Omega Owners Forum

Chat Area => General Car Chat => Topic started by: raywilb on 06 April 2016, 11:15:49

Title: timing chain longevity
Post by: raywilb on 06 April 2016, 11:15:49
how long is the life of timing chains. my window cleaner has just rang me asking if I know of any cheap motors for sale. apparently his Astra car has broken down with a snapped timing chain. he cannot even change a bulb so was not aware of what had happened so kept trying to start it. but the call made me think what can I do so I'm never in that situation. if anything ? :-\
Title: Re: timing chain longevity
Post by: Marks DTM Calib on 06 April 2016, 11:25:19
Which engine did he have.

Timing chain life is very dependent on design and how well serviced they are
Title: Re: timing chain longevity
Post by: tunnie on 06 April 2016, 11:25:35
Regular oil changes, neglecting the oil, letting it clog up and reduce the lubrication it what kills them I hear, as a tiny drip of oil lubes the chain.

I suspect your window cleaners Astra had 20k oil changes all it's life, maybe worse.
Title: Re: timing chain longevity
Post by: raywilb on 06 April 2016, 11:34:17
Regular oil changes, neglecting the oil, letting it clog up and reduce the lubrication it what kills them I hear, as a tiny drip of oil lubes the chain.

I suspect your window cleaners Astra had 20k oil changes all it's life, maybe worse.
  he starts it on a morning & that's it. I'm always telling him to get the gear for a service and I,d do it for him. he never has.
Title: Re: timing chain longevity
Post by: Nick W on 06 April 2016, 11:49:45
Regular oil changes, neglecting the oil, letting it clog up and reduce the lubrication it what kills them I hear, as a tiny drip of oil lubes the chain.


Chains in crankcases don't need much(if any) extra fed lubrication, but a good supply of pressurised oil to the hydraulic tensioner is critical for it to work, let alone be durable. Once the tensioner stops working as designed bad things happen.
Title: Re: timing chain longevity
Post by: Bigron on 06 April 2016, 11:55:32
I've commented before, so I won't go into detail, but if you are interested, look up how the Morris Minor/Austin A30 engines (BMC A series) used to do it - perfect!

Ron.
Title: Re: timing chain longevity
Post by: Varche on 06 April 2016, 12:57:34
I was talking to quite an educated person(woman) and she forgot to service her car (Land Rover discovery) for FIVE years.
Title: Re: timing chain longevity
Post by: Nick W on 06 April 2016, 14:53:29
I've commented before, so I won't go into detail, but if you are interested, look up how the Morris Minor/Austin A30 engines (BMC A series) used to do it - perfect!

Ron.


A rubber coated flap is only going to be of 'use' when the chain is on an OHV engine and very short. And A/B series never have noisy timing chains do they? Better OHV engines have hydraulic tensioner; just look at any of the  Rootes 4s.
Title: Re: timing chain longevity
Post by: Bigron on 06 April 2016, 15:19:47
Yes Nick, I agree. After I posted that, I Googled the Minor engine and saw the silly tensioner you are referring to, but that differs from my memory of an A30 engine I had in which the Reynolds tensioner was a neoprene slipper arrangement force-lubricated via a centre hole. The pumped oil also tensioned the slipper by putting pressure on a piston that forced the slipper into firm contact with the chain.
That piston had a notched, spiral groove in it to prevent its return by more than a small amount, thus ensuring permanent contact, and as wear took place it notched around one more step.
Now, I didn't imagine all of the above, but I cannot find details anywhere on Google - am I going mad or can any Oofer confirm (NOT the madness, the description!)?

Ron.
Title: Re: timing chain longevity
Post by: Viral_Jim on 06 April 2016, 15:40:58
how long is the life of timing chains. my window cleaner has just rang me asking if I know of any cheap motors for sale. apparently his Astra car has broken down with a snapped timing chain. he cannot even change a bulb so was not aware of what had happened so kept trying to start it. but the call made me think what can I do so I'm never in that situation. if anything ? :-\

I ran saabs before moving to the mig. Their Achilles heel was oil starvation caused by problems with the breathers. That said, if correctly serviced the chains had a very long life - I'm given to understand that 200-250k was usual on the 2.3T engines. Certainly the last one I had (bought at 160k sold at about 190k) showed no signs of chain wear.

In short, change your oil regularly and listen for any rattle from the chain - particularly on a cold start. Also, a bit of googling will highlight if a particular car model has issues. For example I think some of the Jag v8's from around  1997-2000 had plastic chain tensioner/guide parts that could fail and a number have been replaced under warranty.
Title: Re: timing chain longevity
Post by: ronnyd on 06 April 2016, 17:22:54
Couple i used to work with both ran cars and neither realised that they, the cars that is, were fitted with a dipstick. ;D
Title: Re: timing chain longevity
Post by: omega2018 on 07 April 2016, 22:22:04
timing chains are pretty strong it will take a lot to destroy one but they do 'stretch' with age and wear - the links don't actually stretch but wear the causes the chain to get longer as the links get further apart, causing timing issues - cam timing gets retarded.
Title: Re: timing chain longevity
Post by: Viral_Jim on 07 April 2016, 22:49:50
Oo, that reminds me, any Saab/GM 2.8T (looking at you M'lud Opti) can suffer stretched chaos screwing the timing.

Lots of info on the insignia vxr fora about it.
Title: Re: timing chain longevity
Post by: Broomies Mate on 07 April 2016, 22:53:50
Oo, that reminds me, any Saab/GM 2.8T (looking at you M'lud Opti) can suffer stretched chaos screwing the timing.

Lots of info on the insignia vxr fora about it.

Good advice for the VX crew - I believe from UKS it wasn't an issue on the Saab after they revised the guide setup.  :y
Title: Re: timing chain longevity
Post by: Viral_Jim on 07 April 2016, 23:14:08
Ah, good knowledge! I only vaguely know about the 2.8T, 2.3T is my power plant of choice, but only because of the car it gets attached to.

Once again GM taking a Saab idea and making it worse :P.
Title: Re: timing chain longevity
Post by: krabi_one on 09 April 2016, 15:09:39
Guys i got as well Saab 93 2.0t that one with 175hp .
i bought it with 179 000 miles and now is 189 000 and there is no sound of chain rattle at all, but Im changing oil every 5k,
I am so surprise how that engine sound, nothing like that mileage, just so healthy  (  got small oil leak but I'm waiting till summer for proper cleaning and servicing the small leak )
Title: Re: timing chain longevity
Post by: Broomies Mate on 09 April 2016, 16:48:03
Guys i got as well Saab 93 2.0t that one with 175hp .
i bought it with 179 000 miles and now is 189 000 and there is no sound of chain rattle at all, but Im changing oil every 5k,
I am so surprise how that engine sound, nothing like that mileage, just so healthy  (  got small oil leak but I'm waiting till summer for proper cleaning and servicing the small leak )

Oil at the back of the engine?  If so, probably Oil Pressure Switch.  Cheap part to buy, bit of a bugger to fit without a ramp as space is limited around the back.  My local Saab specialist charged £60 for the part including fitting.