pretty much all 24v's do is due to a badly designed chain tensioner, essentially the oil drains out of them when the engine has been turned off for a while, worst when cold starting but should not last longer then a few seconds,

if it lasts longer then you may have

1. wrong grading of oil, low oil or wrong type of oil
2. worn oil pump
3. the worst one , failure of the chain guides which is known on these engines,

first thing i would do it get then engine warmed up then drain the oil into a container, then once all the oil is drained allow the drained oil to stand for a hour then have a feel at the bottom of the container for any bits

if none first refill the engine with a cheap oil, again run the engine till hot then drain that oil off, replace the oil filter then refill using a good quality fully synth oil, i always use 0w-40, its about £50 but does the job

Title: Re: 24V Timing Chain Tensioning
Post by John Dickinson on May 11^th, 2010, 1:35pm

I had the start-up rattle not long after first getting the car which was initially cured with a new device (behind the alternator) not actually the tensioner as I understand it. The start-up rattle returned but after reading an article on them, stopped using additives with oil changes and have never had this issue since. This time the noise started firstly on the LH side, today spreading to the right. I've had no oil pressure warnings, oil level is OK and was last changed with filter about three months ago. I've resigned myself to losing the car but just trying to understand what happened. Seems most likely to be an oil supply problem as suggested and likely that the damage is already done.

Title: Re: 24V Timing Chain Tensioning
Post by Matt on May 11^th, 2010, 1:40pm

on the off chance

drop both of the drive belts off the front and run the engine for a few moments, may be a failed belt tensioner

Title: Re: 24V Timing Chain Tensioning
Post by John Dickinson on May 11^th, 2010, 2:09pm

Matt, Thanks for the suggestion but tried that yesterday after going into clutching at straws mode. Unfortunately that wasn't the problem.

Title: Re: 24V Timing Chain Tensioning
Post by Highlander on May 11^th, 2010, 2:12pm

John, is the rattle just at start up or is it constant?

Title: Re: 24V Timing Chain Tensioning
Post by John Dickinson on May 11^th, 2010, 2:32pm

Unfortunately Highlander it's constant, not a regular sound but always present.

Title: Re: 24V Timing Chain Tensioning
Post by Highlander on May 11^th, 2010, 2:37pm

If you press the throttle to the floor and then turn the engine over do you still hear it?

If it detects WOT (Wide Open Throttle) the engine SHOULD just crank over and not start BUT we have heard of an occasion where it DID start, be ready for it just in case it does as it will be rather noisy ;D

Title: Re: 24V Timing Chain Tensioning
Post by a900one on May 11^th, 2010, 7:01pm

I have been having problems with the death rattle as well, did it on most startups. Changed oil to 10-60, expencive but seems worth it, as 80% of rattle has now gone. Have tried taking revs up to 2000 just before turning off, hoping that the extra pressure takes the slack out of the chains. WOT starting, make sure you push hard on throttle as mine has started using this method. Ps. engine sounds very sweet now.

Title: Re: 24V Timing Chain Tensioning
Post by John Dickinson on May 11^th, 2010, 9:05pm

Highlander, will have to try the cranking test but is there any other way of inhibiting the start other than WOT. I don't fancy it starting with high revs considering how it sounds at idle.

Can you tell me what your line of thought is with regard to this test?

Title: Re: 24V Timing Chain Tensioning
Post by tonyboy on May 11^th, 2010, 11:09pm

Or you could try parking your car on a kerb over night so one side is higher than the other. Not sure which side but i think it's the passenger side thats higher.............

Title: Re: 24V Timing Chain Tensioning
Post by tlundkvi on May 12^th, 2010, 6:47am

Anyway, it's probably worth to get the tensioners while one still can. £50 + delivery is the price for the kit (plungers and valves) here: http://www.burtonpower.com/Default.aspx

The large guides are also for sale for £20 a piece.

Title: Re: 24V Timing Chain Tensioning
Post by John Dickinson on May 12^th, 2010, 7:33am

In a previous life I would probably have had the engine out and in bits by now but the deterrent now is the size of the job.

Start-up rattle has been mentioned by a couple of members but that is not the issue.....if only it were. I have experienced this in the past and I mentioned my thoughts in a previous post.

I'm now convinced the tensioning system has failed big time and as well as replacing the bits the cause of the failure would need to be determined as well. I'd hate to make a repair only to have it fail again. Failing a miracle I think it may be time for the Scorps retirement but I can't quite believe it's come to that yet. I'm trying to convince myself it's only a car.

Title: Re: 24V Timing Chain Tensioning
Post by Dave2302 on May 12^th, 2010, 9:31am

If you can be bothered, get the spanners out and pull the sump and front cover.

Most BOB engines with a rattle can be fixed for less than 100 quid, if you do the work yourself.

The one way valve in the tensioners often sticks causing this problem, these can be fixed without taking off the front cover, they are the bits that bolt on externally, need a very thorough clean and working in and out until they are spotless and moving freely.

HTH Dave

Title: Re: 24V Timing Chain Tensioning
Post by a900one on May 12^th, 2010, 6:23pm

Its the front drivers side corner that needs to be lower than the rest of the car. Tonyboy.

Title: Re: 24V Timing Chain Tensioning
Post by martin_rowe on May 13^th, 2010, 3:50pm

if you've got the rattle, then the only fix is to replace the worn out parts, some of which arent available any more. the sump will have to come off as well there will be bits of broken ttensioner & guides stuck in the strainer.

Title: Re: 24V Timing Chain Tensioning
Post by faffi on May 17^th, 2010, 9:49pm

Is there something one can do to reduce the chance of these failures/issues? I have seen many Cosworths in Germany with engine damage due to thrown cam chains, but it isn't a typical problem in cars here in Norway. This leads me to believe that high rpm use, particularly over time, is the main culprit for these problems, although it could also be hard use from cold, something the Germans are infamous for due to their high-speed Autobahns.

Title: Re: 24V Timing Chain Tensioning
Post by tlundkvi on May 18^th, 2010, 7:48am

I agree with you on that.

Some thoughts (and I may be wrong too). Germany has a huge export of older premium cars particularly to eastern Europe. Be at the border between Poland and Germany along the Potsdam-Poznan and one will see. If a workshop rate in Germany is 90€ and 15€ in eastern Europe, cars with major flaws which can be repaired, albeit with huge work effort are attractive to sell complete "Export Only". I think Autobahn is one reason for cam chain/belt damages (snap at 5k rpm etc. and nowhere to stop), but I also think mobile.de is flooded with improperly flagged "scrap" cars (search for a 10 year old car and look at the cheapest 20%), which in many other countries would have been towed to a breaker straight away. This does give the illusion cam chain/belt failures are very common (which they probably are), but they are brought to "daylight" perhaps more often. I am not saying German sold cars are worse than others, most of the ads are pretty upfront with all known problems, and theres a lot to choose from.

But e.g. Germany has winter too, and in the Nordic countries almost everybody uses block heaters, speed limits are low, distances may be longer allowing the car to slowly heat up etc. That surely affects engine life.

Title: Re: 24V Timing Chain Tensioning
Post by martin_rowe on May 18^th, 2010, 8:46am

leaving the engine idling seems to be detrimental, low oil pressure, the chains whipping about, causes havoc.

Title: Re: 24V Timing Chain Tensioning
Post by 5stud on May 18^th, 2010, 10:33am

can you revert to boa duplex set up ?.why did ford change.maybe cost.ive never heard of a boa duplex letting go but prove me wrong.same ase the fiesta-escort 1600diesel.changed to belts on the 1800.spent the next ten years trying to sort the problems out and failed then went back to the 1600 way

Title: Re: 24V Timing Chain Tensioning
Post by faffi on May 18^th, 2010, 10:46am

So I take it the engine use a simplex chain, then?

As to duplex chains failing - it did on me mate's Mercedes 230. Or rather, it was saved at the brink of disaster, but he needed a new chain, spanner, slider and camshafts IIRC (I believe the sprockets are carved into the camshafts and not seprately replaceable - and they were completely worn out).

Looking at motorcycles, which almost always use a single chain design, single chains seems to be sufficient. And these rev up to 20,000 rpm for small engines and over 14,000 for some of the litre bikes with really radical valve lifts and hence stiff valve springs (which is what cause the majority of the strain).

Belts are a PITA. I just replaced the belts on my son's Ducati Monster. Having to do this every 12,000 miles or 2 years (whatever comes first) seems silly when single row chains often last as long as the rest of the engine.

Title: Re: 24V Timing Chain Tensioning
Post by a900one on May 19^th, 2010, 6:37pm

I think Martin has a point, with the tic over, I rev mine to 2000 when is starts and then keep the revs below 2500 untill hot. I now rev to 2000 when I turn it off, it may keep tension in the chains. Mine has the updated tensioner and it still rattles a small bit, 10-60 oil has cut the time on startup by alot.