An expesive day

My 2010 Toyota Corolla 1.8 litre has a cam chain with spring-loaded tensioner. Toyota does not schedule any maintenance on either. They are rated to last the lifetime of the engine -- an expected 200,000 miles. Many seem to go longer than that to 250,000 miles. Not many people do more than that in a car before all the plastic and rubber bits fall apart, regardless of how good the engine and gearbox may still be. Which is good because to replace the chain (or fix an oil leak in its cover) you have to pull the engine out. Mucho moneys.

Just about every Japanese motorcycle made since the 1960s has chain driven cams and they seem to run for phenomenal mileages without problems. Only BMW has managed to fit cam chain tensioners that wear or break early -- and you have to split the engine crankcases to replace the tensioner blades. Doh!

I think the appeal of wet timing belts includes quieter running to help get past noise laws, and less friction to help get past fuel economy laws. Every little bit counts. Can't see any other reason they would go away from the dead simple external belt method which yes it needed changed every 60,000 miles but in most cases it was not a huge job, albeit a bit awkward between the end of the engine and the wheel well on smaller bodied cars.

But if you Google Ford Ecoboost Timing Belt Problem, the tales of woe are legion. Would make me think twice about keeping it after repair.

You can buy the timing tools for <£100, but that doesn't include the torque multiplier for the crank bolt. It's a job I really wouldn't want to do without a lift. Ford took over a week to deliver half the ordered(in advance) parts when ours was done last year.

Many mechanics suggest it saves time to remove the engine on Fiestas.

A properly designed timing chain isn't noisy until the rest of the engine is so knackered you'd be rebuilding the whole thing. Jag 6s and Rootes 4s are good examples. But they have tensioners; Rover V8s and A&B series don't, and exhibit noise and wear as a result.

I'll be getting rid of the Focus at the first opportunity, but my mother(it was her car) and sister have managed to damage every panel lower than the bonnet so the value is badly affected.

One thing we haven't mentioned in all the nostalgia is that cams do work harder than they used to, driving more valves, through oil driven VVT mechanisms, often at higher speed into high compression cylinders. And that's without considering the high pressure fuel pump for the direct injection.

Edited By Nick Wheeler on 15/06/2023 08:34:23

Don't worry. All such concerns will be a thing of the past when we are all driving electric cars.

(Runs away...............)

Funny you should say that...
Earlier this year I paid several hundred pounds to sort out a blocked strainer in the electrical coolant circuit of my Plug-in Hybrid. Caused by gel formation causing blockage. Needed acid flush and a right pain to bleed apparently. No recall and extended warranty company didn't want to know as nothing was broken. Seems I should have waited until it blocked the control valve as they would have covered that.....

Robert.

Hopper, BMW are not alone in failing to produce reliable timing chains. VAG, Jaguar and Nissan are known for similar problems.

Current hydraulic tensioners don't seem to be compatible with modern oil usage, and the plastic guides they tension for the chain to run on are worse. And then there's the curious decision to put the chain on the back of the engine

Problem is with someone else as none of them produce chains, they just give a spec to suppliers

Just had the timing and oil pump wet belts changed on our 9 year old 1.0 Ecoboost C-Max at 60,000 miles. Looks like there was a good chance of it failing before the 10 year / 150,000 mile interval! There are multiple cracks half the belt thickness deep, across the full width. Ours has always been serviced by me with the correct Castrol Magnatec Ford approved oil and I never used any additives or flushes that some say can attack the belts. According to the garage and talking to work colleagues there are many wet belts failing after only five years and as little as 40,000 miles, don't know how many as a percentage though.

There's a guy on Youtube who does "engine teardowns", he's done the 1.0Ltr Ecopoo and it failed due to the wet belt stripping.. he wasnt very complimentary with Ford's design. His videos are very interesting to watch.

Andrew

One wonders how much of the belt has shed in the way of particles into the oil system as your photos show the belt beginning to deteriorate. Dave W

My 10 year old 54,000 mile citroen c3 has just had a complete clutch kit fitted at a local garage (it included the thrust mechanism, which was totally worn out). Total cost was £540. My 90 year old Austin seven has probably had several new clutches in its 300 to 400,000 mile life. But is still fitted with the same clutch thrust mechanism. Perhaps citroen should buy used A7 parts?

Hi Dave, the sump had to come off for the job anyway so the oil pickup gauze was checked but all found to be spotless. Apparently in worse cases than mine even when the belt debris is picked off the gauze there can be some higher up which causes failure after the belt change.

Lee, the same C-Max clutch slave failed at <40k and I think at 5 years old, costing £500.

I am currently rebuilding the back axle of my Austin Seven and I am amazed how little wear there is in any of it. The only things that really needed attention were the oil seals; or lack thereof.

James.